FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/h261dec.c
Date: 2026-01-23 19:11:46
Exec Total Coverage
Lines: 239 294 81.3%
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/mem_internal.h"
29 #include "libavutil/thread.h"
30 #include "avcodec.h"
31 #include "codec_internal.h"
32 #include "decode.h"
33 #include "get_bits.h"
34 #include "mpeg_er.h"
35 #include "mpegutils.h"
36 #include "mpegvideo.h"
37 #include "mpegvideodec.h"
38 #include "h261.h"
39
40 #define SLICE_OK 0
41 #define SLICE_ERROR -1
42 #define SLICE_END -2 ///<end marker found
43
44 #define H261_MBA_VLC_BITS 8
45 #define H261_MTYPE_VLC_BITS 6
46 #define H261_MV_VLC_BITS 7
47 #define H261_CBP_VLC_BITS 9
48 #define TCOEFF_VLC_BITS 9
49 #define MBA_STUFFING 33
50 #define MBA_STARTCODE 34
51
52 static VLCElem h261_mba_vlc[540];
53 static VLCElem h261_mtype_vlc[80];
54 static VLCElem h261_mv_vlc[144];
55 static VLCElem h261_cbp_vlc[512];
56
57 typedef struct H261DecContext {
58 MpegEncContext s;
59
60 GetBitContext gb;
61
62 int current_mba;
63 int mba_diff;
64 int current_mv_x;
65 int current_mv_y;
66 int gob_number;
67 int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read
68
69 DECLARE_ALIGNED_32(int16_t, block)[6][64];
70 } H261DecContext;
71
72 7 static av_cold void h261_decode_init_static(void)
73 {
74 7 VLC_INIT_STATIC_TABLE(h261_mba_vlc, H261_MBA_VLC_BITS, 35,
75 ff_h261_mba_bits, 1, 1,
76 ff_h261_mba_code, 1, 1, 0);
77 7 VLC_INIT_STATIC_SPARSE_TABLE(h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
78 ff_h261_mtype_bits, 1, 1,
79 ff_h261_mtype_code, 1, 1,
80 ff_h261_mtype_map, 2, 2, 0);
81 7 VLC_INIT_STATIC_TABLE(h261_mv_vlc, H261_MV_VLC_BITS, 17,
82 &ff_h261_mv_tab[0][1], 2, 1,
83 &ff_h261_mv_tab[0][0], 2, 1, 0);
84 7 VLC_INIT_STATIC_TABLE(h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
85 &ff_h261_cbp_tab[0][1], 2, 1,
86 &ff_h261_cbp_tab[0][0], 2, 1, 0);
87 7 INIT_FIRST_VLC_RL(ff_h261_rl_tcoeff, 552);
88 7 }
89
90 13 static av_cold int h261_decode_init(AVCodecContext *avctx)
91 {
92 static AVOnce init_static_once = AV_ONCE_INIT;
93 13 H261DecContext *const h = avctx->priv_data;
94 13 MpegEncContext *const s = &h->s;
95 int ret;
96
97 13 avctx->framerate = (AVRational) { 30000, 1001 };
98
99 /* The H.261 analog of intra/key frames is setting the freeze picture release flag,
100 * but this does not guarantee that the frame uses intra-only encoding,
101 * so we still need to allocate dummy frames. So set pict_type to P here
102 * for all frames and override it after having decoded the frame. */
103 13 s->pict_type = AV_PICTURE_TYPE_P;
104
105 // set defaults
106 13 ret = ff_mpv_decode_init(s, avctx);
107
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 13 if (ret < 0)
108 ✗ return ret;
109
110 13 s->out_format = FMT_H261;
111 13 s->low_delay = 1;
112 13 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
113
114 13 ff_thread_once(&init_static_once, h261_decode_init_static);
115
116 13 return 0;
117 }
118
119 118800 static inline void h261_init_dest(MpegEncContext *s)
120 {
121 118800 const unsigned block_size = 8 >> s->avctx->lowres;
122 118800 ff_init_block_index(s);
123 118800 s->dest[0] += 2 * block_size;
124 118800 s->dest[1] += block_size;
125 118800 s->dest[2] += block_size;
126 118800 }
127
128 /**
129 * Decode the group of blocks header or slice header.
130 * @return <0 if an error occurred
131 */
132 3600 static int h261_decode_gob_header(H261DecContext *h)
133 {
134 unsigned int val;
135 3600 MpegEncContext *const s = &h->s;
136
137
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 3600 if (!h->gob_start_code_skipped) {
138 /* Check for GOB Start Code */
139 300 val = show_bits(&h->gb, 15);
140
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 300 if (val)
141 ✗ return -1;
142
143 /* We have a GBSC */
144 300 skip_bits(&h->gb, 16);
145 }
146
147 3600 h->gob_start_code_skipped = 0;
148
149 3600 h->gob_number = get_bits(&h->gb, 4); /* GN */
150 3600 s->qscale = get_bits(&h->gb, 5); /* GQUANT */
151
152 /* Check if gob_number is valid */
153
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 3600 if (s->mb_height == 18) { // CIF
154
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 3600 if ((h->gob_number <= 0) || (h->gob_number > 12))
155 ✗ return -1;
156 } else { // QCIF
157 ✗ if ((h->gob_number != 1) && (h->gob_number != 3) &&
158 ✗ (h->gob_number != 5))
159 ✗ return -1;
160 }
161
162 /* GEI */
163
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 3600 if (skip_1stop_8data_bits(&h->gb) < 0)
164 ✗ return AVERROR_INVALIDDATA;
165
166
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 3600 if (s->qscale == 0) {
167 ✗ av_log(s->avctx, AV_LOG_ERROR, "qscale has forbidden 0 value\n");
168 ✗ if (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
169 ✗ return -1;
170 ✗ s->qscale = 1;
171 }
172
173 /* For the first transmitted macroblock in a GOB, MBA is the absolute
174 * address. For subsequent macroblocks, MBA is the difference between
175 * the absolute addresses of the macroblock and the last transmitted
176 * macroblock. */
177 3600 h->current_mba = 0;
178 3600 h->mba_diff = 0;
179
180 3600 return 0;
181 }
182
183 /**
184 * Decode skipped macroblocks.
185 * @return 0
186 */
187 121541 static int h261_decode_mb_skipped(H261DecContext *h, int mba1, int mba2)
188 {
189 121541 MpegEncContext *const s = &h->s;
190 int i;
191
192 121541 s->mb_intra = 0;
193
194
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 122400 for (i = mba1; i < mba2; i++) {
195 int j, xy;
196
197 859 s->mb_x = ((h->gob_number - 1) % 2) * 11 + i % 11;
198 859 s->mb_y = ((h->gob_number - 1) / 2) * 3 + i / 11;
199 859 xy = s->mb_x + s->mb_y * s->mb_stride;
200 859 h261_init_dest(s);
201
202
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 6013 for (j = 0; j < 6; j++)
203 5154 s->block_last_index[j] = -1;
204
205 859 s->mv_dir = MV_DIR_FORWARD;
206 859 s->mv_type = MV_TYPE_16X16;
207 859 s->cur_pic.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
208 859 s->mv[0][0][0] = 0;
209 859 s->mv[0][0][1] = 0;
210 859 s->mb_skipped = 1;
211 859 s->mtype &= ~MB_TYPE_H261_FIL;
212
213
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 859 if (s->cur_pic.motion_val[0]) {
214 ✗ int b_stride = 2*s->mb_width + 1;
215 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
216 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
217 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
218 }
219
220 859 ff_mpv_reconstruct_mb(s, h->block);
221 }
222
223 121541 return 0;
224 }
225
226 198948 static int decode_mv_component(GetBitContext *gb, int v)
227 {
228 198948 int mv_diff = get_vlc2(gb, h261_mv_vlc, H261_MV_VLC_BITS, 2);
229
230 /* check if mv_diff is valid */
231
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 198948 if (mv_diff < 0)
232 ✗ return v;
233
234
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 198948 if (mv_diff && get_bits1(gb))
235 45885 mv_diff = -mv_diff;
236
237 198948 v += mv_diff;
238
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 198948 if (v <= -16)
239 32 v += 32;
240
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 198916 else if (v >= 16)
241 35 v -= 32;
242
243 198948 return v;
244 }
245
246 /**
247 * Decode a macroblock.
248 * @return <0 if an error occurred
249 */
250 591000 static int h261_decode_block(H261DecContext *h, int16_t *block, int n, int coded)
251 {
252 591000 MpegEncContext *const s = &h->s;
253 int level, i, j, run;
254 591000 const RLTable *rl = &ff_h261_rl_tcoeff;
255 const uint8_t *scan_table;
256 591000 const int qmul = s->qscale << 1, qadd = (s->qscale - 1) | 1;
257
258 /* For the variable length encoding there are two code tables, one being
259 * used for the first transmitted LEVEL in INTER, INTER + MC and
260 * INTER + MC + FIL blocks, the second for all other LEVELs except the
261 * first one in INTRA blocks which is fixed length coded with 8 bits.
262 * NOTE: The two code tables only differ in one VLC so we handle that
263 * manually. */
264 591000 scan_table = s->intra_scantable.permutated;
265
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 591000 if (s->mb_intra) {
266 /* DC coef */
267 101472 level = get_bits(&h->gb, 8);
268 // 0 (00000000b) and -128 (10000000b) are FORBIDDEN
269
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 101472 if ((level & 0x7F) == 0) {
270 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n",
271 level, s->mb_x, s->mb_y);
272 ✗ return -1;
273 }
274 /* The code 1000 0000 is not used, the reconstruction level of 1024
275 * being coded as 1111 1111. */
276
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 101472 if (level == 255)
277 1145 level = 128;
278 101472 block[0] = level * 8;
279 101472 i = 1;
280
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 489528 } else if (coded) {
281 // Run Level Code
282 // EOB Not possible for first level when cbp is available (that's why the table is different)
283 // 0 1 1s
284 // * * 0*
285 259485 int check = show_bits(&h->gb, 2);
286 259485 i = 0;
287
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 259485 if (check & 0x2) {
288 87589 skip_bits(&h->gb, 2);
289 87589 block[0] = qmul + qadd;
290
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 87589 block[0] *= (check & 0x1) ? -1 : 1;
291 87589 i = 1;
292 }
293 } else {
294 230043 i = 0;
295 }
296
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 591000 if (!coded) {
297 230043 s->block_last_index[n] = i - 1;
298 230043 return 0;
299 }
300 {
301 360957 OPEN_READER(re, &h->gb);
302 360957 i--; // offset by -1 to allow direct indexing of scan_table
303 for (;;) {
304 5175539 UPDATE_CACHE(re, &h->gb);
305
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 2768248 GET_RL_VLC(level, run, re, &h->gb, rl->rl_vlc[0], TCOEFF_VLC_BITS, 2, 0);
306
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 2768248 if (run == 66) {
307
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 40537 if (level) {
308 ✗ CLOSE_READER(re, &h->gb);
309 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
310 s->mb_x, s->mb_y);
311 ✗ return -1;
312 }
313 /* escape */
314 /* The remaining combinations of (run, level) are encoded with a
315 * 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
316 * level. */
317 40537 run = SHOW_UBITS(re, &h->gb, 6) + 1;
318 40537 SKIP_CACHE(re, &h->gb, 6);
319 40537 level = SHOW_SBITS(re, &h->gb, 8);
320
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 40537 if (level > 0)
321 21553 level = level * qmul + qadd;
322
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 18984 else if (level < 0)
323 18984 level = level * qmul - qadd;
324 40537 SKIP_COUNTER(re, &h->gb, 6 + 8);
325
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 2727711 } else if (level == 0) {
326 360957 break;
327 } else {
328 2366754 level = level * qmul + qadd;
329
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 2366754 if (SHOW_UBITS(re, &h->gb, 1))
330 1184977 level = -level;
331 2366754 SKIP_COUNTER(re, &h->gb, 1);
332 }
333 2407291 i += run;
334
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 2407291 if (i >= 64) {
335 ✗ CLOSE_READER(re, &h->gb);
336 ✗ av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
337 s->mb_x, s->mb_y);
338 ✗ return -1;
339 }
340 2407291 j = scan_table[i];
341 2407291 block[j] = level;
342 }
343 360957 CLOSE_READER(re, &h->gb);
344 }
345 360957 s->block_last_index[n] = i;
346 360957 return 0;
347 }
348
349 121541 static int h261_decode_mb(H261DecContext *h)
350 {
351 121541 MpegEncContext *const s = &h->s;
352 int i, cbp, xy;
353
354 121541 cbp = 63;
355 // Read mba
356 do {
357 121541 h->mba_diff = get_vlc2(&h->gb, h261_mba_vlc,
358 H261_MBA_VLC_BITS, 2);
359
360 /* Check for slice end */
361 /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */
362
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 121541 if (h->mba_diff == MBA_STARTCODE) { // start code
363 3300 h->gob_start_code_skipped = 1;
364 3300 return SLICE_END;
365 }
366
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 118241 } while (h->mba_diff == MBA_STUFFING); // stuffing
367
368
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 118241 if (h->mba_diff < 0) {
369
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 300 if (get_bits_left(&h->gb) <= 7)
370 300 return SLICE_END;
371
372 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y);
373 ✗ return SLICE_ERROR;
374 }
375
376 117941 h->mba_diff += 1;
377 117941 h->current_mba += h->mba_diff;
378
379
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 117941 if (h->current_mba > MBA_STUFFING)
380 ✗ return SLICE_ERROR;
381
382 117941 s->mb_x = ((h->gob_number - 1) % 2) * 11 + ((h->current_mba - 1) % 11);
383 117941 s->mb_y = ((h->gob_number - 1) / 2) * 3 + ((h->current_mba - 1) / 11);
384 117941 xy = s->mb_x + s->mb_y * s->mb_stride;
385 117941 h261_init_dest(s);
386
387 // Read mtype
388 117941 s->mtype = get_vlc2(&h->gb, h261_mtype_vlc, H261_MTYPE_VLC_BITS, 2);
389
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 117941 if (s->mtype < 0) {
390 ✗ av_log(s->avctx, AV_LOG_ERROR, "Invalid mtype index\n");
391 ✗ return SLICE_ERROR;
392 }
393
394 // Read mquant
395
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 117941 if (IS_QUANT(s->mtype)) {
396 ✗ s->qscale = get_bits(&h->gb, 5);
397 ✗ if (!s->qscale)
398 ✗ s->qscale = 1;
399 }
400
401 117941 s->mb_intra = IS_INTRA4x4(s->mtype);
402
403 // Read mv
404
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 117941 if (IS_16X16(s->mtype)) {
405 /* Motion vector data is included for all MC macroblocks. MVD is
406 * obtained from the macroblock vector by subtracting the vector
407 * of the preceding macroblock. For this calculation the vector
408 * of the preceding macroblock is regarded as zero in the
409 * following three situations:
410 * 1) evaluating MVD for macroblocks 1, 12 and 23;
411 * 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1;
412 * 3) MTYPE of the previous macroblock was not MC. */
413
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 99474 if ((h->current_mba == 1) || (h->current_mba == 12) ||
414
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 93760 (h->current_mba == 23) || (h->mba_diff != 1)) {
415 9175 h->current_mv_x = 0;
416 9175 h->current_mv_y = 0;
417 }
418
419 99474 h->current_mv_x = decode_mv_component(&h->gb, h->current_mv_x);
420 99474 h->current_mv_y = decode_mv_component(&h->gb, h->current_mv_y);
421 } else {
422 18467 h->current_mv_x = 0;
423 18467 h->current_mv_y = 0;
424 }
425
426 // Read cbp
427
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 117941 if (HAS_CBP(s->mtype))
428 81588 cbp = get_vlc2(&h->gb, h261_cbp_vlc, H261_CBP_VLC_BITS, 1) + 1;
429
430
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 117941 if (s->mb_intra) {
431 16912 s->cur_pic.mb_type[xy] = MB_TYPE_INTRA;
432 16912 goto intra;
433 }
434
435 //set motion vectors
436 101029 s->mv_dir = MV_DIR_FORWARD;
437 101029 s->mv_type = MV_TYPE_16X16;
438 101029 s->cur_pic.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
439 101029 s->mv[0][0][0] = h->current_mv_x * 2; // gets divided by 2 in motion compensation
440 101029 s->mv[0][0][1] = h->current_mv_y * 2;
441
442
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 101029 if (s->cur_pic.motion_val[0]) {
443 ✗ int b_stride = 2*s->mb_width + 1;
444 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
445 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
446 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
447 }
448
449 101029 intra:
450 /* decode each block */
451
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 117941 if (s->mb_intra || HAS_CBP(s->mtype)) {
452 98500 s->bdsp.clear_blocks(h->block[0]);
453
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 689500 for (i = 0; i < 6; i++) {
454
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 591000 if (h261_decode_block(h, h->block[i], i, cbp & 32) < 0)
455 ✗ return SLICE_ERROR;
456 591000 cbp += cbp;
457 }
458 } else {
459
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 136087 for (i = 0; i < 6; i++)
460 116646 s->block_last_index[i] = -1;
461 }
462
463 117941 ff_mpv_reconstruct_mb(s, h->block);
464
465 117941 return SLICE_OK;
466 }
467
468 /**
469 * Decode the H.261 picture header.
470 * @return <0 if no startcode found
471 */
472 300 static int h261_decode_picture_header(H261DecContext *h, int *is_key)
473 {
474 300 MpegEncContext *const s = &h->s;
475 300 uint32_t startcode = 0;
476
477
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 6000 for (int i = get_bits_left(&h->gb); i > 24; i -= 1) {
478 6000 startcode = ((startcode << 1) | get_bits(&h->gb, 1)) & 0x000FFFFF;
479
480
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 6000 if (startcode == 0x10)
481 300 break;
482 }
483
484
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 300 if (startcode != 0x10) {
485 ✗ av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
486 ✗ return -1;
487 }
488
489 /* temporal reference */
490 300 skip_bits(&h->gb, 5); /* picture timestamp */
491
492 /* PTYPE starts here */
493 300 skip_bits1(&h->gb); /* split screen off */
494 300 skip_bits1(&h->gb); /* camera off */
495 300 *is_key = get_bits1(&h->gb); /* freeze picture release off */
496
497 300 int format = get_bits1(&h->gb);
498
499 // only 2 formats possible
500
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 300 if (format == 0) { // QCIF
501 ✗ s->width = 176;
502 ✗ s->height = 144;
503 } else { // CIF
504 300 s->width = 352;
505 300 s->height = 288;
506 }
507
508 300 skip_bits1(&h->gb); /* still image mode off */
509 300 skip_bits1(&h->gb); /* Reserved */
510
511 /* PEI */
512
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 300 if (skip_1stop_8data_bits(&h->gb) < 0)
513 ✗ return AVERROR_INVALIDDATA;
514
515 300 h->gob_number = 0;
516 300 return 0;
517 }
518
519 3600 static int h261_decode_gob(H261DecContext *h)
520 {
521 3600 MpegEncContext *const s = &h->s;
522
523 /* decode mb's */
524
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 121541 while (h->current_mba <= MBA_STUFFING) {
525 int ret;
526 /* DCT & quantize */
527 121541 ret = h261_decode_mb(h);
528
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 121541 if (ret < 0) {
529
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 3600 if (ret == SLICE_END) {
530 3600 h261_decode_mb_skipped(h, h->current_mba, 33);
531 3600 return 0;
532 }
533 ✗ av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n",
534 ✗ s->mb_x + s->mb_y * s->mb_stride);
535 ✗ return -1;
536 }
537
538 117941 h261_decode_mb_skipped(h,
539 117941 h->current_mba - h->mba_diff,
540 117941 h->current_mba - 1);
541 }
542
543 ✗ return -1;
544 }
545
546 300 static int h261_decode_frame(AVCodecContext *avctx, AVFrame *pict,
547 int *got_frame, AVPacket *avpkt)
548 {
549 300 H261DecContext *const h = avctx->priv_data;
550 300 const uint8_t *buf = avpkt->data;
551 300 int buf_size = avpkt->size;
552 300 MpegEncContext *s = &h->s;
553 int ret, is_key;
554
555 ff_dlog(avctx, "*****frame %"PRId64" size=%d\n", avctx->frame_num, buf_size);
556 ff_dlog(avctx, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
557
558 300 h->gob_start_code_skipped = 0;
559
560 300 init_get_bits(&h->gb, buf, buf_size * 8);
561
562 300 ret = h261_decode_picture_header(h, &is_key);
563
564 /* skip if the header was thrashed */
565
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 300 if (ret < 0) {
566 ✗ av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
567 ✗ return -1;
568 }
569
570
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 300 if (s->width != avctx->coded_width || s->height != avctx->coded_height) {
571 ✗ ff_mpv_common_end(s);
572 }
573
574
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 300 if (!s->context_initialized) {
575
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 6 if ((ret = ff_mpv_common_init(s)) < 0)
576 ✗ return ret;
577
578 6 ret = ff_set_dimensions(avctx, s->width, s->height);
579
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 6 if (ret < 0)
580 ✗ return ret;
581 }
582
583
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 300 if ((avctx->skip_frame >= AVDISCARD_NONINTRA && !is_key) ||
584
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 300 avctx->skip_frame >= AVDISCARD_ALL)
585 ✗ return buf_size;
586
587
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 300 if (ff_mpv_frame_start(s, avctx) < 0)
588 ✗ return -1;
589
590 300 ff_mpeg_er_frame_start(s);
591
592 /* decode each macroblock */
593 300 s->mb_x = 0;
594 300 s->mb_y = 0;
595
596
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 3900 while (h->gob_number < (s->mb_height == 18 ? 12 : 5)) {
597
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 3600 if (h261_decode_gob_header(h) < 0)
598 ✗ break;
599 3600 h261_decode_gob(h);
600 }
601 300 ff_mpv_frame_end(s);
602
603
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 300 if (is_key) {
604 30 s->cur_pic.ptr->f->pict_type = AV_PICTURE_TYPE_I;
605 30 s->cur_pic.ptr->f->flags |= AV_FRAME_FLAG_KEY;
606 }
607
608
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 300 if ((ret = av_frame_ref(pict, s->cur_pic.ptr->f)) < 0)
609 ✗ return ret;
610 300 ff_print_debug_info(s, s->cur_pic.ptr, pict);
611
612 300 *got_frame = 1;
613
614 300 return buf_size;
615 }
616
617 const FFCodec ff_h261_decoder = {
618 .p.name = "h261",
619 CODEC_LONG_NAME("H.261"),
620 .p.type = AVMEDIA_TYPE_VIDEO,
621 .p.id = AV_CODEC_ID_H261,
622 .priv_data_size = sizeof(H261DecContext),
623 .init = h261_decode_init,
624 FF_CODEC_DECODE_CB(h261_decode_frame),
625 .close = ff_mpv_decode_close,
626 .p.capabilities = AV_CODEC_CAP_DR1,
627 .p.max_lowres = 3,
628 .caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
629 };
630