• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * RV10/RV20 decoder
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2002-2004 Michael Niedermayer
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 /**
24  * @file
25  * RV10/RV20 decoder
26  */
27 
28 #include <inttypes.h>
29 
30 #include "libavutil/imgutils.h"
31 #include "libavutil/thread.h"
32 
33 #include "avcodec.h"
34 #include "error_resilience.h"
35 #include "h263.h"
36 #include "h263data.h"
37 #include "internal.h"
38 #include "mpeg_er.h"
39 #include "mpegutils.h"
40 #include "mpegvideo.h"
41 #include "mpeg4video.h"
42 #include "mpegvideodata.h"
43 #include "rv10.h"
44 
45 #define RV_GET_MAJOR_VER(x)  ((x) >> 28)
46 #define RV_GET_MINOR_VER(x) (((x) >> 20) & 0xFF)
47 #define RV_GET_MICRO_VER(x) (((x) >> 12) & 0xFF)
48 
49 #define MAX_VLC_ENTRIES 1023 // Note: Does not include the skip entries.
50 #define DC_VLC_BITS        9
51 
52 typedef struct RVDecContext {
53     MpegEncContext m;
54     int sub_id;
55     int orig_width, orig_height;
56 } RVDecContext;
57 
58 /* (run, length) encoded value for the symbols table. The actual symbols
59  * are run..run - length (mod 256).
60  * The last two entries in the following table apply to luma only.
61  * The skip values are not included in this list. */
62 static const uint8_t rv_sym_run_len[][2] = {
63     {   0,   0 }, {   1,   0 }, { 255,   0 }, {   3,   1 }, { 254,  1 },
64     {   7,   3 }, { 252,   3 }, {  15,   7 }, { 248,   7 }, {  31, 15 },
65     { 240,  15 }, {  63,  31 }, { 224,  31 }, { 127,  63 }, { 192, 63 },
66     { 255, 127 }, { 128, 127 }, { 127, 255 }, { 128, 255 },
67 };
68 
69 /* entry[i] of the following tables gives
70  * the number of VLC codes of length i + 2. */
71 static const uint16_t rv_lum_len_count[15] = {
72     1,  0,  2,  4,  8, 16, 32,  0, 64,  0, 128,  0, 256,  0, 512,
73 };
74 
75 static const uint16_t rv_chrom_len_count[15] = {
76     1,  2,  4,  0,  8,  0, 16,  0, 32,  0,  64,  0, 128,  0, 256,
77 };
78 
79 static VLC rv_dc_lum, rv_dc_chrom;
80 
ff_rv_decode_dc(MpegEncContext * s,int n)81 int ff_rv_decode_dc(MpegEncContext *s, int n)
82 {
83     int code;
84 
85     if (n < 4) {
86         code = get_vlc2(&s->gb, rv_dc_lum.table, DC_VLC_BITS, 2);
87     } else {
88         code = get_vlc2(&s->gb, rv_dc_chrom.table, DC_VLC_BITS, 2);
89         if (code < 0) {
90             av_log(s->avctx, AV_LOG_ERROR, "chroma dc error\n");
91             return -1;
92         }
93     }
94     return code;
95 }
96 
97 /* read RV 1.0 compatible frame header */
rv10_decode_picture_header(MpegEncContext * s)98 static int rv10_decode_picture_header(MpegEncContext *s)
99 {
100     int mb_count, pb_frame, marker, mb_xy;
101 
102     marker = get_bits1(&s->gb);
103 
104     if (get_bits1(&s->gb))
105         s->pict_type = AV_PICTURE_TYPE_P;
106     else
107         s->pict_type = AV_PICTURE_TYPE_I;
108 
109     if (!marker)
110         av_log(s->avctx, AV_LOG_ERROR, "marker missing\n");
111 
112     pb_frame = get_bits1(&s->gb);
113 
114     ff_dlog(s->avctx, "pict_type=%d pb_frame=%d\n", s->pict_type, pb_frame);
115 
116     if (pb_frame) {
117         avpriv_request_sample(s->avctx, "PB-frame");
118         return AVERROR_PATCHWELCOME;
119     }
120 
121     s->qscale = get_bits(&s->gb, 5);
122     if (s->qscale == 0) {
123         av_log(s->avctx, AV_LOG_ERROR, "Invalid qscale value: 0\n");
124         return AVERROR_INVALIDDATA;
125     }
126 
127     if (s->pict_type == AV_PICTURE_TYPE_I) {
128         if (s->rv10_version == 3) {
129             /* specific MPEG like DC coding not used */
130             s->last_dc[0] = get_bits(&s->gb, 8);
131             s->last_dc[1] = get_bits(&s->gb, 8);
132             s->last_dc[2] = get_bits(&s->gb, 8);
133             ff_dlog(s->avctx, "DC:%d %d %d\n", s->last_dc[0],
134                     s->last_dc[1], s->last_dc[2]);
135         }
136     }
137     /* if multiple packets per frame are sent, the position at which
138      * to display the macroblocks is coded here */
139 
140     mb_xy = s->mb_x + s->mb_y * s->mb_width;
141     if (show_bits(&s->gb, 12) == 0 || (mb_xy && mb_xy < s->mb_num)) {
142         s->mb_x  = get_bits(&s->gb, 6); /* mb_x */
143         s->mb_y  = get_bits(&s->gb, 6); /* mb_y */
144         mb_count = get_bits(&s->gb, 12);
145     } else {
146         s->mb_x  = 0;
147         s->mb_y  = 0;
148         mb_count = s->mb_width * s->mb_height;
149     }
150     skip_bits(&s->gb, 3);   /* ignored */
151     s->f_code          = 1;
152     s->unrestricted_mv = 1;
153 
154     return mb_count;
155 }
156 
rv20_decode_picture_header(RVDecContext * rv,int whole_size)157 static int rv20_decode_picture_header(RVDecContext *rv, int whole_size)
158 {
159     MpegEncContext *s = &rv->m;
160     int seq, mb_pos, i, ret;
161     int rpr_max;
162 
163     i = get_bits(&s->gb, 2);
164     switch (i) {
165     case 0:
166         s->pict_type = AV_PICTURE_TYPE_I;
167         break;
168     case 1:
169         s->pict_type = AV_PICTURE_TYPE_I;
170         break;                                  // hmm ...
171     case 2:
172         s->pict_type = AV_PICTURE_TYPE_P;
173         break;
174     case 3:
175         s->pict_type = AV_PICTURE_TYPE_B;
176         break;
177     default:
178         av_log(s->avctx, AV_LOG_ERROR, "unknown frame type\n");
179         return AVERROR_INVALIDDATA;
180     }
181 
182     if (s->low_delay && s->pict_type == AV_PICTURE_TYPE_B) {
183         av_log(s->avctx, AV_LOG_ERROR, "low delay B\n");
184         return -1;
185     }
186     if (!s->last_picture_ptr && s->pict_type == AV_PICTURE_TYPE_B) {
187         av_log(s->avctx, AV_LOG_ERROR, "early B-frame\n");
188         return AVERROR_INVALIDDATA;
189     }
190 
191     if (get_bits1(&s->gb)) {
192         av_log(s->avctx, AV_LOG_ERROR, "reserved bit set\n");
193         return AVERROR_INVALIDDATA;
194     }
195 
196     s->qscale = get_bits(&s->gb, 5);
197     if (s->qscale == 0) {
198         av_log(s->avctx, AV_LOG_ERROR, "Invalid qscale value: 0\n");
199         return AVERROR_INVALIDDATA;
200     }
201 
202     if (RV_GET_MINOR_VER(rv->sub_id) >= 2)
203         s->loop_filter = get_bits1(&s->gb) && !s->avctx->lowres;
204 
205     if (RV_GET_MINOR_VER(rv->sub_id) <= 1)
206         seq = get_bits(&s->gb, 8) << 7;
207     else
208         seq = get_bits(&s->gb, 13) << 2;
209 
210     rpr_max = s->avctx->extradata[1] & 7;
211     if (rpr_max) {
212         int f, new_w, new_h;
213         int rpr_bits = av_log2(rpr_max) + 1;
214 
215         f = get_bits(&s->gb, rpr_bits);
216 
217         if (f) {
218             if (s->avctx->extradata_size < 8 + 2 * f) {
219                 av_log(s->avctx, AV_LOG_ERROR, "Extradata too small.\n");
220                 return AVERROR_INVALIDDATA;
221             }
222 
223             new_w = 4 * ((uint8_t *) s->avctx->extradata)[6 + 2 * f];
224             new_h = 4 * ((uint8_t *) s->avctx->extradata)[7 + 2 * f];
225         } else {
226             new_w = rv->orig_width;
227             new_h = rv->orig_height;
228         }
229         if (new_w != s->width || new_h != s->height || !s->context_initialized) {
230             AVRational old_aspect = s->avctx->sample_aspect_ratio;
231             av_log(s->avctx, AV_LOG_DEBUG,
232                    "attempting to change resolution to %dx%d\n", new_w, new_h);
233             if (av_image_check_size(new_w, new_h, 0, s->avctx) < 0)
234                 return AVERROR_INVALIDDATA;
235 
236             if (whole_size < (new_w + 15)/16 * ((new_h + 15)/16) / 8)
237                 return AVERROR_INVALIDDATA;
238 
239             ff_mpv_common_end(s);
240 
241             // attempt to keep aspect during typical resolution switches
242             if (!old_aspect.num)
243                 old_aspect = (AVRational){1, 1};
244             if (2 * (int64_t)new_w * s->height == (int64_t)new_h * s->width)
245                 s->avctx->sample_aspect_ratio = av_mul_q(old_aspect, (AVRational){2, 1});
246             if ((int64_t)new_w * s->height == 2 * (int64_t)new_h * s->width)
247                 s->avctx->sample_aspect_ratio = av_mul_q(old_aspect, (AVRational){1, 2});
248 
249             ret = ff_set_dimensions(s->avctx, new_w, new_h);
250             if (ret < 0)
251                 return ret;
252 
253             s->width  = new_w;
254             s->height = new_h;
255             if ((ret = ff_mpv_common_init(s)) < 0)
256                 return ret;
257         }
258 
259         if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
260             av_log(s->avctx, AV_LOG_DEBUG, "F %d/%d/%d\n", f, rpr_bits, rpr_max);
261         }
262     }
263     if (av_image_check_size(s->width, s->height, 0, s->avctx) < 0)
264         return AVERROR_INVALIDDATA;
265 
266     mb_pos = ff_h263_decode_mba(s);
267 
268     seq |= s->time & ~0x7FFF;
269     if (seq - s->time >  0x4000)
270         seq -= 0x8000;
271     if (seq - s->time < -0x4000)
272         seq += 0x8000;
273 
274     if (seq != s->time) {
275         if (s->pict_type != AV_PICTURE_TYPE_B) {
276             s->time            = seq;
277             s->pp_time         = s->time - s->last_non_b_time;
278             s->last_non_b_time = s->time;
279         } else {
280             s->time    = seq;
281             s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
282         }
283     }
284     if (s->pict_type == AV_PICTURE_TYPE_B) {
285         if (s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0) {
286             av_log(s->avctx, AV_LOG_DEBUG,
287                    "messed up order, possible from seeking? skipping current B-frame\n");
288 #define ERROR_SKIP_FRAME -123
289             return ERROR_SKIP_FRAME;
290         }
291         ff_mpeg4_init_direct_mv(s);
292     }
293 
294     s->no_rounding = get_bits1(&s->gb);
295 
296     if (RV_GET_MINOR_VER(rv->sub_id) <= 1 && s->pict_type == AV_PICTURE_TYPE_B)
297         // binary decoder reads 3+2 bits here but they don't seem to be used
298         skip_bits(&s->gb, 5);
299 
300     s->f_code          = 1;
301     s->unrestricted_mv = 1;
302     s->h263_aic        = s->pict_type == AV_PICTURE_TYPE_I;
303     s->modified_quant  = 1;
304     if (!s->avctx->lowres)
305         s->loop_filter = 1;
306 
307     if (s->avctx->debug & FF_DEBUG_PICT_INFO) {
308         av_log(s->avctx, AV_LOG_INFO,
309                "num:%5d x:%2d y:%2d type:%d qscale:%2d rnd:%d\n",
310                seq, s->mb_x, s->mb_y, s->pict_type, s->qscale,
311                s->no_rounding);
312     }
313 
314     av_assert0(s->pict_type != AV_PICTURE_TYPE_B || !s->low_delay);
315 
316     return s->mb_width * s->mb_height - mb_pos;
317 }
318 
rv10_build_vlc(VLC * vlc,const uint16_t len_count[15],const uint8_t sym_rl[][2],int sym_rl_elems)319 static av_cold void rv10_build_vlc(VLC *vlc, const uint16_t len_count[15],
320                                    const uint8_t sym_rl[][2], int sym_rl_elems)
321 {
322     uint16_t syms[MAX_VLC_ENTRIES];
323     uint8_t  lens[MAX_VLC_ENTRIES];
324     unsigned nb_syms = 0, nb_lens = 0;
325 
326     for (unsigned i = 0; i < sym_rl_elems; i++) {
327         unsigned cur_sym = sym_rl[i][0];
328         for (unsigned tmp = nb_syms + sym_rl[i][1]; nb_syms <= tmp; nb_syms++)
329             syms[nb_syms] = 0xFF & cur_sym--;
330     }
331 
332     for (unsigned i = 0; i < 15; i++)
333         for (unsigned tmp = nb_lens + len_count[i]; nb_lens < tmp; nb_lens++)
334             lens[nb_lens] = i + 2;
335     av_assert1(nb_lens == nb_syms);
336     ff_init_vlc_from_lengths(vlc, DC_VLC_BITS, nb_lens, lens, 1,
337                              syms, 2, 2, 0, INIT_VLC_STATIC_OVERLONG, NULL);
338 }
339 
rv10_init_static(void)340 static av_cold void rv10_init_static(void)
341 {
342     static VLC_TYPE table[1472 + 992][2];
343 
344     rv_dc_lum.table             = table;
345     rv_dc_lum.table_allocated   = 1472;
346     rv10_build_vlc(&rv_dc_lum, rv_lum_len_count,
347                    rv_sym_run_len, FF_ARRAY_ELEMS(rv_sym_run_len));
348     for (int i = 0; i < 1 << (DC_VLC_BITS - 7 /* Length of skip prefix */); i++) {
349         /* All codes beginning with 0x7F have the same length and value.
350          * Modifying the table directly saves us the useless subtables. */
351         rv_dc_lum.table[(0x7F << (DC_VLC_BITS - 7)) + i][0] = 255;
352         rv_dc_lum.table[(0x7F << (DC_VLC_BITS - 7)) + i][1] = 18;
353     }
354     rv_dc_chrom.table           = &table[1472];
355     rv_dc_chrom.table_allocated = 992;
356     rv10_build_vlc(&rv_dc_chrom, rv_chrom_len_count,
357                    rv_sym_run_len, FF_ARRAY_ELEMS(rv_sym_run_len) - 2);
358     for (int i = 0; i < 1 << (DC_VLC_BITS - 9 /* Length of skip prefix */); i++) {
359         /* Same as above. */
360         rv_dc_chrom.table[(0x1FE << (DC_VLC_BITS - 9)) + i][0] = 255;
361         rv_dc_chrom.table[(0x1FE << (DC_VLC_BITS - 9)) + i][1] = 18;
362     }
363     ff_h263_decode_init_vlc();
364 }
365 
rv10_decode_init(AVCodecContext * avctx)366 static av_cold int rv10_decode_init(AVCodecContext *avctx)
367 {
368     static AVOnce init_static_once = AV_ONCE_INIT;
369     RVDecContext *rv = avctx->priv_data;
370     MpegEncContext *s = &rv->m;
371     int major_ver, minor_ver, micro_ver, ret;
372 
373     if (avctx->extradata_size < 8) {
374         av_log(avctx, AV_LOG_ERROR, "Extradata is too small.\n");
375         return AVERROR_INVALIDDATA;
376     }
377     if ((ret = av_image_check_size(avctx->coded_width,
378                                    avctx->coded_height, 0, avctx)) < 0)
379         return ret;
380 
381     ff_mpv_decode_init(s, avctx);
382 
383     s->out_format  = FMT_H263;
384 
385     rv->orig_width  =
386     s->width        = avctx->coded_width;
387     rv->orig_height =
388     s->height       = avctx->coded_height;
389 
390     s->h263_long_vectors = ((uint8_t *) avctx->extradata)[3] & 1;
391     rv->sub_id           = AV_RB32((uint8_t *) avctx->extradata + 4);
392 
393     major_ver = RV_GET_MAJOR_VER(rv->sub_id);
394     minor_ver = RV_GET_MINOR_VER(rv->sub_id);
395     micro_ver = RV_GET_MICRO_VER(rv->sub_id);
396 
397     s->low_delay = 1;
398     switch (major_ver) {
399     case 1:
400         s->rv10_version = micro_ver ? 3 : 1;
401         s->obmc         = micro_ver == 2;
402         break;
403     case 2:
404         if (minor_ver >= 2) {
405             s->low_delay           = 0;
406             s->avctx->has_b_frames = 1;
407         }
408         break;
409     default:
410         av_log(s->avctx, AV_LOG_ERROR, "unknown header %X\n", rv->sub_id);
411         avpriv_request_sample(avctx, "RV1/2 version");
412         return AVERROR_PATCHWELCOME;
413     }
414 
415     if (avctx->debug & FF_DEBUG_PICT_INFO) {
416         av_log(avctx, AV_LOG_DEBUG, "ver:%X ver0:%"PRIX32"\n", rv->sub_id,
417                ((uint32_t *) avctx->extradata)[0]);
418     }
419 
420     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
421 
422     ff_mpv_idct_init(s);
423     if ((ret = ff_mpv_common_init(s)) < 0)
424         return ret;
425 
426     ff_h263dsp_init(&s->h263dsp);
427 
428     /* init static VLCs */
429     ff_thread_once(&init_static_once, rv10_init_static);
430 
431     return 0;
432 }
433 
rv10_decode_end(AVCodecContext * avctx)434 static av_cold int rv10_decode_end(AVCodecContext *avctx)
435 {
436     MpegEncContext *s = avctx->priv_data;
437 
438     ff_mpv_common_end(s);
439     return 0;
440 }
441 
rv10_decode_packet(AVCodecContext * avctx,const uint8_t * buf,int buf_size,int buf_size2,int whole_size)442 static int rv10_decode_packet(AVCodecContext *avctx, const uint8_t *buf,
443                               int buf_size, int buf_size2, int whole_size)
444 {
445     RVDecContext *rv = avctx->priv_data;
446     MpegEncContext *s = &rv->m;
447     int mb_count, mb_pos, left, start_mb_x, active_bits_size, ret;
448 
449     active_bits_size = buf_size * 8;
450     init_get_bits(&s->gb, buf, FFMAX(buf_size, buf_size2) * 8);
451     if (s->codec_id == AV_CODEC_ID_RV10)
452         mb_count = rv10_decode_picture_header(s);
453     else
454         mb_count = rv20_decode_picture_header(rv, whole_size);
455     if (mb_count < 0) {
456         if (mb_count != ERROR_SKIP_FRAME)
457             av_log(s->avctx, AV_LOG_ERROR, "HEADER ERROR\n");
458         return AVERROR_INVALIDDATA;
459     }
460 
461     if (s->mb_x >= s->mb_width ||
462         s->mb_y >= s->mb_height) {
463         av_log(s->avctx, AV_LOG_ERROR, "POS ERROR %d %d\n", s->mb_x, s->mb_y);
464         return AVERROR_INVALIDDATA;
465     }
466     mb_pos = s->mb_y * s->mb_width + s->mb_x;
467     left   = s->mb_width * s->mb_height - mb_pos;
468     if (mb_count > left) {
469         av_log(s->avctx, AV_LOG_ERROR, "COUNT ERROR\n");
470         return AVERROR_INVALIDDATA;
471     }
472 
473     if (whole_size < s->mb_width * s->mb_height / 8)
474         return AVERROR_INVALIDDATA;
475 
476     if ((s->mb_x == 0 && s->mb_y == 0) || !s->current_picture_ptr) {
477         // FIXME write parser so we always have complete frames?
478         if (s->current_picture_ptr) {
479             ff_er_frame_end(&s->er);
480             ff_mpv_frame_end(s);
481             s->mb_x = s->mb_y = s->resync_mb_x = s->resync_mb_y = 0;
482         }
483         if ((ret = ff_mpv_frame_start(s, avctx)) < 0)
484             return ret;
485         ff_mpeg_er_frame_start(s);
486     } else {
487         if (s->current_picture_ptr->f->pict_type != s->pict_type) {
488             av_log(s->avctx, AV_LOG_ERROR, "Slice type mismatch\n");
489             return AVERROR_INVALIDDATA;
490         }
491     }
492 
493 
494     ff_dlog(avctx, "qscale=%d\n", s->qscale);
495 
496     /* default quantization values */
497     if (s->codec_id == AV_CODEC_ID_RV10) {
498         if (s->mb_y == 0)
499             s->first_slice_line = 1;
500     } else {
501         s->first_slice_line = 1;
502         s->resync_mb_x      = s->mb_x;
503     }
504     start_mb_x     = s->mb_x;
505     s->resync_mb_y = s->mb_y;
506     if (s->h263_aic) {
507         s->y_dc_scale_table =
508         s->c_dc_scale_table = ff_aic_dc_scale_table;
509     } else {
510         s->y_dc_scale_table =
511         s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
512     }
513 
514     if (s->modified_quant)
515         s->chroma_qscale_table = ff_h263_chroma_qscale_table;
516 
517     ff_set_qscale(s, s->qscale);
518 
519     s->rv10_first_dc_coded[0] = 0;
520     s->rv10_first_dc_coded[1] = 0;
521     s->rv10_first_dc_coded[2] = 0;
522     s->block_wrap[0] =
523     s->block_wrap[1] =
524     s->block_wrap[2] =
525     s->block_wrap[3] = s->b8_stride;
526     s->block_wrap[4] =
527     s->block_wrap[5] = s->mb_stride;
528     ff_init_block_index(s);
529 
530     /* decode each macroblock */
531     for (s->mb_num_left = mb_count; s->mb_num_left > 0; s->mb_num_left--) {
532         int ret;
533         ff_update_block_index(s);
534         ff_tlog(avctx, "**mb x=%d y=%d\n", s->mb_x, s->mb_y);
535 
536         s->mv_dir  = MV_DIR_FORWARD;
537         s->mv_type = MV_TYPE_16X16;
538         ret = ff_h263_decode_mb(s, s->block);
539 
540         // Repeat the slice end check from ff_h263_decode_mb with our active
541         // bitstream size
542         if (ret != SLICE_ERROR && active_bits_size >= get_bits_count(&s->gb)) {
543             int v = show_bits(&s->gb, 16);
544 
545             if (get_bits_count(&s->gb) + 16 > active_bits_size)
546                 v >>= get_bits_count(&s->gb) + 16 - active_bits_size;
547 
548             if (!v)
549                 ret = SLICE_END;
550         }
551         if (ret != SLICE_ERROR && active_bits_size < get_bits_count(&s->gb) &&
552             8 * buf_size2 >= get_bits_count(&s->gb)) {
553             active_bits_size = buf_size2 * 8;
554             av_log(avctx, AV_LOG_DEBUG, "update size from %d to %d\n",
555                    8 * buf_size, active_bits_size);
556             ret = SLICE_OK;
557         }
558 
559         if (ret == SLICE_ERROR || active_bits_size < get_bits_count(&s->gb)) {
560             av_log(s->avctx, AV_LOG_ERROR, "ERROR at MB %d %d\n", s->mb_x,
561                    s->mb_y);
562             return AVERROR_INVALIDDATA;
563         }
564         if (s->pict_type != AV_PICTURE_TYPE_B)
565             ff_h263_update_motion_val(s);
566         ff_mpv_reconstruct_mb(s, s->block);
567         if (s->loop_filter)
568             ff_h263_loop_filter(s);
569 
570         if (++s->mb_x == s->mb_width) {
571             s->mb_x = 0;
572             s->mb_y++;
573             ff_init_block_index(s);
574         }
575         if (s->mb_x == s->resync_mb_x)
576             s->first_slice_line = 0;
577         if (ret == SLICE_END)
578             break;
579     }
580 
581     ff_er_add_slice(&s->er, start_mb_x, s->resync_mb_y, s->mb_x - 1, s->mb_y,
582                     ER_MB_END);
583 
584     return active_bits_size;
585 }
586 
get_slice_offset(AVCodecContext * avctx,const uint8_t * buf,int n)587 static int get_slice_offset(AVCodecContext *avctx, const uint8_t *buf, int n)
588 {
589     if (avctx->slice_count)
590         return avctx->slice_offset[n];
591     else
592         return AV_RL32(buf + n * 8);
593 }
594 
rv10_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)595 static int rv10_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
596                              AVPacket *avpkt)
597 {
598     const uint8_t *buf = avpkt->data;
599     int buf_size       = avpkt->size;
600     MpegEncContext *s = avctx->priv_data;
601     AVFrame *pict = data;
602     int i, ret;
603     int slice_count;
604     const uint8_t *slices_hdr = NULL;
605 
606     ff_dlog(avctx, "*****frame %d size=%d\n", avctx->frame_number, buf_size);
607 
608     /* no supplementary picture */
609     if (buf_size == 0) {
610         return 0;
611     }
612 
613     if (!avctx->slice_count) {
614         slice_count = (*buf++) + 1;
615         buf_size--;
616 
617         if (!slice_count || buf_size <= 8 * slice_count) {
618             av_log(avctx, AV_LOG_ERROR, "Invalid slice count: %d.\n",
619                    slice_count);
620             return AVERROR_INVALIDDATA;
621         }
622 
623         slices_hdr = buf + 4;
624         buf       += 8 * slice_count;
625         buf_size  -= 8 * slice_count;
626     } else
627         slice_count = avctx->slice_count;
628 
629     for (i = 0; i < slice_count; i++) {
630         unsigned offset = get_slice_offset(avctx, slices_hdr, i);
631         int size, size2;
632 
633         if (offset >= buf_size)
634             return AVERROR_INVALIDDATA;
635 
636         if (i + 1 == slice_count)
637             size = buf_size - offset;
638         else
639             size = get_slice_offset(avctx, slices_hdr, i + 1) - offset;
640 
641         if (i + 2 >= slice_count)
642             size2 = buf_size - offset;
643         else
644             size2 = get_slice_offset(avctx, slices_hdr, i + 2) - offset;
645 
646         if (size <= 0 || size2 <= 0 ||
647             offset + FFMAX(size, size2) > buf_size)
648             return AVERROR_INVALIDDATA;
649 
650         if ((ret = rv10_decode_packet(avctx, buf + offset, size, size2, buf_size)) < 0)
651             return ret;
652 
653         if (ret > 8 * size)
654             i++;
655     }
656 
657     if (s->current_picture_ptr && s->mb_y >= s->mb_height) {
658         ff_er_frame_end(&s->er);
659         ff_mpv_frame_end(s);
660 
661         if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {
662             if ((ret = av_frame_ref(pict, s->current_picture_ptr->f)) < 0)
663                 return ret;
664             ff_print_debug_info(s, s->current_picture_ptr, pict);
665             ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG1);
666         } else if (s->last_picture_ptr) {
667             if ((ret = av_frame_ref(pict, s->last_picture_ptr->f)) < 0)
668                 return ret;
669             ff_print_debug_info(s, s->last_picture_ptr, pict);
670             ff_mpv_export_qp_table(s, pict,s->last_picture_ptr, FF_QSCALE_TYPE_MPEG1);
671         }
672 
673         if (s->last_picture_ptr || s->low_delay) {
674             *got_frame = 1;
675         }
676 
677         // so we can detect if frame_end was not called (find some nicer solution...)
678         s->current_picture_ptr = NULL;
679     }
680 
681     return avpkt->size;
682 }
683 
684 AVCodec ff_rv10_decoder = {
685     .name           = "rv10",
686     .long_name      = NULL_IF_CONFIG_SMALL("RealVideo 1.0"),
687     .type           = AVMEDIA_TYPE_VIDEO,
688     .id             = AV_CODEC_ID_RV10,
689     .priv_data_size = sizeof(RVDecContext),
690     .init           = rv10_decode_init,
691     .close          = rv10_decode_end,
692     .decode         = rv10_decode_frame,
693     .capabilities   = AV_CODEC_CAP_DR1,
694     .max_lowres     = 3,
695     .pix_fmts       = (const enum AVPixelFormat[]) {
696         AV_PIX_FMT_YUV420P,
697         AV_PIX_FMT_NONE
698     },
699 };
700 
701 AVCodec ff_rv20_decoder = {
702     .name           = "rv20",
703     .long_name      = NULL_IF_CONFIG_SMALL("RealVideo 2.0"),
704     .type           = AVMEDIA_TYPE_VIDEO,
705     .id             = AV_CODEC_ID_RV20,
706     .priv_data_size = sizeof(RVDecContext),
707     .init           = rv10_decode_init,
708     .close          = rv10_decode_end,
709     .decode         = rv10_decode_frame,
710     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
711     .flush          = ff_mpeg_flush,
712     .max_lowres     = 3,
713     .pix_fmts       = (const enum AVPixelFormat[]) {
714         AV_PIX_FMT_YUV420P,
715         AV_PIX_FMT_NONE
716     },
717 };
718