FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavcodec/h261dec.c
Date: 2025-07-08 13:42:56
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/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 H261Context common;
63
64 int current_mba;
65 int mba_diff;
66 int current_mv_x;
67 int current_mv_y;
68 int gob_number;
69 int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read
70
71 DECLARE_ALIGNED_32(int16_t, block)[6][64];
72 } H261DecContext;
73
74 7 static av_cold void h261_decode_init_static(void)
75 {
76 7 VLC_INIT_STATIC_TABLE(h261_mba_vlc, H261_MBA_VLC_BITS, 35,
77 ff_h261_mba_bits, 1, 1,
78 ff_h261_mba_code, 1, 1, 0);
79 7 VLC_INIT_STATIC_SPARSE_TABLE(h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
80 ff_h261_mtype_bits, 1, 1,
81 ff_h261_mtype_code, 1, 1,
82 ff_h261_mtype_map, 2, 2, 0);
83 7 VLC_INIT_STATIC_TABLE(h261_mv_vlc, H261_MV_VLC_BITS, 17,
84 &ff_h261_mv_tab[0][1], 2, 1,
85 &ff_h261_mv_tab[0][0], 2, 1, 0);
86 7 VLC_INIT_STATIC_TABLE(h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
87 &ff_h261_cbp_tab[0][1], 2, 1,
88 &ff_h261_cbp_tab[0][0], 2, 1, 0);
89 7 INIT_FIRST_VLC_RL(ff_h261_rl_tcoeff, 552);
90 7 }
91
92 13 static av_cold int h261_decode_init(AVCodecContext *avctx)
93 {
94 static AVOnce init_static_once = AV_ONCE_INIT;
95 13 H261DecContext *const h = avctx->priv_data;
96 13 MpegEncContext *const s = &h->s;
97 int ret;
98
99 13 avctx->framerate = (AVRational) { 30000, 1001 };
100
101 /* The H.261 analog of intra/key frames is setting the freeze picture release flag,
102 * but this does not guarantee that the frame uses intra-only encoding,
103 * so we still need to allocate dummy frames. So set pict_type to P here
104 * for all frames and override it after having decoded the frame. */
105 13 s->pict_type = AV_PICTURE_TYPE_P;
106
107 13 s->private_ctx = &h->common;
108 // set defaults
109 13 ret = ff_mpv_decode_init(s, avctx);
110
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 13 if (ret < 0)
111 ✗ return ret;
112
113 13 s->out_format = FMT_H261;
114 13 s->low_delay = 1;
115 13 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
116
117 13 ff_thread_once(&init_static_once, h261_decode_init_static);
118
119 13 return 0;
120 }
121
122 118800 static inline void h261_init_dest(MpegEncContext *s)
123 {
124 118800 const unsigned block_size = 8 >> s->avctx->lowres;
125 118800 ff_init_block_index(s);
126 118800 s->dest[0] += 2 * block_size;
127 118800 s->dest[1] += block_size;
128 118800 s->dest[2] += block_size;
129 118800 }
130
131 /**
132 * Decode the group of blocks header or slice header.
133 * @return <0 if an error occurred
134 */
135 3600 static int h261_decode_gob_header(H261DecContext *h)
136 {
137 unsigned int val;
138 3600 MpegEncContext *const s = &h->s;
139
140
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 3600 if (!h->gob_start_code_skipped) {
141 /* Check for GOB Start Code */
142 300 val = show_bits(&h->gb, 15);
143
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 300 if (val)
144 ✗ return -1;
145
146 /* We have a GBSC */
147 300 skip_bits(&h->gb, 16);
148 }
149
150 3600 h->gob_start_code_skipped = 0;
151
152 3600 h->gob_number = get_bits(&h->gb, 4); /* GN */
153 3600 s->qscale = get_bits(&h->gb, 5); /* GQUANT */
154
155 /* Check if gob_number is valid */
156
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 3600 if (s->mb_height == 18) { // CIF
157
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 3600 if ((h->gob_number <= 0) || (h->gob_number > 12))
158 ✗ return -1;
159 } else { // QCIF
160 ✗ if ((h->gob_number != 1) && (h->gob_number != 3) &&
161 ✗ (h->gob_number != 5))
162 ✗ return -1;
163 }
164
165 /* GEI */
166
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 3600 if (skip_1stop_8data_bits(&h->gb) < 0)
167 ✗ return AVERROR_INVALIDDATA;
168
169
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 3600 if (s->qscale == 0) {
170 ✗ av_log(s->avctx, AV_LOG_ERROR, "qscale has forbidden 0 value\n");
171 ✗ if (s->avctx->err_recognition & (AV_EF_BITSTREAM | AV_EF_COMPLIANT))
172 ✗ return -1;
173 ✗ s->qscale = 1;
174 }
175
176 /* For the first transmitted macroblock in a GOB, MBA is the absolute
177 * address. For subsequent macroblocks, MBA is the difference between
178 * the absolute addresses of the macroblock and the last transmitted
179 * macroblock. */
180 3600 h->current_mba = 0;
181 3600 h->mba_diff = 0;
182
183 3600 return 0;
184 }
185
186 /**
187 * Decode skipped macroblocks.
188 * @return 0
189 */
190 121541 static int h261_decode_mb_skipped(H261DecContext *h, int mba1, int mba2)
191 {
192 121541 MpegEncContext *const s = &h->s;
193 int i;
194
195 121541 s->mb_intra = 0;
196
197
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 122400 for (i = mba1; i < mba2; i++) {
198 int j, xy;
199
200 859 s->mb_x = ((h->gob_number - 1) % 2) * 11 + i % 11;
201 859 s->mb_y = ((h->gob_number - 1) / 2) * 3 + i / 11;
202 859 xy = s->mb_x + s->mb_y * s->mb_stride;
203 859 h261_init_dest(s);
204
205
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 6013 for (j = 0; j < 6; j++)
206 5154 s->block_last_index[j] = -1;
207
208 859 s->mv_dir = MV_DIR_FORWARD;
209 859 s->mv_type = MV_TYPE_16X16;
210 859 s->cur_pic.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
211 859 s->mv[0][0][0] = 0;
212 859 s->mv[0][0][1] = 0;
213 859 s->mb_skipped = 1;
214 859 h->common.mtype &= ~MB_TYPE_H261_FIL;
215
216
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 859 if (s->cur_pic.motion_val[0]) {
217 ✗ int b_stride = 2*s->mb_width + 1;
218 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
219 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
220 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
221 }
222
223 859 ff_mpv_reconstruct_mb(s, h->block);
224 }
225
226 121541 return 0;
227 }
228
229 198948 static int decode_mv_component(GetBitContext *gb, int v)
230 {
231 198948 int mv_diff = get_vlc2(gb, h261_mv_vlc, H261_MV_VLC_BITS, 2);
232
233 /* check if mv_diff is valid */
234
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 198948 if (mv_diff < 0)
235 ✗ return v;
236
237
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 198948 if (mv_diff && get_bits1(gb))
238 45885 mv_diff = -mv_diff;
239
240 198948 v += mv_diff;
241
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 198948 if (v <= -16)
242 32 v += 32;
243
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 198916 else if (v >= 16)
244 35 v -= 32;
245
246 198948 return v;
247 }
248
249 /**
250 * Decode a macroblock.
251 * @return <0 if an error occurred
252 */
253 591000 static int h261_decode_block(H261DecContext *h, int16_t *block, int n, int coded)
254 {
255 591000 MpegEncContext *const s = &h->s;
256 int level, i, j, run;
257 591000 const RLTable *rl = &ff_h261_rl_tcoeff;
258 const uint8_t *scan_table;
259 591000 const int qmul = s->qscale << 1, qadd = (s->qscale - 1) | 1;
260
261 /* For the variable length encoding there are two code tables, one being
262 * used for the first transmitted LEVEL in INTER, INTER + MC and
263 * INTER + MC + FIL blocks, the second for all other LEVELs except the
264 * first one in INTRA blocks which is fixed length coded with 8 bits.
265 * NOTE: The two code tables only differ in one VLC so we handle that
266 * manually. */
267 591000 scan_table = s->intra_scantable.permutated;
268
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 591000 if (s->mb_intra) {
269 /* DC coef */
270 101472 level = get_bits(&h->gb, 8);
271 // 0 (00000000b) and -128 (10000000b) are FORBIDDEN
272
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 101472 if ((level & 0x7F) == 0) {
273 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n",
274 level, s->mb_x, s->mb_y);
275 ✗ return -1;
276 }
277 /* The code 1000 0000 is not used, the reconstruction level of 1024
278 * being coded as 1111 1111. */
279
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 101472 if (level == 255)
280 1145 level = 128;
281 101472 block[0] = level * 8;
282 101472 i = 1;
283
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 489528 } else if (coded) {
284 // Run Level Code
285 // EOB Not possible for first level when cbp is available (that's why the table is different)
286 // 0 1 1s
287 // * * 0*
288 259485 int check = show_bits(&h->gb, 2);
289 259485 i = 0;
290
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 259485 if (check & 0x2) {
291 87589 skip_bits(&h->gb, 2);
292 87589 block[0] = qmul + qadd;
293
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 87589 block[0] *= (check & 0x1) ? -1 : 1;
294 87589 i = 1;
295 }
296 } else {
297 230043 i = 0;
298 }
299
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 591000 if (!coded) {
300 230043 s->block_last_index[n] = i - 1;
301 230043 return 0;
302 }
303 {
304 360957 OPEN_READER(re, &h->gb);
305 360957 i--; // offset by -1 to allow direct indexing of scan_table
306 for (;;) {
307 5175539 UPDATE_CACHE(re, &h->gb);
308
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 2768248 GET_RL_VLC(level, run, re, &h->gb, rl->rl_vlc[0], TCOEFF_VLC_BITS, 2, 0);
309
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 2768248 if (run == 66) {
310
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 40537 if (level) {
311 ✗ CLOSE_READER(re, &h->gb);
312 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n",
313 s->mb_x, s->mb_y);
314 ✗ return -1;
315 }
316 /* escape */
317 /* The remaining combinations of (run, level) are encoded with a
318 * 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits
319 * level. */
320 40537 run = SHOW_UBITS(re, &h->gb, 6) + 1;
321 40537 SKIP_CACHE(re, &h->gb, 6);
322 40537 level = SHOW_SBITS(re, &h->gb, 8);
323
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 40537 if (level > 0)
324 21553 level = level * qmul + qadd;
325
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 18984 else if (level < 0)
326 18984 level = level * qmul - qadd;
327 40537 SKIP_COUNTER(re, &h->gb, 6 + 8);
328
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 2727711 } else if (level == 0) {
329 360957 break;
330 } else {
331 2366754 level = level * qmul + qadd;
332
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 2366754 if (SHOW_UBITS(re, &h->gb, 1))
333 1184977 level = -level;
334 2366754 SKIP_COUNTER(re, &h->gb, 1);
335 }
336 2407291 i += run;
337
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 2407291 if (i >= 64) {
338 ✗ CLOSE_READER(re, &h->gb);
339 ✗ av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n",
340 s->mb_x, s->mb_y);
341 ✗ return -1;
342 }
343 2407291 j = scan_table[i];
344 2407291 block[j] = level;
345 }
346 360957 CLOSE_READER(re, &h->gb);
347 }
348 360957 s->block_last_index[n] = i;
349 360957 return 0;
350 }
351
352 121541 static int h261_decode_mb(H261DecContext *h)
353 {
354 121541 MpegEncContext *const s = &h->s;
355 121541 H261Context *const com = &h->common;
356 int i, cbp, xy;
357
358 121541 cbp = 63;
359 // Read mba
360 do {
361 121541 h->mba_diff = get_vlc2(&h->gb, h261_mba_vlc,
362 H261_MBA_VLC_BITS, 2);
363
364 /* Check for slice end */
365 /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */
366
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 121541 if (h->mba_diff == MBA_STARTCODE) { // start code
367 3300 h->gob_start_code_skipped = 1;
368 3300 return SLICE_END;
369 }
370
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 118241 } while (h->mba_diff == MBA_STUFFING); // stuffing
371
372
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 118241 if (h->mba_diff < 0) {
373
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 300 if (get_bits_left(&h->gb) <= 7)
374 300 return SLICE_END;
375
376 ✗ av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y);
377 ✗ return SLICE_ERROR;
378 }
379
380 117941 h->mba_diff += 1;
381 117941 h->current_mba += h->mba_diff;
382
383
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 117941 if (h->current_mba > MBA_STUFFING)
384 ✗ return SLICE_ERROR;
385
386 117941 s->mb_x = ((h->gob_number - 1) % 2) * 11 + ((h->current_mba - 1) % 11);
387 117941 s->mb_y = ((h->gob_number - 1) / 2) * 3 + ((h->current_mba - 1) / 11);
388 117941 xy = s->mb_x + s->mb_y * s->mb_stride;
389 117941 h261_init_dest(s);
390
391 // Read mtype
392 117941 com->mtype = get_vlc2(&h->gb, h261_mtype_vlc, H261_MTYPE_VLC_BITS, 2);
393
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 117941 if (com->mtype < 0) {
394 ✗ av_log(s->avctx, AV_LOG_ERROR, "Invalid mtype index\n");
395 ✗ return SLICE_ERROR;
396 }
397
398 // Read mquant
399
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 117941 if (IS_QUANT(com->mtype)) {
400 ✗ s->qscale = get_bits(&h->gb, 5);
401 ✗ if (!s->qscale)
402 ✗ s->qscale = 1;
403 }
404
405 117941 s->mb_intra = IS_INTRA4x4(com->mtype);
406
407 // Read mv
408
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 117941 if (IS_16X16(com->mtype)) {
409 /* Motion vector data is included for all MC macroblocks. MVD is
410 * obtained from the macroblock vector by subtracting the vector
411 * of the preceding macroblock. For this calculation the vector
412 * of the preceding macroblock is regarded as zero in the
413 * following three situations:
414 * 1) evaluating MVD for macroblocks 1, 12 and 23;
415 * 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1;
416 * 3) MTYPE of the previous macroblock was not MC. */
417
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 99474 if ((h->current_mba == 1) || (h->current_mba == 12) ||
418
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 93760 (h->current_mba == 23) || (h->mba_diff != 1)) {
419 9175 h->current_mv_x = 0;
420 9175 h->current_mv_y = 0;
421 }
422
423 99474 h->current_mv_x = decode_mv_component(&h->gb, h->current_mv_x);
424 99474 h->current_mv_y = decode_mv_component(&h->gb, h->current_mv_y);
425 } else {
426 18467 h->current_mv_x = 0;
427 18467 h->current_mv_y = 0;
428 }
429
430 // Read cbp
431
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 117941 if (HAS_CBP(com->mtype))
432 81588 cbp = get_vlc2(&h->gb, h261_cbp_vlc, H261_CBP_VLC_BITS, 1) + 1;
433
434
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 117941 if (s->mb_intra) {
435 16912 s->cur_pic.mb_type[xy] = MB_TYPE_INTRA;
436 16912 goto intra;
437 }
438
439 //set motion vectors
440 101029 s->mv_dir = MV_DIR_FORWARD;
441 101029 s->mv_type = MV_TYPE_16X16;
442 101029 s->cur_pic.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_FORWARD_MV;
443 101029 s->mv[0][0][0] = h->current_mv_x * 2; // gets divided by 2 in motion compensation
444 101029 s->mv[0][0][1] = h->current_mv_y * 2;
445
446
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 101029 if (s->cur_pic.motion_val[0]) {
447 ✗ int b_stride = 2*s->mb_width + 1;
448 ✗ int b_xy = 2 * s->mb_x + (2 * s->mb_y) * b_stride;
449 ✗ s->cur_pic.motion_val[0][b_xy][0] = s->mv[0][0][0];
450 ✗ s->cur_pic.motion_val[0][b_xy][1] = s->mv[0][0][1];
451 }
452
453 101029 intra:
454 /* decode each block */
455
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 117941 if (s->mb_intra || HAS_CBP(com->mtype)) {
456 98500 s->bdsp.clear_blocks(h->block[0]);
457
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 689500 for (i = 0; i < 6; i++) {
458
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 591000 if (h261_decode_block(h, h->block[i], i, cbp & 32) < 0)
459 ✗ return SLICE_ERROR;
460 591000 cbp += cbp;
461 }
462 } else {
463
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 136087 for (i = 0; i < 6; i++)
464 116646 s->block_last_index[i] = -1;
465 }
466
467 117941 ff_mpv_reconstruct_mb(s, h->block);
468
469 117941 return SLICE_OK;
470 }
471
472 /**
473 * Decode the H.261 picture header.
474 * @return <0 if no startcode found
475 */
476 300 static int h261_decode_picture_header(H261DecContext *h, int *is_key)
477 {
478 300 MpegEncContext *const s = &h->s;
479 300 uint32_t startcode = 0;
480
481
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 6000 for (int i = get_bits_left(&h->gb); i > 24; i -= 1) {
482 6000 startcode = ((startcode << 1) | get_bits(&h->gb, 1)) & 0x000FFFFF;
483
484
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 6000 if (startcode == 0x10)
485 300 break;
486 }
487
488
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 300 if (startcode != 0x10) {
489 ✗ av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
490 ✗ return -1;
491 }
492
493 /* temporal reference */
494 300 skip_bits(&h->gb, 5); /* picture timestamp */
495
496 /* PTYPE starts here */
497 300 skip_bits1(&h->gb); /* split screen off */
498 300 skip_bits1(&h->gb); /* camera off */
499 300 *is_key = get_bits1(&h->gb); /* freeze picture release off */
500
501 300 int format = get_bits1(&h->gb);
502
503 // only 2 formats possible
504
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 300 if (format == 0) { // QCIF
505 ✗ s->width = 176;
506 ✗ s->height = 144;
507 } else { // CIF
508 300 s->width = 352;
509 300 s->height = 288;
510 }
511
512 300 skip_bits1(&h->gb); /* still image mode off */
513 300 skip_bits1(&h->gb); /* Reserved */
514
515 /* PEI */
516
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 300 if (skip_1stop_8data_bits(&h->gb) < 0)
517 ✗ return AVERROR_INVALIDDATA;
518
519 300 h->gob_number = 0;
520 300 return 0;
521 }
522
523 3600 static int h261_decode_gob(H261DecContext *h)
524 {
525 3600 MpegEncContext *const s = &h->s;
526
527 /* decode mb's */
528
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 121541 while (h->current_mba <= MBA_STUFFING) {
529 int ret;
530 /* DCT & quantize */
531 121541 ret = h261_decode_mb(h);
532
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 121541 if (ret < 0) {
533
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 3600 if (ret == SLICE_END) {
534 3600 h261_decode_mb_skipped(h, h->current_mba, 33);
535 3600 return 0;
536 }
537 ✗ av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n",
538 ✗ s->mb_x + s->mb_y * s->mb_stride);
539 ✗ return -1;
540 }
541
542 117941 h261_decode_mb_skipped(h,
543 117941 h->current_mba - h->mba_diff,
544 117941 h->current_mba - 1);
545 }
546
547 ✗ return -1;
548 }
549
550 300 static int h261_decode_frame(AVCodecContext *avctx, AVFrame *pict,
551 int *got_frame, AVPacket *avpkt)
552 {
553 300 H261DecContext *const h = avctx->priv_data;
554 300 const uint8_t *buf = avpkt->data;
555 300 int buf_size = avpkt->size;
556 300 MpegEncContext *s = &h->s;
557 int ret, is_key;
558
559 ff_dlog(avctx, "*****frame %"PRId64" size=%d\n", avctx->frame_num, buf_size);
560 ff_dlog(avctx, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
561
562 300 h->gob_start_code_skipped = 0;
563
564 300 init_get_bits(&h->gb, buf, buf_size * 8);
565
566 300 ret = h261_decode_picture_header(h, &is_key);
567
568 /* skip if the header was thrashed */
569
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 300 if (ret < 0) {
570 ✗ av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");
571 ✗ return -1;
572 }
573
574
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 300 if (s->width != avctx->coded_width || s->height != avctx->coded_height) {
575 ✗ ff_mpv_common_end(s);
576 }
577
578
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 300 if (!s->context_initialized) {
579
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 6 if ((ret = ff_mpv_common_init(s)) < 0)
580 ✗ return ret;
581
582 6 ret = ff_set_dimensions(avctx, s->width, s->height);
583
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 6 if (ret < 0)
584 ✗ return ret;
585 }
586
587
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 300 if ((avctx->skip_frame >= AVDISCARD_NONINTRA && !is_key) ||
588
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 300 avctx->skip_frame >= AVDISCARD_ALL)
589 ✗ return buf_size;
590
591
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 300 if (ff_mpv_frame_start(s, avctx) < 0)
592 ✗ return -1;
593
594 300 ff_mpeg_er_frame_start(s);
595
596 /* decode each macroblock */
597 300 s->mb_x = 0;
598 300 s->mb_y = 0;
599
600
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 3900 while (h->gob_number < (s->mb_height == 18 ? 12 : 5)) {
601
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 3600 if (h261_decode_gob_header(h) < 0)
602 ✗ break;
603 3600 h261_decode_gob(h);
604 }
605 300 ff_mpv_frame_end(s);
606
607
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 300 if (is_key) {
608 30 s->cur_pic.ptr->f->pict_type = AV_PICTURE_TYPE_I;
609 30 s->cur_pic.ptr->f->flags |= AV_FRAME_FLAG_KEY;
610 }
611
612
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 300 if ((ret = av_frame_ref(pict, s->cur_pic.ptr->f)) < 0)
613 ✗ return ret;
614 300 ff_print_debug_info(s, s->cur_pic.ptr, pict);
615
616 300 *got_frame = 1;
617
618 300 return buf_size;
619 }
620
621 const FFCodec ff_h261_decoder = {
622 .p.name = "h261",
623 CODEC_LONG_NAME("H.261"),
624 .p.type = AVMEDIA_TYPE_VIDEO,
625 .p.id = AV_CODEC_ID_H261,
626 .priv_data_size = sizeof(H261DecContext),
627 .init = h261_decode_init,
628 FF_CODEC_DECODE_CB(h261_decode_frame),
629 .close = ff_mpv_decode_close,
630 .p.capabilities = AV_CODEC_CAP_DR1,
631 .p.max_lowres = 3,
632 .caps_internal = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
633 };
634