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1 /*
2  * ClearVideo decoder
3  * Copyright (c) 2012-2018 Konstantin Shishkov
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * ClearVideo decoder
25  */
26 
27 #include "libavutil/mem_internal.h"
28 #include "libavutil/thread.h"
29 
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "get_bits.h"
33 #include "idctdsp.h"
34 #include "internal.h"
35 #include "mathops.h"
36 #include "clearvideodata.h"
37 
38 #define CLV_VLC_BITS 9
39 
40 typedef struct LevelCodes {
41     VLC         flags_cb;
42     VLC         mv_cb;
43     VLC         bias_cb;
44 } LevelCodes;
45 
46 typedef struct MV {
47     int16_t x, y;
48 } MV;
49 
50 static const MV zero_mv = { 0 };
51 
52 typedef struct MVInfo {
53     int mb_w;
54     int mb_h;
55     int mb_size;
56     int mb_stride;
57     int top;
58     MV  *mv;
59 } MVInfo;
60 
61 typedef struct TileInfo {
62     uint16_t        flags;
63     int16_t         bias;
64     MV              mv;
65     struct TileInfo *child[4];
66 } TileInfo;
67 
68 typedef struct CLVContext {
69     AVCodecContext *avctx;
70     IDCTDSPContext idsp;
71     AVFrame        *pic;
72     AVFrame        *prev;
73     GetBitContext  gb;
74     int            mb_width, mb_height;
75     int            pmb_width, pmb_height;
76     MVInfo         mvi;
77     int            tile_size;
78     int            tile_shift;
79     int            luma_dc_quant, chroma_dc_quant, ac_quant;
80     DECLARE_ALIGNED(16, int16_t, block)[64];
81     int            top_dc[3], left_dc[4];
82 } CLVContext;
83 
84 static VLC        dc_vlc, ac_vlc;
85 static LevelCodes lev[4 + 3 + 3]; // 0..3: Y, 4..6: U, 7..9: V
86 static VLC_TYPE   vlc_buf[16716][2];
87 
decode_block(CLVContext * ctx,int16_t * blk,int has_ac,int ac_quant)88 static inline int decode_block(CLVContext *ctx, int16_t *blk, int has_ac,
89                                int ac_quant)
90 {
91     GetBitContext *gb = &ctx->gb;
92     int idx = 1, last = 0, val, skip;
93 
94     memset(blk, 0, sizeof(*blk) * 64);
95     blk[0] = get_vlc2(gb, dc_vlc.table, CLV_VLC_BITS, 3);
96 
97     if (!has_ac)
98         return 0;
99 
100     while (idx < 64 && !last) {
101         val = get_vlc2(gb, ac_vlc.table, CLV_VLC_BITS, 2);
102         if (val < 0)
103             return AVERROR_INVALIDDATA;
104         if (val != 0x1BFF) {
105             last =  val >> 12;
106             skip = (val >> 4) & 0xFF;
107             val &= 0xF;
108             if (get_bits1(gb))
109                 val = -val;
110         } else {
111             last = get_bits1(gb);
112             skip = get_bits(gb, 6);
113             val  = get_sbits(gb, 8);
114         }
115         if (val) {
116             int aval = FFABS(val), sign = val < 0;
117             val = ac_quant * (2 * aval + 1);
118             if (!(ac_quant & 1))
119                 val--;
120             if (sign)
121                 val = -val;
122         }
123         idx += skip;
124         if (idx >= 64)
125             return AVERROR_INVALIDDATA;
126         blk[ff_zigzag_direct[idx++]] = val;
127     }
128 
129     return (idx <= 64 && last) ? 0 : -1;
130 }
131 
132 #define DCT_TEMPLATE(blk, step, bias, shift, dshift, OP)                \
133     const int t0 = OP(2841 * blk[1 * step] +  565 * blk[7 * step]);     \
134     const int t1 = OP( 565 * blk[1 * step] - 2841 * blk[7 * step]);     \
135     const int t2 = OP(1609 * blk[5 * step] + 2408 * blk[3 * step]);     \
136     const int t3 = OP(2408 * blk[5 * step] - 1609 * blk[3 * step]);     \
137     const int t4 = OP(1108 * blk[2 * step] - 2676 * blk[6 * step]);     \
138     const int t5 = OP(2676 * blk[2 * step] + 1108 * blk[6 * step]);     \
139     const int t6 = ((blk[0 * step] + blk[4 * step]) * (1 << dshift)) + bias;  \
140     const int t7 = ((blk[0 * step] - blk[4 * step]) * (1 << dshift)) + bias;  \
141     const int t8 = t0 + t2;                                             \
142     const int t9 = t0 - t2;                                             \
143     const int tA = (int)(181U * (t9 + (t1 - t3)) + 0x80) >> 8;          \
144     const int tB = (int)(181U * (t9 - (t1 - t3)) + 0x80) >> 8;          \
145     const int tC = t1 + t3;                                             \
146                                                                         \
147     blk[0 * step] = (t6 + t5 + t8) >> shift;                            \
148     blk[1 * step] = (t7 + t4 + tA) >> shift;                            \
149     blk[2 * step] = (t7 - t4 + tB) >> shift;                            \
150     blk[3 * step] = (t6 - t5 + tC) >> shift;                            \
151     blk[4 * step] = (t6 - t5 - tC) >> shift;                            \
152     blk[5 * step] = (t7 - t4 - tB) >> shift;                            \
153     blk[6 * step] = (t7 + t4 - tA) >> shift;                            \
154     blk[7 * step] = (t6 + t5 - t8) >> shift;                            \
155 
156 #define ROP(x) x
157 #define COP(x) (((x) + 4) >> 3)
158 
clv_dct(int16_t * block)159 static void clv_dct(int16_t *block)
160 {
161     int i;
162     int16_t *ptr;
163 
164     ptr = block;
165     for (i = 0; i < 8; i++) {
166         DCT_TEMPLATE(ptr, 1, 0x80, 8, 11, ROP);
167         ptr += 8;
168     }
169 
170     ptr = block;
171     for (i = 0; i < 8; i++) {
172         DCT_TEMPLATE(ptr, 8, 0x2000, 14, 8, COP);
173         ptr++;
174     }
175 }
176 
decode_mb(CLVContext * c,int x,int y)177 static int decode_mb(CLVContext *c, int x, int y)
178 {
179     int i, has_ac[6], off;
180 
181     for (i = 0; i < 6; i++)
182         has_ac[i] = get_bits1(&c->gb);
183 
184     off = x * 16 + y * 16 * c->pic->linesize[0];
185     for (i = 0; i < 4; i++) {
186         if (decode_block(c, c->block, has_ac[i], c->ac_quant) < 0)
187             return AVERROR_INVALIDDATA;
188         if (!x && !(i & 1)) {
189             c->block[0] += c->top_dc[0];
190             c->top_dc[0] = c->block[0];
191         } else {
192             c->block[0] += c->left_dc[(i & 2) >> 1];
193         }
194         c->left_dc[(i & 2) >> 1] = c->block[0];
195         c->block[0]             *= c->luma_dc_quant;
196         clv_dct(c->block);
197         if (i == 2)
198             off += c->pic->linesize[0] * 8;
199         c->idsp.put_pixels_clamped(c->block,
200                                    c->pic->data[0] + off + (i & 1) * 8,
201                                    c->pic->linesize[0]);
202     }
203 
204     off = x * 8 + y * 8 * c->pic->linesize[1];
205     for (i = 1; i < 3; i++) {
206         if (decode_block(c, c->block, has_ac[i + 3], c->ac_quant) < 0)
207             return AVERROR_INVALIDDATA;
208         if (!x) {
209             c->block[0] += c->top_dc[i];
210             c->top_dc[i] = c->block[0];
211         } else {
212             c->block[0] += c->left_dc[i + 1];
213         }
214         c->left_dc[i + 1] = c->block[0];
215         c->block[0]      *= c->chroma_dc_quant;
216         clv_dct(c->block);
217         c->idsp.put_pixels_clamped(c->block, c->pic->data[i] + off,
218                                    c->pic->linesize[i]);
219     }
220 
221     return 0;
222 }
223 
copy_block(AVCodecContext * avctx,AVFrame * dst,AVFrame * src,int plane,int x,int y,int dx,int dy,int size)224 static int copy_block(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
225                       int plane, int x, int y, int dx, int dy, int size)
226 {
227     int shift = plane > 0;
228     int sx = x + dx;
229     int sy = y + dy;
230     int sstride, dstride, soff, doff;
231     uint8_t *sbuf, *dbuf;
232     int i;
233 
234     if (x < 0 || sx < 0 || y < 0 || sy < 0 ||
235         x + size > avctx->coded_width >> shift ||
236         y + size > avctx->coded_height >> shift ||
237         sx + size > avctx->coded_width >> shift ||
238         sy + size > avctx->coded_height >> shift)
239         return AVERROR_INVALIDDATA;
240 
241     sstride = src->linesize[plane];
242     dstride = dst->linesize[plane];
243     soff    = sx + sy * sstride;
244     sbuf    = src->data[plane];
245     doff    = x + y * dstride;
246     dbuf    = dst->data[plane];
247 
248     for (i = 0; i < size; i++) {
249         uint8_t *dptr = &dbuf[doff];
250         uint8_t *sptr = &sbuf[soff];
251 
252         memcpy(dptr, sptr, size);
253         doff += dstride;
254         soff += sstride;
255     }
256 
257     return 0;
258 }
259 
copyadd_block(AVCodecContext * avctx,AVFrame * dst,AVFrame * src,int plane,int x,int y,int dx,int dy,int size,int bias)260 static int copyadd_block(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
261                          int plane, int x, int y, int dx, int dy, int size, int bias)
262 {
263     int shift = plane > 0;
264     int sx = x + dx;
265     int sy = y + dy;
266     int sstride   = src->linesize[plane];
267     int dstride   = dst->linesize[plane];
268     int soff      = sx + sy * sstride;
269     uint8_t *sbuf = src->data[plane];
270     int doff      = x + y * dstride;
271     uint8_t *dbuf = dst->data[plane];
272     int i, j;
273 
274     if (x < 0 || sx < 0 || y < 0 || sy < 0 ||
275         x + size > avctx->coded_width >> shift ||
276         y + size > avctx->coded_height >> shift ||
277         sx + size > avctx->coded_width >> shift ||
278         sy + size > avctx->coded_height >> shift)
279         return AVERROR_INVALIDDATA;
280 
281     for (j = 0; j < size; j++) {
282         uint8_t *dptr = &dbuf[doff];
283         uint8_t *sptr = &sbuf[soff];
284 
285         for (i = 0; i < size; i++) {
286             int val = sptr[i] + bias;
287 
288             dptr[i] = av_clip_uint8(val);
289         }
290 
291         doff += dstride;
292         soff += sstride;
293     }
294 
295     return 0;
296 }
297 
mvi_predict(MVInfo * mvi,int mb_x,int mb_y,MV diff)298 static MV mvi_predict(MVInfo *mvi, int mb_x, int mb_y, MV diff)
299 {
300     MV res, pred_mv;
301     int left_mv, right_mv, top_mv, bot_mv;
302 
303     if (mvi->top) {
304         if (mb_x > 0) {
305             pred_mv = mvi->mv[mvi->mb_stride + mb_x - 1];
306         } else {
307             pred_mv = zero_mv;
308         }
309     } else if ((mb_x == 0) || (mb_x == mvi->mb_w - 1)) {
310         pred_mv = mvi->mv[mb_x];
311     } else {
312         MV A = mvi->mv[mvi->mb_stride + mb_x - 1];
313         MV B = mvi->mv[                 mb_x    ];
314         MV C = mvi->mv[                 mb_x + 1];
315         pred_mv.x = mid_pred(A.x, B.x, C.x);
316         pred_mv.y = mid_pred(A.y, B.y, C.y);
317     }
318 
319     res = pred_mv;
320 
321     left_mv = -((mb_x * mvi->mb_size));
322     right_mv = ((mvi->mb_w - mb_x - 1) * mvi->mb_size);
323     if (res.x < left_mv) {
324         res.x = left_mv;
325     }
326     if (res.x > right_mv) {
327         res.x = right_mv;
328     }
329     top_mv = -((mb_y * mvi->mb_size));
330     bot_mv = ((mvi->mb_h - mb_y - 1) * mvi->mb_size);
331     if (res.y < top_mv) {
332         res.y = top_mv;
333     }
334     if (res.y > bot_mv) {
335         res.y = bot_mv;
336     }
337 
338     mvi->mv[mvi->mb_stride + mb_x].x = res.x + diff.x;
339     mvi->mv[mvi->mb_stride + mb_x].y = res.y + diff.y;
340 
341     return res;
342 }
343 
mvi_reset(MVInfo * mvi,int mb_w,int mb_h,int mb_size)344 static void mvi_reset(MVInfo *mvi, int mb_w, int mb_h, int mb_size)
345 {
346     mvi->top       = 1;
347     mvi->mb_w      = mb_w;
348     mvi->mb_h      = mb_h;
349     mvi->mb_size   = mb_size;
350     mvi->mb_stride = mb_w;
351     memset(mvi->mv, 0, sizeof(MV) * mvi->mb_stride * 2);
352 }
353 
mvi_update_row(MVInfo * mvi)354 static void mvi_update_row(MVInfo *mvi)
355 {
356     int i;
357 
358     mvi->top = 0;
359     for (i = 0 ; i < mvi->mb_stride; i++) {
360         mvi->mv[i] = mvi->mv[mvi->mb_stride + i];
361     }
362 }
363 
decode_tile_info(GetBitContext * gb,const LevelCodes * lc,int level)364 static TileInfo *decode_tile_info(GetBitContext *gb, const LevelCodes *lc, int level)
365 {
366     TileInfo *ti;
367     int i, flags = 0;
368     int16_t bias = 0;
369     MV mv = { 0 };
370 
371     if (lc[level].flags_cb.table) {
372         flags = get_vlc2(gb, lc[level].flags_cb.table, CLV_VLC_BITS, 2);
373     }
374 
375     if (lc[level].mv_cb.table) {
376         uint16_t mv_code = get_vlc2(gb, lc[level].mv_cb.table, CLV_VLC_BITS, 2);
377 
378         if (mv_code != MV_ESC) {
379             mv.x = (int8_t)(mv_code & 0xff);
380             mv.y = (int8_t)(mv_code >> 8);
381         } else {
382             mv.x = get_sbits(gb, 8);
383             mv.y = get_sbits(gb, 8);
384         }
385     }
386 
387     if (lc[level].bias_cb.table) {
388         uint16_t bias_val = get_vlc2(gb, lc[level].bias_cb.table, CLV_VLC_BITS, 2);
389 
390         if (bias_val != BIAS_ESC) {
391             bias = (int16_t)(bias_val);
392         } else {
393             bias = get_sbits(gb, 16);
394         }
395     }
396 
397     ti = av_calloc(1, sizeof(*ti));
398     if (!ti)
399         return NULL;
400 
401     ti->flags = flags;
402     ti->mv = mv;
403     ti->bias = bias;
404 
405     if (ti->flags) {
406         for (i = 0; i < 4; i++) {
407             if (ti->flags & (1 << i)) {
408                 TileInfo *subti = decode_tile_info(gb, lc, level + 1);
409                 ti->child[i] = subti;
410             }
411         }
412     }
413 
414     return ti;
415 }
416 
tile_do_block(AVCodecContext * avctx,AVFrame * dst,AVFrame * src,int plane,int x,int y,int dx,int dy,int size,int bias)417 static int tile_do_block(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
418                          int plane, int x, int y, int dx, int dy, int size, int bias)
419 {
420     int ret;
421 
422     if (!bias) {
423         ret = copy_block(avctx, dst, src, plane, x, y, dx, dy, size);
424     } else {
425         ret = copyadd_block(avctx, dst, src, plane, x, y, dx, dy, size, bias);
426     }
427 
428     return ret;
429 }
430 
restore_tree(AVCodecContext * avctx,AVFrame * dst,AVFrame * src,int plane,int x,int y,int size,TileInfo * tile,MV root_mv)431 static int restore_tree(AVCodecContext *avctx, AVFrame *dst, AVFrame *src,
432                         int plane, int x, int y, int size,
433                         TileInfo *tile, MV root_mv)
434 {
435     int ret;
436     MV mv;
437 
438     mv.x = root_mv.x + tile->mv.x;
439     mv.y = root_mv.y + tile->mv.y;
440 
441     if (!tile->flags) {
442         ret = tile_do_block(avctx, dst, src, plane, x, y, mv.x, mv.y, size, tile->bias);
443     } else {
444         int i, hsize = size >> 1;
445 
446         for (i = 0; i < 4; i++) {
447             int xoff = (i & 2) == 0 ? 0 : hsize;
448             int yoff = (i & 1) == 0 ? 0 : hsize;
449 
450             if (tile->child[i]) {
451                 ret = restore_tree(avctx, dst, src, plane, x + xoff, y + yoff, hsize, tile->child[i], root_mv);
452                 av_freep(&tile->child[i]);
453             } else {
454                 ret = tile_do_block(avctx, dst, src, plane, x + xoff, y + yoff, mv.x, mv.y, hsize, tile->bias);
455             }
456         }
457     }
458 
459     return ret;
460 }
461 
extend_edges(AVFrame * buf,int tile_size)462 static void extend_edges(AVFrame *buf, int tile_size)
463 {
464     int comp, i, j;
465 
466     for (comp = 0; comp < 3; comp++) {
467         int shift = comp > 0;
468         int w = buf->width  >> shift;
469         int h = buf->height >> shift;
470         int size = comp == 0 ? tile_size : tile_size >> 1;
471         int stride = buf->linesize[comp];
472         uint8_t *framebuf = buf->data[comp];
473 
474         int right  = size - (w & (size - 1));
475         int bottom = size - (h & (size - 1));
476 
477         if ((right == size) && (bottom == size)) {
478             return;
479         }
480         if (right != size) {
481             int off = w;
482             for (j = 0; j < h; j++) {
483                 for (i = 0; i < right; i++) {
484                     framebuf[off + i] = 0x80;
485                 }
486                 off += stride;
487             }
488         }
489         if (bottom != size) {
490             int off = h * stride;
491             for (j = 0; j < bottom; j++) {
492                 for (i = 0; i < stride; i++) {
493                     framebuf[off + i] = 0x80;
494                 }
495                 off += stride;
496             }
497         }
498     }
499 }
500 
clv_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)501 static int clv_decode_frame(AVCodecContext *avctx, void *data,
502                             int *got_frame, AVPacket *avpkt)
503 {
504     const uint8_t *buf = avpkt->data;
505     int buf_size = avpkt->size;
506     CLVContext *c = avctx->priv_data;
507     GetByteContext gb;
508     uint32_t frame_type;
509     int i, j, ret;
510     int mb_ret = 0;
511 
512     bytestream2_init(&gb, buf, buf_size);
513     if (avctx->codec_tag == MKTAG('C', 'L', 'V', '1')) {
514         int skip = bytestream2_get_byte(&gb);
515         bytestream2_skip(&gb, (skip + 1) * 8);
516     }
517 
518     frame_type = bytestream2_get_byte(&gb);
519 
520     if ((frame_type & 0x7f) == 0x30) {
521         *got_frame = 0;
522         return buf_size;
523     } else if (frame_type & 0x2) {
524         if (buf_size < c->mb_width * c->mb_height) {
525             av_log(avctx, AV_LOG_ERROR, "Packet too small\n");
526             return AVERROR_INVALIDDATA;
527         }
528 
529         if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
530             return ret;
531 
532         c->pic->key_frame = 1;
533         c->pic->pict_type = AV_PICTURE_TYPE_I;
534 
535         bytestream2_get_be32(&gb); // frame size;
536         c->ac_quant        = bytestream2_get_byte(&gb);
537         c->luma_dc_quant   = 32;
538         c->chroma_dc_quant = 32;
539 
540         if ((ret = init_get_bits8(&c->gb, buf + bytestream2_tell(&gb),
541                                   buf_size - bytestream2_tell(&gb))) < 0)
542             return ret;
543 
544         for (i = 0; i < 3; i++)
545             c->top_dc[i] = 32;
546         for (i = 0; i < 4; i++)
547             c->left_dc[i] = 32;
548 
549         for (j = 0; j < c->mb_height; j++) {
550             for (i = 0; i < c->mb_width; i++) {
551                 ret = decode_mb(c, i, j);
552                 if (ret < 0)
553                     mb_ret = ret;
554             }
555         }
556         extend_edges(c->pic, c->tile_size);
557     } else {
558         int plane;
559 
560         if (c->pmb_width * c->pmb_height > 8LL*(buf_size - bytestream2_tell(&gb)))
561             return AVERROR_INVALIDDATA;
562 
563         if ((ret = ff_reget_buffer(avctx, c->pic, 0)) < 0)
564             return ret;
565 
566         ret = av_frame_copy(c->pic, c->prev);
567         if (ret < 0)
568             return ret;
569 
570         if ((ret = init_get_bits8(&c->gb, buf + bytestream2_tell(&gb),
571                                   buf_size - bytestream2_tell(&gb))) < 0)
572             return ret;
573 
574         mvi_reset(&c->mvi, c->pmb_width, c->pmb_height, 1 << c->tile_shift);
575 
576         for (j = 0; j < c->pmb_height; j++) {
577             for (i = 0; i < c->pmb_width; i++) {
578                 if (get_bits_left(&c->gb) <= 0)
579                     return AVERROR_INVALIDDATA;
580                 if (get_bits1(&c->gb)) {
581                     MV mv = mvi_predict(&c->mvi, i, j, zero_mv);
582 
583                     for (plane = 0; plane < 3; plane++) {
584                         int16_t x = plane == 0 ? i << c->tile_shift : i << (c->tile_shift - 1);
585                         int16_t y = plane == 0 ? j << c->tile_shift : j << (c->tile_shift - 1);
586                         int16_t size = plane == 0 ? 1 << c->tile_shift : 1 << (c->tile_shift - 1);
587                         int16_t mx = plane == 0 ? mv.x : mv.x / 2;
588                         int16_t my = plane == 0 ? mv.y : mv.y / 2;
589 
590                         ret = copy_block(avctx, c->pic, c->prev, plane, x, y, mx, my, size);
591                         if (ret < 0)
592                             mb_ret = ret;
593                     }
594                 } else {
595                     int x = i << c->tile_shift;
596                     int y = j << c->tile_shift;
597                     int size = 1 << c->tile_shift;
598                     TileInfo *tile;
599                     MV mv, cmv;
600 
601                     tile = decode_tile_info(&c->gb, &lev[0], 0); // Y
602                     if (!tile)
603                         return AVERROR(ENOMEM);
604                     mv = mvi_predict(&c->mvi, i, j, tile->mv);
605                     ret = restore_tree(avctx, c->pic, c->prev, 0, x, y, size, tile, mv);
606                     if (ret < 0)
607                         mb_ret = ret;
608                     x = i << (c->tile_shift - 1);
609                     y = j << (c->tile_shift - 1);
610                     size = 1 << (c->tile_shift - 1);
611                     cmv.x = mv.x + tile->mv.x;
612                     cmv.y = mv.y + tile->mv.y;
613                     cmv.x /= 2;
614                     cmv.y /= 2;
615                     av_freep(&tile);
616                     tile = decode_tile_info(&c->gb, &lev[4], 0); // U
617                     if (!tile)
618                         return AVERROR(ENOMEM);
619                     ret = restore_tree(avctx, c->pic, c->prev, 1, x, y, size, tile, cmv);
620                     if (ret < 0)
621                         mb_ret = ret;
622                     av_freep(&tile);
623                     tile = decode_tile_info(&c->gb, &lev[7], 0); // V
624                     if (!tile)
625                         return AVERROR(ENOMEM);
626                     ret = restore_tree(avctx, c->pic, c->prev, 2, x, y, size, tile, cmv);
627                     if (ret < 0)
628                         mb_ret = ret;
629                     av_freep(&tile);
630                 }
631             }
632             mvi_update_row(&c->mvi);
633         }
634         extend_edges(c->pic, c->tile_size);
635 
636         c->pic->key_frame = 0;
637         c->pic->pict_type = AV_PICTURE_TYPE_P;
638     }
639 
640     if ((ret = av_frame_ref(data, c->pic)) < 0)
641         return ret;
642 
643     FFSWAP(AVFrame *, c->pic, c->prev);
644 
645     *got_frame = 1;
646 
647     if (get_bits_left(&c->gb) < 0)
648         av_log(c->avctx, AV_LOG_WARNING, "overread %d\n", -get_bits_left(&c->gb));
649 
650     return mb_ret < 0 ? mb_ret : buf_size;
651 }
652 
build_vlc(VLC * vlc,const uint8_t counts[16],const uint16_t ** syms,unsigned * offset)653 static av_cold void build_vlc(VLC *vlc, const uint8_t counts[16],
654                               const uint16_t **syms, unsigned *offset)
655 {
656     uint8_t lens[MAX_VLC_ENTRIES];
657     unsigned num = 0;
658 
659     for (int i = 0; i < 16; i++) {
660         unsigned count = counts[i];
661         if (count == 255) /* Special case for Y_3 table */
662             count = 303;
663         for (count += num; num < count; num++)
664             lens[num] = i + 1;
665     }
666     vlc->table           = &vlc_buf[*offset];
667     vlc->table_allocated = FF_ARRAY_ELEMS(vlc_buf) - *offset;
668     ff_init_vlc_from_lengths(vlc, CLV_VLC_BITS, num, lens, 1,
669                              *syms, 2, 2, 0, INIT_VLC_STATIC_OVERLONG, NULL);
670     *syms += num;
671     *offset += vlc->table_size;
672 }
673 
clv_init_static(void)674 static av_cold void clv_init_static(void)
675 {
676     const uint16_t *mv_syms = clv_mv_syms, *bias_syms = clv_bias_syms;
677 
678     INIT_VLC_STATIC_FROM_LENGTHS(&dc_vlc, CLV_VLC_BITS, NUM_DC_CODES,
679                                  clv_dc_lens, 1,
680                                  clv_dc_syms, 1, 1, -63, 0, 1104);
681     INIT_VLC_STATIC_FROM_LENGTHS(&ac_vlc, CLV_VLC_BITS, NUM_AC_CODES,
682                                  clv_ac_bits, 1,
683                                  clv_ac_syms, 2, 2, 0, 0, 554);
684     for (unsigned i = 0, j = 0, k = 0, offset = 0;; i++) {
685         if (0x36F & (1 << i)) {
686             build_vlc(&lev[i].mv_cb, clv_mv_len_counts[k], &mv_syms, &offset);
687             k++;
688         }
689         if (i == FF_ARRAY_ELEMS(lev) - 1)
690             break;
691         if (0x1B7 & (1 << i)) {
692             lev[i].flags_cb.table           = &vlc_buf[offset];
693             lev[i].flags_cb.table_allocated = FF_ARRAY_ELEMS(vlc_buf) - offset;
694             ff_init_vlc_from_lengths(&lev[i].flags_cb, CLV_VLC_BITS, 16,
695                                      clv_flags_bits[j], 1,
696                                      clv_flags_syms[j], 1, 1,
697                                      0, INIT_VLC_STATIC_OVERLONG, NULL);
698             offset += lev[i].flags_cb.table_size;
699 
700             build_vlc(&lev[i + 1].bias_cb, clv_bias_len_counts[j],
701                       &bias_syms, &offset);
702             j++;
703         }
704     }
705 }
706 
clv_decode_init(AVCodecContext * avctx)707 static av_cold int clv_decode_init(AVCodecContext *avctx)
708 {
709     static AVOnce init_static_once = AV_ONCE_INIT;
710     CLVContext *const c = avctx->priv_data;
711     int ret, w, h;
712 
713     if (avctx->extradata_size == 110) {
714         c->tile_size = AV_RL32(&avctx->extradata[94]);
715     } else if (avctx->extradata_size == 150) {
716         c->tile_size = AV_RB32(&avctx->extradata[134]);
717     } else if (!avctx->extradata_size) {
718         c->tile_size = 16;
719     } else {
720         av_log(avctx, AV_LOG_ERROR, "Unsupported extradata size: %d\n", avctx->extradata_size);
721         return AVERROR_INVALIDDATA;
722     }
723 
724     c->tile_shift = av_log2(c->tile_size);
725     if (1U << c->tile_shift != c->tile_size || c->tile_shift < 1 || c->tile_shift > 30) {
726         av_log(avctx, AV_LOG_ERROR, "Tile size: %d, is not power of 2 > 1 and < 2^31\n", c->tile_size);
727         return AVERROR_INVALIDDATA;
728     }
729 
730     avctx->pix_fmt = AV_PIX_FMT_YUV420P;
731     w = avctx->width;
732     h = avctx->height;
733     ret = ff_set_dimensions(avctx, FFALIGN(w, 1 << c->tile_shift), FFALIGN(h, 1 << c->tile_shift));
734     if (ret < 0)
735         return ret;
736     avctx->width  = w;
737     avctx->height = h;
738 
739     c->avctx           = avctx;
740     c->mb_width        = FFALIGN(avctx->width,  16) >> 4;
741     c->mb_height       = FFALIGN(avctx->height, 16) >> 4;
742     c->pmb_width       = (w + c->tile_size - 1) >> c->tile_shift;
743     c->pmb_height      = (h + c->tile_size - 1) >> c->tile_shift;
744     c->pic             = av_frame_alloc();
745     c->prev            = av_frame_alloc();
746     c->mvi.mv          = av_calloc(c->pmb_width * 2, sizeof(*c->mvi.mv));
747     if (!c->pic || !c->prev || !c->mvi.mv)
748         return AVERROR(ENOMEM);
749 
750     ff_idctdsp_init(&c->idsp, avctx);
751 
752     ff_thread_once(&init_static_once, clv_init_static);
753 
754     return 0;
755 }
756 
clv_decode_end(AVCodecContext * avctx)757 static av_cold int clv_decode_end(AVCodecContext *avctx)
758 {
759     CLVContext *const c = avctx->priv_data;
760 
761     av_frame_free(&c->prev);
762     av_frame_free(&c->pic);
763 
764     av_freep(&c->mvi.mv);
765 
766     return 0;
767 }
768 
769 AVCodec ff_clearvideo_decoder = {
770     .name           = "clearvideo",
771     .long_name      = NULL_IF_CONFIG_SMALL("Iterated Systems ClearVideo"),
772     .type           = AVMEDIA_TYPE_VIDEO,
773     .id             = AV_CODEC_ID_CLEARVIDEO,
774     .priv_data_size = sizeof(CLVContext),
775     .init           = clv_decode_init,
776     .close          = clv_decode_end,
777     .decode         = clv_decode_frame,
778     .capabilities   = AV_CODEC_CAP_DR1,
779     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
780 };
781