2 * This file is part of Libav.
4 * Libav 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.
9 * Libav 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.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with Libav; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 #include "bytestream.h"
24 #include "h264_parse.h"
27 int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
28 const int *ref_count, int slice_type_nos,
29 H264PredWeightTable *pwt)
32 int luma_def, chroma_def;
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 luma_def = 1 << pwt->luma_log2_weight_denom;
40 chroma_def = 1 << pwt->chroma_log2_weight_denom;
42 for (list = 0; list < 2; list++) {
43 pwt->luma_weight_flag[list] = 0;
44 pwt->chroma_weight_flag[list] = 0;
45 for (i = 0; i < ref_count[list]; i++) {
46 int luma_weight_flag, chroma_weight_flag;
48 luma_weight_flag = get_bits1(gb);
49 if (luma_weight_flag) {
50 pwt->luma_weight[i][list][0] = get_se_golomb(gb);
51 pwt->luma_weight[i][list][1] = get_se_golomb(gb);
52 if (pwt->luma_weight[i][list][0] != luma_def ||
53 pwt->luma_weight[i][list][1] != 0) {
55 pwt->luma_weight_flag[list] = 1;
58 pwt->luma_weight[i][list][0] = luma_def;
59 pwt->luma_weight[i][list][1] = 0;
62 if (sps->chroma_format_idc) {
63 chroma_weight_flag = get_bits1(gb);
64 if (chroma_weight_flag) {
66 for (j = 0; j < 2; j++) {
67 pwt->chroma_weight[i][list][j][0] = get_se_golomb(gb);
68 pwt->chroma_weight[i][list][j][1] = get_se_golomb(gb);
69 if (pwt->chroma_weight[i][list][j][0] != chroma_def ||
70 pwt->chroma_weight[i][list][j][1] != 0) {
71 pwt->use_weight_chroma = 1;
72 pwt->chroma_weight_flag[list] = 1;
77 for (j = 0; j < 2; j++) {
78 pwt->chroma_weight[i][list][j][0] = chroma_def;
79 pwt->chroma_weight[i][list][j][1] = 0;
85 pwt->luma_weight[16 + 2 * i][list][0] = pwt->luma_weight[16 + 2 * i + 1][list][0] = pwt->luma_weight[i][list][0];
86 pwt->luma_weight[16 + 2 * i][list][1] = pwt->luma_weight[16 + 2 * i + 1][list][1] = pwt->luma_weight[i][list][1];
87 for (j = 0; j < 2; j++) {
88 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];
89 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];
92 if (slice_type_nos != AV_PICTURE_TYPE_B)
95 pwt->use_weight = pwt->use_weight || pwt->use_weight_chroma;
100 * Check if the top & left blocks are available if needed and
101 * change the dc mode so it only uses the available blocks.
103 int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
104 int top_samples_available, int left_samples_available)
106 static const int8_t top[12] = {
107 -1, 0, LEFT_DC_PRED, -1, -1, -1, -1, -1, 0
109 static const int8_t left[12] = {
110 0, -1, TOP_DC_PRED, 0, -1, -1, -1, 0, -1, DC_128_PRED
114 if (!(top_samples_available & 0x8000)) {
115 for (i = 0; i < 4; i++) {
116 int status = top[pred_mode_cache[scan8[0] + i]];
118 av_log(logctx, AV_LOG_ERROR,
119 "top block unavailable for requested intra4x4 mode %d\n",
121 return AVERROR_INVALIDDATA;
123 pred_mode_cache[scan8[0] + i] = status;
128 if ((left_samples_available & 0x8888) != 0x8888) {
129 static const int mask[4] = { 0x8000, 0x2000, 0x80, 0x20 };
130 for (i = 0; i < 4; i++)
131 if (!(left_samples_available & mask[i])) {
132 int status = left[pred_mode_cache[scan8[0] + 8 * i]];
134 av_log(logctx, AV_LOG_ERROR,
135 "left block unavailable for requested intra4x4 mode %d\n",
137 return AVERROR_INVALIDDATA;
139 pred_mode_cache[scan8[0] + 8 * i] = status;
148 * Check if the top & left blocks are available if needed and
149 * change the dc mode so it only uses the available blocks.
151 int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
152 int left_samples_available,
153 int mode, int is_chroma)
155 static const int8_t top[4] = { LEFT_DC_PRED8x8, 1, -1, -1 };
156 static const int8_t left[5] = { TOP_DC_PRED8x8, -1, 2, -1, DC_128_PRED8x8 };
159 av_log(logctx, AV_LOG_ERROR,
160 "out of range intra chroma pred mode\n");
161 return AVERROR_INVALIDDATA;
164 if (!(top_samples_available & 0x8000)) {
167 av_log(logctx, AV_LOG_ERROR,
168 "top block unavailable for requested intra mode\n");
169 return AVERROR_INVALIDDATA;
173 if ((left_samples_available & 0x8080) != 0x8080) {
175 if (is_chroma && (left_samples_available & 0x8080)) {
176 // mad cow disease mode, aka MBAFF + constrained_intra_pred
177 mode = ALZHEIMER_DC_L0T_PRED8x8 +
178 (!(left_samples_available & 0x8000)) +
179 2 * (mode == DC_128_PRED8x8);
182 av_log(logctx, AV_LOG_ERROR,
183 "left block unavailable for requested intra mode\n");
184 return AVERROR_INVALIDDATA;
191 int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
192 GetBitContext *gb, const PPS *pps,
193 int slice_type_nos, int picture_structure)
196 int num_ref_idx_active_override_flag, max_refs;
198 // set defaults, might be overridden a few lines later
199 ref_count[0] = pps->ref_count[0];
200 ref_count[1] = pps->ref_count[1];
202 if (slice_type_nos != AV_PICTURE_TYPE_I) {
203 num_ref_idx_active_override_flag = get_bits1(gb);
205 if (num_ref_idx_active_override_flag) {
206 ref_count[0] = get_ue_golomb(gb) + 1;
207 if (ref_count[0] < 1)
209 if (slice_type_nos == AV_PICTURE_TYPE_B) {
210 ref_count[1] = get_ue_golomb(gb) + 1;
211 if (ref_count[1] < 1)
216 if (slice_type_nos == AV_PICTURE_TYPE_B)
222 ref_count[0] = ref_count[1] = 0;
225 max_refs = picture_structure == PICT_FRAME ? 16 : 32;
227 if (ref_count[0] > max_refs || ref_count[1] > max_refs)
230 *plist_count = list_count;
237 return AVERROR_INVALIDDATA;
240 int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
241 const SPS *sps, H264POCContext *pc,
242 int picture_structure, int nal_ref_idc)
244 const int max_frame_num = 1 << sps->log2_max_frame_num;
247 pc->frame_num_offset = pc->prev_frame_num_offset;
248 if (pc->frame_num < pc->prev_frame_num)
249 pc->frame_num_offset += max_frame_num;
251 if (sps->poc_type == 0) {
252 const int max_poc_lsb = 1 << sps->log2_max_poc_lsb;
254 if (pc->poc_lsb < pc->prev_poc_lsb &&
255 pc->prev_poc_lsb - pc->poc_lsb >= max_poc_lsb / 2)
256 pc->poc_msb = pc->prev_poc_msb + max_poc_lsb;
257 else if (pc->poc_lsb > pc->prev_poc_lsb &&
258 pc->prev_poc_lsb - pc->poc_lsb < -max_poc_lsb / 2)
259 pc->poc_msb = pc->prev_poc_msb - max_poc_lsb;
261 pc->poc_msb = pc->prev_poc_msb;
263 field_poc[1] = pc->poc_msb + pc->poc_lsb;
264 if (picture_structure == PICT_FRAME)
265 field_poc[1] += pc->delta_poc_bottom;
266 } else if (sps->poc_type == 1) {
267 int abs_frame_num, expected_delta_per_poc_cycle, expectedpoc;
270 if (sps->poc_cycle_length != 0)
271 abs_frame_num = pc->frame_num_offset + pc->frame_num;
275 if (nal_ref_idc == 0 && abs_frame_num > 0)
278 expected_delta_per_poc_cycle = 0;
279 for (i = 0; i < sps->poc_cycle_length; i++)
280 // FIXME integrate during sps parse
281 expected_delta_per_poc_cycle += sps->offset_for_ref_frame[i];
283 if (abs_frame_num > 0) {
284 int poc_cycle_cnt = (abs_frame_num - 1) / sps->poc_cycle_length;
285 int frame_num_in_poc_cycle = (abs_frame_num - 1) % sps->poc_cycle_length;
287 expectedpoc = poc_cycle_cnt * expected_delta_per_poc_cycle;
288 for (i = 0; i <= frame_num_in_poc_cycle; i++)
289 expectedpoc = expectedpoc + sps->offset_for_ref_frame[i];
293 if (nal_ref_idc == 0)
294 expectedpoc = expectedpoc + sps->offset_for_non_ref_pic;
296 field_poc[0] = expectedpoc + pc->delta_poc[0];
297 field_poc[1] = field_poc[0] + sps->offset_for_top_to_bottom_field;
299 if (picture_structure == PICT_FRAME)
300 field_poc[1] += pc->delta_poc[1];
302 int poc = 2 * (pc->frame_num_offset + pc->frame_num);
311 if (picture_structure != PICT_BOTTOM_FIELD)
312 pic_field_poc[0] = field_poc[0];
313 if (picture_structure != PICT_TOP_FIELD)
314 pic_field_poc[1] = field_poc[1];
315 *pic_poc = FFMIN(pic_field_poc[0], pic_field_poc[1]);
320 static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
321 int is_avc, void *logctx)
323 H2645Packet pkt = { 0 };
326 ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264);
330 for (i = 0; i < pkt.nb_nals; i++) {
331 H2645NAL *nal = &pkt.nals[i];
334 ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps);
339 ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
345 av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
352 ff_h2645_packet_uninit(&pkt);
356 /* There are (invalid) samples in the wild with mp4-style extradata, where the
357 * parameter sets are stored unescaped (i.e. as RBSP).
358 * This function catches the parameter set decoding failure and tries again
359 * after escaping it */
360 static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
361 int err_recognition, void *logctx)
365 ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
366 if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
369 uint8_t *escaped_buf;
370 int escaped_buf_size;
372 av_log(logctx, AV_LOG_WARNING,
373 "SPS decoding failure, trying again after escaping the NAL\n");
375 if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
376 return AVERROR(ERANGE);
377 escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
378 escaped_buf = av_mallocz(escaped_buf_size);
380 return AVERROR(ENOMEM);
382 bytestream2_init(&gbc, buf, buf_size);
383 bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
385 while (bytestream2_get_bytes_left(&gbc)) {
386 if (bytestream2_get_bytes_left(&gbc) >= 3 &&
387 bytestream2_peek_be24(&gbc) <= 3) {
388 bytestream2_put_be24(&pbc, 3);
389 bytestream2_skip(&gbc, 2);
391 bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
394 escaped_buf_size = bytestream2_tell_p(&pbc);
395 AV_WB16(escaped_buf, escaped_buf_size - 2);
397 ret = decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
398 av_freep(&escaped_buf);
406 int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
407 int *is_avc, int *nal_length_size,
408 int err_recognition, void *logctx)
414 const uint8_t *p = data;
419 av_log(logctx, AV_LOG_ERROR, "avcC %d too short\n", size);
420 return AVERROR_INVALIDDATA;
423 // Decode sps from avcC
424 cnt = *(p + 5) & 0x1f; // Number of sps
426 for (i = 0; i < cnt; i++) {
427 nalsize = AV_RB16(p) + 2;
428 if (p - data + nalsize > size)
429 return AVERROR_INVALIDDATA;
430 ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
432 av_log(logctx, AV_LOG_ERROR,
433 "Decoding sps %d from avcC failed\n", i);
438 // Decode pps from avcC
439 cnt = *(p++); // Number of pps
440 for (i = 0; i < cnt; i++) {
441 nalsize = AV_RB16(p) + 2;
442 if (p - data + nalsize > size)
443 return AVERROR_INVALIDDATA;
444 ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
446 av_log(logctx, AV_LOG_ERROR,
447 "Decoding pps %d from avcC failed\n", i);
452 // Store right nal length size that will be used to parse all other nals
453 *nal_length_size = (data[4] & 0x03) + 1;
456 ret = decode_extradata_ps(data, size, ps, 0, logctx);
464 * Compute profile from profile_idc and constraint_set?_flags.
468 * @return profile as defined by FF_PROFILE_H264_*
470 int ff_h264_get_profile(const SPS *sps)
472 int profile = sps->profile_idc;
474 switch (sps->profile_idc) {
475 case FF_PROFILE_H264_BASELINE:
476 // constraint_set1_flag set to 1
477 profile |= (sps->constraint_set_flags & 1 << 1) ? FF_PROFILE_H264_CONSTRAINED : 0;
479 case FF_PROFILE_H264_HIGH_10:
480 case FF_PROFILE_H264_HIGH_422:
481 case FF_PROFILE_H264_HIGH_444_PREDICTIVE:
482 // constraint_set3_flag set to 1
483 profile |= (sps->constraint_set_flags & 1 << 3) ? FF_PROFILE_H264_INTRA : 0;