FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/h261dec.c
Date: 2025-03-08 20:38:41
Exec Total Coverage
Lines: 239 294 81.3%
Functions: 11 11 100.0%
Branches: 108 158 68.4%
Line Branch Exec Source
1 /*
2 * H.261 decoder
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
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 * H.261 decoder.
26 */
27
28 #include "libavutil/avassert.h"
29 #include "libavutil/thread.h"
30 #include "avcodec.h"
31 #include "codec_internal.h"
32 #include "decode.h"
33 #include "mpeg_er.h"
34 #include "mpegutils.h"
35 #include "mpegvideo.h"
36 #include "mpegvideodec.h"
37 #include "h261.h"
38
39 #define H261_MBA_VLC_BITS 8
40 #define H261_MTYPE_VLC_BITS 6
41 #define H261_MV_VLC_BITS 7
42 #define H261_CBP_VLC_BITS 9
43 #define TCOEFF_VLC_BITS 9
44 #define MBA_STUFFING 33
45 #define MBA_STARTCODE 34
46
47 static VLCElem h261_mba_vlc[540];
48 static VLCElem h261_mtype_vlc[80];
49 static VLCElem h261_mv_vlc[144];
50 static VLCElem h261_cbp_vlc[512];
51
52 typedef struct H261DecContext {
53 MpegEncContext s;
54
55 H261Context common;
56
57 int current_mba;
58 int mba_diff;
59 int current_mv_x;
60 int current_mv_y;
61 int gob_number;
62 int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read
63 } H261DecContext;
64
65 7 static av_cold void h261_decode_init_static(void)
66 {
67 7 VLC_INIT_STATIC_TABLE(h261_mba_vlc, H261_MBA_VLC_BITS, 35,
68 ff_h261_mba_bits, 1, 1,
69 ff_h261_mba_code, 1, 1, 0);
70 7 VLC_INIT_STATIC_SPARSE_TABLE(h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
71 ff_h261_mtype_bits, 1, 1,
72 ff_h261_mtype_code, 1, 1,
73 ff_h261_mtype_map, 2, 2, 0);
74 7 VLC_INIT_STATIC_TABLE(h261_mv_vlc, H261_MV_VLC_BITS, 17,
75 &ff_h261_mv_tab[0][1], 2, 1,
76 &ff_h261_mv_tab[0][0], 2, 1, 0);
77 7 VLC_INIT_STATIC_TABLE(h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
78 &ff_h261_cbp_tab[0][1], 2, 1,
79 &ff_h261_cbp_tab[0][0], 2, 1, 0);
80 7 INIT_FIRST_VLC_RL(ff_h261_rl_tcoeff, 552);
81 7 }
82
83 13 static av_cold int h261_decode_init(AVCodecContext *avctx)
84 {
85 static AVOnce init_static_once = AV_ONCE_INIT;
86 13 H261DecContext *const h = avctx->priv_data;
87 13 MpegEncContext *const s = &h->s;
88 int ret;
89
90 13 avctx->framerate = (AVRational) { 30000, 1001 };
91
92 13 s->private_ctx = &h->common;
93 // set defaults
94 13 ret = ff_mpv_decode_init(s, avctx);
95
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 13 if (ret < 0)
96 ✗ return ret;
97
98 13 s->out_format = FMT_H261;
99 13 s->low_delay = 1;
100 13 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
101
102 13 ff_thread_once(&init_static_once, h261_decode_init_static);
103
104 13 return 0;
105 }
106
107 118800 static inline void h261_init_dest(MpegEncContext *s)
108 {
109 118800 const unsigned block_size = 8 >> s->avctx->lowres;
110 118800 ff_init_block_index(s);
111 118800 s->dest[0] += 2 * block_size;
112 118800 s->dest[1] += block_size;
113 118800 s->dest[2] += block_size;
114 118800 }
115
116 /**
117 * Decode the group of blocks header or slice header.
118 * @return <0 if an error occurred
119 */
120 3600 static int h261_decode_gob_header(H261DecContext *h)
121 {
122 unsigned int val;
123 3600 MpegEncContext *const s = &h->s;
124
125
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 3600 if (!h->gob_start_code_skipped) {
126 /* Check for GOB Start Code */
127 300 val = show_bits(&s->gb, 15);
128
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 300 if (val)
129 ✗ return -1;
130
131 /* We have a GBSC */
132 300 skip_bits(&s->gb, 16);
133 }
134
135 3600 h->gob_start_code_skipped = 0;
136
137 3600 h->gob_number = get_bits(&s->gb, 4); /* GN */
138 3600 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
139
140 /* Check if gob_number is valid */
141
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 3600 if (s->mb_height == 18) { // CIF
142
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 3600 if ((h->gob_number <= 0) || (h->gob_number > 12))
143 ✗ return -1;
144 } else { // QCIF
145 ✗ if ((h->gob_number != 1) && (h->gob_number != 3) &&
146 ✗ (h->gob_number != 5))
147 ✗ return -1;
148 }
149
150 /* GEI */
151
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 3600 if (skip_1stop_8data_bits(&s->gb) < 0)
152 ✗ return AVERROR_INVALIDDATA;
153
154
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 3600 if (s->qscale == 0) {
155 ✗ av_log(s->avctx, AV_LOG_ERROR, "qscale has forbidden 0 value\n");
156 ✗ if (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
157 ✗ return -1;
158 ✗ s->qscale = 1;
159 }
160
161 /* For the first transmitted macroblock in a GOB, MBA is the absolute
162 * address. For subsequent macroblocks, MBA is the difference between
163 * the absolute addresses of the macroblock and the last transmitted
164 * macroblock. */
165 3600 h->current_mba = 0;
166 3600 h->mba_diff = 0;
167
168 3600 return 0;
169 }
170
171 /**
172 * Decode skipped macroblocks.
173 * @return 0
174 */
175 121541 static int h261_decode_mb_skipped(H261DecContext *h, int mba1, int mba2)
176 {
177 121541 MpegEncContext *const s = &h->s;
178 int i;
179
180 121541 s->mb_intra = 0;
181
182
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 122400 for (i = mba1; i < mba2; i++) {
183 int j, xy;
184
185 859 s->mb_x = ((h->gob_number - 1) % 2) * 11 + i % 11;
186 859 s->mb_y = ((h->gob_number - 1) / 2) * 3 + i / 11;
187 859 xy = s->mb_x + s->mb_y * s->mb_stride;
188 859 h261_init_dest(s);
189
190
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 6013 for (j = 0; j < 6; j++)
191 5154 s->block_last_index[j] = -1;
192
193 859 s->mv_dir = MV_DIR_FORWARD;
194 859 s->mv_type = MV_TYPE_16X16;
195 859 s->cur_pic.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
196 859 s->mv[0][0][0] = 0;
197 859 s->mv[0][0][1] = 0;
198 859 s->mb_skipped = 1;
199 859 h->common.mtype &= ~MB_TYPE_H261_FIL;
200
201
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 859 if (s->cur_pic.motion_val[0]) {
202 ✗ int b_stride = 2*s->mb_width + 1;
203 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
204 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
205 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
206 }
207
208 859 ff_mpv_reconstruct_mb(s, s->block);
209 }
210
211 121541 return 0;
212 }
213
214 198948 static int decode_mv_component(GetBitContext *gb, int v)
215 {
216 198948 int mv_diff = get_vlc2(gb, h261_mv_vlc, H261_MV_VLC_BITS, 2);
217
218 /* check if mv_diff is valid */
219
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 198948 if (mv_diff < 0)
220 ✗ return v;
221
222
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 198948 if (mv_diff && get_bits1(gb))
223 45885 mv_diff = -mv_diff;
224
225 198948 v += mv_diff;
226
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 198948 if (v <= -16)
227 32 v += 32;
228
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 198916 else if (v >= 16)
229 35 v -= 32;
230
231 198948 return v;
232 }
233
234 /**
235 * Decode a macroblock.
236 * @return <0 if an error occurred
237 */
238 591000 static int h261_decode_block(H261DecContext *h, int16_t *block, int n, int coded)
239 {
240 591000 MpegEncContext *const s = &h->s;
241 int level, i, j, run;
242 591000 const RLTable *rl = &ff_h261_rl_tcoeff;
243 const uint8_t *scan_table;
244 591000 const int qmul = s->qscale << 1, qadd = (s->qscale - 1) | 1;
245
246 /* For the variable length encoding there are two code tables, one being
247 * used for the first transmitted LEVEL in INTER, INTER + MC and
248 * INTER + MC + FIL blocks, the second for all other LEVELs except the
249 * first one in INTRA blocks which is fixed length coded with 8 bits.
250 * NOTE: The two code tables only differ in one VLC so we handle that
251 * manually. */
252 591000 scan_table = s->intra_scantable.permutated;
253
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 591000 if (s->mb_intra) {
254 /* DC coef */
255 101472 level = get_bits(&s->gb, 8);
256 // 0 (00000000b) and -128 (10000000b) are FORBIDDEN
257
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 101472 if ((level & 0x7F) == 0) {
258 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n",
259 level, s->mb_x, s->mb_y);
260 ✗ return -1;
261 }
262 /* The code 1000 0000 is not used, the reconstruction level of 1024
263 * being coded as 1111 1111. */
264
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 101472 if (level == 255)
265 1145 level = 128;
266 101472 block[0] = level * 8;
267 101472 i = 1;
268
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 489528 } else if (coded) {
269 // Run Level Code
270 // EOB Not possible for first level when cbp is available (that's why the table is different)
271 // 0 1 1s
272 // * * 0*
273 259485 int check = show_bits(&s->gb, 2);
274 259485 i = 0;
275
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 259485 if (check & 0x2) {
276 87589 skip_bits(&s->gb, 2);
277 87589 block[0] = qmul + qadd;
278
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 87589 block[0] *= (check & 0x1) ? -1 : 1;
279 87589 i = 1;
280 }
281 } else {
282 230043 i = 0;
283 }
284
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 591000 if (!coded) {
285 230043 s->block_last_index[n] = i - 1;
286 230043 return 0;
287 }
288 {
289 360957 OPEN_READER(re, &s->gb);
290 360957 i--; // offset by -1 to allow direct indexing of scan_table
291 for (;;) {
292 5175539 UPDATE_CACHE(re, &s->gb);
293
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 2768248 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TCOEFF_VLC_BITS, 2, 0);
294
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 2768248 if (run == 66) {
295
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 40537 if (level) {
296 ✗ CLOSE_READER(re, &s->gb);
297 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
298 s->mb_x, s->mb_y);
299 ✗ return -1;
300 }
301 /* escape */
302 /* The remaining combinations of (run, level) are encoded with a
303 * 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
304 * level. */
305 40537 run = SHOW_UBITS(re, &s->gb, 6) + 1;
306 40537 SKIP_CACHE(re, &s->gb, 6);
307 40537 level = SHOW_SBITS(re, &s->gb, 8);
308
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 40537 if (level > 0)
309 21553 level = level * qmul + qadd;
310
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 18984 else if (level < 0)
311 18984 level = level * qmul - qadd;
312 40537 SKIP_COUNTER(re, &s->gb, 6 + 8);
313
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 2727711 } else if (level == 0) {
314 360957 break;
315 } else {
316 2366754 level = level * qmul + qadd;
317
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 2366754 if (SHOW_UBITS(re, &s->gb, 1))
318 1184977 level = -level;
319 2366754 SKIP_COUNTER(re, &s->gb, 1);
320 }
321 2407291 i += run;
322
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 2407291 if (i >= 64) {
323 ✗ CLOSE_READER(re, &s->gb);
324 ✗ av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
325 s->mb_x, s->mb_y);
326 ✗ return -1;
327 }
328 2407291 j = scan_table[i];
329 2407291 block[j] = level;
330 }
331 360957 CLOSE_READER(re, &s->gb);
332 }
333 360957 s->block_last_index[n] = i;
334 360957 return 0;
335 }
336
337 121541 static int h261_decode_mb(H261DecContext *h)
338 {
339 121541 MpegEncContext *const s = &h->s;
340 121541 H261Context *const com = &h->common;
341 int i, cbp, xy;
342
343 121541 cbp = 63;
344 // Read mba
345 do {
346 121541 h->mba_diff = get_vlc2(&s->gb, h261_mba_vlc,
347 H261_MBA_VLC_BITS, 2);
348
349 /* Check for slice end */
350 /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */
351
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 121541 if (h->mba_diff == MBA_STARTCODE) { // start code
352 3300 h->gob_start_code_skipped = 1;
353 3300 return SLICE_END;
354 }
355
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 118241 } while (h->mba_diff == MBA_STUFFING); // stuffing
356
357
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 118241 if (h->mba_diff < 0) {
358
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 300 if (get_bits_left(&s->gb) <= 7)
359 300 return SLICE_END;
360
361 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y);
362 ✗ return SLICE_ERROR;
363 }
364
365 117941 h->mba_diff += 1;
366 117941 h->current_mba += h->mba_diff;
367
368
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 117941 if (h->current_mba > MBA_STUFFING)
369 ✗ return SLICE_ERROR;
370
371 117941 s->mb_x = ((h->gob_number - 1) % 2) * 11 + ((h->current_mba - 1) % 11);
372 117941 s->mb_y = ((h->gob_number - 1) / 2) * 3 + ((h->current_mba - 1) / 11);
373 117941 xy = s->mb_x + s->mb_y * s->mb_stride;
374 117941 h261_init_dest(s);
375
376 // Read mtype
377 117941 com->mtype = get_vlc2(&s->gb, h261_mtype_vlc, H261_MTYPE_VLC_BITS, 2);
378
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 117941 if (com->mtype < 0) {
379 ✗ av_log(s->avctx, AV_LOG_ERROR, "Invalid mtype index\n");
380 ✗ return SLICE_ERROR;
381 }
382
383 // Read mquant
384
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 117941 if (IS_QUANT(com->mtype)) {
385 ✗ s->qscale = get_bits(&s->gb, 5);
386 ✗ if (!s->qscale)
387 ✗ s->qscale = 1;
388 }
389
390 117941 s->mb_intra = IS_INTRA4x4(com->mtype);
391
392 // Read mv
393
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 117941 if (IS_16X16(com->mtype)) {
394 /* Motion vector data is included for all MC macroblocks. MVD is
395 * obtained from the macroblock vector by subtracting the vector
396 * of the preceding macroblock. For this calculation the vector
397 * of the preceding macroblock is regarded as zero in the
398 * following three situations:
399 * 1) evaluating MVD for macroblocks 1, 12 and 23;
400 * 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1;
401 * 3) MTYPE of the previous macroblock was not MC. */
402
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 99474 if ((h->current_mba == 1) || (h->current_mba == 12) ||
403
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 93760 (h->current_mba == 23) || (h->mba_diff != 1)) {
404 9175 h->current_mv_x = 0;
405 9175 h->current_mv_y = 0;
406 }
407
408 99474 h->current_mv_x = decode_mv_component(&s->gb, h->current_mv_x);
409 99474 h->current_mv_y = decode_mv_component(&s->gb, h->current_mv_y);
410 } else {
411 18467 h->current_mv_x = 0;
412 18467 h->current_mv_y = 0;
413 }
414
415 // Read cbp
416
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 117941 if (HAS_CBP(com->mtype))
417 81588 cbp = get_vlc2(&s->gb, h261_cbp_vlc, H261_CBP_VLC_BITS, 1) + 1;
418
419
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 117941 if (s->mb_intra) {
420 16912 s->cur_pic.mb_type[xy] = MB_TYPE_INTRA;
421 16912 goto intra;
422 }
423
424 //set motion vectors
425 101029 s->mv_dir = MV_DIR_FORWARD;
426 101029 s->mv_type = MV_TYPE_16X16;
427 101029 s->cur_pic.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
428 101029 s->mv[0][0][0] = h->current_mv_x * 2; // gets divided by 2 in motion compensation
429 101029 s->mv[0][0][1] = h->current_mv_y * 2;
430
431
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 101029 if (s->cur_pic.motion_val[0]) {
432 ✗ int b_stride = 2*s->mb_width + 1;
433 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
434 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
435 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
436 }
437
438 101029 intra:
439 /* decode each block */
440
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 117941 if (s->mb_intra || HAS_CBP(com->mtype)) {
441 98500 s->bdsp.clear_blocks(s->block[0]);
442
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 689500 for (i = 0; i < 6; i++) {
443
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 591000 if (h261_decode_block(h, s->block[i], i, cbp & 32) < 0)
444 ✗ return SLICE_ERROR;
445 591000 cbp += cbp;
446 }
447 } else {
448
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 136087 for (i = 0; i < 6; i++)
449 116646 s->block_last_index[i] = -1;
450 }
451
452 117941 ff_mpv_reconstruct_mb(s, s->block);
453
454 117941 return SLICE_OK;
455 }
456
457 /**
458 * Decode the H.261 picture header.
459 * @return <0 if no startcode found
460 */
461 300 static int h261_decode_picture_header(H261DecContext *h)
462 {
463 300 MpegEncContext *const s = &h->s;
464 int format, i;
465 300 uint32_t startcode = 0;
466
467
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 6000 for (i = get_bits_left(&s->gb); i > 24; i -= 1) {
468 6000 startcode = ((startcode << 1) | get_bits(&s->gb, 1)) & 0x000FFFFF;
469
470
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 6000 if (startcode == 0x10)
471 300 break;
472 }
473
474
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 300 if (startcode != 0x10) {
475 ✗ av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
476 ✗ return -1;
477 }
478
479 /* temporal reference */
480 300 skip_bits(&s->gb, 5); /* picture timestamp */
481
482 /* PTYPE starts here */
483 300 skip_bits1(&s->gb); /* split screen off */
484 300 skip_bits1(&s->gb); /* camera off */
485 300 skip_bits1(&s->gb); /* freeze picture release off */
486
487 300 format = get_bits1(&s->gb);
488
489 // only 2 formats possible
490
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 300 if (format == 0) { // QCIF
491 ✗ s->width = 176;
492 ✗ s->height = 144;
493 } else { // CIF
494 300 s->width = 352;
495 300 s->height = 288;
496 }
497
498 300 skip_bits1(&s->gb); /* still image mode off */
499 300 skip_bits1(&s->gb); /* Reserved */
500
501 /* PEI */
502
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 300 if (skip_1stop_8data_bits(&s->gb) < 0)
503 ✗ return AVERROR_INVALIDDATA;
504
505 /* H.261 has no I-frames, but if we pass AV_PICTURE_TYPE_I for the first
506 * frame, the codec crashes if it does not contain all I-blocks
507 * (e.g. when a packet is lost). */
508 300 s->pict_type = AV_PICTURE_TYPE_P;
509
510 300 h->gob_number = 0;
511 300 return 0;
512 }
513
514 3600 static int h261_decode_gob(H261DecContext *h)
515 {
516 3600 MpegEncContext *const s = &h->s;
517
518 /* decode mb's */
519
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520 int ret;
521 /* DCT & quantize */
522 121541 ret = h261_decode_mb(h);
523
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 121541 if (ret < 0) {
524
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 3600 if (ret == SLICE_END) {
525 3600 h261_decode_mb_skipped(h, h->current_mba, 33);
526 3600 return 0;
527 }
528 ✗ av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n",
529 ✗ s->mb_x + s->mb_y * s->mb_stride);
530 ✗ return -1;
531 }
532
533 117941 h261_decode_mb_skipped(h,
534 117941 h->current_mba - h->mba_diff,
535 117941 h->current_mba - 1);
536 }
537
538 ✗ return -1;
539 }
540
541 300 static int h261_decode_frame(AVCodecContext *avctx, AVFrame *pict,
542 int *got_frame, AVPacket *avpkt)
543 {
544 300 H261DecContext *const h = avctx->priv_data;
545 300 const uint8_t *buf = avpkt->data;
546 300 int buf_size = avpkt->size;
547 300 MpegEncContext *s = &h->s;
548 int ret;
549
550 ff_dlog(avctx, "*****frame %"PRId64" size=%d\n", avctx->frame_num, buf_size);
551 ff_dlog(avctx, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
552
553 300 h->gob_start_code_skipped = 0;
554
555 300 init_get_bits(&s->gb, buf, buf_size * 8);
556
557 300 ret = h261_decode_picture_header(h);
558
559 /* skip if the header was thrashed */
560
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 300 if (ret < 0) {
561 ✗ av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
562 ✗ return -1;
563 }
564
565
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 300 if (s->width != avctx->coded_width || s->height != avctx->coded_height) {
566 ✗ ff_mpv_common_end(s);
567 }
568
569
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 300 if (!s->context_initialized) {
570
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 6 if ((ret = ff_mpv_common_init(s)) < 0)
571 ✗ return ret;
572
573 6 ret = ff_set_dimensions(avctx, s->width, s->height);
574
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 6 if (ret < 0)
575 ✗ return ret;
576 }
577
578
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 300 if ((avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type != AV_PICTURE_TYPE_I) ||
579
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 300 avctx->skip_frame >= AVDISCARD_ALL)
580 ✗ return buf_size;
581
582
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 300 if (ff_mpv_frame_start(s, avctx) < 0)
583 ✗ return -1;
584
585 300 ff_mpeg_er_frame_start(s);
586
587 /* decode each macroblock */
588 300 s->mb_x = 0;
589 300 s->mb_y = 0;
590
591
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 3900 while (h->gob_number < (s->mb_height == 18 ? 12 : 5)) {
592
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 3600 if (h261_decode_gob_header(h) < 0)
593 ✗ break;
594 3600 h261_decode_gob(h);
595 }
596 300 ff_mpv_frame_end(s);
597
598
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 300 av_assert0(s->pict_type == s->cur_pic.ptr->f->pict_type);
599
600
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 300 if ((ret = av_frame_ref(pict, s->cur_pic.ptr->f)) < 0)
601 ✗ return ret;
602 300 ff_print_debug_info(s, s->cur_pic.ptr, pict);
603
604 300 *got_frame = 1;
605
606 300 return buf_size;
607 }
608
609 const FFCodec ff_h261_decoder = {
610 .p.name = "h261",
611 CODEC_LONG_NAME("H.261"),
612 .p.type = AVMEDIA_TYPE_VIDEO,
613 .p.id = AV_CODEC_ID_H261,
614 .priv_data_size = sizeof(H261DecContext),
615 .init = h261_decode_init,
616 FF_CODEC_DECODE_CB(h261_decode_frame),
617 .close = ff_mpv_decode_close,
618 .p.capabilities = AV_CODEC_CAP_DR1,
619 .p.max_lowres = 3,
620 };
621