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1 /*
2  * MPEG-4 decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #define UNCHECKED_BITSTREAM_READER 1
24 
25 #include "config_components.h"
26 
27 #include "libavutil/internal.h"
28 #include "libavutil/opt.h"
29 #include "libavutil/thread.h"
30 #include "codec_internal.h"
31 #include "error_resilience.h"
32 #include "hwconfig.h"
33 #include "idctdsp.h"
34 #include "mpegutils.h"
35 #include "mpegvideo.h"
36 #include "mpegvideodata.h"
37 #include "mpegvideodec.h"
38 #include "mpeg4video.h"
39 #include "mpeg4videodata.h"
40 #include "mpeg4videodec.h"
41 #include "h263.h"
42 #include "h263data.h"
43 #include "h263dec.h"
44 #include "profiles.h"
45 #include "threadframe.h"
46 #include "xvididct.h"
47 #include "unary.h"
48 
49 /* The defines below define the number of bits that are read at once for
50  * reading vlc values. Changing these may improve speed and data cache needs
51  * be aware though that decreasing them may need the number of stages that is
52  * passed to get_vlc* to be increased. */
53 #define SPRITE_TRAJ_VLC_BITS 6
54 #define DC_VLC_BITS 9
55 #define MB_TYPE_B_VLC_BITS 4
56 #define STUDIO_INTRA_BITS 9
57 
58 static VLC dc_lum, dc_chrom;
59 static VLC sprite_trajectory;
60 static VLC mb_type_b_vlc;
61 static VLC studio_intra_tab[12];
62 static VLC studio_luma_dc;
63 static VLC studio_chroma_dc;
64 
65 static const uint8_t mpeg4_block_count[4] = { 0, 6, 8, 12 };
66 
67 static const int mb_type_b_map[4] = {
68     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
69     MB_TYPE_L0L1    | MB_TYPE_16x16,
70     MB_TYPE_L1      | MB_TYPE_16x16,
71     MB_TYPE_L0      | MB_TYPE_16x16,
72 };
73 
ff_mpeg4_decode_studio(MpegEncContext * s,uint8_t * dest_y,uint8_t * dest_cb,uint8_t * dest_cr,int block_size,int uvlinesize,int dct_linesize,int dct_offset)74 void ff_mpeg4_decode_studio(MpegEncContext *s, uint8_t *dest_y, uint8_t *dest_cb,
75                             uint8_t *dest_cr, int block_size, int uvlinesize,
76                             int dct_linesize, int dct_offset)
77 {
78     Mpeg4DecContext *const ctx = (Mpeg4DecContext*)s;
79     const int act_block_size = block_size * 2;
80 
81     if (ctx->dpcm_direction == 0) {
82         s->idsp.idct_put(dest_y,                               dct_linesize, (int16_t*)ctx->block32[0]);
83         s->idsp.idct_put(dest_y              + act_block_size, dct_linesize, (int16_t*)ctx->block32[1]);
84         s->idsp.idct_put(dest_y + dct_offset,                  dct_linesize, (int16_t*)ctx->block32[2]);
85         s->idsp.idct_put(dest_y + dct_offset + act_block_size, dct_linesize, (int16_t*)ctx->block32[3]);
86 
87         dct_linesize = uvlinesize << s->interlaced_dct;
88         dct_offset   = s->interlaced_dct ? uvlinesize : uvlinesize*block_size;
89 
90         s->idsp.idct_put(dest_cb,              dct_linesize, (int16_t*)ctx->block32[4]);
91         s->idsp.idct_put(dest_cr,              dct_linesize, (int16_t*)ctx->block32[5]);
92         s->idsp.idct_put(dest_cb + dct_offset, dct_linesize, (int16_t*)ctx->block32[6]);
93         s->idsp.idct_put(dest_cr + dct_offset, dct_linesize, (int16_t*)ctx->block32[7]);
94         if (!s->chroma_x_shift){ //Chroma444
95             s->idsp.idct_put(dest_cb + act_block_size,              dct_linesize, (int16_t*)ctx->block32[8]);
96             s->idsp.idct_put(dest_cr + act_block_size,              dct_linesize, (int16_t*)ctx->block32[9]);
97             s->idsp.idct_put(dest_cb + act_block_size + dct_offset, dct_linesize, (int16_t*)ctx->block32[10]);
98             s->idsp.idct_put(dest_cr + act_block_size + dct_offset, dct_linesize, (int16_t*)ctx->block32[11]);
99         }
100     } else if (ctx->dpcm_direction == 1) {
101         uint16_t *dest_pcm[3] = {(uint16_t*)dest_y, (uint16_t*)dest_cb, (uint16_t*)dest_cr};
102         int linesize[3] = {dct_linesize, uvlinesize, uvlinesize};
103         for (int i = 0; i < 3; i++) {
104             const uint16_t *src = ctx->dpcm_macroblock[i];
105             int vsub = i ? s->chroma_y_shift : 0;
106             int hsub = i ? s->chroma_x_shift : 0;
107             int lowres = s->avctx->lowres;
108             int step = 1 << lowres;
109             for (int h = 0; h < (16 >> (vsub + lowres)); h++){
110                 for (int w = 0, idx = 0; w < (16 >> (hsub + lowres)); w++, idx += step)
111                     dest_pcm[i][w] = src[idx];
112                 dest_pcm[i] += linesize[i] / 2;
113                 src         += (16 >> hsub) * step;
114             }
115         }
116     } else {
117         uint16_t *dest_pcm[3] = {(uint16_t*)dest_y, (uint16_t*)dest_cb, (uint16_t*)dest_cr};
118         int linesize[3] = {dct_linesize, uvlinesize, uvlinesize};
119         av_assert2(ctx->dpcm_direction == -1);
120         for (int i = 0; i < 3; i++) {
121             const uint16_t *src = ctx->dpcm_macroblock[i];
122             int vsub = i ? s->chroma_y_shift : 0;
123             int hsub = i ? s->chroma_x_shift : 0;
124             int lowres = s->avctx->lowres;
125             int step = 1 << lowres;
126             dest_pcm[i] += (linesize[i] / 2) * ((16 >> vsub + lowres) - 1);
127             for (int h = (16 >> (vsub + lowres)) - 1; h >= 0; h--){
128                 for (int w = (16 >> (hsub + lowres)) - 1, idx = 0; w >= 0; w--, idx += step)
129                     dest_pcm[i][w] = src[idx];
130                 src += step * (16 >> hsub);
131                 dest_pcm[i] -= linesize[i] / 2;
132             }
133         }
134     }
135 }
136 
137 /**
138  * Predict the ac.
139  * @param n block index (0-3 are luma, 4-5 are chroma)
140  * @param dir the ac prediction direction
141  */
ff_mpeg4_pred_ac(MpegEncContext * s,int16_t * block,int n,int dir)142 void ff_mpeg4_pred_ac(MpegEncContext *s, int16_t *block, int n, int dir)
143 {
144     int i;
145     int16_t *ac_val, *ac_val1;
146     int8_t *const qscale_table = s->current_picture.qscale_table;
147 
148     /* find prediction */
149     ac_val  = &s->ac_val[0][0][0] + s->block_index[n] * 16;
150     ac_val1 = ac_val;
151     if (s->ac_pred) {
152         if (dir == 0) {
153             const int xy = s->mb_x - 1 + s->mb_y * s->mb_stride;
154             /* left prediction */
155             ac_val -= 16;
156 
157             if (s->mb_x == 0 || s->qscale == qscale_table[xy] ||
158                 n == 1 || n == 3) {
159                 /* same qscale */
160                 for (i = 1; i < 8; i++)
161                     block[s->idsp.idct_permutation[i << 3]] += ac_val[i];
162             } else {
163                 /* different qscale, we must rescale */
164                 for (i = 1; i < 8; i++)
165                     block[s->idsp.idct_permutation[i << 3]] += ROUNDED_DIV(ac_val[i] * qscale_table[xy], s->qscale);
166             }
167         } else {
168             const int xy = s->mb_x + s->mb_y * s->mb_stride - s->mb_stride;
169             /* top prediction */
170             ac_val -= 16 * s->block_wrap[n];
171 
172             if (s->mb_y == 0 || s->qscale == qscale_table[xy] ||
173                 n == 2 || n == 3) {
174                 /* same qscale */
175                 for (i = 1; i < 8; i++)
176                     block[s->idsp.idct_permutation[i]] += ac_val[i + 8];
177             } else {
178                 /* different qscale, we must rescale */
179                 for (i = 1; i < 8; i++)
180                     block[s->idsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8] * qscale_table[xy], s->qscale);
181             }
182         }
183     }
184     /* left copy */
185     for (i = 1; i < 8; i++)
186         ac_val1[i] = block[s->idsp.idct_permutation[i << 3]];
187 
188     /* top copy */
189     for (i = 1; i < 8; i++)
190         ac_val1[8 + i] = block[s->idsp.idct_permutation[i]];
191 }
192 
193 /**
194  * check if the next stuff is a resync marker or the end.
195  * @return 0 if not
196  */
mpeg4_is_resync(Mpeg4DecContext * ctx)197 static inline int mpeg4_is_resync(Mpeg4DecContext *ctx)
198 {
199     MpegEncContext *s = &ctx->m;
200     int bits_count = get_bits_count(&s->gb);
201     int v          = show_bits(&s->gb, 16);
202 
203     if (s->workaround_bugs & FF_BUG_NO_PADDING && !ctx->resync_marker)
204         return 0;
205 
206     while (v <= 0xFF) {
207         if (s->pict_type == AV_PICTURE_TYPE_B ||
208             (v >> (8 - s->pict_type) != 1) || s->partitioned_frame)
209             break;
210         skip_bits(&s->gb, 8 + s->pict_type);
211         bits_count += 8 + s->pict_type;
212         v = show_bits(&s->gb, 16);
213     }
214 
215     if (bits_count + 8 >= s->gb.size_in_bits) {
216         v >>= 8;
217         v  |= 0x7F >> (7 - (bits_count & 7));
218 
219         if (v == 0x7F)
220             return s->mb_num;
221     } else {
222         if (v == ff_mpeg4_resync_prefix[bits_count & 7]) {
223             int len, mb_num;
224             int mb_num_bits = av_log2(s->mb_num - 1) + 1;
225             GetBitContext gb = s->gb;
226 
227             skip_bits(&s->gb, 1);
228             align_get_bits(&s->gb);
229 
230             for (len = 0; len < 32; len++)
231                 if (get_bits1(&s->gb))
232                     break;
233 
234             mb_num = get_bits(&s->gb, mb_num_bits);
235             if (!mb_num || mb_num > s->mb_num || get_bits_count(&s->gb)+6 > s->gb.size_in_bits)
236                 mb_num= -1;
237 
238             s->gb = gb;
239 
240             if (len >= ff_mpeg4_get_video_packet_prefix_length(s))
241                 return mb_num;
242         }
243     }
244     return 0;
245 }
246 
mpeg4_decode_sprite_trajectory(Mpeg4DecContext * ctx,GetBitContext * gb)247 static int mpeg4_decode_sprite_trajectory(Mpeg4DecContext *ctx, GetBitContext *gb)
248 {
249     MpegEncContext *s = &ctx->m;
250     int a     = 2 << s->sprite_warping_accuracy;
251     int rho   = 3  - s->sprite_warping_accuracy;
252     int r     = 16 / a;
253     int alpha = 1;
254     int beta  = 0;
255     int w     = s->width;
256     int h     = s->height;
257     int min_ab, i, w2, h2, w3, h3;
258     int sprite_ref[4][2];
259     int virtual_ref[2][2];
260     int64_t sprite_offset[2][2];
261     int64_t sprite_delta[2][2];
262 
263     // only true for rectangle shapes
264     const int vop_ref[4][2] = { { 0, 0 },         { s->width, 0 },
265                                 { 0, s->height }, { s->width, s->height } };
266     int d[4][2]             = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } };
267 
268     if (w <= 0 || h <= 0)
269         return AVERROR_INVALIDDATA;
270 
271     for (i = 0; i < ctx->num_sprite_warping_points; i++) {
272         int length;
273         int x = 0, y = 0;
274 
275         length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 2);
276         if (length > 0)
277             x = get_xbits(gb, length);
278 
279         if (!(ctx->divx_version == 500 && ctx->divx_build == 413))
280             check_marker(s->avctx, gb, "before sprite_trajectory");
281 
282         length = get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 2);
283         if (length > 0)
284             y = get_xbits(gb, length);
285 
286         check_marker(s->avctx, gb, "after sprite_trajectory");
287         ctx->sprite_traj[i][0] = d[i][0] = x;
288         ctx->sprite_traj[i][1] = d[i][1] = y;
289     }
290     for (; i < 4; i++)
291         ctx->sprite_traj[i][0] = ctx->sprite_traj[i][1] = 0;
292 
293     while ((1 << alpha) < w)
294         alpha++;
295     while ((1 << beta) < h)
296         beta++;  /* typo in the MPEG-4 std for the definition of w' and h' */
297     w2 = 1 << alpha;
298     h2 = 1 << beta;
299 
300     // Note, the 4th point isn't used for GMC
301     if (ctx->divx_version == 500 && ctx->divx_build == 413) {
302         sprite_ref[0][0] = a * vop_ref[0][0] + d[0][0];
303         sprite_ref[0][1] = a * vop_ref[0][1] + d[0][1];
304         sprite_ref[1][0] = a * vop_ref[1][0] + d[0][0] + d[1][0];
305         sprite_ref[1][1] = a * vop_ref[1][1] + d[0][1] + d[1][1];
306         sprite_ref[2][0] = a * vop_ref[2][0] + d[0][0] + d[2][0];
307         sprite_ref[2][1] = a * vop_ref[2][1] + d[0][1] + d[2][1];
308     } else {
309         sprite_ref[0][0] = (a >> 1) * (2 * vop_ref[0][0] + d[0][0]);
310         sprite_ref[0][1] = (a >> 1) * (2 * vop_ref[0][1] + d[0][1]);
311         sprite_ref[1][0] = (a >> 1) * (2 * vop_ref[1][0] + d[0][0] + d[1][0]);
312         sprite_ref[1][1] = (a >> 1) * (2 * vop_ref[1][1] + d[0][1] + d[1][1]);
313         sprite_ref[2][0] = (a >> 1) * (2 * vop_ref[2][0] + d[0][0] + d[2][0]);
314         sprite_ref[2][1] = (a >> 1) * (2 * vop_ref[2][1] + d[0][1] + d[2][1]);
315     }
316     /* sprite_ref[3][0] = (a >> 1) * (2 * vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
317      * sprite_ref[3][1] = (a >> 1) * (2 * vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
318 
319     /* This is mostly identical to the MPEG-4 std (and is totally unreadable
320      * because of that...). Perhaps it should be reordered to be more readable.
321      * The idea behind this virtual_ref mess is to be able to use shifts later
322      * per pixel instead of divides so the distance between points is converted
323      * from w&h based to w2&h2 based which are of the 2^x form. */
324     virtual_ref[0][0] = 16 * (vop_ref[0][0] + w2) +
325                          ROUNDED_DIV(((w - w2) *
326                                            (r * sprite_ref[0][0] - 16LL * vop_ref[0][0]) +
327                                       w2 * (r * sprite_ref[1][0] - 16LL * vop_ref[1][0])), w);
328     virtual_ref[0][1] = 16 * vop_ref[0][1] +
329                         ROUNDED_DIV(((w - w2) *
330                                           (r * sprite_ref[0][1] - 16LL * vop_ref[0][1]) +
331                                      w2 * (r * sprite_ref[1][1] - 16LL * vop_ref[1][1])), w);
332     virtual_ref[1][0] = 16 * vop_ref[0][0] +
333                         ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][0] - 16LL * vop_ref[0][0]) +
334                                            h2 * (r * sprite_ref[2][0] - 16LL * vop_ref[2][0])), h);
335     virtual_ref[1][1] = 16 * (vop_ref[0][1] + h2) +
336                         ROUNDED_DIV(((h - h2) * (r * sprite_ref[0][1] - 16LL * vop_ref[0][1]) +
337                                            h2 * (r * sprite_ref[2][1] - 16LL * vop_ref[2][1])), h);
338 
339     switch (ctx->num_sprite_warping_points) {
340     case 0:
341         sprite_offset[0][0]    =
342         sprite_offset[0][1]    =
343         sprite_offset[1][0]    =
344         sprite_offset[1][1]    = 0;
345         sprite_delta[0][0]     = a;
346         sprite_delta[0][1]     =
347         sprite_delta[1][0]     = 0;
348         sprite_delta[1][1]     = a;
349         ctx->sprite_shift[0]   =
350         ctx->sprite_shift[1]   = 0;
351         break;
352     case 1:     // GMC only
353         sprite_offset[0][0]    = sprite_ref[0][0] - a * vop_ref[0][0];
354         sprite_offset[0][1]    = sprite_ref[0][1] - a * vop_ref[0][1];
355         sprite_offset[1][0]    = ((sprite_ref[0][0] >> 1) | (sprite_ref[0][0] & 1)) -
356                                  a * (vop_ref[0][0] / 2);
357         sprite_offset[1][1]    = ((sprite_ref[0][1] >> 1) | (sprite_ref[0][1] & 1)) -
358                                  a * (vop_ref[0][1] / 2);
359         sprite_delta[0][0]     = a;
360         sprite_delta[0][1]     =
361         sprite_delta[1][0]     = 0;
362         sprite_delta[1][1]     = a;
363         ctx->sprite_shift[0]   =
364         ctx->sprite_shift[1]   = 0;
365         break;
366     case 2:
367         sprite_offset[0][0]    = ((int64_t)      sprite_ref[0][0] * (1 << alpha + rho)) +
368                                  ((int64_t) -r * sprite_ref[0][0] + virtual_ref[0][0]) *
369                                  ((int64_t)        -vop_ref[0][0]) +
370                                  ((int64_t)  r * sprite_ref[0][1] - virtual_ref[0][1]) *
371                                  ((int64_t)        -vop_ref[0][1]) + (1 << (alpha + rho - 1));
372         sprite_offset[0][1]    = ((int64_t)      sprite_ref[0][1] * (1 << alpha + rho)) +
373                                  ((int64_t) -r * sprite_ref[0][1] + virtual_ref[0][1]) *
374                                  ((int64_t)        -vop_ref[0][0]) +
375                                  ((int64_t) -r * sprite_ref[0][0] + virtual_ref[0][0]) *
376                                  ((int64_t)        -vop_ref[0][1]) + (1 << (alpha + rho - 1));
377         sprite_offset[1][0]    = (((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) *
378                                   ((int64_t)-2 *    vop_ref[0][0] + 1) +
379                                   ((int64_t) r * sprite_ref[0][1] - virtual_ref[0][1]) *
380                                   ((int64_t)-2 *    vop_ref[0][1] + 1) + 2 * w2 * r *
381                                    (int64_t)     sprite_ref[0][0] - 16 * w2 + (1 << (alpha + rho + 1)));
382         sprite_offset[1][1]    = (((int64_t)-r * sprite_ref[0][1] + virtual_ref[0][1]) *
383                                   ((int64_t)-2 *    vop_ref[0][0] + 1) +
384                                   ((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) *
385                                   ((int64_t)-2 *    vop_ref[0][1] + 1) + 2 * w2 * r *
386                                   (int64_t)      sprite_ref[0][1] - 16 * w2 + (1 << (alpha + rho + 1)));
387         sprite_delta[0][0] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
388         sprite_delta[0][1] = (+r * sprite_ref[0][1] - virtual_ref[0][1]);
389         sprite_delta[1][0] = (-r * sprite_ref[0][1] + virtual_ref[0][1]);
390         sprite_delta[1][1] = (-r * sprite_ref[0][0] + virtual_ref[0][0]);
391 
392         ctx->sprite_shift[0]  = alpha + rho;
393         ctx->sprite_shift[1]  = alpha + rho + 2;
394         break;
395     case 3:
396         min_ab = FFMIN(alpha, beta);
397         w3     = w2 >> min_ab;
398         h3     = h2 >> min_ab;
399         sprite_offset[0][0]    = ((int64_t)sprite_ref[0][0] * (1 << (alpha + beta + rho - min_ab))) +
400                                  ((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3 * (-vop_ref[0][0]) +
401                                  ((int64_t)-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3 * (-vop_ref[0][1]) +
402                                  ((int64_t)1 << (alpha + beta + rho - min_ab - 1));
403         sprite_offset[0][1]    = ((int64_t)sprite_ref[0][1] * (1 << (alpha + beta + rho - min_ab))) +
404                                  ((int64_t)-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3 * (-vop_ref[0][0]) +
405                                  ((int64_t)-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3 * (-vop_ref[0][1]) +
406                                  ((int64_t)1 << (alpha + beta + rho - min_ab - 1));
407         sprite_offset[1][0]    = ((int64_t)-r * sprite_ref[0][0] + virtual_ref[0][0]) * h3 * (-2 * vop_ref[0][0] + 1) +
408                                  ((int64_t)-r * sprite_ref[0][0] + virtual_ref[1][0]) * w3 * (-2 * vop_ref[0][1] + 1) +
409                                   (int64_t)2 * w2 * h3 * r * sprite_ref[0][0] - 16 * w2 * h3 +
410                                  ((int64_t)1 << (alpha + beta + rho - min_ab + 1));
411         sprite_offset[1][1]    = ((int64_t)-r * sprite_ref[0][1] + virtual_ref[0][1]) * h3 * (-2 * vop_ref[0][0] + 1) +
412                                  ((int64_t)-r * sprite_ref[0][1] + virtual_ref[1][1]) * w3 * (-2 * vop_ref[0][1] + 1) +
413                                   (int64_t)2 * w2 * h3 * r * sprite_ref[0][1] - 16 * w2 * h3 +
414                                  ((int64_t)1 << (alpha + beta + rho - min_ab + 1));
415         sprite_delta[0][0] = (-r * (int64_t)sprite_ref[0][0] + virtual_ref[0][0]) * h3;
416         sprite_delta[0][1] = (-r * (int64_t)sprite_ref[0][0] + virtual_ref[1][0]) * w3;
417         sprite_delta[1][0] = (-r * (int64_t)sprite_ref[0][1] + virtual_ref[0][1]) * h3;
418         sprite_delta[1][1] = (-r * (int64_t)sprite_ref[0][1] + virtual_ref[1][1]) * w3;
419 
420         ctx->sprite_shift[0]  = alpha + beta + rho - min_ab;
421         ctx->sprite_shift[1]  = alpha + beta + rho - min_ab + 2;
422         break;
423     }
424     /* try to simplify the situation */
425     if (sprite_delta[0][0] == a << ctx->sprite_shift[0] &&
426         sprite_delta[0][1] == 0 &&
427         sprite_delta[1][0] == 0 &&
428         sprite_delta[1][1] == a << ctx->sprite_shift[0]) {
429         sprite_offset[0][0] >>= ctx->sprite_shift[0];
430         sprite_offset[0][1] >>= ctx->sprite_shift[0];
431         sprite_offset[1][0] >>= ctx->sprite_shift[1];
432         sprite_offset[1][1] >>= ctx->sprite_shift[1];
433         sprite_delta[0][0] = a;
434         sprite_delta[0][1] = 0;
435         sprite_delta[1][0] = 0;
436         sprite_delta[1][1] = a;
437         ctx->sprite_shift[0] = 0;
438         ctx->sprite_shift[1] = 0;
439         s->real_sprite_warping_points = 1;
440     } else {
441         int shift_y = 16 - ctx->sprite_shift[0];
442         int shift_c = 16 - ctx->sprite_shift[1];
443 
444         for (i = 0; i < 2; i++) {
445             if (shift_c < 0 || shift_y < 0 ||
446                 FFABS(  sprite_offset[0][i]) >= INT_MAX >> shift_y  ||
447                 FFABS(  sprite_offset[1][i]) >= INT_MAX >> shift_c  ||
448                 FFABS(   sprite_delta[0][i]) >= INT_MAX >> shift_y  ||
449                 FFABS(   sprite_delta[1][i]) >= INT_MAX >> shift_y
450             ) {
451                 avpriv_request_sample(s->avctx, "Too large sprite shift, delta or offset");
452                 goto overflow;
453             }
454         }
455 
456         for (i = 0; i < 2; i++) {
457             sprite_offset[0][i]    *= 1 << shift_y;
458             sprite_offset[1][i]    *= 1 << shift_c;
459             sprite_delta[0][i]     *= 1 << shift_y;
460             sprite_delta[1][i]     *= 1 << shift_y;
461             ctx->sprite_shift[i]     = 16;
462 
463         }
464         for (i = 0; i < 2; i++) {
465             int64_t sd[2] = {
466                 sprite_delta[i][0] - a * (1LL<<16),
467                 sprite_delta[i][1] - a * (1LL<<16)
468             };
469 
470             if (llabs(sprite_offset[0][i] + sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
471                 llabs(sprite_offset[0][i] + sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
472                 llabs(sprite_offset[0][i] + sprite_delta[i][0] * (w+16LL) + sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
473                 llabs(sprite_delta[i][0] * (w+16LL)) >= INT_MAX ||
474                 llabs(sprite_delta[i][1] * (h+16LL)) >= INT_MAX ||
475                 llabs(sd[0]) >= INT_MAX ||
476                 llabs(sd[1]) >= INT_MAX ||
477                 llabs(sprite_offset[0][i] + sd[0] * (w+16LL)) >= INT_MAX ||
478                 llabs(sprite_offset[0][i] + sd[1] * (h+16LL)) >= INT_MAX ||
479                 llabs(sprite_offset[0][i] + sd[0] * (w+16LL) + sd[1] * (h+16LL)) >= INT_MAX
480             ) {
481                 avpriv_request_sample(s->avctx, "Overflow on sprite points");
482                 goto overflow;
483             }
484         }
485         s->real_sprite_warping_points = ctx->num_sprite_warping_points;
486     }
487 
488     for (i = 0; i < 4; i++) {
489         s->sprite_offset[i&1][i>>1] = sprite_offset[i&1][i>>1];
490         s->sprite_delta [i&1][i>>1] = sprite_delta [i&1][i>>1];
491     }
492 
493     return 0;
494 overflow:
495     memset(s->sprite_offset, 0, sizeof(s->sprite_offset));
496     memset(s->sprite_delta, 0, sizeof(s->sprite_delta));
497     return AVERROR_PATCHWELCOME;
498 }
499 
decode_new_pred(Mpeg4DecContext * ctx,GetBitContext * gb)500 static int decode_new_pred(Mpeg4DecContext *ctx, GetBitContext *gb) {
501     MpegEncContext *s = &ctx->m;
502     int len = FFMIN(ctx->time_increment_bits + 3, 15);
503 
504     get_bits(gb, len);
505     if (get_bits1(gb))
506         get_bits(gb, len);
507     check_marker(s->avctx, gb, "after new_pred");
508 
509     return 0;
510 }
511 
512 /**
513  * Decode the next video packet.
514  * @return <0 if something went wrong
515  */
ff_mpeg4_decode_video_packet_header(Mpeg4DecContext * ctx)516 int ff_mpeg4_decode_video_packet_header(Mpeg4DecContext *ctx)
517 {
518     MpegEncContext *s = &ctx->m;
519 
520     int mb_num_bits      = av_log2(s->mb_num - 1) + 1;
521     int header_extension = 0, mb_num, len;
522 
523     /* is there enough space left for a video packet + header */
524     if (get_bits_count(&s->gb) > s->gb.size_in_bits - 20)
525         return AVERROR_INVALIDDATA;
526 
527     for (len = 0; len < 32; len++)
528         if (get_bits1(&s->gb))
529             break;
530 
531     if (len != ff_mpeg4_get_video_packet_prefix_length(s)) {
532         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
533         return AVERROR_INVALIDDATA;
534     }
535 
536     if (ctx->shape != RECT_SHAPE) {
537         header_extension = get_bits1(&s->gb);
538         // FIXME more stuff here
539     }
540 
541     mb_num = get_bits(&s->gb, mb_num_bits);
542     if (mb_num >= s->mb_num || !mb_num) {
543         av_log(s->avctx, AV_LOG_ERROR,
544                "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
545         return AVERROR_INVALIDDATA;
546     }
547 
548     s->mb_x = mb_num % s->mb_width;
549     s->mb_y = mb_num / s->mb_width;
550 
551     if (ctx->shape != BIN_ONLY_SHAPE) {
552         int qscale = get_bits(&s->gb, s->quant_precision);
553         if (qscale)
554             s->chroma_qscale = s->qscale = qscale;
555     }
556 
557     if (ctx->shape == RECT_SHAPE)
558         header_extension = get_bits1(&s->gb);
559 
560     if (header_extension) {
561         int time_incr = 0;
562 
563         while (get_bits1(&s->gb) != 0)
564             time_incr++;
565 
566         check_marker(s->avctx, &s->gb, "before time_increment in video packed header");
567         skip_bits(&s->gb, ctx->time_increment_bits);      /* time_increment */
568         check_marker(s->avctx, &s->gb, "before vop_coding_type in video packed header");
569 
570         skip_bits(&s->gb, 2); /* vop coding type */
571         // FIXME not rect stuff here
572 
573         if (ctx->shape != BIN_ONLY_SHAPE) {
574             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
575             // FIXME don't just ignore everything
576             if (s->pict_type == AV_PICTURE_TYPE_S &&
577                 ctx->vol_sprite_usage == GMC_SPRITE) {
578                 if (mpeg4_decode_sprite_trajectory(ctx, &s->gb) < 0)
579                     return AVERROR_INVALIDDATA;
580                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
581             }
582 
583             // FIXME reduced res stuff here
584 
585             if (s->pict_type != AV_PICTURE_TYPE_I) {
586                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
587                 if (f_code == 0)
588                     av_log(s->avctx, AV_LOG_ERROR,
589                            "Error, video packet header damaged (f_code=0)\n");
590             }
591             if (s->pict_type == AV_PICTURE_TYPE_B) {
592                 int b_code = get_bits(&s->gb, 3);
593                 if (b_code == 0)
594                     av_log(s->avctx, AV_LOG_ERROR,
595                            "Error, video packet header damaged (b_code=0)\n");
596             }
597         }
598     }
599     if (ctx->new_pred)
600         decode_new_pred(ctx, &s->gb);
601 
602     return 0;
603 }
604 
reset_studio_dc_predictors(MpegEncContext * s)605 static void reset_studio_dc_predictors(MpegEncContext *s)
606 {
607     /* Reset DC Predictors */
608     s->last_dc[0] =
609     s->last_dc[1] =
610     s->last_dc[2] = 1 << (s->avctx->bits_per_raw_sample + s->dct_precision + s->intra_dc_precision - 1);
611 }
612 
613 /**
614  * Decode the next video packet.
615  * @return <0 if something went wrong
616  */
ff_mpeg4_decode_studio_slice_header(Mpeg4DecContext * ctx)617 int ff_mpeg4_decode_studio_slice_header(Mpeg4DecContext *ctx)
618 {
619     MpegEncContext *s = &ctx->m;
620     GetBitContext *gb = &s->gb;
621     unsigned vlc_len;
622     uint16_t mb_num;
623 
624     if (get_bits_left(gb) >= 32 && get_bits_long(gb, 32) == SLICE_STARTCODE) {
625         vlc_len = av_log2(s->mb_width * s->mb_height) + 1;
626         mb_num = get_bits(gb, vlc_len);
627 
628         if (mb_num >= s->mb_num)
629             return AVERROR_INVALIDDATA;
630 
631         s->mb_x = mb_num % s->mb_width;
632         s->mb_y = mb_num / s->mb_width;
633 
634         if (ctx->shape != BIN_ONLY_SHAPE)
635             s->qscale = mpeg_get_qscale(s);
636 
637         if (get_bits1(gb)) {  /* slice_extension_flag */
638             skip_bits1(gb);   /* intra_slice */
639             skip_bits1(gb);   /* slice_VOP_id_enable */
640             skip_bits(gb, 6); /* slice_VOP_id */
641             while (get_bits1(gb)) /* extra_bit_slice */
642                 skip_bits(gb, 8); /* extra_information_slice */
643         }
644 
645         reset_studio_dc_predictors(s);
646     }
647     else {
648         return AVERROR_INVALIDDATA;
649     }
650 
651     return 0;
652 }
653 
654 /**
655  * Get the average motion vector for a GMC MB.
656  * @param n either 0 for the x component or 1 for y
657  * @return the average MV for a GMC MB
658  */
get_amv(Mpeg4DecContext * ctx,int n)659 static inline int get_amv(Mpeg4DecContext *ctx, int n)
660 {
661     MpegEncContext *s = &ctx->m;
662     int x, y, mb_v, sum, dx, dy, shift;
663     int len     = 1 << (s->f_code + 4);
664     const int a = s->sprite_warping_accuracy;
665 
666     if (s->workaround_bugs & FF_BUG_AMV)
667         len >>= s->quarter_sample;
668 
669     if (s->real_sprite_warping_points == 1) {
670         if (ctx->divx_version == 500 && ctx->divx_build == 413 && a >= s->quarter_sample)
671             sum = s->sprite_offset[0][n] / (1 << (a - s->quarter_sample));
672         else
673             sum = RSHIFT(s->sprite_offset[0][n] * (1 << s->quarter_sample), a);
674     } else {
675         dx    = s->sprite_delta[n][0];
676         dy    = s->sprite_delta[n][1];
677         shift = ctx->sprite_shift[0];
678         if (n)
679             dy -= 1 << (shift + a + 1);
680         else
681             dx -= 1 << (shift + a + 1);
682         mb_v = s->sprite_offset[0][n] + dx * s->mb_x * 16U + dy * s->mb_y * 16U;
683 
684         sum = 0;
685         for (y = 0; y < 16; y++) {
686             int v;
687 
688             v = mb_v + (unsigned)dy * y;
689             // FIXME optimize
690             for (x = 0; x < 16; x++) {
691                 sum += v >> shift;
692                 v   += dx;
693             }
694         }
695         sum = RSHIFT(sum, a + 8 - s->quarter_sample);
696     }
697 
698     if (sum < -len)
699         sum = -len;
700     else if (sum >= len)
701         sum = len - 1;
702 
703     return sum;
704 }
705 
706 /**
707  * Decode the dc value.
708  * @param n block index (0-3 are luma, 4-5 are chroma)
709  * @param dir_ptr the prediction direction will be stored here
710  * @return the quantized dc
711  */
mpeg4_decode_dc(MpegEncContext * s,int n,int * dir_ptr)712 static inline int mpeg4_decode_dc(MpegEncContext *s, int n, int *dir_ptr)
713 {
714     int level, code;
715 
716     if (n < 4)
717         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
718     else
719         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
720 
721     if (code < 0 || code > 9 /* && s->nbit < 9 */) {
722         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
723         return AVERROR_INVALIDDATA;
724     }
725 
726     if (code == 0) {
727         level = 0;
728     } else {
729         if (IS_3IV1) {
730             if (code == 1)
731                 level = 2 * get_bits1(&s->gb) - 1;
732             else {
733                 if (get_bits1(&s->gb))
734                     level = get_bits(&s->gb, code - 1) + (1 << (code - 1));
735                 else
736                     level = -get_bits(&s->gb, code - 1) - (1 << (code - 1));
737             }
738         } else {
739             level = get_xbits(&s->gb, code);
740         }
741 
742         if (code > 8) {
743             if (get_bits1(&s->gb) == 0) { /* marker */
744                 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT)) {
745                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
746                     return AVERROR_INVALIDDATA;
747                 }
748             }
749         }
750     }
751 
752     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
753 }
754 
755 /**
756  * Decode first partition.
757  * @return number of MBs decoded or <0 if an error occurred
758  */
mpeg4_decode_partition_a(Mpeg4DecContext * ctx)759 static int mpeg4_decode_partition_a(Mpeg4DecContext *ctx)
760 {
761     MpegEncContext *s = &ctx->m;
762     int mb_num = 0;
763     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
764 
765     /* decode first partition */
766     s->first_slice_line = 1;
767     for (; s->mb_y < s->mb_height; s->mb_y++) {
768         ff_init_block_index(s);
769         for (; s->mb_x < s->mb_width; s->mb_x++) {
770             const int xy = s->mb_x + s->mb_y * s->mb_stride;
771             int cbpc;
772             int dir = 0;
773 
774             mb_num++;
775             ff_update_block_index(s);
776             if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
777                 s->first_slice_line = 0;
778 
779             if (s->pict_type == AV_PICTURE_TYPE_I) {
780                 int i;
781 
782                 do {
783                     if (show_bits(&s->gb, 19) == DC_MARKER)
784                         return mb_num - 1;
785 
786                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
787                     if (cbpc < 0) {
788                         av_log(s->avctx, AV_LOG_ERROR,
789                                "mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
790                         return AVERROR_INVALIDDATA;
791                     }
792                 } while (cbpc == 8);
793 
794                 s->cbp_table[xy]               = cbpc & 3;
795                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
796                 s->mb_intra                    = 1;
797 
798                 if (cbpc & 4)
799                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
800 
801                 s->current_picture.qscale_table[xy] = s->qscale;
802 
803                 s->mbintra_table[xy] = 1;
804                 for (i = 0; i < 6; i++) {
805                     int dc_pred_dir;
806                     int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
807                     if (dc < 0) {
808                         av_log(s->avctx, AV_LOG_ERROR,
809                                "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
810                         return dc;
811                     }
812                     dir <<= 1;
813                     if (dc_pred_dir)
814                         dir |= 1;
815                 }
816                 s->pred_dir_table[xy] = dir;
817             } else { /* P/S_TYPE */
818                 int mx, my, pred_x, pred_y, bits;
819                 int16_t *const mot_val = s->current_picture.motion_val[0][s->block_index[0]];
820                 const int stride       = s->b8_stride * 2;
821 
822 try_again:
823                 bits = show_bits(&s->gb, 17);
824                 if (bits == MOTION_MARKER)
825                     return mb_num - 1;
826 
827                 skip_bits1(&s->gb);
828                 if (bits & 0x10000) {
829                     /* skip mb */
830                     if (s->pict_type == AV_PICTURE_TYPE_S &&
831                         ctx->vol_sprite_usage == GMC_SPRITE) {
832                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
833                                                          MB_TYPE_16x16 |
834                                                          MB_TYPE_GMC   |
835                                                          MB_TYPE_L0;
836                         mx = get_amv(ctx, 0);
837                         my = get_amv(ctx, 1);
838                     } else {
839                         s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
840                                                          MB_TYPE_16x16 |
841                                                          MB_TYPE_L0;
842                         mx = my = 0;
843                     }
844                     mot_val[0]          =
845                     mot_val[2]          =
846                     mot_val[0 + stride] =
847                     mot_val[2 + stride] = mx;
848                     mot_val[1]          =
849                     mot_val[3]          =
850                     mot_val[1 + stride] =
851                     mot_val[3 + stride] = my;
852 
853                     if (s->mbintra_table[xy])
854                         ff_clean_intra_table_entries(s);
855                     continue;
856                 }
857 
858                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
859                 if (cbpc < 0) {
860                     av_log(s->avctx, AV_LOG_ERROR,
861                            "mcbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
862                     return AVERROR_INVALIDDATA;
863                 }
864                 if (cbpc == 20)
865                     goto try_again;
866 
867                 s->cbp_table[xy] = cbpc & (8 + 3);  // 8 is dquant
868 
869                 s->mb_intra = ((cbpc & 4) != 0);
870 
871                 if (s->mb_intra) {
872                     s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
873                     s->mbintra_table[xy] = 1;
874                     mot_val[0]          =
875                     mot_val[2]          =
876                     mot_val[0 + stride] =
877                     mot_val[2 + stride] = 0;
878                     mot_val[1]          =
879                     mot_val[3]          =
880                     mot_val[1 + stride] =
881                     mot_val[3 + stride] = 0;
882                 } else {
883                     if (s->mbintra_table[xy])
884                         ff_clean_intra_table_entries(s);
885 
886                     if (s->pict_type == AV_PICTURE_TYPE_S &&
887                         ctx->vol_sprite_usage == GMC_SPRITE &&
888                         (cbpc & 16) == 0)
889                         s->mcsel = get_bits1(&s->gb);
890                     else
891                         s->mcsel = 0;
892 
893                     if ((cbpc & 16) == 0) {
894                         /* 16x16 motion prediction */
895 
896                         ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
897                         if (!s->mcsel) {
898                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
899                             if (mx >= 0xffff)
900                                 return AVERROR_INVALIDDATA;
901 
902                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
903                             if (my >= 0xffff)
904                                 return AVERROR_INVALIDDATA;
905                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
906                                                              MB_TYPE_L0;
907                         } else {
908                             mx = get_amv(ctx, 0);
909                             my = get_amv(ctx, 1);
910                             s->current_picture.mb_type[xy] = MB_TYPE_16x16 |
911                                                              MB_TYPE_GMC   |
912                                                              MB_TYPE_L0;
913                         }
914 
915                         mot_val[0]          =
916                         mot_val[2]          =
917                         mot_val[0 + stride] =
918                         mot_val[2 + stride] = mx;
919                         mot_val[1]          =
920                         mot_val[3]          =
921                         mot_val[1 + stride] =
922                         mot_val[3 + stride] = my;
923                     } else {
924                         int i;
925                         s->current_picture.mb_type[xy] = MB_TYPE_8x8 |
926                                                          MB_TYPE_L0;
927                         for (i = 0; i < 4; i++) {
928                             int16_t *mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
929                             mx = ff_h263_decode_motion(s, pred_x, s->f_code);
930                             if (mx >= 0xffff)
931                                 return AVERROR_INVALIDDATA;
932 
933                             my = ff_h263_decode_motion(s, pred_y, s->f_code);
934                             if (my >= 0xffff)
935                                 return AVERROR_INVALIDDATA;
936                             mot_val[0] = mx;
937                             mot_val[1] = my;
938                         }
939                     }
940                 }
941             }
942         }
943         s->mb_x = 0;
944     }
945 
946     return mb_num;
947 }
948 
949 /**
950  * decode second partition.
951  * @return <0 if an error occurred
952  */
mpeg4_decode_partition_b(MpegEncContext * s,int mb_count)953 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count)
954 {
955     int mb_num = 0;
956     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
957 
958     s->mb_x = s->resync_mb_x;
959     s->first_slice_line = 1;
960     for (s->mb_y = s->resync_mb_y; mb_num < mb_count; s->mb_y++) {
961         ff_init_block_index(s);
962         for (; mb_num < mb_count && s->mb_x < s->mb_width; s->mb_x++) {
963             const int xy = s->mb_x + s->mb_y * s->mb_stride;
964 
965             mb_num++;
966             ff_update_block_index(s);
967             if (s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y + 1)
968                 s->first_slice_line = 0;
969 
970             if (s->pict_type == AV_PICTURE_TYPE_I) {
971                 int ac_pred = get_bits1(&s->gb);
972                 int cbpy    = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
973                 if (cbpy < 0) {
974                     av_log(s->avctx, AV_LOG_ERROR,
975                            "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
976                     return AVERROR_INVALIDDATA;
977                 }
978 
979                 s->cbp_table[xy]               |= cbpy << 2;
980                 s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
981             } else { /* P || S_TYPE */
982                 if (IS_INTRA(s->current_picture.mb_type[xy])) {
983                     int i;
984                     int dir     = 0;
985                     int ac_pred = get_bits1(&s->gb);
986                     int cbpy    = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
987 
988                     if (cbpy < 0) {
989                         av_log(s->avctx, AV_LOG_ERROR,
990                                "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
991                         return AVERROR_INVALIDDATA;
992                     }
993 
994                     if (s->cbp_table[xy] & 8)
995                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
996                     s->current_picture.qscale_table[xy] = s->qscale;
997 
998                     for (i = 0; i < 6; i++) {
999                         int dc_pred_dir;
1000                         int dc = mpeg4_decode_dc(s, i, &dc_pred_dir);
1001                         if (dc < 0) {
1002                             av_log(s->avctx, AV_LOG_ERROR,
1003                                    "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
1004                             return dc;
1005                         }
1006                         dir <<= 1;
1007                         if (dc_pred_dir)
1008                             dir |= 1;
1009                     }
1010                     s->cbp_table[xy]               &= 3;  // remove dquant
1011                     s->cbp_table[xy]               |= cbpy << 2;
1012                     s->current_picture.mb_type[xy] |= ac_pred * MB_TYPE_ACPRED;
1013                     s->pred_dir_table[xy]           = dir;
1014                 } else if (IS_SKIP(s->current_picture.mb_type[xy])) {
1015                     s->current_picture.qscale_table[xy] = s->qscale;
1016                     s->cbp_table[xy]                    = 0;
1017                 } else {
1018                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1019 
1020                     if (cbpy < 0) {
1021                         av_log(s->avctx, AV_LOG_ERROR,
1022                                "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
1023                         return AVERROR_INVALIDDATA;
1024                     }
1025 
1026                     if (s->cbp_table[xy] & 8)
1027                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1028                     s->current_picture.qscale_table[xy] = s->qscale;
1029 
1030                     s->cbp_table[xy] &= 3;  // remove dquant
1031                     s->cbp_table[xy] |= (cbpy ^ 0xf) << 2;
1032                 }
1033             }
1034         }
1035         if (mb_num >= mb_count)
1036             return 0;
1037         s->mb_x = 0;
1038     }
1039     return 0;
1040 }
1041 
1042 /**
1043  * Decode the first and second partition.
1044  * @return <0 if error (and sets error type in the error_status_table)
1045  */
ff_mpeg4_decode_partitions(Mpeg4DecContext * ctx)1046 int ff_mpeg4_decode_partitions(Mpeg4DecContext *ctx)
1047 {
1048     MpegEncContext *s = &ctx->m;
1049     int mb_num;
1050     int ret;
1051     const int part_a_error = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_ERROR | ER_MV_ERROR) : ER_MV_ERROR;
1052     const int part_a_end   = s->pict_type == AV_PICTURE_TYPE_I ? (ER_DC_END   | ER_MV_END)   : ER_MV_END;
1053 
1054     mb_num = mpeg4_decode_partition_a(ctx);
1055     if (mb_num <= 0) {
1056         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1057                         s->mb_x, s->mb_y, part_a_error);
1058         return mb_num ? mb_num : AVERROR_INVALIDDATA;
1059     }
1060 
1061     if (s->resync_mb_x + s->resync_mb_y * s->mb_width + mb_num > s->mb_num) {
1062         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
1063         ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1064                         s->mb_x, s->mb_y, part_a_error);
1065         return AVERROR_INVALIDDATA;
1066     }
1067 
1068     s->mb_num_left = mb_num;
1069 
1070     if (s->pict_type == AV_PICTURE_TYPE_I) {
1071         while (show_bits(&s->gb, 9) == 1)
1072             skip_bits(&s->gb, 9);
1073         if (get_bits(&s->gb, 19) != DC_MARKER) {
1074             av_log(s->avctx, AV_LOG_ERROR,
1075                    "marker missing after first I partition at %d %d\n",
1076                    s->mb_x, s->mb_y);
1077             return AVERROR_INVALIDDATA;
1078         }
1079     } else {
1080         while (show_bits(&s->gb, 10) == 1)
1081             skip_bits(&s->gb, 10);
1082         if (get_bits(&s->gb, 17) != MOTION_MARKER) {
1083             av_log(s->avctx, AV_LOG_ERROR,
1084                    "marker missing after first P partition at %d %d\n",
1085                    s->mb_x, s->mb_y);
1086             return AVERROR_INVALIDDATA;
1087         }
1088     }
1089     ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1090                     s->mb_x - 1, s->mb_y, part_a_end);
1091 
1092     ret = mpeg4_decode_partition_b(s, mb_num);
1093     if (ret < 0) {
1094         if (s->pict_type == AV_PICTURE_TYPE_P)
1095             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1096                             s->mb_x, s->mb_y, ER_DC_ERROR);
1097         return ret;
1098     } else {
1099         if (s->pict_type == AV_PICTURE_TYPE_P)
1100             ff_er_add_slice(&s->er, s->resync_mb_x, s->resync_mb_y,
1101                             s->mb_x - 1, s->mb_y, ER_DC_END);
1102     }
1103 
1104     return 0;
1105 }
1106 
1107 /**
1108  * Decode a block.
1109  * @return <0 if an error occurred
1110  */
mpeg4_decode_block(Mpeg4DecContext * ctx,int16_t * block,int n,int coded,int intra,int use_intra_dc_vlc,int rvlc)1111 static inline int mpeg4_decode_block(Mpeg4DecContext *ctx, int16_t *block,
1112                                      int n, int coded, int intra,
1113                                      int use_intra_dc_vlc, int rvlc)
1114 {
1115     MpegEncContext *s = &ctx->m;
1116     int level, i, last, run, qmul, qadd;
1117     int av_uninit(dc_pred_dir);
1118     RLTable *rl;
1119     RL_VLC_ELEM *rl_vlc;
1120     const uint8_t *scan_table;
1121 
1122     // Note intra & rvlc should be optimized away if this is inlined
1123 
1124     if (intra) {
1125         if (use_intra_dc_vlc) {
1126             /* DC coef */
1127             if (s->partitioned_frame) {
1128                 level = s->dc_val[0][s->block_index[n]];
1129                 if (n < 4)
1130                     level = FASTDIV((level + (s->y_dc_scale >> 1)), s->y_dc_scale);
1131                 else
1132                     level = FASTDIV((level + (s->c_dc_scale >> 1)), s->c_dc_scale);
1133                 dc_pred_dir = (s->pred_dir_table[s->mb_x + s->mb_y * s->mb_stride] << n) & 32;
1134             } else {
1135                 level = mpeg4_decode_dc(s, n, &dc_pred_dir);
1136                 if (level < 0)
1137                     return level;
1138             }
1139             block[0] = level;
1140             i        = 0;
1141         } else {
1142             i = -1;
1143             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
1144         }
1145         if (!coded)
1146             goto not_coded;
1147 
1148         if (rvlc) {
1149             rl     = &ff_rvlc_rl_intra;
1150             rl_vlc = ff_rvlc_rl_intra.rl_vlc[0];
1151         } else {
1152             rl     = &ff_mpeg4_rl_intra;
1153             rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
1154         }
1155         if (s->ac_pred) {
1156             if (dc_pred_dir == 0)
1157                 scan_table = s->intra_v_scantable.permutated;  /* left */
1158             else
1159                 scan_table = s->intra_h_scantable.permutated;  /* top */
1160         } else {
1161             scan_table = s->intra_scantable.permutated;
1162         }
1163         qmul = 1;
1164         qadd = 0;
1165     } else {
1166         i = -1;
1167         if (!coded) {
1168             s->block_last_index[n] = i;
1169             return 0;
1170         }
1171         if (rvlc)
1172             rl = &ff_rvlc_rl_inter;
1173         else
1174             rl = &ff_h263_rl_inter;
1175 
1176         scan_table = s->intra_scantable.permutated;
1177 
1178         if (s->mpeg_quant) {
1179             qmul = 1;
1180             qadd = 0;
1181             if (rvlc)
1182                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[0];
1183             else
1184                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
1185         } else {
1186             qmul = s->qscale << 1;
1187             qadd = (s->qscale - 1) | 1;
1188             if (rvlc)
1189                 rl_vlc = ff_rvlc_rl_inter.rl_vlc[s->qscale];
1190             else
1191                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
1192         }
1193     }
1194     {
1195         OPEN_READER(re, &s->gb);
1196         for (;;) {
1197             UPDATE_CACHE(re, &s->gb);
1198             GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
1199             if (level == 0) {
1200                 /* escape */
1201                 if (rvlc) {
1202                     if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1203                         av_log(s->avctx, AV_LOG_ERROR,
1204                                "1. marker bit missing in rvlc esc\n");
1205                         return AVERROR_INVALIDDATA;
1206                     }
1207                     SKIP_CACHE(re, &s->gb, 1);
1208 
1209                     last = SHOW_UBITS(re, &s->gb, 1);
1210                     SKIP_CACHE(re, &s->gb, 1);
1211                     run = SHOW_UBITS(re, &s->gb, 6);
1212                     SKIP_COUNTER(re, &s->gb, 1 + 1 + 6);
1213                     UPDATE_CACHE(re, &s->gb);
1214 
1215                     if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1216                         av_log(s->avctx, AV_LOG_ERROR,
1217                                "2. marker bit missing in rvlc esc\n");
1218                         return AVERROR_INVALIDDATA;
1219                     }
1220                     SKIP_CACHE(re, &s->gb, 1);
1221 
1222                     level = SHOW_UBITS(re, &s->gb, 11);
1223                     SKIP_CACHE(re, &s->gb, 11);
1224 
1225                     if (SHOW_UBITS(re, &s->gb, 5) != 0x10) {
1226                         av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
1227                         return AVERROR_INVALIDDATA;
1228                     }
1229                     SKIP_CACHE(re, &s->gb, 5);
1230 
1231                     level = level * qmul + qadd;
1232                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1233                     SKIP_COUNTER(re, &s->gb, 1 + 11 + 5 + 1);
1234 
1235                     i += run + 1;
1236                     if (last)
1237                         i += 192;
1238                 } else {
1239                     int cache;
1240                     cache = GET_CACHE(re, &s->gb);
1241 
1242                     if (IS_3IV1)
1243                         cache ^= 0xC0000000;
1244 
1245                     if (cache & 0x80000000) {
1246                         if (cache & 0x40000000) {
1247                             /* third escape */
1248                             SKIP_CACHE(re, &s->gb, 2);
1249                             last = SHOW_UBITS(re, &s->gb, 1);
1250                             SKIP_CACHE(re, &s->gb, 1);
1251                             run = SHOW_UBITS(re, &s->gb, 6);
1252                             SKIP_COUNTER(re, &s->gb, 2 + 1 + 6);
1253                             UPDATE_CACHE(re, &s->gb);
1254 
1255                             if (IS_3IV1) {
1256                                 level = SHOW_SBITS(re, &s->gb, 12);
1257                                 LAST_SKIP_BITS(re, &s->gb, 12);
1258                             } else {
1259                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1260                                     av_log(s->avctx, AV_LOG_ERROR,
1261                                            "1. marker bit missing in 3. esc\n");
1262                                     if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR) || get_bits_left(&s->gb) <= 0)
1263                                         return AVERROR_INVALIDDATA;
1264                                 }
1265                                 SKIP_CACHE(re, &s->gb, 1);
1266 
1267                                 level = SHOW_SBITS(re, &s->gb, 12);
1268                                 SKIP_CACHE(re, &s->gb, 12);
1269 
1270                                 if (SHOW_UBITS(re, &s->gb, 1) == 0) {
1271                                     av_log(s->avctx, AV_LOG_ERROR,
1272                                            "2. marker bit missing in 3. esc\n");
1273                                     if (!(s->avctx->err_recognition & AV_EF_IGNORE_ERR) || get_bits_left(&s->gb) <= 0)
1274                                         return AVERROR_INVALIDDATA;
1275                                 }
1276 
1277                                 SKIP_COUNTER(re, &s->gb, 1 + 12 + 1);
1278                             }
1279 
1280 #if 0
1281                             if (s->error_recognition >= FF_ER_COMPLIANT) {
1282                                 const int abs_level= FFABS(level);
1283                                 if (abs_level<=MAX_LEVEL && run<=MAX_RUN) {
1284                                     const int run1= run - rl->max_run[last][abs_level] - 1;
1285                                     if (abs_level <= rl->max_level[last][run]) {
1286                                         av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
1287                                         return AVERROR_INVALIDDATA;
1288                                     }
1289                                     if (s->error_recognition > FF_ER_COMPLIANT) {
1290                                         if (abs_level <= rl->max_level[last][run]*2) {
1291                                             av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
1292                                             return AVERROR_INVALIDDATA;
1293                                         }
1294                                         if (run1 >= 0 && abs_level <= rl->max_level[last][run1]) {
1295                                             av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
1296                                             return AVERROR_INVALIDDATA;
1297                                         }
1298                                     }
1299                                 }
1300                             }
1301 #endif
1302                             if (level > 0)
1303                                 level = level * qmul + qadd;
1304                             else
1305                                 level = level * qmul - qadd;
1306 
1307                             if ((unsigned)(level + 2048) > 4095) {
1308                                 if (s->avctx->err_recognition & (AV_EF_BITSTREAM|AV_EF_AGGRESSIVE)) {
1309                                     if (level > 2560 || level < -2560) {
1310                                         av_log(s->avctx, AV_LOG_ERROR,
1311                                                "|level| overflow in 3. esc, qp=%d\n",
1312                                                s->qscale);
1313                                         return AVERROR_INVALIDDATA;
1314                                     }
1315                                 }
1316                                 level = level < 0 ? -2048 : 2047;
1317                             }
1318 
1319                             i += run + 1;
1320                             if (last)
1321                                 i += 192;
1322                         } else {
1323                             /* second escape */
1324                             SKIP_BITS(re, &s->gb, 2);
1325                             GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1326                             i    += run + rl->max_run[run >> 7][level / qmul] + 1;  // FIXME opt indexing
1327                             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1328                             LAST_SKIP_BITS(re, &s->gb, 1);
1329                         }
1330                     } else {
1331                         /* first escape */
1332                         SKIP_BITS(re, &s->gb, 1);
1333                         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
1334                         i    += run;
1335                         level = level + rl->max_level[run >> 7][(run - 1) & 63] * qmul;  // FIXME opt indexing
1336                         level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1337                         LAST_SKIP_BITS(re, &s->gb, 1);
1338                     }
1339                 }
1340             } else {
1341                 i    += run;
1342                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
1343                 LAST_SKIP_BITS(re, &s->gb, 1);
1344             }
1345             ff_tlog(s->avctx, "dct[%d][%d] = %- 4d end?:%d\n", scan_table[i&63]&7, scan_table[i&63] >> 3, level, i>62);
1346             if (i > 62) {
1347                 i -= 192;
1348                 if (i & (~63)) {
1349                     av_log(s->avctx, AV_LOG_ERROR,
1350                            "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
1351                     return AVERROR_INVALIDDATA;
1352                 }
1353 
1354                 block[scan_table[i]] = level;
1355                 break;
1356             }
1357 
1358             block[scan_table[i]] = level;
1359         }
1360         CLOSE_READER(re, &s->gb);
1361     }
1362 
1363 not_coded:
1364     if (intra) {
1365         if (!use_intra_dc_vlc) {
1366             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
1367 
1368             i -= i >> 31;  // if (i == -1) i = 0;
1369         }
1370 
1371         ff_mpeg4_pred_ac(s, block, n, dc_pred_dir);
1372         if (s->ac_pred)
1373             i = 63;  // FIXME not optimal
1374     }
1375     s->block_last_index[n] = i;
1376     return 0;
1377 }
1378 
1379 /**
1380  * decode partition C of one MB.
1381  * @return <0 if an error occurred
1382  */
mpeg4_decode_partitioned_mb(MpegEncContext * s,int16_t block[6][64])1383 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, int16_t block[6][64])
1384 {
1385     Mpeg4DecContext *ctx = s->avctx->priv_data;
1386     int cbp, mb_type, use_intra_dc_vlc;
1387     const int xy = s->mb_x + s->mb_y * s->mb_stride;
1388 
1389     av_assert2(s == (void*)ctx);
1390 
1391     mb_type = s->current_picture.mb_type[xy];
1392     cbp     = s->cbp_table[xy];
1393 
1394     use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1395 
1396     if (s->current_picture.qscale_table[xy] != s->qscale)
1397         ff_set_qscale(s, s->current_picture.qscale_table[xy]);
1398 
1399     if (s->pict_type == AV_PICTURE_TYPE_P ||
1400         s->pict_type == AV_PICTURE_TYPE_S) {
1401         int i;
1402         for (i = 0; i < 4; i++) {
1403             s->mv[0][i][0] = s->current_picture.motion_val[0][s->block_index[i]][0];
1404             s->mv[0][i][1] = s->current_picture.motion_val[0][s->block_index[i]][1];
1405         }
1406         s->mb_intra = IS_INTRA(mb_type);
1407 
1408         if (IS_SKIP(mb_type)) {
1409             /* skip mb */
1410             for (i = 0; i < 6; i++)
1411                 s->block_last_index[i] = -1;
1412             s->mv_dir  = MV_DIR_FORWARD;
1413             s->mv_type = MV_TYPE_16X16;
1414             if (s->pict_type == AV_PICTURE_TYPE_S
1415                 && ctx->vol_sprite_usage == GMC_SPRITE) {
1416                 s->mcsel      = 1;
1417                 s->mb_skipped = 0;
1418             } else {
1419                 s->mcsel      = 0;
1420                 s->mb_skipped = 1;
1421             }
1422         } else if (s->mb_intra) {
1423             s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
1424         } else if (!s->mb_intra) {
1425             // s->mcsel = 0;  // FIXME do we need to init that?
1426 
1427             s->mv_dir = MV_DIR_FORWARD;
1428             if (IS_8X8(mb_type)) {
1429                 s->mv_type = MV_TYPE_8X8;
1430             } else {
1431                 s->mv_type = MV_TYPE_16X16;
1432             }
1433         }
1434     } else { /* I-Frame */
1435         s->mb_intra = 1;
1436         s->ac_pred  = IS_ACPRED(s->current_picture.mb_type[xy]);
1437     }
1438 
1439     if (!IS_SKIP(mb_type)) {
1440         int i;
1441         s->bdsp.clear_blocks(s->block[0]);
1442         /* decode each block */
1443         for (i = 0; i < 6; i++) {
1444             if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, s->mb_intra,
1445                                    use_intra_dc_vlc, ctx->rvlc) < 0) {
1446                 av_log(s->avctx, AV_LOG_ERROR,
1447                        "texture corrupted at %d %d %d\n",
1448                        s->mb_x, s->mb_y, s->mb_intra);
1449                 return AVERROR_INVALIDDATA;
1450             }
1451             cbp += cbp;
1452         }
1453     }
1454 
1455     /* per-MB end of slice check */
1456     if (--s->mb_num_left <= 0) {
1457         if (mpeg4_is_resync(ctx))
1458             return SLICE_END;
1459         else
1460             return SLICE_NOEND;
1461     } else {
1462         if (mpeg4_is_resync(ctx)) {
1463             const int delta = s->mb_x + 1 == s->mb_width ? 2 : 1;
1464             if (s->cbp_table[xy + delta])
1465                 return SLICE_END;
1466         }
1467         return SLICE_OK;
1468     }
1469 }
1470 
mpeg4_decode_mb(MpegEncContext * s,int16_t block[6][64])1471 static int mpeg4_decode_mb(MpegEncContext *s, int16_t block[6][64])
1472 {
1473     Mpeg4DecContext *ctx = s->avctx->priv_data;
1474     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
1475     int16_t *mot_val;
1476     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
1477     const int xy = s->mb_x + s->mb_y * s->mb_stride;
1478 
1479     av_assert2(s ==  (void*)ctx);
1480     av_assert2(s->h263_pred);
1481 
1482     if (s->pict_type == AV_PICTURE_TYPE_P ||
1483         s->pict_type == AV_PICTURE_TYPE_S) {
1484         do {
1485             if (get_bits1(&s->gb)) {
1486                 /* skip mb */
1487                 s->mb_intra = 0;
1488                 for (i = 0; i < 6; i++)
1489                     s->block_last_index[i] = -1;
1490                 s->mv_dir  = MV_DIR_FORWARD;
1491                 s->mv_type = MV_TYPE_16X16;
1492                 if (s->pict_type == AV_PICTURE_TYPE_S &&
1493                     ctx->vol_sprite_usage == GMC_SPRITE) {
1494                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1495                                                      MB_TYPE_GMC   |
1496                                                      MB_TYPE_16x16 |
1497                                                      MB_TYPE_L0;
1498                     s->mcsel       = 1;
1499                     s->mv[0][0][0] = get_amv(ctx, 0);
1500                     s->mv[0][0][1] = get_amv(ctx, 1);
1501                     s->mb_skipped  = 0;
1502                 } else {
1503                     s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1504                                                      MB_TYPE_16x16 |
1505                                                      MB_TYPE_L0;
1506                     s->mcsel       = 0;
1507                     s->mv[0][0][0] = 0;
1508                     s->mv[0][0][1] = 0;
1509                     s->mb_skipped  = 1;
1510                 }
1511                 goto end;
1512             }
1513             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
1514             if (cbpc < 0) {
1515                 av_log(s->avctx, AV_LOG_ERROR,
1516                        "mcbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1517                 return AVERROR_INVALIDDATA;
1518             }
1519         } while (cbpc == 20);
1520 
1521         s->bdsp.clear_blocks(s->block[0]);
1522         dquant      = cbpc & 8;
1523         s->mb_intra = ((cbpc & 4) != 0);
1524         if (s->mb_intra)
1525             goto intra;
1526 
1527         if (s->pict_type == AV_PICTURE_TYPE_S &&
1528             ctx->vol_sprite_usage == GMC_SPRITE && (cbpc & 16) == 0)
1529             s->mcsel = get_bits1(&s->gb);
1530         else
1531             s->mcsel = 0;
1532         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
1533         if (cbpy < 0) {
1534             av_log(s->avctx, AV_LOG_ERROR,
1535                    "P cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1536             return AVERROR_INVALIDDATA;
1537         }
1538 
1539         cbp = (cbpc & 3) | (cbpy << 2);
1540         if (dquant)
1541             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1542         if ((!s->progressive_sequence) &&
1543             (cbp || (s->workaround_bugs & FF_BUG_XVID_ILACE)))
1544             s->interlaced_dct = get_bits1(&s->gb);
1545 
1546         s->mv_dir = MV_DIR_FORWARD;
1547         if ((cbpc & 16) == 0) {
1548             if (s->mcsel) {
1549                 s->current_picture.mb_type[xy] = MB_TYPE_GMC   |
1550                                                  MB_TYPE_16x16 |
1551                                                  MB_TYPE_L0;
1552                 /* 16x16 global motion prediction */
1553                 s->mv_type     = MV_TYPE_16X16;
1554                 mx             = get_amv(ctx, 0);
1555                 my             = get_amv(ctx, 1);
1556                 s->mv[0][0][0] = mx;
1557                 s->mv[0][0][1] = my;
1558             } else if ((!s->progressive_sequence) && get_bits1(&s->gb)) {
1559                 s->current_picture.mb_type[xy] = MB_TYPE_16x8 |
1560                                                  MB_TYPE_L0   |
1561                                                  MB_TYPE_INTERLACED;
1562                 /* 16x8 field motion prediction */
1563                 s->mv_type = MV_TYPE_FIELD;
1564 
1565                 s->field_select[0][0] = get_bits1(&s->gb);
1566                 s->field_select[0][1] = get_bits1(&s->gb);
1567 
1568                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1569 
1570                 for (i = 0; i < 2; i++) {
1571                     mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1572                     if (mx >= 0xffff)
1573                         return AVERROR_INVALIDDATA;
1574 
1575                     my = ff_h263_decode_motion(s, pred_y / 2, s->f_code);
1576                     if (my >= 0xffff)
1577                         return AVERROR_INVALIDDATA;
1578 
1579                     s->mv[0][i][0] = mx;
1580                     s->mv[0][i][1] = my;
1581                 }
1582             } else {
1583                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
1584                 /* 16x16 motion prediction */
1585                 s->mv_type = MV_TYPE_16X16;
1586                 ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
1587                 mx = ff_h263_decode_motion(s, pred_x, s->f_code);
1588 
1589                 if (mx >= 0xffff)
1590                     return AVERROR_INVALIDDATA;
1591 
1592                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1593 
1594                 if (my >= 0xffff)
1595                     return AVERROR_INVALIDDATA;
1596                 s->mv[0][0][0] = mx;
1597                 s->mv[0][0][1] = my;
1598             }
1599         } else {
1600             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
1601             s->mv_type                     = MV_TYPE_8X8;
1602             for (i = 0; i < 4; i++) {
1603                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
1604                 mx      = ff_h263_decode_motion(s, pred_x, s->f_code);
1605                 if (mx >= 0xffff)
1606                     return AVERROR_INVALIDDATA;
1607 
1608                 my = ff_h263_decode_motion(s, pred_y, s->f_code);
1609                 if (my >= 0xffff)
1610                     return AVERROR_INVALIDDATA;
1611                 s->mv[0][i][0] = mx;
1612                 s->mv[0][i][1] = my;
1613                 mot_val[0]     = mx;
1614                 mot_val[1]     = my;
1615             }
1616         }
1617     } else if (s->pict_type == AV_PICTURE_TYPE_B) {
1618         int modb1;   // first bit of modb
1619         int modb2;   // second bit of modb
1620         int mb_type;
1621 
1622         s->mb_intra = 0;  // B-frames never contain intra blocks
1623         s->mcsel    = 0;  //      ...               true gmc blocks
1624 
1625         if (s->mb_x == 0) {
1626             for (i = 0; i < 2; i++) {
1627                 s->last_mv[i][0][0] =
1628                 s->last_mv[i][0][1] =
1629                 s->last_mv[i][1][0] =
1630                 s->last_mv[i][1][1] = 0;
1631             }
1632 
1633             ff_thread_await_progress(&s->next_picture_ptr->tf, s->mb_y, 0);
1634         }
1635 
1636         /* if we skipped it in the future P-frame than skip it now too */
1637         s->mb_skipped = s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x];  // Note, skiptab=0 if last was GMC
1638 
1639         if (s->mb_skipped) {
1640             /* skip mb */
1641             for (i = 0; i < 6; i++)
1642                 s->block_last_index[i] = -1;
1643 
1644             s->mv_dir      = MV_DIR_FORWARD;
1645             s->mv_type     = MV_TYPE_16X16;
1646             s->mv[0][0][0] =
1647             s->mv[0][0][1] =
1648             s->mv[1][0][0] =
1649             s->mv[1][0][1] = 0;
1650             s->current_picture.mb_type[xy] = MB_TYPE_SKIP  |
1651                                              MB_TYPE_16x16 |
1652                                              MB_TYPE_L0;
1653             goto end;
1654         }
1655 
1656         modb1 = get_bits1(&s->gb);
1657         if (modb1) {
1658             // like MB_TYPE_B_DIRECT but no vectors coded
1659             mb_type = MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1;
1660             cbp     = 0;
1661         } else {
1662             modb2   = get_bits1(&s->gb);
1663             mb_type = get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
1664             if (mb_type < 0) {
1665                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
1666                 return AVERROR_INVALIDDATA;
1667             }
1668             mb_type = mb_type_b_map[mb_type];
1669             if (modb2) {
1670                 cbp = 0;
1671             } else {
1672                 s->bdsp.clear_blocks(s->block[0]);
1673                 cbp = get_bits(&s->gb, 6);
1674             }
1675 
1676             if ((!IS_DIRECT(mb_type)) && cbp) {
1677                 if (get_bits1(&s->gb))
1678                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb) * 4 - 2);
1679             }
1680 
1681             if (!s->progressive_sequence) {
1682                 if (cbp)
1683                     s->interlaced_dct = get_bits1(&s->gb);
1684 
1685                 if (!IS_DIRECT(mb_type) && get_bits1(&s->gb)) {
1686                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
1687                     mb_type &= ~MB_TYPE_16x16;
1688 
1689                     if (USES_LIST(mb_type, 0)) {
1690                         s->field_select[0][0] = get_bits1(&s->gb);
1691                         s->field_select[0][1] = get_bits1(&s->gb);
1692                     }
1693                     if (USES_LIST(mb_type, 1)) {
1694                         s->field_select[1][0] = get_bits1(&s->gb);
1695                         s->field_select[1][1] = get_bits1(&s->gb);
1696                     }
1697                 }
1698             }
1699 
1700             s->mv_dir = 0;
1701             if ((mb_type & (MB_TYPE_DIRECT2 | MB_TYPE_INTERLACED)) == 0) {
1702                 s->mv_type = MV_TYPE_16X16;
1703 
1704                 if (USES_LIST(mb_type, 0)) {
1705                     s->mv_dir = MV_DIR_FORWARD;
1706 
1707                     mx = ff_h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
1708                     my = ff_h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
1709                     s->last_mv[0][1][0] =
1710                     s->last_mv[0][0][0] =
1711                     s->mv[0][0][0]      = mx;
1712                     s->last_mv[0][1][1] =
1713                     s->last_mv[0][0][1] =
1714                     s->mv[0][0][1]      = my;
1715                 }
1716 
1717                 if (USES_LIST(mb_type, 1)) {
1718                     s->mv_dir |= MV_DIR_BACKWARD;
1719 
1720                     mx = ff_h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
1721                     my = ff_h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
1722                     s->last_mv[1][1][0] =
1723                     s->last_mv[1][0][0] =
1724                     s->mv[1][0][0]      = mx;
1725                     s->last_mv[1][1][1] =
1726                     s->last_mv[1][0][1] =
1727                     s->mv[1][0][1]      = my;
1728                 }
1729             } else if (!IS_DIRECT(mb_type)) {
1730                 s->mv_type = MV_TYPE_FIELD;
1731 
1732                 if (USES_LIST(mb_type, 0)) {
1733                     s->mv_dir = MV_DIR_FORWARD;
1734 
1735                     for (i = 0; i < 2; i++) {
1736                         mx = ff_h263_decode_motion(s, s->last_mv[0][i][0], s->f_code);
1737                         my = ff_h263_decode_motion(s, s->last_mv[0][i][1] / 2, s->f_code);
1738                         s->last_mv[0][i][0] =
1739                         s->mv[0][i][0]      = mx;
1740                         s->last_mv[0][i][1] = (s->mv[0][i][1] = my) * 2;
1741                     }
1742                 }
1743 
1744                 if (USES_LIST(mb_type, 1)) {
1745                     s->mv_dir |= MV_DIR_BACKWARD;
1746 
1747                     for (i = 0; i < 2; i++) {
1748                         mx = ff_h263_decode_motion(s, s->last_mv[1][i][0], s->b_code);
1749                         my = ff_h263_decode_motion(s, s->last_mv[1][i][1] / 2, s->b_code);
1750                         s->last_mv[1][i][0] =
1751                         s->mv[1][i][0]      = mx;
1752                         s->last_mv[1][i][1] = (s->mv[1][i][1] = my) * 2;
1753                     }
1754                 }
1755             }
1756         }
1757 
1758         if (IS_DIRECT(mb_type)) {
1759             if (IS_SKIP(mb_type)) {
1760                 mx =
1761                 my = 0;
1762             } else {
1763                 mx = ff_h263_decode_motion(s, 0, 1);
1764                 my = ff_h263_decode_motion(s, 0, 1);
1765             }
1766 
1767             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
1768             mb_type  |= ff_mpeg4_set_direct_mv(s, mx, my);
1769         }
1770         s->current_picture.mb_type[xy] = mb_type;
1771     } else { /* I-Frame */
1772         int use_intra_dc_vlc;
1773 
1774         do {
1775             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
1776             if (cbpc < 0) {
1777                 av_log(s->avctx, AV_LOG_ERROR,
1778                        "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
1779                 return AVERROR_INVALIDDATA;
1780             }
1781         } while (cbpc == 8);
1782 
1783         dquant = cbpc & 4;
1784         s->mb_intra = 1;
1785 
1786 intra:
1787         s->ac_pred = get_bits1(&s->gb);
1788         if (s->ac_pred)
1789             s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
1790         else
1791             s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
1792 
1793         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
1794         if (cbpy < 0) {
1795             av_log(s->avctx, AV_LOG_ERROR,
1796                    "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
1797             return AVERROR_INVALIDDATA;
1798         }
1799         cbp = (cbpc & 3) | (cbpy << 2);
1800 
1801         use_intra_dc_vlc = s->qscale < ctx->intra_dc_threshold;
1802 
1803         if (dquant)
1804             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
1805 
1806         if (!s->progressive_sequence)
1807             s->interlaced_dct = get_bits1(&s->gb);
1808 
1809         s->bdsp.clear_blocks(s->block[0]);
1810         /* decode each block */
1811         for (i = 0; i < 6; i++) {
1812             if (mpeg4_decode_block(ctx, block[i], i, cbp & 32,
1813                                    1, use_intra_dc_vlc, 0) < 0)
1814                 return AVERROR_INVALIDDATA;
1815             cbp += cbp;
1816         }
1817         goto end;
1818     }
1819 
1820     /* decode each block */
1821     for (i = 0; i < 6; i++) {
1822         if (mpeg4_decode_block(ctx, block[i], i, cbp & 32, 0, 0, 0) < 0)
1823             return AVERROR_INVALIDDATA;
1824         cbp += cbp;
1825     }
1826 
1827 end:
1828     /* per-MB end of slice check */
1829     if (s->codec_id == AV_CODEC_ID_MPEG4) {
1830         int next = mpeg4_is_resync(ctx);
1831         if (next) {
1832             if        (s->mb_x + s->mb_y*s->mb_width + 1 >  next && (s->avctx->err_recognition & AV_EF_AGGRESSIVE)) {
1833                 return AVERROR_INVALIDDATA;
1834             } else if (s->mb_x + s->mb_y*s->mb_width + 1 >= next)
1835                 return SLICE_END;
1836 
1837             if (s->pict_type == AV_PICTURE_TYPE_B) {
1838                 const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
1839                 ff_thread_await_progress(&s->next_picture_ptr->tf,
1840                                          (s->mb_x + delta >= s->mb_width)
1841                                          ? FFMIN(s->mb_y + 1, s->mb_height - 1)
1842                                          : s->mb_y, 0);
1843                 if (s->next_picture.mbskip_table[xy + delta])
1844                     return SLICE_OK;
1845             }
1846 
1847             return SLICE_END;
1848         }
1849     }
1850 
1851     return SLICE_OK;
1852 }
1853 
1854 /* As per spec, studio start code search isn't the same as the old type of start code */
next_start_code_studio(GetBitContext * gb)1855 static void next_start_code_studio(GetBitContext *gb)
1856 {
1857     align_get_bits(gb);
1858 
1859     while (get_bits_left(gb) >= 24 && show_bits(gb, 24) != 0x1) {
1860         get_bits(gb, 8);
1861     }
1862 }
1863 
1864 /* additional_code, vlc index */
1865 static const uint8_t ac_state_tab[22][2] =
1866 {
1867     {0, 0},
1868     {0, 1},
1869     {1, 1},
1870     {2, 1},
1871     {3, 1},
1872     {4, 1},
1873     {5, 1},
1874     {1, 2},
1875     {2, 2},
1876     {3, 2},
1877     {4, 2},
1878     {5, 2},
1879     {6, 2},
1880     {1, 3},
1881     {2, 4},
1882     {3, 5},
1883     {4, 6},
1884     {5, 7},
1885     {6, 8},
1886     {7, 9},
1887     {8, 10},
1888     {0, 11}
1889 };
1890 
mpeg4_decode_studio_block(MpegEncContext * s,int32_t block[64],int n)1891 static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n)
1892 {
1893     Mpeg4DecContext *ctx = s->avctx->priv_data;
1894 
1895     int cc, dct_dc_size, dct_diff, code, j, idx = 1, group = 0, run = 0,
1896         additional_code_len, sign, mismatch;
1897     const VLC *cur_vlc = &studio_intra_tab[0];
1898     uint8_t *const scantable = s->intra_scantable.permutated;
1899     const uint16_t *quant_matrix;
1900     uint32_t flc;
1901     const int min = -1 *  (1 << (s->avctx->bits_per_raw_sample + 6));
1902     const int max =      ((1 << (s->avctx->bits_per_raw_sample + 6)) - 1);
1903     int shift =  3 - s->dct_precision;
1904 
1905     mismatch = 1;
1906 
1907     memset(block, 0, 64 * sizeof(int32_t));
1908 
1909     if (n < 4) {
1910         cc = 0;
1911         dct_dc_size = get_vlc2(&s->gb, studio_luma_dc.table, STUDIO_INTRA_BITS, 2);
1912         quant_matrix = s->intra_matrix;
1913     } else {
1914         cc = (n & 1) + 1;
1915         if (ctx->rgb)
1916             dct_dc_size = get_vlc2(&s->gb, studio_luma_dc.table, STUDIO_INTRA_BITS, 2);
1917         else
1918             dct_dc_size = get_vlc2(&s->gb, studio_chroma_dc.table, STUDIO_INTRA_BITS, 2);
1919         quant_matrix = s->chroma_intra_matrix;
1920     }
1921 
1922     if (dct_dc_size == 0) {
1923         dct_diff = 0;
1924     } else {
1925         dct_diff = get_xbits(&s->gb, dct_dc_size);
1926 
1927         if (dct_dc_size > 8) {
1928             if(!check_marker(s->avctx, &s->gb, "dct_dc_size > 8"))
1929                 return AVERROR_INVALIDDATA;
1930         }
1931 
1932     }
1933 
1934     s->last_dc[cc] += dct_diff;
1935 
1936     if (s->mpeg_quant)
1937         block[0] = s->last_dc[cc] * (8 >> s->intra_dc_precision);
1938     else
1939         block[0] = s->last_dc[cc] * (8 >> s->intra_dc_precision) * (8 >> s->dct_precision);
1940     /* TODO: support mpeg_quant for AC coefficients */
1941 
1942     block[0] = av_clip(block[0], min, max);
1943     mismatch ^= block[0];
1944 
1945     /* AC Coefficients */
1946     while (1) {
1947         group = get_vlc2(&s->gb, cur_vlc->table, STUDIO_INTRA_BITS, 2);
1948 
1949         if (group < 0) {
1950             av_log(s->avctx, AV_LOG_ERROR, "illegal ac coefficient group vlc\n");
1951             return AVERROR_INVALIDDATA;
1952         }
1953 
1954         additional_code_len = ac_state_tab[group][0];
1955         cur_vlc = &studio_intra_tab[ac_state_tab[group][1]];
1956 
1957         if (group == 0) {
1958             /* End of Block */
1959             break;
1960         } else if (group >= 1 && group <= 6) {
1961             /* Zero run length (Table B.47) */
1962             run = 1 << additional_code_len;
1963             if (additional_code_len)
1964                 run += get_bits(&s->gb, additional_code_len);
1965             idx += run;
1966             continue;
1967         } else if (group >= 7 && group <= 12) {
1968             /* Zero run length and +/-1 level (Table B.48) */
1969             code = get_bits(&s->gb, additional_code_len);
1970             sign = code & 1;
1971             code >>= 1;
1972             run = (1 << (additional_code_len - 1)) + code;
1973             idx += run;
1974             if (idx > 63)
1975                 return AVERROR_INVALIDDATA;
1976             j = scantable[idx++];
1977             block[j] = sign ? 1 : -1;
1978         } else if (group >= 13 && group <= 20) {
1979             /* Level value (Table B.49) */
1980             if (idx > 63)
1981                 return AVERROR_INVALIDDATA;
1982             j = scantable[idx++];
1983             block[j] = get_xbits(&s->gb, additional_code_len);
1984         } else if (group == 21) {
1985             /* Escape */
1986             if (idx > 63)
1987                 return AVERROR_INVALIDDATA;
1988             j = scantable[idx++];
1989             additional_code_len = s->avctx->bits_per_raw_sample + s->dct_precision + 4;
1990             flc = get_bits(&s->gb, additional_code_len);
1991             if (flc >> (additional_code_len-1))
1992                 block[j] = -1 * (( flc ^ ((1 << additional_code_len) -1)) + 1);
1993             else
1994                 block[j] = flc;
1995         }
1996         block[j] = ((block[j] * quant_matrix[j] * s->qscale) * (1 << shift)) / 16;
1997         block[j] = av_clip(block[j], min, max);
1998         mismatch ^= block[j];
1999     }
2000 
2001     block[63] ^= mismatch & 1;
2002 
2003     return 0;
2004 }
2005 
mpeg4_decode_dpcm_macroblock(MpegEncContext * s,int16_t macroblock[256],int n)2006 static int mpeg4_decode_dpcm_macroblock(MpegEncContext *s, int16_t macroblock[256], int n)
2007 {
2008     int i, j, w, h, idx = 0;
2009     int block_mean, rice_parameter, rice_prefix_code, rice_suffix_code,
2010         dpcm_residual, left, top, topleft, min_left_top, max_left_top, p, p2, output;
2011     h = 16 >> (n ? s->chroma_y_shift : 0);
2012     w = 16 >> (n ? s->chroma_x_shift : 0);
2013 
2014     block_mean = get_bits(&s->gb, s->avctx->bits_per_raw_sample);
2015     if (block_mean == 0){
2016         av_log(s->avctx, AV_LOG_ERROR, "Forbidden block_mean\n");
2017         return AVERROR_INVALIDDATA;
2018     }
2019     s->last_dc[n] = block_mean * (1 << (s->dct_precision + s->intra_dc_precision));
2020 
2021     rice_parameter = get_bits(&s->gb, 4);
2022     if (rice_parameter == 0) {
2023         av_log(s->avctx, AV_LOG_ERROR, "Forbidden rice_parameter\n");
2024         return AVERROR_INVALIDDATA;
2025     }
2026 
2027     if (rice_parameter == 15)
2028         rice_parameter = 0;
2029 
2030     if (rice_parameter > 11) {
2031         av_log(s->avctx, AV_LOG_ERROR, "Forbidden rice_parameter\n");
2032         return AVERROR_INVALIDDATA;
2033     }
2034 
2035     for (i = 0; i < h; i++) {
2036         output = 1 << (s->avctx->bits_per_raw_sample - 1);
2037         top = 1 << (s->avctx->bits_per_raw_sample - 1);
2038 
2039         for (j = 0; j < w; j++) {
2040             left = output;
2041             topleft = top;
2042 
2043             rice_prefix_code = get_unary(&s->gb, 1, 12);
2044 
2045             /* Escape */
2046             if (rice_prefix_code == 11)
2047                 dpcm_residual = get_bits(&s->gb, s->avctx->bits_per_raw_sample);
2048             else {
2049                 if (rice_prefix_code == 12) {
2050                     av_log(s->avctx, AV_LOG_ERROR, "Forbidden rice_prefix_code\n");
2051                     return AVERROR_INVALIDDATA;
2052                 }
2053                 rice_suffix_code = get_bitsz(&s->gb, rice_parameter);
2054                 dpcm_residual = (rice_prefix_code << rice_parameter) + rice_suffix_code;
2055             }
2056 
2057             /* Map to a signed residual */
2058             if (dpcm_residual & 1)
2059                 dpcm_residual = (-1 * dpcm_residual) >> 1;
2060             else
2061                 dpcm_residual = (dpcm_residual >> 1);
2062 
2063             if (i != 0)
2064                 top = macroblock[idx-w];
2065 
2066             p = left + top - topleft;
2067             min_left_top = FFMIN(left, top);
2068             if (p < min_left_top)
2069                 p = min_left_top;
2070 
2071             max_left_top = FFMAX(left, top);
2072             if (p > max_left_top)
2073                 p = max_left_top;
2074 
2075             p2 = (FFMIN(min_left_top, topleft) + FFMAX(max_left_top, topleft)) >> 1;
2076             if (p2 == p)
2077                 p2 = block_mean;
2078 
2079             if (p2 > p)
2080                 dpcm_residual *= -1;
2081 
2082             macroblock[idx++] = output = (dpcm_residual + p) & ((1 << s->avctx->bits_per_raw_sample) - 1);
2083         }
2084     }
2085 
2086     return 0;
2087 }
2088 
mpeg4_decode_studio_mb(MpegEncContext * s,int16_t block_[12][64])2089 static int mpeg4_decode_studio_mb(MpegEncContext *s, int16_t block_[12][64])
2090 {
2091     Mpeg4DecContext *const ctx = (Mpeg4DecContext*)s;
2092     int i;
2093 
2094     ctx->dpcm_direction = 0;
2095 
2096     /* StudioMacroblock */
2097     /* Assumes I-VOP */
2098     s->mb_intra = 1;
2099     if (get_bits1(&s->gb)) { /* compression_mode */
2100         /* DCT */
2101         /* macroblock_type, 1 or 2-bit VLC */
2102         if (!get_bits1(&s->gb)) {
2103             skip_bits1(&s->gb);
2104             s->qscale = mpeg_get_qscale(s);
2105         }
2106 
2107         for (i = 0; i < mpeg4_block_count[s->chroma_format]; i++) {
2108             if (mpeg4_decode_studio_block(s, ctx->block32[i], i) < 0)
2109                 return AVERROR_INVALIDDATA;
2110         }
2111     } else {
2112         /* DPCM */
2113         check_marker(s->avctx, &s->gb, "DPCM block start");
2114         ctx->dpcm_direction = get_bits1(&s->gb) ? -1 : 1;
2115         for (i = 0; i < 3; i++) {
2116             if (mpeg4_decode_dpcm_macroblock(s, ctx->dpcm_macroblock[i], i) < 0)
2117                 return AVERROR_INVALIDDATA;
2118         }
2119     }
2120 
2121     if (get_bits_left(&s->gb) >= 24 && show_bits(&s->gb, 23) == 0) {
2122         next_start_code_studio(&s->gb);
2123         return SLICE_END;
2124     }
2125 
2126     //vcon-stp9L1.bits (first frame)
2127     if (get_bits_left(&s->gb) == 0)
2128         return SLICE_END;
2129 
2130     //vcon-stp2L1.bits, vcon-stp3L1.bits, vcon-stp6L1.bits, vcon-stp7L1.bits, vcon-stp8L1.bits, vcon-stp10L1.bits (first frame)
2131     if (get_bits_left(&s->gb) < 8U && show_bits(&s->gb, get_bits_left(&s->gb)) == 0)
2132         return SLICE_END;
2133 
2134     return SLICE_OK;
2135 }
2136 
mpeg4_decode_gop_header(MpegEncContext * s,GetBitContext * gb)2137 static int mpeg4_decode_gop_header(MpegEncContext *s, GetBitContext *gb)
2138 {
2139     int hours, minutes, seconds;
2140 
2141     if (!show_bits(gb, 23)) {
2142         av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
2143         return AVERROR_INVALIDDATA;
2144     }
2145 
2146     hours   = get_bits(gb, 5);
2147     minutes = get_bits(gb, 6);
2148     check_marker(s->avctx, gb, "in gop_header");
2149     seconds = get_bits(gb, 6);
2150 
2151     s->time_base = seconds + 60*(minutes + 60*hours);
2152 
2153     skip_bits1(gb);
2154     skip_bits1(gb);
2155 
2156     return 0;
2157 }
2158 
mpeg4_decode_profile_level(MpegEncContext * s,GetBitContext * gb,int * profile,int * level)2159 static int mpeg4_decode_profile_level(MpegEncContext *s, GetBitContext *gb, int *profile, int *level)
2160 {
2161 
2162     *profile = get_bits(gb, 4);
2163     *level   = get_bits(gb, 4);
2164 
2165     // for Simple profile, level 0
2166     if (*profile == 0 && *level == 8) {
2167         *level = 0;
2168     }
2169 
2170     return 0;
2171 }
2172 
mpeg4_decode_visual_object(MpegEncContext * s,GetBitContext * gb)2173 static int mpeg4_decode_visual_object(MpegEncContext *s, GetBitContext *gb)
2174 {
2175     int visual_object_type;
2176     int is_visual_object_identifier = get_bits1(gb);
2177 
2178     if (is_visual_object_identifier) {
2179         skip_bits(gb, 4+3);
2180     }
2181     visual_object_type = get_bits(gb, 4);
2182 
2183     if (visual_object_type == VOT_VIDEO_ID ||
2184         visual_object_type == VOT_STILL_TEXTURE_ID) {
2185         int video_signal_type = get_bits1(gb);
2186         if (video_signal_type) {
2187             int video_range, color_description;
2188             skip_bits(gb, 3); // video_format
2189             video_range = get_bits1(gb);
2190             color_description = get_bits1(gb);
2191 
2192             s->avctx->color_range = video_range ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
2193 
2194             if (color_description) {
2195                 s->avctx->color_primaries = get_bits(gb, 8);
2196                 s->avctx->color_trc       = get_bits(gb, 8);
2197                 s->avctx->colorspace      = get_bits(gb, 8);
2198             }
2199         }
2200     }
2201 
2202     return 0;
2203 }
2204 
mpeg4_load_default_matrices(MpegEncContext * s)2205 static void mpeg4_load_default_matrices(MpegEncContext *s)
2206 {
2207     int i, v;
2208 
2209     /* load default matrices */
2210     for (i = 0; i < 64; i++) {
2211         int j = s->idsp.idct_permutation[i];
2212         v = ff_mpeg4_default_intra_matrix[i];
2213         s->intra_matrix[j]        = v;
2214         s->chroma_intra_matrix[j] = v;
2215 
2216         v = ff_mpeg4_default_non_intra_matrix[i];
2217         s->inter_matrix[j]        = v;
2218         s->chroma_inter_matrix[j] = v;
2219     }
2220 }
2221 
read_quant_matrix_ext(MpegEncContext * s,GetBitContext * gb)2222 static int read_quant_matrix_ext(MpegEncContext *s, GetBitContext *gb)
2223 {
2224     int i, j, v;
2225 
2226     if (get_bits1(gb)) {
2227         if (get_bits_left(gb) < 64*8)
2228             return AVERROR_INVALIDDATA;
2229         /* intra_quantiser_matrix */
2230         for (i = 0; i < 64; i++) {
2231             v = get_bits(gb, 8);
2232             j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2233             s->intra_matrix[j]        = v;
2234             s->chroma_intra_matrix[j] = v;
2235         }
2236     }
2237 
2238     if (get_bits1(gb)) {
2239         if (get_bits_left(gb) < 64*8)
2240             return AVERROR_INVALIDDATA;
2241         /* non_intra_quantiser_matrix */
2242         for (i = 0; i < 64; i++) {
2243             get_bits(gb, 8);
2244         }
2245     }
2246 
2247     if (get_bits1(gb)) {
2248         if (get_bits_left(gb) < 64*8)
2249             return AVERROR_INVALIDDATA;
2250         /* chroma_intra_quantiser_matrix */
2251         for (i = 0; i < 64; i++) {
2252             v = get_bits(gb, 8);
2253             j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2254             s->chroma_intra_matrix[j] = v;
2255         }
2256     }
2257 
2258     if (get_bits1(gb)) {
2259         if (get_bits_left(gb) < 64*8)
2260             return AVERROR_INVALIDDATA;
2261         /* chroma_non_intra_quantiser_matrix */
2262         for (i = 0; i < 64; i++) {
2263             get_bits(gb, 8);
2264         }
2265     }
2266 
2267     next_start_code_studio(gb);
2268     return 0;
2269 }
2270 
extension_and_user_data(MpegEncContext * s,GetBitContext * gb,int id)2271 static void extension_and_user_data(MpegEncContext *s, GetBitContext *gb, int id)
2272 {
2273     uint32_t startcode;
2274     uint8_t extension_type;
2275 
2276     startcode = show_bits_long(gb, 32);
2277     if (startcode == USER_DATA_STARTCODE || startcode == EXT_STARTCODE) {
2278 
2279         if ((id == 2 || id == 4) && startcode == EXT_STARTCODE) {
2280             skip_bits_long(gb, 32);
2281             extension_type = get_bits(gb, 4);
2282             if (extension_type == QUANT_MATRIX_EXT_ID)
2283                 read_quant_matrix_ext(s, gb);
2284         }
2285     }
2286 }
2287 
decode_studio_vol_header(Mpeg4DecContext * ctx,GetBitContext * gb)2288 static int decode_studio_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2289 {
2290     MpegEncContext *s = &ctx->m;
2291     int width, height, aspect_ratio_info;
2292     int bits_per_raw_sample;
2293     int rgb, chroma_format;
2294 
2295     // random_accessible_vol and video_object_type_indication have already
2296     // been read by the caller decode_vol_header()
2297     skip_bits(gb, 4); /* video_object_layer_verid */
2298     ctx->shape = get_bits(gb, 2); /* video_object_layer_shape */
2299     skip_bits(gb, 4); /* video_object_layer_shape_extension */
2300     skip_bits1(gb); /* progressive_sequence */
2301     if (ctx->shape != RECT_SHAPE) {
2302         avpriv_request_sample(s->avctx, "MPEG-4 Studio profile non rectangular shape");
2303         return AVERROR_PATCHWELCOME;
2304     }
2305     if (ctx->shape != BIN_ONLY_SHAPE) {
2306         rgb = get_bits1(gb); /* rgb_components */
2307         chroma_format = get_bits(gb, 2); /* chroma_format */
2308         if (!chroma_format || chroma_format == CHROMA_420 || (rgb && chroma_format == CHROMA_422)) {
2309             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
2310             return AVERROR_INVALIDDATA;
2311         }
2312 
2313         bits_per_raw_sample = get_bits(gb, 4); /* bit_depth */
2314         if (bits_per_raw_sample == 10) {
2315             if (rgb) {
2316                 s->avctx->pix_fmt = AV_PIX_FMT_GBRP10;
2317             } else {
2318                 s->avctx->pix_fmt = chroma_format == CHROMA_422 ? AV_PIX_FMT_YUV422P10 : AV_PIX_FMT_YUV444P10;
2319             }
2320         } else {
2321             avpriv_request_sample(s->avctx, "MPEG-4 Studio profile bit-depth %u", bits_per_raw_sample);
2322             return AVERROR_PATCHWELCOME;
2323         }
2324         if (rgb != ctx->rgb || s->chroma_format != chroma_format)
2325             s->context_reinit = 1;
2326         s->avctx->bits_per_raw_sample = bits_per_raw_sample;
2327         ctx->rgb = rgb;
2328         s->chroma_format = chroma_format;
2329     }
2330     if (ctx->shape == RECT_SHAPE) {
2331         check_marker(s->avctx, gb, "before video_object_layer_width");
2332         width  = get_bits(gb, 14); /* video_object_layer_width */
2333         check_marker(s->avctx, gb, "before video_object_layer_height");
2334         height = get_bits(gb, 14); /* video_object_layer_height */
2335         check_marker(s->avctx, gb, "after video_object_layer_height");
2336 
2337         /* Do the same check as non-studio profile */
2338         if (width && height) {
2339             if (s->width && s->height &&
2340                 (s->width != width || s->height != height))
2341                 s->context_reinit = 1;
2342             s->width  = width;
2343             s->height = height;
2344         }
2345     }
2346     aspect_ratio_info = get_bits(gb, 4);
2347     if (aspect_ratio_info == FF_ASPECT_EXTENDED) {
2348         s->avctx->sample_aspect_ratio.num = get_bits(gb, 8);  // par_width
2349         s->avctx->sample_aspect_ratio.den = get_bits(gb, 8);  // par_height
2350     } else {
2351         s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[aspect_ratio_info];
2352     }
2353     skip_bits(gb, 4); /* frame_rate_code */
2354     skip_bits(gb, 15); /* first_half_bit_rate */
2355     check_marker(s->avctx, gb, "after first_half_bit_rate");
2356     skip_bits(gb, 15); /* latter_half_bit_rate */
2357     check_marker(s->avctx, gb, "after latter_half_bit_rate");
2358     skip_bits(gb, 15); /* first_half_vbv_buffer_size */
2359     check_marker(s->avctx, gb, "after first_half_vbv_buffer_size");
2360     skip_bits(gb, 3); /* latter_half_vbv_buffer_size */
2361     skip_bits(gb, 11); /* first_half_vbv_buffer_size */
2362     check_marker(s->avctx, gb, "after first_half_vbv_buffer_size");
2363     skip_bits(gb, 15); /* latter_half_vbv_occupancy */
2364     check_marker(s->avctx, gb, "after latter_half_vbv_occupancy");
2365     s->low_delay  = get_bits1(gb);
2366     s->mpeg_quant = get_bits1(gb); /* mpeg2_stream */
2367 
2368     next_start_code_studio(gb);
2369     extension_and_user_data(s, gb, 2);
2370 
2371     return 0;
2372 }
2373 
decode_vol_header(Mpeg4DecContext * ctx,GetBitContext * gb)2374 static int decode_vol_header(Mpeg4DecContext *ctx, GetBitContext *gb)
2375 {
2376     MpegEncContext *s = &ctx->m;
2377     int width, height, vo_ver_id, aspect_ratio_info;
2378 
2379     /* vol header */
2380     skip_bits(gb, 1);                   /* random access */
2381     ctx->vo_type = get_bits(gb, 8);
2382 
2383     /* If we are in studio profile (per vo_type), check if its all consistent
2384      * and if so continue pass control to decode_studio_vol_header().
2385      * elIf something is inconsistent, error out
2386      * else continue with (non studio) vol header decpoding.
2387      */
2388     if (ctx->vo_type == CORE_STUDIO_VO_TYPE ||
2389         ctx->vo_type == SIMPLE_STUDIO_VO_TYPE) {
2390         if (s->avctx->profile != FF_PROFILE_UNKNOWN && s->avctx->profile != FF_PROFILE_MPEG4_SIMPLE_STUDIO)
2391             return AVERROR_INVALIDDATA;
2392         s->studio_profile = 1;
2393         s->avctx->profile = FF_PROFILE_MPEG4_SIMPLE_STUDIO;
2394         return decode_studio_vol_header(ctx, gb);
2395     } else if (s->studio_profile) {
2396         return AVERROR_PATCHWELCOME;
2397     }
2398 
2399     if (get_bits1(gb) != 0) {           /* is_ol_id */
2400         vo_ver_id = get_bits(gb, 4);    /* vo_ver_id */
2401         skip_bits(gb, 3);               /* vo_priority */
2402     } else {
2403         vo_ver_id = 1;
2404     }
2405     aspect_ratio_info = get_bits(gb, 4);
2406     if (aspect_ratio_info == FF_ASPECT_EXTENDED) {
2407         s->avctx->sample_aspect_ratio.num = get_bits(gb, 8);  // par_width
2408         s->avctx->sample_aspect_ratio.den = get_bits(gb, 8);  // par_height
2409     } else {
2410         s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[aspect_ratio_info];
2411     }
2412 
2413     if ((ctx->vol_control_parameters = get_bits1(gb))) { /* vol control parameter */
2414         int chroma_format = get_bits(gb, 2);
2415         if (chroma_format != CHROMA_420)
2416             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
2417 
2418         s->low_delay = get_bits1(gb);
2419         if (get_bits1(gb)) {    /* vbv parameters */
2420             get_bits(gb, 15);   /* first_half_bitrate */
2421             check_marker(s->avctx, gb, "after first_half_bitrate");
2422             get_bits(gb, 15);   /* latter_half_bitrate */
2423             check_marker(s->avctx, gb, "after latter_half_bitrate");
2424             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
2425             check_marker(s->avctx, gb, "after first_half_vbv_buffer_size");
2426             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
2427             get_bits(gb, 11);   /* first_half_vbv_occupancy */
2428             check_marker(s->avctx, gb, "after first_half_vbv_occupancy");
2429             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
2430             check_marker(s->avctx, gb, "after latter_half_vbv_occupancy");
2431         }
2432     } else {
2433         /* is setting low delay flag only once the smartest thing to do?
2434          * low delay detection will not be overridden. */
2435         if (s->picture_number == 0) {
2436             switch (ctx->vo_type) {
2437             case SIMPLE_VO_TYPE:
2438             case ADV_SIMPLE_VO_TYPE:
2439                 s->low_delay = 1;
2440                 break;
2441             default:
2442                 s->low_delay = 0;
2443             }
2444         }
2445     }
2446 
2447     ctx->shape = get_bits(gb, 2); /* vol shape */
2448     if (ctx->shape != RECT_SHAPE)
2449         av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
2450     if (ctx->shape == GRAY_SHAPE && vo_ver_id != 1) {
2451         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
2452         skip_bits(gb, 4);  /* video_object_layer_shape_extension */
2453     }
2454 
2455     check_marker(s->avctx, gb, "before time_increment_resolution");
2456 
2457     s->avctx->framerate.num = get_bits(gb, 16);
2458     if (!s->avctx->framerate.num) {
2459         av_log(s->avctx, AV_LOG_ERROR, "framerate==0\n");
2460         return AVERROR_INVALIDDATA;
2461     }
2462 
2463     ctx->time_increment_bits = av_log2(s->avctx->framerate.num - 1) + 1;
2464     if (ctx->time_increment_bits < 1)
2465         ctx->time_increment_bits = 1;
2466 
2467     check_marker(s->avctx, gb, "before fixed_vop_rate");
2468 
2469     if (get_bits1(gb) != 0)     /* fixed_vop_rate  */
2470         s->avctx->framerate.den = get_bits(gb, ctx->time_increment_bits);
2471     else
2472         s->avctx->framerate.den = 1;
2473 
2474     s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
2475 
2476     ctx->t_frame = 0;
2477 
2478     if (ctx->shape != BIN_ONLY_SHAPE) {
2479         if (ctx->shape == RECT_SHAPE) {
2480             check_marker(s->avctx, gb, "before width");
2481             width = get_bits(gb, 13);
2482             check_marker(s->avctx, gb, "before height");
2483             height = get_bits(gb, 13);
2484             check_marker(s->avctx, gb, "after height");
2485             if (width && height &&  /* they should be non zero but who knows */
2486                 !(s->width && s->codec_tag == AV_RL32("MP4S"))) {
2487                 if (s->width && s->height &&
2488                     (s->width != width || s->height != height))
2489                     s->context_reinit = 1;
2490                 s->width  = width;
2491                 s->height = height;
2492             }
2493         }
2494 
2495         s->progressive_sequence  =
2496         s->progressive_frame     = get_bits1(gb) ^ 1;
2497         s->interlaced_dct        = 0;
2498         if (!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
2499             av_log(s->avctx, AV_LOG_INFO,           /* OBMC Disable */
2500                    "MPEG-4 OBMC not supported (very likely buggy encoder)\n");
2501         if (vo_ver_id == 1)
2502             ctx->vol_sprite_usage = get_bits1(gb);    /* vol_sprite_usage */
2503         else
2504             ctx->vol_sprite_usage = get_bits(gb, 2);  /* vol_sprite_usage */
2505 
2506         if (ctx->vol_sprite_usage == STATIC_SPRITE)
2507             av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
2508         if (ctx->vol_sprite_usage == STATIC_SPRITE ||
2509             ctx->vol_sprite_usage == GMC_SPRITE) {
2510             if (ctx->vol_sprite_usage == STATIC_SPRITE) {
2511                 skip_bits(gb, 13); // sprite_width
2512                 check_marker(s->avctx, gb, "after sprite_width");
2513                 skip_bits(gb, 13); // sprite_height
2514                 check_marker(s->avctx, gb, "after sprite_height");
2515                 skip_bits(gb, 13); // sprite_left
2516                 check_marker(s->avctx, gb, "after sprite_left");
2517                 skip_bits(gb, 13); // sprite_top
2518                 check_marker(s->avctx, gb, "after sprite_top");
2519             }
2520             ctx->num_sprite_warping_points = get_bits(gb, 6);
2521             if (ctx->num_sprite_warping_points > 3) {
2522                 av_log(s->avctx, AV_LOG_ERROR,
2523                        "%d sprite_warping_points\n",
2524                        ctx->num_sprite_warping_points);
2525                 ctx->num_sprite_warping_points = 0;
2526                 return AVERROR_INVALIDDATA;
2527             }
2528             s->sprite_warping_accuracy  = get_bits(gb, 2);
2529             ctx->sprite_brightness_change = get_bits1(gb);
2530             if (ctx->vol_sprite_usage == STATIC_SPRITE)
2531                 skip_bits1(gb); // low_latency_sprite
2532         }
2533         // FIXME sadct disable bit if verid!=1 && shape not rect
2534 
2535         if (get_bits1(gb) == 1) {                   /* not_8_bit */
2536             s->quant_precision = get_bits(gb, 4);   /* quant_precision */
2537             if (get_bits(gb, 4) != 8)               /* bits_per_pixel */
2538                 av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n");
2539             if (s->quant_precision != 5)
2540                 av_log(s->avctx, AV_LOG_ERROR,
2541                        "quant precision %d\n", s->quant_precision);
2542             if (s->quant_precision<3 || s->quant_precision>9) {
2543                 s->quant_precision = 5;
2544             }
2545         } else {
2546             s->quant_precision = 5;
2547         }
2548 
2549         // FIXME a bunch of grayscale shape things
2550 
2551         if ((s->mpeg_quant = get_bits1(gb))) { /* vol_quant_type */
2552             int i, v;
2553 
2554             mpeg4_load_default_matrices(s);
2555 
2556             /* load custom intra matrix */
2557             if (get_bits1(gb)) {
2558                 int last = 0;
2559                 for (i = 0; i < 64; i++) {
2560                     int j;
2561                     if (get_bits_left(gb) < 8) {
2562                         av_log(s->avctx, AV_LOG_ERROR, "insufficient data for custom matrix\n");
2563                         return AVERROR_INVALIDDATA;
2564                     }
2565                     v = get_bits(gb, 8);
2566                     if (v == 0)
2567                         break;
2568 
2569                     last = v;
2570                     j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2571                     s->intra_matrix[j]        = last;
2572                     s->chroma_intra_matrix[j] = last;
2573                 }
2574 
2575                 /* replicate last value */
2576                 for (; i < 64; i++) {
2577                     int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2578                     s->intra_matrix[j]        = last;
2579                     s->chroma_intra_matrix[j] = last;
2580                 }
2581             }
2582 
2583             /* load custom non intra matrix */
2584             if (get_bits1(gb)) {
2585                 int last = 0;
2586                 for (i = 0; i < 64; i++) {
2587                     int j;
2588                     if (get_bits_left(gb) < 8) {
2589                         av_log(s->avctx, AV_LOG_ERROR, "insufficient data for custom matrix\n");
2590                         return AVERROR_INVALIDDATA;
2591                     }
2592                     v = get_bits(gb, 8);
2593                     if (v == 0)
2594                         break;
2595 
2596                     last = v;
2597                     j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2598                     s->inter_matrix[j]        = v;
2599                     s->chroma_inter_matrix[j] = v;
2600                 }
2601 
2602                 /* replicate last value */
2603                 for (; i < 64; i++) {
2604                     int j = s->idsp.idct_permutation[ff_zigzag_direct[i]];
2605                     s->inter_matrix[j]        = last;
2606                     s->chroma_inter_matrix[j] = last;
2607                 }
2608             }
2609 
2610             // FIXME a bunch of grayscale shape things
2611         }
2612 
2613         if (vo_ver_id != 1)
2614             s->quarter_sample = get_bits1(gb);
2615         else
2616             s->quarter_sample = 0;
2617 
2618         if (get_bits_left(gb) < 4) {
2619             av_log(s->avctx, AV_LOG_ERROR, "VOL Header truncated\n");
2620             return AVERROR_INVALIDDATA;
2621         }
2622 
2623         if (!get_bits1(gb)) {
2624             int pos               = get_bits_count(gb);
2625             int estimation_method = get_bits(gb, 2);
2626             if (estimation_method < 2) {
2627                 if (!get_bits1(gb)) {
2628                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* opaque */
2629                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* transparent */
2630                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* intra_cae */
2631                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* inter_cae */
2632                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* no_update */
2633                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* upsampling */
2634                 }
2635                 if (!get_bits1(gb)) {
2636                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* intra_blocks */
2637                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* inter_blocks */
2638                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* inter4v_blocks */
2639                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* not coded blocks */
2640                 }
2641                 if (!check_marker(s->avctx, gb, "in complexity estimation part 1")) {
2642                     skip_bits_long(gb, pos - get_bits_count(gb));
2643                     goto no_cplx_est;
2644                 }
2645                 if (!get_bits1(gb)) {
2646                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* dct_coeffs */
2647                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* dct_lines */
2648                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* vlc_syms */
2649                     ctx->cplx_estimation_trash_i += 4 * get_bits1(gb);  /* vlc_bits */
2650                 }
2651                 if (!get_bits1(gb)) {
2652                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* apm */
2653                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* npm */
2654                     ctx->cplx_estimation_trash_b += 8 * get_bits1(gb);  /* interpolate_mc_q */
2655                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* forwback_mc_q */
2656                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* halfpel2 */
2657                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* halfpel4 */
2658                 }
2659                 if (!check_marker(s->avctx, gb, "in complexity estimation part 2")) {
2660                     skip_bits_long(gb, pos - get_bits_count(gb));
2661                     goto no_cplx_est;
2662                 }
2663                 if (estimation_method == 1) {
2664                     ctx->cplx_estimation_trash_i += 8 * get_bits1(gb);  /* sadct */
2665                     ctx->cplx_estimation_trash_p += 8 * get_bits1(gb);  /* qpel */
2666                 }
2667             } else
2668                 av_log(s->avctx, AV_LOG_ERROR,
2669                        "Invalid Complexity estimation method %d\n",
2670                        estimation_method);
2671         } else {
2672 
2673 no_cplx_est:
2674             ctx->cplx_estimation_trash_i =
2675             ctx->cplx_estimation_trash_p =
2676             ctx->cplx_estimation_trash_b = 0;
2677         }
2678 
2679         ctx->resync_marker = !get_bits1(gb); /* resync_marker_disabled */
2680 
2681         s->data_partitioning = get_bits1(gb);
2682         if (s->data_partitioning)
2683             ctx->rvlc = get_bits1(gb);
2684 
2685         if (vo_ver_id != 1) {
2686             ctx->new_pred = get_bits1(gb);
2687             if (ctx->new_pred) {
2688                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
2689                 skip_bits(gb, 2); /* requested upstream message type */
2690                 skip_bits1(gb);   /* newpred segment type */
2691             }
2692             if (get_bits1(gb)) // reduced_res_vop
2693                 av_log(s->avctx, AV_LOG_ERROR,
2694                        "reduced resolution VOP not supported\n");
2695         } else {
2696             ctx->new_pred = 0;
2697         }
2698 
2699         ctx->scalability = get_bits1(gb);
2700 
2701         if (ctx->scalability) {
2702             GetBitContext bak = *gb;
2703             int h_sampling_factor_n;
2704             int h_sampling_factor_m;
2705             int v_sampling_factor_n;
2706             int v_sampling_factor_m;
2707 
2708             skip_bits1(gb);    // hierarchy_type
2709             skip_bits(gb, 4);  /* ref_layer_id */
2710             skip_bits1(gb);    /* ref_layer_sampling_dir */
2711             h_sampling_factor_n = get_bits(gb, 5);
2712             h_sampling_factor_m = get_bits(gb, 5);
2713             v_sampling_factor_n = get_bits(gb, 5);
2714             v_sampling_factor_m = get_bits(gb, 5);
2715             ctx->enhancement_type = get_bits1(gb);
2716 
2717             if (h_sampling_factor_n == 0 || h_sampling_factor_m == 0 ||
2718                 v_sampling_factor_n == 0 || v_sampling_factor_m == 0) {
2719                 /* illegal scalability header (VERY broken encoder),
2720                  * trying to workaround */
2721                 ctx->scalability = 0;
2722                 *gb            = bak;
2723             } else
2724                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
2725 
2726             // bin shape stuff FIXME
2727         }
2728     }
2729 
2730     if (s->avctx->debug&FF_DEBUG_PICT_INFO) {
2731         av_log(s->avctx, AV_LOG_DEBUG, "tb %d/%d, tincrbits:%d, qp_prec:%d, ps:%d, low_delay:%d  %s%s%s%s\n",
2732                s->avctx->framerate.den, s->avctx->framerate.num,
2733                ctx->time_increment_bits,
2734                s->quant_precision,
2735                s->progressive_sequence,
2736                s->low_delay,
2737                ctx->scalability ? "scalability " :"" , s->quarter_sample ? "qpel " : "",
2738                s->data_partitioning ? "partition " : "", ctx->rvlc ? "rvlc " : ""
2739         );
2740     }
2741 
2742     return 0;
2743 }
2744 
2745 /**
2746  * Decode the user data stuff in the header.
2747  * Also initializes divx/xvid/lavc_version/build.
2748  */
decode_user_data(Mpeg4DecContext * ctx,GetBitContext * gb)2749 static int decode_user_data(Mpeg4DecContext *ctx, GetBitContext *gb)
2750 {
2751     MpegEncContext *s = &ctx->m;
2752     char buf[256];
2753     int i;
2754     int e;
2755     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
2756     char last;
2757 
2758     for (i = 0; i < 255 && get_bits_count(gb) < gb->size_in_bits; i++) {
2759         if (show_bits(gb, 23) == 0)
2760             break;
2761         buf[i] = get_bits(gb, 8);
2762     }
2763     buf[i] = 0;
2764 
2765     /* divx detection */
2766     e = sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
2767     if (e < 2)
2768         e = sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
2769     if (e >= 2) {
2770         ctx->divx_version = ver;
2771         ctx->divx_build   = build;
2772         s->divx_packed  = e == 3 && last == 'p';
2773     }
2774 
2775     /* libavcodec detection */
2776     e = sscanf(buf, "FFmpe%*[^b]b%d", &build) + 3;
2777     if (e != 4)
2778         e = sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
2779     if (e != 4) {
2780         e = sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3) + 1;
2781         if (e > 1) {
2782             if (ver > 0xFFU || ver2 > 0xFFU || ver3 > 0xFFU) {
2783                 av_log(s->avctx, AV_LOG_WARNING,
2784                      "Unknown Lavc version string encountered, %d.%d.%d; "
2785                      "clamping sub-version values to 8-bits.\n",
2786                      ver, ver2, ver3);
2787             }
2788             build = ((ver & 0xFF) << 16) + ((ver2 & 0xFF) << 8) + (ver3 & 0xFF);
2789         }
2790     }
2791     if (e != 4) {
2792         if (strcmp(buf, "ffmpeg") == 0)
2793             ctx->lavc_build = 4600;
2794     }
2795     if (e == 4)
2796         ctx->lavc_build = build;
2797 
2798     /* Xvid detection */
2799     e = sscanf(buf, "XviD%d", &build);
2800     if (e == 1)
2801         ctx->xvid_build = build;
2802 
2803     return 0;
2804 }
2805 
ff_mpeg4_workaround_bugs(AVCodecContext * avctx)2806 int ff_mpeg4_workaround_bugs(AVCodecContext *avctx)
2807 {
2808     Mpeg4DecContext *ctx = avctx->priv_data;
2809     MpegEncContext *s = &ctx->m;
2810 
2811     if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1) {
2812         if (s->codec_tag        == AV_RL32("XVID") ||
2813             s->codec_tag        == AV_RL32("XVIX") ||
2814             s->codec_tag        == AV_RL32("RMP4") ||
2815             s->codec_tag        == AV_RL32("ZMP4") ||
2816             s->codec_tag        == AV_RL32("SIPP"))
2817             ctx->xvid_build = 0;
2818     }
2819 
2820     if (ctx->xvid_build == -1 && ctx->divx_version == -1 && ctx->lavc_build == -1)
2821         if (s->codec_tag == AV_RL32("DIVX") && ctx->vo_type == 0 &&
2822             ctx->vol_control_parameters == 0)
2823             ctx->divx_version = 400;  // divx 4
2824 
2825     if (ctx->xvid_build >= 0 && ctx->divx_version >= 0) {
2826         ctx->divx_version =
2827         ctx->divx_build   = -1;
2828     }
2829 
2830     if (s->workaround_bugs & FF_BUG_AUTODETECT) {
2831         if (s->codec_tag == AV_RL32("XVIX"))
2832             s->workaround_bugs |= FF_BUG_XVID_ILACE;
2833 
2834         if (s->codec_tag == AV_RL32("UMP4"))
2835             s->workaround_bugs |= FF_BUG_UMP4;
2836 
2837         if (ctx->divx_version >= 500 && ctx->divx_build < 1814)
2838             s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2839 
2840         if (ctx->divx_version > 502 && ctx->divx_build < 1814)
2841             s->workaround_bugs |= FF_BUG_QPEL_CHROMA2;
2842 
2843         if (ctx->xvid_build <= 3U)
2844             s->padding_bug_score = 256 * 256 * 256 * 64;
2845 
2846         if (ctx->xvid_build <= 1U)
2847             s->workaround_bugs |= FF_BUG_QPEL_CHROMA;
2848 
2849         if (ctx->xvid_build <= 12U)
2850             s->workaround_bugs |= FF_BUG_EDGE;
2851 
2852         if (ctx->xvid_build <= 32U)
2853             s->workaround_bugs |= FF_BUG_DC_CLIP;
2854 
2855 #define SET_QPEL_FUNC(postfix1, postfix2)                           \
2856     s->qdsp.put_        ## postfix1 = ff_put_        ## postfix2;   \
2857     s->qdsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;   \
2858     s->qdsp.avg_        ## postfix1 = ff_avg_        ## postfix2;
2859 
2860         if (ctx->lavc_build < 4653U)
2861             s->workaround_bugs |= FF_BUG_STD_QPEL;
2862 
2863         if (ctx->lavc_build < 4655U)
2864             s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2865 
2866         if (ctx->lavc_build < 4670U)
2867             s->workaround_bugs |= FF_BUG_EDGE;
2868 
2869         if (ctx->lavc_build <= 4712U)
2870             s->workaround_bugs |= FF_BUG_DC_CLIP;
2871 
2872         if ((ctx->lavc_build&0xFF) >= 100) {
2873             if (ctx->lavc_build > 3621476 && ctx->lavc_build < 3752552 &&
2874                (ctx->lavc_build < 3752037 || ctx->lavc_build > 3752191) // 3.2.1+
2875             )
2876                 s->workaround_bugs |= FF_BUG_IEDGE;
2877         }
2878 
2879         if (ctx->divx_version >= 0)
2880             s->workaround_bugs |= FF_BUG_DIRECT_BLOCKSIZE;
2881         if (ctx->divx_version == 501 && ctx->divx_build == 20020416)
2882             s->padding_bug_score = 256 * 256 * 256 * 64;
2883 
2884         if (ctx->divx_version < 500U)
2885             s->workaround_bugs |= FF_BUG_EDGE;
2886 
2887         if (ctx->divx_version >= 0)
2888             s->workaround_bugs |= FF_BUG_HPEL_CHROMA;
2889     }
2890 
2891     if (s->workaround_bugs & FF_BUG_STD_QPEL) {
2892         SET_QPEL_FUNC(qpel_pixels_tab[0][5], qpel16_mc11_old_c)
2893         SET_QPEL_FUNC(qpel_pixels_tab[0][7], qpel16_mc31_old_c)
2894         SET_QPEL_FUNC(qpel_pixels_tab[0][9], qpel16_mc12_old_c)
2895         SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)
2896         SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)
2897         SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)
2898 
2899         SET_QPEL_FUNC(qpel_pixels_tab[1][5], qpel8_mc11_old_c)
2900         SET_QPEL_FUNC(qpel_pixels_tab[1][7], qpel8_mc31_old_c)
2901         SET_QPEL_FUNC(qpel_pixels_tab[1][9], qpel8_mc12_old_c)
2902         SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)
2903         SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)
2904         SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)
2905     }
2906 
2907     if (avctx->debug & FF_DEBUG_BUGS)
2908         av_log(s->avctx, AV_LOG_DEBUG,
2909                "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",
2910                s->workaround_bugs, ctx->lavc_build, ctx->xvid_build,
2911                ctx->divx_version, ctx->divx_build, s->divx_packed ? "p" : "");
2912 
2913     if (CONFIG_MPEG4_DECODER && ctx->xvid_build >= 0 &&
2914         s->codec_id == AV_CODEC_ID_MPEG4 &&
2915         avctx->idct_algo == FF_IDCT_AUTO) {
2916         avctx->idct_algo = FF_IDCT_XVID;
2917         ff_mpv_idct_init(s);
2918         return 1;
2919     }
2920 
2921     return 0;
2922 }
2923 
decode_vop_header(Mpeg4DecContext * ctx,GetBitContext * gb,int parse_only)2924 static int decode_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb,
2925                              int parse_only)
2926 {
2927     MpegEncContext *s = &ctx->m;
2928     int time_incr, time_increment;
2929     int64_t pts;
2930 
2931     s->mcsel       = 0;
2932     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I;        /* pict type: I = 0 , P = 1 */
2933     if (s->pict_type == AV_PICTURE_TYPE_B && s->low_delay &&
2934         ctx->vol_control_parameters == 0 && !(s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)) {
2935         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag set incorrectly, clearing it\n");
2936         s->low_delay = 0;
2937     }
2938 
2939     s->partitioned_frame = s->data_partitioning && s->pict_type != AV_PICTURE_TYPE_B;
2940     if (s->partitioned_frame)
2941         s->decode_mb = mpeg4_decode_partitioned_mb;
2942     else
2943         s->decode_mb = mpeg4_decode_mb;
2944 
2945     time_incr = 0;
2946     while (get_bits1(gb) != 0)
2947         time_incr++;
2948 
2949     check_marker(s->avctx, gb, "before time_increment");
2950 
2951     if (ctx->time_increment_bits == 0 ||
2952         !(show_bits(gb, ctx->time_increment_bits + 1) & 1)) {
2953         av_log(s->avctx, AV_LOG_WARNING,
2954                "time_increment_bits %d is invalid in relation to the current bitstream, this is likely caused by a missing VOL header\n", ctx->time_increment_bits);
2955 
2956         for (ctx->time_increment_bits = 1;
2957              ctx->time_increment_bits < 16;
2958              ctx->time_increment_bits++) {
2959             if (s->pict_type == AV_PICTURE_TYPE_P ||
2960                 (s->pict_type == AV_PICTURE_TYPE_S &&
2961                  ctx->vol_sprite_usage == GMC_SPRITE)) {
2962                 if ((show_bits(gb, ctx->time_increment_bits + 6) & 0x37) == 0x30)
2963                     break;
2964             } else if ((show_bits(gb, ctx->time_increment_bits + 5) & 0x1F) == 0x18)
2965                 break;
2966         }
2967 
2968         av_log(s->avctx, AV_LOG_WARNING,
2969                "time_increment_bits set to %d bits, based on bitstream analysis\n", ctx->time_increment_bits);
2970         if (s->avctx->framerate.num && 4*s->avctx->framerate.num < 1<<ctx->time_increment_bits) {
2971             s->avctx->framerate.num = 1<<ctx->time_increment_bits;
2972             s->avctx->time_base = av_inv_q(av_mul_q(s->avctx->framerate, (AVRational){s->avctx->ticks_per_frame, 1}));
2973         }
2974     }
2975 
2976     if (IS_3IV1)
2977         time_increment = get_bits1(gb);        // FIXME investigate further
2978     else
2979         time_increment = get_bits(gb, ctx->time_increment_bits);
2980 
2981     if (s->pict_type != AV_PICTURE_TYPE_B) {
2982         s->last_time_base = s->time_base;
2983         s->time_base     += time_incr;
2984         s->time = s->time_base * (int64_t)s->avctx->framerate.num + time_increment;
2985         if (s->workaround_bugs & FF_BUG_UMP4) {
2986             if (s->time < s->last_non_b_time) {
2987                 /* header is not mpeg-4-compatible, broken encoder,
2988                  * trying to workaround */
2989                 s->time_base++;
2990                 s->time += s->avctx->framerate.num;
2991             }
2992         }
2993         s->pp_time         = s->time - s->last_non_b_time;
2994         s->last_non_b_time = s->time;
2995     } else {
2996         s->time    = (s->last_time_base + time_incr) * (int64_t)s->avctx->framerate.num + time_increment;
2997         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
2998         if (s->pp_time <= s->pb_time ||
2999             s->pp_time <= s->pp_time - s->pb_time ||
3000             s->pp_time <= 0) {
3001             /* messed up order, maybe after seeking? skipping current B-frame */
3002             return FRAME_SKIPPED;
3003         }
3004         ff_mpeg4_init_direct_mv(s);
3005 
3006         if (ctx->t_frame == 0)
3007             ctx->t_frame = s->pb_time;
3008         if (ctx->t_frame == 0)
3009             ctx->t_frame = 1;  // 1/0 protection
3010         s->pp_field_time = (ROUNDED_DIV(s->last_non_b_time, ctx->t_frame) -
3011                             ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
3012         s->pb_field_time = (ROUNDED_DIV(s->time, ctx->t_frame) -
3013                             ROUNDED_DIV(s->last_non_b_time - s->pp_time, ctx->t_frame)) * 2;
3014         if (s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1) {
3015             s->pb_field_time = 2;
3016             s->pp_field_time = 4;
3017             if (!s->progressive_sequence)
3018                 return FRAME_SKIPPED;
3019         }
3020     }
3021 
3022     if (s->avctx->framerate.den)
3023         pts = ROUNDED_DIV(s->time, s->avctx->framerate.den);
3024     else
3025         pts = AV_NOPTS_VALUE;
3026     ff_dlog(s->avctx, "MPEG4 PTS: %"PRId64"\n", pts);
3027 
3028     check_marker(s->avctx, gb, "before vop_coded");
3029 
3030     /* vop coded */
3031     if (get_bits1(gb) != 1) {
3032         if (s->avctx->debug & FF_DEBUG_PICT_INFO)
3033             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
3034         return FRAME_SKIPPED;
3035     }
3036     if (ctx->new_pred)
3037         decode_new_pred(ctx, gb);
3038 
3039     if (ctx->shape != BIN_ONLY_SHAPE &&
3040                     (s->pict_type == AV_PICTURE_TYPE_P ||
3041                      (s->pict_type == AV_PICTURE_TYPE_S &&
3042                       ctx->vol_sprite_usage == GMC_SPRITE))) {
3043         /* rounding type for motion estimation */
3044         s->no_rounding = get_bits1(gb);
3045     } else {
3046         s->no_rounding = 0;
3047     }
3048     // FIXME reduced res stuff
3049 
3050     if (ctx->shape != RECT_SHAPE) {
3051         if (ctx->vol_sprite_usage != 1 || s->pict_type != AV_PICTURE_TYPE_I) {
3052             skip_bits(gb, 13);  /* width */
3053             check_marker(s->avctx, gb, "after width");
3054             skip_bits(gb, 13);  /* height */
3055             check_marker(s->avctx, gb, "after height");
3056             skip_bits(gb, 13);  /* hor_spat_ref */
3057             check_marker(s->avctx, gb, "after hor_spat_ref");
3058             skip_bits(gb, 13);  /* ver_spat_ref */
3059         }
3060         skip_bits1(gb);         /* change_CR_disable */
3061 
3062         if (get_bits1(gb) != 0)
3063             skip_bits(gb, 8);   /* constant_alpha_value */
3064     }
3065 
3066     // FIXME complexity estimation stuff
3067 
3068     if (ctx->shape != BIN_ONLY_SHAPE) {
3069         skip_bits_long(gb, ctx->cplx_estimation_trash_i);
3070         if (s->pict_type != AV_PICTURE_TYPE_I)
3071             skip_bits_long(gb, ctx->cplx_estimation_trash_p);
3072         if (s->pict_type == AV_PICTURE_TYPE_B)
3073             skip_bits_long(gb, ctx->cplx_estimation_trash_b);
3074 
3075         if (get_bits_left(gb) < 3) {
3076             av_log(s->avctx, AV_LOG_ERROR, "Header truncated\n");
3077             return AVERROR_INVALIDDATA;
3078         }
3079         ctx->intra_dc_threshold = ff_mpeg4_dc_threshold[get_bits(gb, 3)];
3080         if (!s->progressive_sequence) {
3081             s->top_field_first = get_bits1(gb);
3082             s->alternate_scan  = get_bits1(gb);
3083         } else
3084             s->alternate_scan = 0;
3085     }
3086 
3087     if (s->alternate_scan) {
3088         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_alternate_vertical_scan);
3089         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_alternate_vertical_scan);
3090         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
3091         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
3092     } else {
3093         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_zigzag_direct);
3094         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_zigzag_direct);
3095         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
3096         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
3097     }
3098 
3099     /* Skip at this point when only parsing since the remaining
3100      * data is not useful for a parser and requires the
3101      * sprite_trajectory VLC to be initialized. */
3102     if (parse_only)
3103         goto end;
3104 
3105     if (s->pict_type == AV_PICTURE_TYPE_S) {
3106         if((ctx->vol_sprite_usage == STATIC_SPRITE ||
3107             ctx->vol_sprite_usage == GMC_SPRITE)) {
3108             if (mpeg4_decode_sprite_trajectory(ctx, gb) < 0)
3109                 return AVERROR_INVALIDDATA;
3110             if (ctx->sprite_brightness_change)
3111                 av_log(s->avctx, AV_LOG_ERROR,
3112                     "sprite_brightness_change not supported\n");
3113             if (ctx->vol_sprite_usage == STATIC_SPRITE)
3114                 av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
3115         } else {
3116             memset(s->sprite_offset, 0, sizeof(s->sprite_offset));
3117             memset(s->sprite_delta, 0, sizeof(s->sprite_delta));
3118         }
3119     }
3120 
3121     if (ctx->shape != BIN_ONLY_SHAPE) {
3122         s->chroma_qscale = s->qscale = get_bits(gb, s->quant_precision);
3123         if (s->qscale == 0) {
3124             av_log(s->avctx, AV_LOG_ERROR,
3125                    "Error, header damaged or not MPEG-4 header (qscale=0)\n");
3126             return AVERROR_INVALIDDATA;  // makes no sense to continue, as there is nothing left from the image then
3127         }
3128 
3129         if (s->pict_type != AV_PICTURE_TYPE_I) {
3130             s->f_code = get_bits(gb, 3);        /* fcode_for */
3131             if (s->f_code == 0) {
3132                 av_log(s->avctx, AV_LOG_ERROR,
3133                        "Error, header damaged or not MPEG-4 header (f_code=0)\n");
3134                 s->f_code = 1;
3135                 return AVERROR_INVALIDDATA;  // makes no sense to continue, as there is nothing left from the image then
3136             }
3137         } else
3138             s->f_code = 1;
3139 
3140         if (s->pict_type == AV_PICTURE_TYPE_B) {
3141             s->b_code = get_bits(gb, 3);
3142             if (s->b_code == 0) {
3143                 av_log(s->avctx, AV_LOG_ERROR,
3144                        "Error, header damaged or not MPEG4 header (b_code=0)\n");
3145                 s->b_code=1;
3146                 return AVERROR_INVALIDDATA; // makes no sense to continue, as the MV decoding will break very quickly
3147             }
3148         } else
3149             s->b_code = 1;
3150 
3151         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
3152             av_log(s->avctx, AV_LOG_DEBUG,
3153                    "qp:%d fc:%d,%d %c size:%d pro:%d alt:%d top:%d %cpel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d time:%"PRId64" tincr:%d\n",
3154                    s->qscale, s->f_code, s->b_code,
3155                    s->pict_type == AV_PICTURE_TYPE_I ? 'I' : (s->pict_type == AV_PICTURE_TYPE_P ? 'P' : (s->pict_type == AV_PICTURE_TYPE_B ? 'B' : 'S')),
3156                    gb->size_in_bits,s->progressive_sequence, s->alternate_scan,
3157                    s->top_field_first, s->quarter_sample ? 'q' : 'h',
3158                    s->data_partitioning, ctx->resync_marker,
3159                    ctx->num_sprite_warping_points, s->sprite_warping_accuracy,
3160                    1 - s->no_rounding, ctx->vo_type,
3161                    ctx->vol_control_parameters ? " VOLC" : " ", ctx->intra_dc_threshold,
3162                    ctx->cplx_estimation_trash_i, ctx->cplx_estimation_trash_p,
3163                    ctx->cplx_estimation_trash_b,
3164                    s->time,
3165                    time_increment
3166                   );
3167         }
3168 
3169         if (!ctx->scalability) {
3170             if (ctx->shape != RECT_SHAPE && s->pict_type != AV_PICTURE_TYPE_I)
3171                 skip_bits1(gb);  // vop shape coding type
3172         } else {
3173             if (ctx->enhancement_type) {
3174                 int load_backward_shape = get_bits1(gb);
3175                 if (load_backward_shape)
3176                     av_log(s->avctx, AV_LOG_ERROR,
3177                            "load backward shape isn't supported\n");
3178             }
3179             skip_bits(gb, 2);  // ref_select_code
3180         }
3181     }
3182 
3183 end:
3184     /* detect buggy encoders which don't set the low_delay flag
3185      * (divx4/xvid/opendivx). Note we cannot detect divx5 without B-frames
3186      * easily (although it's buggy too) */
3187     if (ctx->vo_type == 0 && ctx->vol_control_parameters == 0 &&
3188         ctx->divx_version == -1 && s->picture_number == 0) {
3189         av_log(s->avctx, AV_LOG_WARNING,
3190                "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
3191         s->low_delay = 1;
3192     }
3193 
3194     s->picture_number++;  // better than pic number==0 always ;)
3195 
3196     // FIXME add short header support
3197     s->y_dc_scale_table = ff_mpeg4_y_dc_scale_table;
3198     s->c_dc_scale_table = ff_mpeg4_c_dc_scale_table;
3199 
3200     if (s->workaround_bugs & FF_BUG_EDGE) {
3201         s->h_edge_pos = s->width;
3202         s->v_edge_pos = s->height;
3203     }
3204     return 0;
3205 }
3206 
decode_smpte_tc(Mpeg4DecContext * ctx,GetBitContext * gb)3207 static void decode_smpte_tc(Mpeg4DecContext *ctx, GetBitContext *gb)
3208 {
3209     MpegEncContext *s = &ctx->m;
3210 
3211     skip_bits(gb, 16); /* Time_code[63..48] */
3212     check_marker(s->avctx, gb, "after Time_code[63..48]");
3213     skip_bits(gb, 16); /* Time_code[47..32] */
3214     check_marker(s->avctx, gb, "after Time_code[47..32]");
3215     skip_bits(gb, 16); /* Time_code[31..16] */
3216     check_marker(s->avctx, gb, "after Time_code[31..16]");
3217     skip_bits(gb, 16); /* Time_code[15..0] */
3218     check_marker(s->avctx, gb, "after Time_code[15..0]");
3219     skip_bits(gb, 4); /* reserved_bits */
3220 }
3221 
3222 /**
3223  * Decode the next studio vop header.
3224  * @return <0 if something went wrong
3225  */
decode_studio_vop_header(Mpeg4DecContext * ctx,GetBitContext * gb)3226 static int decode_studio_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
3227 {
3228     MpegEncContext *s = &ctx->m;
3229 
3230     if (get_bits_left(gb) <= 32)
3231         return 0;
3232 
3233     s->partitioned_frame = 0;
3234     s->interlaced_dct = 0;
3235     s->decode_mb = mpeg4_decode_studio_mb;
3236 
3237     decode_smpte_tc(ctx, gb);
3238 
3239     skip_bits(gb, 10); /* temporal_reference */
3240     skip_bits(gb, 2); /* vop_structure */
3241     s->pict_type = get_bits(gb, 2) + AV_PICTURE_TYPE_I; /* vop_coding_type */
3242     if (get_bits1(gb)) { /* vop_coded */
3243         skip_bits1(gb); /* top_field_first */
3244         skip_bits1(gb); /* repeat_first_field */
3245         s->progressive_frame = get_bits1(gb) ^ 1; /* progressive_frame */
3246     }
3247 
3248     if (s->pict_type == AV_PICTURE_TYPE_I) {
3249         if (get_bits1(gb))
3250             reset_studio_dc_predictors(s);
3251     }
3252 
3253     if (ctx->shape != BIN_ONLY_SHAPE) {
3254         s->alternate_scan = get_bits1(gb);
3255         s->frame_pred_frame_dct = get_bits1(gb);
3256         s->dct_precision = get_bits(gb, 2);
3257         s->intra_dc_precision = get_bits(gb, 2);
3258         s->q_scale_type = get_bits1(gb);
3259     }
3260 
3261     if (s->alternate_scan) {
3262         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_alternate_vertical_scan);
3263         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_alternate_vertical_scan);
3264         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
3265         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
3266     } else {
3267         ff_init_scantable(s->idsp.idct_permutation, &s->inter_scantable,   ff_zigzag_direct);
3268         ff_init_scantable(s->idsp.idct_permutation, &s->intra_scantable,   ff_zigzag_direct);
3269         ff_init_scantable(s->idsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
3270         ff_init_scantable(s->idsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
3271     }
3272 
3273     mpeg4_load_default_matrices(s);
3274 
3275     next_start_code_studio(gb);
3276     extension_and_user_data(s, gb, 4);
3277 
3278     return 0;
3279 }
3280 
decode_studiovisualobject(Mpeg4DecContext * ctx,GetBitContext * gb)3281 static int decode_studiovisualobject(Mpeg4DecContext *ctx, GetBitContext *gb)
3282 {
3283     MpegEncContext *s = &ctx->m;
3284     int visual_object_type;
3285 
3286     skip_bits(gb, 4); /* visual_object_verid */
3287     visual_object_type = get_bits(gb, 4);
3288     if (visual_object_type != VOT_VIDEO_ID) {
3289         avpriv_request_sample(s->avctx, "VO type %u", visual_object_type);
3290         return AVERROR_PATCHWELCOME;
3291     }
3292 
3293     next_start_code_studio(gb);
3294     extension_and_user_data(s, gb, 1);
3295 
3296     return 0;
3297 }
3298 
3299 /**
3300  * Decode MPEG-4 headers.
3301  *
3302  * @param  header If set the absence of a VOP is not treated as error; otherwise, it is treated as such.
3303  * @param  parse_only If set, things only relevant to a decoder may be skipped;
3304  *                    furthermore, the VLC tables may be uninitialized.
3305  * @return <0 if an error occurred
3306  *         FRAME_SKIPPED if a not coded VOP is found
3307  *         0 else
3308  */
ff_mpeg4_decode_picture_header(Mpeg4DecContext * ctx,GetBitContext * gb,int header,int parse_only)3309 int ff_mpeg4_decode_picture_header(Mpeg4DecContext *ctx, GetBitContext *gb,
3310                                    int header, int parse_only)
3311 {
3312     MpegEncContext *s = &ctx->m;
3313     unsigned startcode, v;
3314     int ret;
3315     int vol = 0;
3316 
3317     /* search next start code */
3318     align_get_bits(gb);
3319 
3320     // If we have not switched to studio profile than we also did not switch bps
3321     // that means something else (like a previous instance) outside set bps which
3322     // would be inconsistant with the currect state, thus reset it
3323     if (!s->studio_profile && s->avctx->bits_per_raw_sample != 8)
3324         s->avctx->bits_per_raw_sample = 0;
3325 
3326     if (s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630) {
3327         skip_bits(gb, 24);
3328         if (get_bits(gb, 8) == 0xF0)
3329             goto end;
3330     }
3331 
3332     startcode = 0xff;
3333     for (;;) {
3334         if (get_bits_count(gb) >= gb->size_in_bits) {
3335             if (gb->size_in_bits == 8 &&
3336                 (ctx->divx_version >= 0 || ctx->xvid_build >= 0) || s->codec_tag == AV_RL32("QMP4")) {
3337                 av_log(s->avctx, AV_LOG_VERBOSE, "frame skip %d\n", gb->size_in_bits);
3338                 return FRAME_SKIPPED;  // divx bug
3339             } else if (header && get_bits_count(gb) == gb->size_in_bits) {
3340                 return 0; // ordinary return value for parsing of extradata
3341             } else
3342                 return AVERROR_INVALIDDATA;  // end of stream
3343         }
3344 
3345         /* use the bits after the test */
3346         v = get_bits(gb, 8);
3347         startcode = ((startcode << 8) | v) & 0xffffffff;
3348 
3349         if ((startcode & 0xFFFFFF00) != 0x100)
3350             continue;  // no startcode
3351 
3352         if (s->avctx->debug & FF_DEBUG_STARTCODE) {
3353             const char *name;
3354             if (startcode <= 0x11F)
3355                 name = "Video Object Start";
3356             else if (startcode <= 0x12F)
3357                 name = "Video Object Layer Start";
3358             else if (startcode <= 0x13F)
3359                 name = "Reserved";
3360             else if (startcode <= 0x15F)
3361                 name = "FGS bp start";
3362             else if (startcode <= 0x1AF)
3363                 name = "Reserved";
3364             else if (startcode == 0x1B0)
3365                 name = "Visual Object Seq Start";
3366             else if (startcode == 0x1B1)
3367                 name = "Visual Object Seq End";
3368             else if (startcode == 0x1B2)
3369                 name = "User Data";
3370             else if (startcode == 0x1B3)
3371                 name = "Group of VOP start";
3372             else if (startcode == 0x1B4)
3373                 name = "Video Session Error";
3374             else if (startcode == 0x1B5)
3375                 name = "Visual Object Start";
3376             else if (startcode == 0x1B6)
3377                 name = "Video Object Plane start";
3378             else if (startcode == 0x1B7)
3379                 name = "slice start";
3380             else if (startcode == 0x1B8)
3381                 name = "extension start";
3382             else if (startcode == 0x1B9)
3383                 name = "fgs start";
3384             else if (startcode == 0x1BA)
3385                 name = "FBA Object start";
3386             else if (startcode == 0x1BB)
3387                 name = "FBA Object Plane start";
3388             else if (startcode == 0x1BC)
3389                 name = "Mesh Object start";
3390             else if (startcode == 0x1BD)
3391                 name = "Mesh Object Plane start";
3392             else if (startcode == 0x1BE)
3393                 name = "Still Texture Object start";
3394             else if (startcode == 0x1BF)
3395                 name = "Texture Spatial Layer start";
3396             else if (startcode == 0x1C0)
3397                 name = "Texture SNR Layer start";
3398             else if (startcode == 0x1C1)
3399                 name = "Texture Tile start";
3400             else if (startcode == 0x1C2)
3401                 name = "Texture Shape Layer start";
3402             else if (startcode == 0x1C3)
3403                 name = "stuffing start";
3404             else if (startcode <= 0x1C5)
3405                 name = "Reserved";
3406             else if (startcode <= 0x1FF)
3407                 name = "System start";
3408             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X %s at %d\n",
3409                    startcode, name, get_bits_count(gb));
3410         }
3411 
3412         if (startcode >= 0x120 && startcode <= 0x12F) {
3413             if (vol) {
3414                 av_log(s->avctx, AV_LOG_WARNING, "Ignoring multiple VOL headers\n");
3415                 continue;
3416             }
3417             vol++;
3418             if ((ret = decode_vol_header(ctx, gb)) < 0)
3419                 return ret;
3420         } else if (startcode == USER_DATA_STARTCODE) {
3421             decode_user_data(ctx, gb);
3422         } else if (startcode == GOP_STARTCODE) {
3423             mpeg4_decode_gop_header(s, gb);
3424         } else if (startcode == VOS_STARTCODE) {
3425             int profile, level;
3426             mpeg4_decode_profile_level(s, gb, &profile, &level);
3427             if (profile == FF_PROFILE_MPEG4_SIMPLE_STUDIO &&
3428                 (level > 0 && level < 9)) {
3429                 s->studio_profile = 1;
3430                 next_start_code_studio(gb);
3431                 extension_and_user_data(s, gb, 0);
3432             } else if (s->studio_profile) {
3433                 avpriv_request_sample(s->avctx, "Mix of studio and non studio profile");
3434                 return AVERROR_PATCHWELCOME;
3435             }
3436             s->avctx->profile = profile;
3437             s->avctx->level   = level;
3438         } else if (startcode == VISUAL_OBJ_STARTCODE) {
3439             if (s->studio_profile) {
3440                 if ((ret = decode_studiovisualobject(ctx, gb)) < 0)
3441                     return ret;
3442             } else
3443                 mpeg4_decode_visual_object(s, gb);
3444         } else if (startcode == VOP_STARTCODE) {
3445             break;
3446         }
3447 
3448         align_get_bits(gb);
3449         startcode = 0xff;
3450     }
3451 
3452 end:
3453     if (s->avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
3454         s->low_delay = 1;
3455     s->avctx->has_b_frames = !s->low_delay;
3456 
3457     if (s->studio_profile) {
3458         if (!s->avctx->bits_per_raw_sample) {
3459             av_log(s->avctx, AV_LOG_ERROR, "Missing VOL header\n");
3460             return AVERROR_INVALIDDATA;
3461         }
3462         return decode_studio_vop_header(ctx, gb);
3463     } else
3464         return decode_vop_header(ctx, gb, parse_only);
3465 }
3466 
ff_mpeg4_frame_end(AVCodecContext * avctx,const uint8_t * buf,int buf_size)3467 int ff_mpeg4_frame_end(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
3468 {
3469     Mpeg4DecContext *ctx = avctx->priv_data;
3470     MpegEncContext    *s = &ctx->m;
3471 
3472     /* divx 5.01+ bitstream reorder stuff */
3473     /* Since this clobbers the input buffer and hwaccel codecs still need the
3474      * data during hwaccel->end_frame we should not do this any earlier */
3475     if (s->divx_packed) {
3476         int current_pos     = s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb) >> 3);
3477         int startcode_found = 0;
3478 
3479         if (buf_size - current_pos > 7) {
3480 
3481             int i;
3482             for (i = current_pos; i < buf_size - 4; i++)
3483 
3484                 if (buf[i]     == 0 &&
3485                     buf[i + 1] == 0 &&
3486                     buf[i + 2] == 1 &&
3487                     buf[i + 3] == 0xB6) {
3488                     startcode_found = !(buf[i + 4] & 0x40);
3489                     break;
3490                 }
3491         }
3492 
3493         if (startcode_found) {
3494             if (!ctx->showed_packed_warning) {
3495                 av_log(s->avctx, AV_LOG_INFO, "Video uses a non-standard and "
3496                        "wasteful way to store B-frames ('packed B-frames'). "
3497                        "Consider using the mpeg4_unpack_bframes bitstream filter without encoding but stream copy to fix it.\n");
3498                 ctx->showed_packed_warning = 1;
3499             }
3500             av_fast_padded_malloc(&s->bitstream_buffer,
3501                            &s->allocated_bitstream_buffer_size,
3502                            buf_size - current_pos);
3503             if (!s->bitstream_buffer) {
3504                 s->bitstream_buffer_size = 0;
3505                 return AVERROR(ENOMEM);
3506             }
3507             memcpy(s->bitstream_buffer, buf + current_pos,
3508                    buf_size - current_pos);
3509             s->bitstream_buffer_size = buf_size - current_pos;
3510         }
3511     }
3512 
3513     return 0;
3514 }
3515 
3516 #if HAVE_THREADS
mpeg4_update_thread_context(AVCodecContext * dst,const AVCodecContext * src)3517 static int mpeg4_update_thread_context(AVCodecContext *dst,
3518                                        const AVCodecContext *src)
3519 {
3520     Mpeg4DecContext *s = dst->priv_data;
3521     const Mpeg4DecContext *s1 = src->priv_data;
3522     int init = s->m.context_initialized;
3523 
3524     int ret = ff_mpeg_update_thread_context(dst, src);
3525 
3526     if (ret < 0)
3527         return ret;
3528 
3529     // copy all the necessary fields explicitly
3530     s->time_increment_bits       = s1->time_increment_bits;
3531     s->shape                     = s1->shape;
3532     s->vol_sprite_usage          = s1->vol_sprite_usage;
3533     s->sprite_brightness_change  = s1->sprite_brightness_change;
3534     s->num_sprite_warping_points = s1->num_sprite_warping_points;
3535     s->rvlc                      = s1->rvlc;
3536     s->resync_marker             = s1->resync_marker;
3537     s->t_frame                   = s1->t_frame;
3538     s->new_pred                  = s1->new_pred;
3539     s->enhancement_type          = s1->enhancement_type;
3540     s->scalability               = s1->scalability;
3541     s->intra_dc_threshold        = s1->intra_dc_threshold;
3542     s->divx_version              = s1->divx_version;
3543     s->divx_build                = s1->divx_build;
3544     s->xvid_build                = s1->xvid_build;
3545     s->lavc_build                = s1->lavc_build;
3546     s->vo_type                   = s1->vo_type;
3547     s->showed_packed_warning     = s1->showed_packed_warning;
3548     s->vol_control_parameters    = s1->vol_control_parameters;
3549     s->cplx_estimation_trash_i   = s1->cplx_estimation_trash_i;
3550     s->cplx_estimation_trash_p   = s1->cplx_estimation_trash_p;
3551     s->cplx_estimation_trash_b   = s1->cplx_estimation_trash_b;
3552     s->rgb                       = s1->rgb;
3553 
3554     memcpy(s->sprite_shift, s1->sprite_shift, sizeof(s1->sprite_shift));
3555     memcpy(s->sprite_traj,  s1->sprite_traj,  sizeof(s1->sprite_traj));
3556 
3557     if (CONFIG_MPEG4_DECODER && !init && s1->xvid_build >= 0)
3558         ff_xvid_idct_init(&s->m.idsp, dst);
3559 
3560     return 0;
3561 }
3562 
mpeg4_update_thread_context_for_user(AVCodecContext * dst,const AVCodecContext * src)3563 static int mpeg4_update_thread_context_for_user(AVCodecContext *dst,
3564                                                 const AVCodecContext *src)
3565 {
3566     MpegEncContext *m = dst->priv_data;
3567     const MpegEncContext *m1 = src->priv_data;
3568 
3569     m->quarter_sample = m1->quarter_sample;
3570     m->divx_packed    = m1->divx_packed;
3571 
3572     return 0;
3573 }
3574 #endif
3575 
mpeg4_init_static(void)3576 static av_cold void mpeg4_init_static(void)
3577 {
3578     static uint8_t mpeg4_rvlc_rl_tables[2][2][2 * MAX_RUN + MAX_LEVEL + 3];
3579 
3580     INIT_VLC_STATIC_FROM_LENGTHS(&studio_luma_dc, STUDIO_INTRA_BITS, 19,
3581                                  &ff_mpeg4_studio_dc_luma[0][1], 2,
3582                                  &ff_mpeg4_studio_dc_luma[0][0], 2, 1,
3583                                  0, 0, 528);
3584 
3585     INIT_VLC_STATIC_FROM_LENGTHS(&studio_chroma_dc, STUDIO_INTRA_BITS, 19,
3586                                  &ff_mpeg4_studio_dc_chroma[0][1], 2,
3587                                  &ff_mpeg4_studio_dc_chroma[0][0], 2, 1,
3588                                  0, 0, 528);
3589 
3590     for (unsigned i = 0, offset = 0; i < 12; i++) {
3591         static VLCElem vlc_buf[6498];
3592 
3593         studio_intra_tab[i].table           = &vlc_buf[offset];
3594         studio_intra_tab[i].table_allocated = FF_ARRAY_ELEMS(vlc_buf) - offset;
3595         ff_init_vlc_from_lengths(&studio_intra_tab[i],
3596                                  STUDIO_INTRA_BITS, 24,
3597                                  &ff_mpeg4_studio_intra[i][0][1], 2,
3598                                  &ff_mpeg4_studio_intra[i][0][0], 2, 1,
3599                                  0, INIT_VLC_STATIC_OVERLONG, NULL);
3600         offset += studio_intra_tab[i].table_size;
3601     }
3602 
3603     ff_mpeg4_init_rl_intra();
3604     ff_rl_init(&ff_rvlc_rl_inter, mpeg4_rvlc_rl_tables[0]);
3605     ff_rl_init(&ff_rvlc_rl_intra, mpeg4_rvlc_rl_tables[1]);
3606     INIT_FIRST_VLC_RL(ff_mpeg4_rl_intra, 554);
3607     INIT_VLC_RL(ff_rvlc_rl_inter, 1072);
3608     INIT_FIRST_VLC_RL(ff_rvlc_rl_intra, 1072);
3609     INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
3610                     &ff_mpeg4_DCtab_lum[0][1], 2, 1,
3611                     &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
3612     INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
3613                     &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
3614                     &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
3615     INIT_VLC_STATIC_FROM_LENGTHS(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
3616                                  ff_sprite_trajectory_lens, 1,
3617                                  NULL, 0, 0, 0, 0, 128);
3618     INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
3619                     &ff_mb_type_b_tab[0][1], 2, 1,
3620                     &ff_mb_type_b_tab[0][0], 2, 1, 16);
3621 }
3622 
decode_init(AVCodecContext * avctx)3623 static av_cold int decode_init(AVCodecContext *avctx)
3624 {
3625     static AVOnce init_static_once = AV_ONCE_INIT;
3626     Mpeg4DecContext *ctx = avctx->priv_data;
3627     MpegEncContext *s = &ctx->m;
3628     int ret;
3629 
3630     ctx->divx_version =
3631     ctx->divx_build   =
3632     ctx->xvid_build   =
3633     ctx->lavc_build   = -1;
3634 
3635     if ((ret = ff_h263_decode_init(avctx)) < 0)
3636         return ret;
3637 
3638     s->h263_pred = 1;
3639     s->low_delay = 0; /* default, might be overridden in the vol header during header parsing */
3640     s->decode_mb = mpeg4_decode_mb;
3641     ctx->time_increment_bits = 4; /* default value for broken headers */
3642 
3643     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
3644 
3645     ff_thread_once(&init_static_once, mpeg4_init_static);
3646 
3647     return 0;
3648 }
3649 
3650 #define OFFSET(x) offsetof(MpegEncContext, x)
3651 #define FLAGS AV_OPT_FLAG_EXPORT | AV_OPT_FLAG_READONLY
3652 static const AVOption mpeg4_options[] = {
3653     {"quarter_sample", "1/4 subpel MC", OFFSET(quarter_sample), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS},
3654     {"divx_packed", "divx style packed b frames", OFFSET(divx_packed), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS},
3655     {NULL}
3656 };
3657 
3658 static const AVClass mpeg4_class = {
3659     .class_name = "MPEG4 Video Decoder",
3660     .item_name  = av_default_item_name,
3661     .option     = mpeg4_options,
3662     .version    = LIBAVUTIL_VERSION_INT,
3663 };
3664 
3665 const FFCodec ff_mpeg4_decoder = {
3666     .p.name                = "mpeg4",
3667     .p.long_name           = NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
3668     .p.type                = AVMEDIA_TYPE_VIDEO,
3669     .p.id                  = AV_CODEC_ID_MPEG4,
3670     .priv_data_size        = sizeof(Mpeg4DecContext),
3671     .init                  = decode_init,
3672     .close                 = ff_h263_decode_end,
3673     FF_CODEC_DECODE_CB(ff_h263_decode_frame),
3674     .p.capabilities        = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1 |
3675 #if FF_API_FLAG_TRUNCATED
3676                              AV_CODEC_CAP_TRUNCATED |
3677 #endif
3678                              AV_CODEC_CAP_DELAY | AV_CODEC_CAP_FRAME_THREADS,
3679     .caps_internal         = FF_CODEC_CAP_INIT_THREADSAFE |
3680                              FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM |
3681                              FF_CODEC_CAP_ALLOCATE_PROGRESS,
3682     .flush                 = ff_mpeg_flush,
3683     .p.max_lowres          = 3,
3684     .p.pix_fmts            = ff_h263_hwaccel_pixfmt_list_420,
3685     .p.profiles            = NULL_IF_CONFIG_SMALL(ff_mpeg4_video_profiles),
3686     .update_thread_context = ONLY_IF_THREADS_ENABLED(mpeg4_update_thread_context),
3687     .update_thread_context_for_user = ONLY_IF_THREADS_ENABLED(mpeg4_update_thread_context_for_user),
3688     .p.priv_class = &mpeg4_class,
3689     .hw_configs            = (const AVCodecHWConfigInternal *const []) {
3690 #if CONFIG_MPEG4_NVDEC_HWACCEL
3691                                HWACCEL_NVDEC(mpeg4),
3692 #endif
3693 #if CONFIG_MPEG4_VAAPI_HWACCEL
3694                                HWACCEL_VAAPI(mpeg4),
3695 #endif
3696 #if CONFIG_MPEG4_VDPAU_HWACCEL
3697                                HWACCEL_VDPAU(mpeg4),
3698 #endif
3699 #if CONFIG_MPEG4_VIDEOTOOLBOX_HWACCEL
3700                                HWACCEL_VIDEOTOOLBOX(mpeg4),
3701 #endif
3702                                NULL
3703                            },
3704 };
3705