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1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#include "bytestream.h"
20#include "get_bits.h"
21#include "golomb.h"
22#include "h264.h"
23#include "h264dec.h"
24#include "h264_parse.h"
25#include "h264_ps.h"
26
27int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
28 const int *ref_count, int slice_type_nos,
29 H264PredWeightTable *pwt, void *logctx)
30{
31 int list, i, j;
32 int luma_def, chroma_def;
33
34 pwt->use_weight = 0;
35 pwt->use_weight_chroma = 0;
36 pwt->luma_log2_weight_denom = get_ue_golomb(gb);
37 if (sps->chroma_format_idc)
38 pwt->chroma_log2_weight_denom = get_ue_golomb(gb);
39
40 if (pwt->luma_log2_weight_denom > 7U) {
41 av_log(logctx, AV_LOG_ERROR, "luma_log2_weight_denom %d is out of range\n", pwt->luma_log2_weight_denom);
42 pwt->luma_log2_weight_denom = 0;
43 }
44 if (pwt->chroma_log2_weight_denom > 7U) {
45 av_log(logctx, AV_LOG_ERROR, "chroma_log2_weight_denom %d is out of range\n", pwt->chroma_log2_weight_denom);
46 pwt->chroma_log2_weight_denom = 0;
47 }
48
49 luma_def = 1 << pwt->luma_log2_weight_denom;
50 chroma_def = 1 << pwt->chroma_log2_weight_denom;
51
52 for (list = 0; list < 2; list++) {
53 pwt->luma_weight_flag[list] = 0;
54 pwt->chroma_weight_flag[list] = 0;
55 for (i = 0; i < ref_count[list]; i++) {
56 int luma_weight_flag, chroma_weight_flag;
57
58 luma_weight_flag = get_bits1(gb);
59 if (luma_weight_flag) {
60 pwt->luma_weight[i][list][0] = get_se_golomb(gb);
61 pwt->luma_weight[i][list][1] = get_se_golomb(gb);
62 if ((int8_t)pwt->luma_weight[i][list][0] != pwt->luma_weight[i][list][0] ||
63 (int8_t)pwt->luma_weight[i][list][1] != pwt->luma_weight[i][list][1])
64 goto out_range_weight;
65 if (pwt->luma_weight[i][list][0] != luma_def ||
66 pwt->luma_weight[i][list][1] != 0) {
67 pwt->use_weight = 1;
68 pwt->luma_weight_flag[list] = 1;
69 }
70 } else {
71 pwt->luma_weight[i][list][0] = luma_def;
72 pwt->luma_weight[i][list][1] = 0;
73 }
74
75 if (sps->chroma_format_idc) {
76 chroma_weight_flag = get_bits1(gb);
77 if (chroma_weight_flag) {
78 int j;
79 for (j = 0; j < 2; j++) {
80 pwt->chroma_weight[i][list][j][0] = get_se_golomb(gb);
81 pwt->chroma_weight[i][list][j][1] = get_se_golomb(gb);
82 if ((int8_t)pwt->chroma_weight[i][list][j][0] != pwt->chroma_weight[i][list][j][0] ||
83 (int8_t)pwt->chroma_weight[i][list][j][1] != pwt->chroma_weight[i][list][j][1])
84 goto out_range_weight;
85 if (pwt->chroma_weight[i][list][j][0] != chroma_def ||
86 pwt->chroma_weight[i][list][j][1] != 0) {
87 pwt->use_weight_chroma = 1;
88 pwt->chroma_weight_flag[list] = 1;
89 }
90 }
91 } else {
92 int j;
93 for (j = 0; j < 2; j++) {
94 pwt->chroma_weight[i][list][j][0] = chroma_def;
95 pwt->chroma_weight[i][list][j][1] = 0;
96 }
97 }
98 }
99
100 // for MBAFF
101 pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0];
102 pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1];
103 for (j = 0; j < 2; j++) {
104 pwt->chroma_weight[16 + 2 * i][list][j][0] = pwt->chroma_weight[16 + 2 * i + 1][list][j][0] = pwt->chroma_weight[i][list][j][0];
105 pwt->chroma_weight[16 + 2 * i][list][j][1] = pwt->chroma_weight[16 + 2 * i + 1][list][j][1] = pwt->chroma_weight[i][list][j][1];
106 }
107 }
108 if (slice_type_nos != AV_PICTURE_TYPE_B)
109 break;
110 }
111 pwt->use_weight = pwt->use_weight || pwt->use_weight_chroma;
112 return 0;
113out_range_weight:
114 avpriv_request_sample(logctx, "Out of range weight\n");
115 return AVERROR_INVALIDDATA;
116}
117
118/**
119 * Check if the top & left blocks are available if needed and
120 * change the dc mode so it only uses the available blocks.
121 */
122int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
123 int top_samples_available, int left_samples_available)
124{
125 static const int8_t top[12] = {
126 -1, 0, LEFT_DC_PRED, -1, -1, -1, -1, -1, 0
127 };
128 static const int8_t left[12] = {
129 0, -1, TOP_DC_PRED, 0, -1, -1, -1, 0, -1, DC_128_PRED
130 };
131 int i;
132
133 if (!(top_samples_available & 0x8000)) {
134 for (i = 0; i < 4; i++) {
135 int status = top[pred_mode_cache[scan8[0] + i]];
136 if (status < 0) {
137 av_log(logctx, AV_LOG_ERROR,
138 "top block unavailable for requested intra mode %d\n",
139 status);
140 return AVERROR_INVALIDDATA;
141 } else if (status) {
142 pred_mode_cache[scan8[0] + i] = status;
143 }
144 }
145 }
146
147 if ((left_samples_available & 0x8888) != 0x8888) {
148 static const int mask[4] = { 0x8000, 0x2000, 0x80, 0x20 };
149 for (i = 0; i < 4; i++)
150 if (!(left_samples_available & mask[i])) {
151 int status = left[pred_mode_cache[scan8[0] + 8 * i]];
152 if (status < 0) {
153 av_log(logctx, AV_LOG_ERROR,
154 "left block unavailable for requested intra4x4 mode %d\n",
155 status);
156 return AVERROR_INVALIDDATA;
157 } else if (status) {
158 pred_mode_cache[scan8[0] + 8 * i] = status;
159 }
160 }
161 }
162
163 return 0;
164}
165
166/**
167 * Check if the top & left blocks are available if needed and
168 * change the dc mode so it only uses the available blocks.
169 */
170int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
171 int left_samples_available,
172 int mode, int is_chroma)
173{
174 static const int8_t top[4] = { LEFT_DC_PRED8x8, 1, -1, -1 };
175 static const int8_t left[5] = { TOP_DC_PRED8x8, -1, 2, -1, DC_128_PRED8x8 };
176
177 if (mode > 3U) {
178 av_log(logctx, AV_LOG_ERROR,
179 "out of range intra chroma pred mode\n");
180 return AVERROR_INVALIDDATA;
181 }
182
183 if (!(top_samples_available & 0x8000)) {
184 mode = top[mode];
185 if (mode < 0) {
186 av_log(logctx, AV_LOG_ERROR,
187 "top block unavailable for requested intra mode\n");
188 return AVERROR_INVALIDDATA;
189 }
190 }
191
192 if ((left_samples_available & 0x8080) != 0x8080) {
193 mode = left[mode];
194 if (mode < 0) {
195 av_log(logctx, AV_LOG_ERROR,
196 "left block unavailable for requested intra mode\n");
197 return AVERROR_INVALIDDATA;
198 }
199 if (is_chroma && (left_samples_available & 0x8080)) {
200 // mad cow disease mode, aka MBAFF + constrained_intra_pred
201 mode = ALZHEIMER_DC_L0T_PRED8x8 +
202 (!(left_samples_available & 0x8000)) +
203 2 * (mode == DC_128_PRED8x8);
204 }
205 }
206
207 return mode;
208}
209
210int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
211 GetBitContext *gb, const PPS *pps,
212 int slice_type_nos, int picture_structure, void *logctx)
213{
214 int list_count;
215 int num_ref_idx_active_override_flag;
216
217 // set defaults, might be overridden a few lines later
218 ref_count[0] = pps->ref_count[0];
219 ref_count[1] = pps->ref_count[1];
220
221 if (slice_type_nos != AV_PICTURE_TYPE_I) {
222 unsigned max[2];
223 max[0] = max[1] = picture_structure == PICT_FRAME ? 15 : 31;
224
225 num_ref_idx_active_override_flag = get_bits1(gb);
226
227 if (num_ref_idx_active_override_flag) {
228 ref_count[0] = get_ue_golomb(gb) + 1;
229 if (slice_type_nos == AV_PICTURE_TYPE_B) {
230 ref_count[1] = get_ue_golomb(gb) + 1;
231 } else
232 // full range is spec-ok in this case, even for frames
233 ref_count[1] = 1;
234 }
235
236 if (ref_count[0] - 1 > max[0] || ref_count[1] - 1 > max[1]) {
237 av_log(logctx, AV_LOG_ERROR, "reference overflow %u > %u or %u > %u\n",
238 ref_count[0] - 1, max[0], ref_count[1] - 1, max[1]);
239 ref_count[0] = ref_count[1] = 0;
240 *plist_count = 0;
241 goto fail;
242 }
243
244 if (slice_type_nos == AV_PICTURE_TYPE_B)
245 list_count = 2;
246 else
247 list_count = 1;
248 } else {
249 list_count = 0;
250 ref_count[0] = ref_count[1] = 0;
251 }
252
253 *plist_count = list_count;
254
255 return 0;
256fail:
257 *plist_count = 0;
258 ref_count[0] = 0;
259 ref_count[1] = 0;
260 return AVERROR_INVALIDDATA;
261}
262
263int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
264 const SPS *sps, H264POCContext *pc,
265 int picture_structure, int nal_ref_idc)
266{
267 const int max_frame_num = 1 << sps->log2_max_frame_num;
268 int field_poc[2];
269
270 pc->frame_num_offset = pc->prev_frame_num_offset;
271 if (pc->frame_num < pc->prev_frame_num)
272 pc->frame_num_offset += max_frame_num;
273
274 if (sps->poc_type == 0) {
275 const int max_poc_lsb = 1 << sps->log2_max_poc_lsb;
276
277 if (pc->poc_lsb < pc->prev_poc_lsb &&
278 pc->prev_poc_lsb - pc->poc_lsb >= max_poc_lsb / 2)
279 pc->poc_msb = pc->prev_poc_msb + max_poc_lsb;
280 else if (pc->poc_lsb > pc->prev_poc_lsb &&
281 pc->prev_poc_lsb - pc->poc_lsb < -max_poc_lsb / 2)
282 pc->poc_msb = pc->prev_poc_msb - max_poc_lsb;
283 else
284 pc->poc_msb = pc->prev_poc_msb;
285 field_poc[0] =
286 field_poc[1] = pc->poc_msb + pc->poc_lsb;
287 if (picture_structure == PICT_FRAME)
288 field_poc[1] += pc->delta_poc_bottom;
289 } else if (sps->poc_type == 1) {
290 int abs_frame_num, expected_delta_per_poc_cycle, expectedpoc;
291 int i;
292
293 if (sps->poc_cycle_length != 0)
294 abs_frame_num = pc->frame_num_offset + pc->frame_num;
295 else
296 abs_frame_num = 0;
297
298 if (nal_ref_idc == 0 && abs_frame_num > 0)
299 abs_frame_num--;
300
301 expected_delta_per_poc_cycle = 0;
302 for (i = 0; i < sps->poc_cycle_length; i++)
303 // FIXME integrate during sps parse
304 expected_delta_per_poc_cycle += sps->offset_for_ref_frame[i];
305
306 if (abs_frame_num > 0) {
307 int poc_cycle_cnt = (abs_frame_num - 1) / sps->poc_cycle_length;
308 int frame_num_in_poc_cycle = (abs_frame_num - 1) % sps->poc_cycle_length;
309
310 expectedpoc = poc_cycle_cnt * expected_delta_per_poc_cycle;
311 for (i = 0; i <= frame_num_in_poc_cycle; i++)
312 expectedpoc = expectedpoc + sps->offset_for_ref_frame[i];
313 } else
314 expectedpoc = 0;
315
316 if (nal_ref_idc == 0)
317 expectedpoc = expectedpoc + sps->offset_for_non_ref_pic;
318
319 field_poc[0] = expectedpoc + pc->delta_poc[0];
320 field_poc[1] = field_poc[0] + sps->offset_for_top_to_bottom_field;
321
322 if (picture_structure == PICT_FRAME)
323 field_poc[1] += pc->delta_poc[1];
324 } else {
325 int poc = 2 * (pc->frame_num_offset + pc->frame_num);
326
327 if (!nal_ref_idc)
328 poc--;
329
330 field_poc[0] = poc;
331 field_poc[1] = poc;
332 }
333
334 if (picture_structure != PICT_BOTTOM_FIELD)
335 pic_field_poc[0] = field_poc[0];
336 if (picture_structure != PICT_TOP_FIELD)
337 pic_field_poc[1] = field_poc[1];
338 *pic_poc = FFMIN(pic_field_poc[0], pic_field_poc[1]);
339
340 return 0;
341}
342
343static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
344 int is_avc, void *logctx)
345{
346 H2645Packet pkt = { 0 };
347 int i, ret = 0;
348
349 ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264, 1);
350 if (ret < 0) {
351 ret = 0;
352 goto fail;
353 }
354
355 for (i = 0; i < pkt.nb_nals; i++) {
356 H2645NAL *nal = &pkt.nals[i];
357 switch (nal->type) {
358 case H264_NAL_SPS:
359 ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps, 0);
360 if (ret < 0)
361 goto fail;
362 break;
363 case H264_NAL_PPS:
364 ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
365 nal->size_bits);
366 if (ret < 0)
367 goto fail;
368 break;
369 default:
370 av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
371 nal->type);
372 break;
373 }
374 }
375
376fail:
377 ff_h2645_packet_uninit(&pkt);
378 return ret;
379}
380
381/* There are (invalid) samples in the wild with mp4-style extradata, where the
382 * parameter sets are stored unescaped (i.e. as RBSP).
383 * This function catches the parameter set decoding failure and tries again
384 * after escaping it */
385static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
386 int err_recognition, void *logctx)
387{
388 int ret;
389
390 ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
391 if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
392 GetByteContext gbc;
393 PutByteContext pbc;
394 uint8_t *escaped_buf;
395 int escaped_buf_size;
396
397 av_log(logctx, AV_LOG_WARNING,
398 "SPS decoding failure, trying again after escaping the NAL\n");
399
400 if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
401 return AVERROR(ERANGE);
402 escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
403 escaped_buf = av_mallocz(escaped_buf_size);
404 if (!escaped_buf)
405 return AVERROR(ENOMEM);
406
407 bytestream2_init(&gbc, buf, buf_size);
408 bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
409
410 while (bytestream2_get_bytes_left(&gbc)) {
411 if (bytestream2_get_bytes_left(&gbc) >= 3 &&
412 bytestream2_peek_be24(&gbc) <= 3) {
413 bytestream2_put_be24(&pbc, 3);
414 bytestream2_skip(&gbc, 2);
415 } else
416 bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
417 }
418
419 escaped_buf_size = bytestream2_tell_p(&pbc);
420 AV_WB16(escaped_buf, escaped_buf_size - 2);
421
422 ret = decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
423 av_freep(&escaped_buf);
424 if (ret < 0)
425 return ret;
426 }
427
428 return 0;
429}
430
431int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
432 int *is_avc, int *nal_length_size,
433 int err_recognition, void *logctx)
434{
435 int ret;
436
437 if (!data || size <= 0)
438 return -1;
439
440 if (data[0] == 1) {
441 int i, cnt, nalsize;
442 const uint8_t *p = data;
443
444 *is_avc = 1;
445
446 if (size < 7) {
447 av_log(logctx, AV_LOG_ERROR, "avcC %d too short\n", size);
448 return AVERROR_INVALIDDATA;
449 }
450
451 // Decode sps from avcC
452 cnt = *(p + 5) & 0x1f; // Number of sps
453 p += 6;
454 for (i = 0; i < cnt; i++) {
455 nalsize = AV_RB16(p) + 2;
456 if (nalsize > size - (p - data))
457 return AVERROR_INVALIDDATA;
458 ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
459 if (ret < 0) {
460 av_log(logctx, AV_LOG_ERROR,
461 "Decoding sps %d from avcC failed\n", i);
462 return ret;
463 }
464 p += nalsize;
465 }
466 // Decode pps from avcC
467 cnt = *(p++); // Number of pps
468 for (i = 0; i < cnt; i++) {
469 nalsize = AV_RB16(p) + 2;
470 if (nalsize > size - (p - data))
471 return AVERROR_INVALIDDATA;
472 ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
473 if (ret < 0) {
474 av_log(logctx, AV_LOG_ERROR,
475 "Decoding pps %d from avcC failed\n", i);
476 return ret;
477 }
478 p += nalsize;
479 }
480 // Store right nal length size that will be used to parse all other nals
481 *nal_length_size = (data[4] & 0x03) + 1;
482 } else {
483 *is_avc = 0;
484 ret = decode_extradata_ps(data, size, ps, 0, logctx);
485 if (ret < 0)
486 return ret;
487 }
488 return size;
489}
490
491/**
492 * Compute profile from profile_idc and constraint_set?_flags.
493 *
494 * @param sps SPS
495 *
496 * @return profile as defined by FF_PROFILE_H264_*
497 */
498int ff_h264_get_profile(const SPS *sps)
499{
500 int profile = sps->profile_idc;
501
502 switch (sps->profile_idc) {
503 case FF_PROFILE_H264_BASELINE:
504 // constraint_set1_flag set to 1
505 profile |= (sps->constraint_set_flags & 1 << 1) ? FF_PROFILE_H264_CONSTRAINED : 0;
506 break;
507 case FF_PROFILE_H264_HIGH_10:
508 case FF_PROFILE_H264_HIGH_422:
509 case FF_PROFILE_H264_HIGH_444_PREDICTIVE:
510 // constraint_set3_flag set to 1
511 profile |= (sps->constraint_set_flags & 1 << 3) ? FF_PROFILE_H264_INTRA : 0;
512 break;
513 }
514
515 return profile;
516}
517
generated by cgit at 2024-05-10 12:23:34 (GMT)