FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/h261dec.c
Date: 2025-04-25 22:50:00
Exec Total Coverage
Lines: 241 296 81.4%
Functions: 11 11 100.0%
Branches: 109 158 69.0%
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/thread.h"
29 #include "avcodec.h"
30 #include "codec_internal.h"
31 #include "decode.h"
32 #include "mpeg_er.h"
33 #include "mpegutils.h"
34 #include "mpegvideo.h"
35 #include "mpegvideodec.h"
36 #include "h261.h"
37
38 #define H261_MBA_VLC_BITS 8
39 #define H261_MTYPE_VLC_BITS 6
40 #define H261_MV_VLC_BITS 7
41 #define H261_CBP_VLC_BITS 9
42 #define TCOEFF_VLC_BITS 9
43 #define MBA_STUFFING 33
44 #define MBA_STARTCODE 34
45
46 static VLCElem h261_mba_vlc[540];
47 static VLCElem h261_mtype_vlc[80];
48 static VLCElem h261_mv_vlc[144];
49 static VLCElem h261_cbp_vlc[512];
50
51 typedef struct H261DecContext {
52 MpegEncContext s;
53
54 H261Context common;
55
56 int current_mba;
57 int mba_diff;
58 int current_mv_x;
59 int current_mv_y;
60 int gob_number;
61 int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read
62 } H261DecContext;
63
64 7 static av_cold void h261_decode_init_static(void)
65 {
66 7 VLC_INIT_STATIC_TABLE(h261_mba_vlc, H261_MBA_VLC_BITS, 35,
67 ff_h261_mba_bits, 1, 1,
68 ff_h261_mba_code, 1, 1, 0);
69 7 VLC_INIT_STATIC_SPARSE_TABLE(h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
70 ff_h261_mtype_bits, 1, 1,
71 ff_h261_mtype_code, 1, 1,
72 ff_h261_mtype_map, 2, 2, 0);
73 7 VLC_INIT_STATIC_TABLE(h261_mv_vlc, H261_MV_VLC_BITS, 17,
74 &ff_h261_mv_tab[0][1], 2, 1,
75 &ff_h261_mv_tab[0][0], 2, 1, 0);
76 7 VLC_INIT_STATIC_TABLE(h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
77 &ff_h261_cbp_tab[0][1], 2, 1,
78 &ff_h261_cbp_tab[0][0], 2, 1, 0);
79 7 INIT_FIRST_VLC_RL(ff_h261_rl_tcoeff, 552);
80 7 }
81
82 13 static av_cold int h261_decode_init(AVCodecContext *avctx)
83 {
84 static AVOnce init_static_once = AV_ONCE_INIT;
85 13 H261DecContext *const h = avctx->priv_data;
86 13 MpegEncContext *const s = &h->s;
87 int ret;
88
89 13 avctx->framerate = (AVRational) { 30000, 1001 };
90
91 /* The H.261 analog of intra/key frames is setting the freeze picture release flag,
92 * but this does not guarantee that the frame uses intra-only encoding,
93 * so we still need to allocate dummy frames. So set pict_type to P here
94 * for all frames and override it after having decoded the frame. */
95 13 s->pict_type = AV_PICTURE_TYPE_P;
96
97 13 s->private_ctx = &h->common;
98 // set defaults
99 13 ret = ff_mpv_decode_init(s, avctx);
100
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 13 if (ret < 0)
101 ✗ return ret;
102
103 13 s->out_format = FMT_H261;
104 13 s->low_delay = 1;
105 13 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
106
107 13 ff_thread_once(&init_static_once, h261_decode_init_static);
108
109 13 return 0;
110 }
111
112 118800 static inline void h261_init_dest(MpegEncContext *s)
113 {
114 118800 const unsigned block_size = 8 >> s->avctx->lowres;
115 118800 ff_init_block_index(s);
116 118800 s->dest[0] += 2 * block_size;
117 118800 s->dest[1] += block_size;
118 118800 s->dest[2] += block_size;
119 118800 }
120
121 /**
122 * Decode the group of blocks header or slice header.
123 * @return <0 if an error occurred
124 */
125 3600 static int h261_decode_gob_header(H261DecContext *h)
126 {
127 unsigned int val;
128 3600 MpegEncContext *const s = &h->s;
129
130
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 3600 if (!h->gob_start_code_skipped) {
131 /* Check for GOB Start Code */
132 300 val = show_bits(&s->gb, 15);
133
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 300 if (val)
134 ✗ return -1;
135
136 /* We have a GBSC */
137 300 skip_bits(&s->gb, 16);
138 }
139
140 3600 h->gob_start_code_skipped = 0;
141
142 3600 h->gob_number = get_bits(&s->gb, 4); /* GN */
143 3600 s->qscale = get_bits(&s->gb, 5); /* GQUANT */
144
145 /* Check if gob_number is valid */
146
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 3600 if (s->mb_height == 18) { // CIF
147
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 3600 if ((h->gob_number <= 0) || (h->gob_number > 12))
148 ✗ return -1;
149 } else { // QCIF
150 ✗ if ((h->gob_number != 1) && (h->gob_number != 3) &&
151 ✗ (h->gob_number != 5))
152 ✗ return -1;
153 }
154
155 /* GEI */
156
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 3600 if (skip_1stop_8data_bits(&s->gb) < 0)
157 ✗ return AVERROR_INVALIDDATA;
158
159
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 3600 if (s->qscale == 0) {
160 ✗ av_log(s->avctx, AV_LOG_ERROR, "qscale has forbidden 0 value\n");
161 ✗ if (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
162 ✗ return -1;
163 ✗ s->qscale = 1;
164 }
165
166 /* For the first transmitted macroblock in a GOB, MBA is the absolute
167 * address. For subsequent macroblocks, MBA is the difference between
168 * the absolute addresses of the macroblock and the last transmitted
169 * macroblock. */
170 3600 h->current_mba = 0;
171 3600 h->mba_diff = 0;
172
173 3600 return 0;
174 }
175
176 /**
177 * Decode skipped macroblocks.
178 * @return 0
179 */
180 121541 static int h261_decode_mb_skipped(H261DecContext *h, int mba1, int mba2)
181 {
182 121541 MpegEncContext *const s = &h->s;
183 int i;
184
185 121541 s->mb_intra = 0;
186
187
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 122400 for (i = mba1; i < mba2; i++) {
188 int j, xy;
189
190 859 s->mb_x = ((h->gob_number - 1) % 2) * 11 + i % 11;
191 859 s->mb_y = ((h->gob_number - 1) / 2) * 3 + i / 11;
192 859 xy = s->mb_x + s->mb_y * s->mb_stride;
193 859 h261_init_dest(s);
194
195
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 6013 for (j = 0; j < 6; j++)
196 5154 s->block_last_index[j] = -1;
197
198 859 s->mv_dir = MV_DIR_FORWARD;
199 859 s->mv_type = MV_TYPE_16X16;
200 859 s->cur_pic.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
201 859 s->mv[0][0][0] = 0;
202 859 s->mv[0][0][1] = 0;
203 859 s->mb_skipped = 1;
204 859 h->common.mtype &= ~MB_TYPE_H261_FIL;
205
206
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 859 if (s->cur_pic.motion_val[0]) {
207 ✗ int b_stride = 2*s->mb_width + 1;
208 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
209 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
210 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
211 }
212
213 859 ff_mpv_reconstruct_mb(s, s->block);
214 }
215
216 121541 return 0;
217 }
218
219 198948 static int decode_mv_component(GetBitContext *gb, int v)
220 {
221 198948 int mv_diff = get_vlc2(gb, h261_mv_vlc, H261_MV_VLC_BITS, 2);
222
223 /* check if mv_diff is valid */
224
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 198948 if (mv_diff < 0)
225 ✗ return v;
226
227
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 198948 if (mv_diff && get_bits1(gb))
228 45885 mv_diff = -mv_diff;
229
230 198948 v += mv_diff;
231
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 198948 if (v <= -16)
232 32 v += 32;
233
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 198916 else if (v >= 16)
234 35 v -= 32;
235
236 198948 return v;
237 }
238
239 /**
240 * Decode a macroblock.
241 * @return <0 if an error occurred
242 */
243 591000 static int h261_decode_block(H261DecContext *h, int16_t *block, int n, int coded)
244 {
245 591000 MpegEncContext *const s = &h->s;
246 int level, i, j, run;
247 591000 const RLTable *rl = &ff_h261_rl_tcoeff;
248 const uint8_t *scan_table;
249 591000 const int qmul = s->qscale << 1, qadd = (s->qscale - 1) | 1;
250
251 /* For the variable length encoding there are two code tables, one being
252 * used for the first transmitted LEVEL in INTER, INTER + MC and
253 * INTER + MC + FIL blocks, the second for all other LEVELs except the
254 * first one in INTRA blocks which is fixed length coded with 8 bits.
255 * NOTE: The two code tables only differ in one VLC so we handle that
256 * manually. */
257 591000 scan_table = s->intra_scantable.permutated;
258
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 591000 if (s->mb_intra) {
259 /* DC coef */
260 101472 level = get_bits(&s->gb, 8);
261 // 0 (00000000b) and -128 (10000000b) are FORBIDDEN
262
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 101472 if ((level & 0x7F) == 0) {
263 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n",
264 level, s->mb_x, s->mb_y);
265 ✗ return -1;
266 }
267 /* The code 1000 0000 is not used, the reconstruction level of 1024
268 * being coded as 1111 1111. */
269
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 101472 if (level == 255)
270 1145 level = 128;
271 101472 block[0] = level * 8;
272 101472 i = 1;
273
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 489528 } else if (coded) {
274 // Run Level Code
275 // EOB Not possible for first level when cbp is available (that's why the table is different)
276 // 0 1 1s
277 // * * 0*
278 259485 int check = show_bits(&s->gb, 2);
279 259485 i = 0;
280
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 259485 if (check & 0x2) {
281 87589 skip_bits(&s->gb, 2);
282 87589 block[0] = qmul + qadd;
283
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 87589 block[0] *= (check & 0x1) ? -1 : 1;
284 87589 i = 1;
285 }
286 } else {
287 230043 i = 0;
288 }
289
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 591000 if (!coded) {
290 230043 s->block_last_index[n] = i - 1;
291 230043 return 0;
292 }
293 {
294 360957 OPEN_READER(re, &s->gb);
295 360957 i--; // offset by -1 to allow direct indexing of scan_table
296 for (;;) {
297 5175539 UPDATE_CACHE(re, &s->gb);
298
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 2768248 GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TCOEFF_VLC_BITS, 2, 0);
299
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 2768248 if (run == 66) {
300
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 40537 if (level) {
301 ✗ CLOSE_READER(re, &s->gb);
302 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
303 s->mb_x, s->mb_y);
304 ✗ return -1;
305 }
306 /* escape */
307 /* The remaining combinations of (run, level) are encoded with a
308 * 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
309 * level. */
310 40537 run = SHOW_UBITS(re, &s->gb, 6) + 1;
311 40537 SKIP_CACHE(re, &s->gb, 6);
312 40537 level = SHOW_SBITS(re, &s->gb, 8);
313
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 40537 if (level > 0)
314 21553 level = level * qmul + qadd;
315
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 18984 else if (level < 0)
316 18984 level = level * qmul - qadd;
317 40537 SKIP_COUNTER(re, &s->gb, 6 + 8);
318
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 2727711 } else if (level == 0) {
319 360957 break;
320 } else {
321 2366754 level = level * qmul + qadd;
322
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 2366754 if (SHOW_UBITS(re, &s->gb, 1))
323 1184977 level = -level;
324 2366754 SKIP_COUNTER(re, &s->gb, 1);
325 }
326 2407291 i += run;
327
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 2407291 if (i >= 64) {
328 ✗ CLOSE_READER(re, &s->gb);
329 ✗ av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
330 s->mb_x, s->mb_y);
331 ✗ return -1;
332 }
333 2407291 j = scan_table[i];
334 2407291 block[j] = level;
335 }
336 360957 CLOSE_READER(re, &s->gb);
337 }
338 360957 s->block_last_index[n] = i;
339 360957 return 0;
340 }
341
342 121541 static int h261_decode_mb(H261DecContext *h)
343 {
344 121541 MpegEncContext *const s = &h->s;
345 121541 H261Context *const com = &h->common;
346 int i, cbp, xy;
347
348 121541 cbp = 63;
349 // Read mba
350 do {
351 121541 h->mba_diff = get_vlc2(&s->gb, h261_mba_vlc,
352 H261_MBA_VLC_BITS, 2);
353
354 /* Check for slice end */
355 /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */
356
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 121541 if (h->mba_diff == MBA_STARTCODE) { // start code
357 3300 h->gob_start_code_skipped = 1;
358 3300 return SLICE_END;
359 }
360
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 118241 } while (h->mba_diff == MBA_STUFFING); // stuffing
361
362
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 118241 if (h->mba_diff < 0) {
363
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 300 if (get_bits_left(&s->gb) <= 7)
364 300 return SLICE_END;
365
366 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y);
367 ✗ return SLICE_ERROR;
368 }
369
370 117941 h->mba_diff += 1;
371 117941 h->current_mba += h->mba_diff;
372
373
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 117941 if (h->current_mba > MBA_STUFFING)
374 ✗ return SLICE_ERROR;
375
376 117941 s->mb_x = ((h->gob_number - 1) % 2) * 11 + ((h->current_mba - 1) % 11);
377 117941 s->mb_y = ((h->gob_number - 1) / 2) * 3 + ((h->current_mba - 1) / 11);
378 117941 xy = s->mb_x + s->mb_y * s->mb_stride;
379 117941 h261_init_dest(s);
380
381 // Read mtype
382 117941 com->mtype = get_vlc2(&s->gb, h261_mtype_vlc, H261_MTYPE_VLC_BITS, 2);
383
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 117941 if (com->mtype < 0) {
384 ✗ av_log(s->avctx, AV_LOG_ERROR, "Invalid mtype index\n");
385 ✗ return SLICE_ERROR;
386 }
387
388 // Read mquant
389
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 117941 if (IS_QUANT(com->mtype)) {
390 ✗ s->qscale = get_bits(&s->gb, 5);
391 ✗ if (!s->qscale)
392 ✗ s->qscale = 1;
393 }
394
395 117941 s->mb_intra = IS_INTRA4x4(com->mtype);
396
397 // Read mv
398
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 117941 if (IS_16X16(com->mtype)) {
399 /* Motion vector data is included for all MC macroblocks. MVD is
400 * obtained from the macroblock vector by subtracting the vector
401 * of the preceding macroblock. For this calculation the vector
402 * of the preceding macroblock is regarded as zero in the
403 * following three situations:
404 * 1) evaluating MVD for macroblocks 1, 12 and 23;
405 * 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1;
406 * 3) MTYPE of the previous macroblock was not MC. */
407
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 99474 if ((h->current_mba == 1) || (h->current_mba == 12) ||
408
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 93760 (h->current_mba == 23) || (h->mba_diff != 1)) {
409 9175 h->current_mv_x = 0;
410 9175 h->current_mv_y = 0;
411 }
412
413 99474 h->current_mv_x = decode_mv_component(&s->gb, h->current_mv_x);
414 99474 h->current_mv_y = decode_mv_component(&s->gb, h->current_mv_y);
415 } else {
416 18467 h->current_mv_x = 0;
417 18467 h->current_mv_y = 0;
418 }
419
420 // Read cbp
421
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 117941 if (HAS_CBP(com->mtype))
422 81588 cbp = get_vlc2(&s->gb, h261_cbp_vlc, H261_CBP_VLC_BITS, 1) + 1;
423
424
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 117941 if (s->mb_intra) {
425 16912 s->cur_pic.mb_type[xy] = MB_TYPE_INTRA;
426 16912 goto intra;
427 }
428
429 //set motion vectors
430 101029 s->mv_dir = MV_DIR_FORWARD;
431 101029 s->mv_type = MV_TYPE_16X16;
432 101029 s->cur_pic.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
433 101029 s->mv[0][0][0] = h->current_mv_x * 2; // gets divided by 2 in motion compensation
434 101029 s->mv[0][0][1] = h->current_mv_y * 2;
435
436
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 101029 if (s->cur_pic.motion_val[0]) {
437 ✗ int b_stride = 2*s->mb_width + 1;
438 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
439 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
440 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
441 }
442
443 101029 intra:
444 /* decode each block */
445
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 117941 if (s->mb_intra || HAS_CBP(com->mtype)) {
446 98500 s->bdsp.clear_blocks(s->block[0]);
447
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 689500 for (i = 0; i < 6; i++) {
448
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 591000 if (h261_decode_block(h, s->block[i], i, cbp & 32) < 0)
449 ✗ return SLICE_ERROR;
450 591000 cbp += cbp;
451 }
452 } else {
453
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 136087 for (i = 0; i < 6; i++)
454 116646 s->block_last_index[i] = -1;
455 }
456
457 117941 ff_mpv_reconstruct_mb(s, s->block);
458
459 117941 return SLICE_OK;
460 }
461
462 /**
463 * Decode the H.261 picture header.
464 * @return <0 if no startcode found
465 */
466 300 static int h261_decode_picture_header(H261DecContext *h, int *is_key)
467 {
468 300 MpegEncContext *const s = &h->s;
469 int format, i;
470 300 uint32_t startcode = 0;
471
472
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 6000 for (i = get_bits_left(&s->gb); i > 24; i -= 1) {
473 6000 startcode = ((startcode << 1) | get_bits(&s->gb, 1)) & 0x000FFFFF;
474
475
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 6000 if (startcode == 0x10)
476 300 break;
477 }
478
479
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 300 if (startcode != 0x10) {
480 ✗ av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
481 ✗ return -1;
482 }
483
484 /* temporal reference */
485 300 skip_bits(&s->gb, 5); /* picture timestamp */
486
487 /* PTYPE starts here */
488 300 skip_bits1(&s->gb); /* split screen off */
489 300 skip_bits1(&s->gb); /* camera off */
490 300 *is_key = get_bits1(&s->gb); /* freeze picture release off */
491
492 300 format = get_bits1(&s->gb);
493
494 // only 2 formats possible
495
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 300 if (format == 0) { // QCIF
496 ✗ s->width = 176;
497 ✗ s->height = 144;
498 } else { // CIF
499 300 s->width = 352;
500 300 s->height = 288;
501 }
502
503 300 skip_bits1(&s->gb); /* still image mode off */
504 300 skip_bits1(&s->gb); /* Reserved */
505
506 /* PEI */
507
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 300 if (skip_1stop_8data_bits(&s->gb) < 0)
508 ✗ return AVERROR_INVALIDDATA;
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, is_key;
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, &is_key);
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_NONINTRA && !is_key) ||
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 if (is_key) {
599 30 s->cur_pic.ptr->f->pict_type = AV_PICTURE_TYPE_I;
600 30 s->cur_pic.ptr->f->flags |= AV_FRAME_FLAG_KEY;
601 }
602
603
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 300 if ((ret = av_frame_ref(pict, s->cur_pic.ptr->f)) < 0)
604 ✗ return ret;
605 300 ff_print_debug_info(s, s->cur_pic.ptr, pict);
606
607 300 *got_frame = 1;
608
609 300 return buf_size;
610 }
611
612 const FFCodec ff_h261_decoder = {
613 .p.name = "h261",
614 CODEC_LONG_NAME("H.261"),
615 .p.type = AVMEDIA_TYPE_VIDEO,
616 .p.id = AV_CODEC_ID_H261,
617 .priv_data_size = sizeof(H261DecContext),
618 .init = h261_decode_init,
619 FF_CODEC_DECODE_CB(h261_decode_frame),
620 .close = ff_mpv_decode_close,
621 .p.capabilities = AV_CODEC_CAP_DR1,
622 .p.max_lowres = 3,
623 .caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
624 };
625