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"
23 #include "h264_parse.h"
25 int ff_h264_pred_weight_table(GetBitContext *gb, const SPS *sps,
26 const int *ref_count, int slice_type_nos,
27 H264PredWeightTable *pwt)
30 int luma_def, chroma_def;
33 pwt->use_weight_chroma = 0;
34 pwt->luma_log2_weight_denom = get_ue_golomb(gb);
35 if (sps->chroma_format_idc)
36 pwt->chroma_log2_weight_denom = get_ue_golomb(gb);
37 luma_def = 1 << pwt->luma_log2_weight_denom;
38 chroma_def = 1 << pwt->chroma_log2_weight_denom;
40 for (list = 0; list < 2; list++) {
41 pwt->luma_weight_flag[list] = 0;
42 pwt->chroma_weight_flag[list] = 0;
43 for (i = 0; i < ref_count[list]; i++) {
44 int luma_weight_flag, chroma_weight_flag;
46 luma_weight_flag = get_bits1(gb);
47 if (luma_weight_flag) {
48 pwt->luma_weight[i][list][0] = get_se_golomb(gb);
49 pwt->luma_weight[i][list][1] = get_se_golomb(gb);
50 if (pwt->luma_weight[i][list][0] != luma_def ||
51 pwt->luma_weight[i][list][1] != 0) {
53 pwt->luma_weight_flag[list] = 1;
56 pwt->luma_weight[i][list][0] = luma_def;
57 pwt->luma_weight[i][list][1] = 0;
60 if (sps->chroma_format_idc) {
61 chroma_weight_flag = get_bits1(gb);
62 if (chroma_weight_flag) {
64 for (j = 0; j < 2; j++) {
65 pwt->chroma_weight[i][list][j][0] = get_se_golomb(gb);
66 pwt->chroma_weight[i][list][j][1] = get_se_golomb(gb);
67 if (pwt->chroma_weight[i][list][j][0] != chroma_def ||
68 pwt->chroma_weight[i][list][j][1] != 0) {
69 pwt->use_weight_chroma = 1;
70 pwt->chroma_weight_flag[list] = 1;
75 for (j = 0; j < 2; j++) {
76 pwt->chroma_weight[i][list][j][0] = chroma_def;
77 pwt->chroma_weight[i][list][j][1] = 0;
82 if (slice_type_nos != AV_PICTURE_TYPE_B)
85 pwt->use_weight = pwt->use_weight || pwt->use_weight_chroma;
90 * Check if the top & left blocks are available if needed and
91 * change the dc mode so it only uses the available blocks.
93 int ff_h264_check_intra4x4_pred_mode(int8_t *pred_mode_cache, void *logctx,
94 int top_samples_available, int left_samples_available)
96 static const int8_t top[12] = {
97 -1, 0, LEFT_DC_PRED, -1, -1, -1, -1, -1, 0
99 static const int8_t left[12] = {
100 0, -1, TOP_DC_PRED, 0, -1, -1, -1, 0, -1, DC_128_PRED
104 if (!(top_samples_available & 0x8000)) {
105 for (i = 0; i < 4; i++) {
106 int status = top[pred_mode_cache[scan8[0] + i]];
108 av_log(logctx, AV_LOG_ERROR,
109 "top block unavailable for requested intra4x4 mode %d\n",
111 return AVERROR_INVALIDDATA;
113 pred_mode_cache[scan8[0] + i] = status;
118 if ((left_samples_available & 0x8888) != 0x8888) {
119 static const int mask[4] = { 0x8000, 0x2000, 0x80, 0x20 };
120 for (i = 0; i < 4; i++)
121 if (!(left_samples_available & mask[i])) {
122 int status = left[pred_mode_cache[scan8[0] + 8 * i]];
124 av_log(logctx, AV_LOG_ERROR,
125 "left block unavailable for requested intra4x4 mode %d\n",
127 return AVERROR_INVALIDDATA;
129 pred_mode_cache[scan8[0] + 8 * i] = status;
138 * Check if the top & left blocks are available if needed and
139 * change the dc mode so it only uses the available blocks.
141 int ff_h264_check_intra_pred_mode(void *logctx, int top_samples_available,
142 int left_samples_available,
143 int mode, int is_chroma)
145 static const int8_t top[4] = { LEFT_DC_PRED8x8, 1, -1, -1 };
146 static const int8_t left[5] = { TOP_DC_PRED8x8, -1, 2, -1, DC_128_PRED8x8 };
149 av_log(logctx, AV_LOG_ERROR,
150 "out of range intra chroma pred mode\n");
151 return AVERROR_INVALIDDATA;
154 if (!(top_samples_available & 0x8000)) {
157 av_log(logctx, AV_LOG_ERROR,
158 "top block unavailable for requested intra mode\n");
159 return AVERROR_INVALIDDATA;
163 if ((left_samples_available & 0x8080) != 0x8080) {
165 if (is_chroma && (left_samples_available & 0x8080)) {
166 // mad cow disease mode, aka MBAFF + constrained_intra_pred
167 mode = ALZHEIMER_DC_L0T_PRED8x8 +
168 (!(left_samples_available & 0x8000)) +
169 2 * (mode == DC_128_PRED8x8);
172 av_log(logctx, AV_LOG_ERROR,
173 "left block unavailable for requested intra mode\n");
174 return AVERROR_INVALIDDATA;
181 int ff_h264_parse_ref_count(int *plist_count, int ref_count[2],
182 GetBitContext *gb, const PPS *pps,
183 int slice_type_nos, int picture_structure)
186 int num_ref_idx_active_override_flag, max_refs;
188 // set defaults, might be overridden a few lines later
189 ref_count[0] = pps->ref_count[0];
190 ref_count[1] = pps->ref_count[1];
192 if (slice_type_nos != AV_PICTURE_TYPE_I) {
193 num_ref_idx_active_override_flag = get_bits1(gb);
195 if (num_ref_idx_active_override_flag) {
196 ref_count[0] = get_ue_golomb(gb) + 1;
197 if (ref_count[0] < 1)
199 if (slice_type_nos == AV_PICTURE_TYPE_B) {
200 ref_count[1] = get_ue_golomb(gb) + 1;
201 if (ref_count[1] < 1)
206 if (slice_type_nos == AV_PICTURE_TYPE_B)
212 ref_count[0] = ref_count[1] = 0;
215 max_refs = picture_structure == PICT_FRAME ? 16 : 32;
217 if (ref_count[0] > max_refs || ref_count[1] > max_refs)
220 *plist_count = list_count;
227 return AVERROR_INVALIDDATA;
230 int ff_h264_init_poc(int pic_field_poc[2], int *pic_poc,
231 const SPS *sps, H264POCContext *pc,
232 int picture_structure, int nal_ref_idc)
234 const int max_frame_num = 1 << sps->log2_max_frame_num;
237 pc->frame_num_offset = pc->prev_frame_num_offset;
238 if (pc->frame_num < pc->prev_frame_num)
239 pc->frame_num_offset += max_frame_num;
241 if (sps->poc_type == 0) {
242 const int max_poc_lsb = 1 << sps->log2_max_poc_lsb;
244 if (pc->poc_lsb < pc->prev_poc_lsb &&
245 pc->prev_poc_lsb - pc->poc_lsb >= max_poc_lsb / 2)
246 pc->poc_msb = pc->prev_poc_msb + max_poc_lsb;
247 else if (pc->poc_lsb > pc->prev_poc_lsb &&
248 pc->prev_poc_lsb - pc->poc_lsb < -max_poc_lsb / 2)
249 pc->poc_msb = pc->prev_poc_msb - max_poc_lsb;
251 pc->poc_msb = pc->prev_poc_msb;
253 field_poc[1] = pc->poc_msb + pc->poc_lsb;
254 if (picture_structure == PICT_FRAME)
255 field_poc[1] += pc->delta_poc_bottom;
256 } else if (sps->poc_type == 1) {
257 int abs_frame_num, expected_delta_per_poc_cycle, expectedpoc;
260 if (sps->poc_cycle_length != 0)
261 abs_frame_num = pc->frame_num_offset + pc->frame_num;
265 if (nal_ref_idc == 0 && abs_frame_num > 0)
268 expected_delta_per_poc_cycle = 0;
269 for (i = 0; i < sps->poc_cycle_length; i++)
270 // FIXME integrate during sps parse
271 expected_delta_per_poc_cycle += sps->offset_for_ref_frame[i];
273 if (abs_frame_num > 0) {
274 int poc_cycle_cnt = (abs_frame_num - 1) / sps->poc_cycle_length;
275 int frame_num_in_poc_cycle = (abs_frame_num - 1) % sps->poc_cycle_length;
277 expectedpoc = poc_cycle_cnt * expected_delta_per_poc_cycle;
278 for (i = 0; i <= frame_num_in_poc_cycle; i++)
279 expectedpoc = expectedpoc + sps->offset_for_ref_frame[i];
283 if (nal_ref_idc == 0)
284 expectedpoc = expectedpoc + sps->offset_for_non_ref_pic;
286 field_poc[0] = expectedpoc + pc->delta_poc[0];
287 field_poc[1] = field_poc[0] + sps->offset_for_top_to_bottom_field;
289 if (picture_structure == PICT_FRAME)
290 field_poc[1] += pc->delta_poc[1];
292 int poc = 2 * (pc->frame_num_offset + pc->frame_num);
301 if (picture_structure != PICT_BOTTOM_FIELD)
302 pic_field_poc[0] = field_poc[0];
303 if (picture_structure != PICT_TOP_FIELD)
304 pic_field_poc[1] = field_poc[1];
305 *pic_poc = FFMIN(pic_field_poc[0], pic_field_poc[1]);
310 static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
311 int is_avc, void *logctx)
313 H2645Packet pkt = { 0 };
316 ret = ff_h2645_packet_split(&pkt, data, size, logctx, is_avc, 2, AV_CODEC_ID_H264);
320 for (i = 0; i < pkt.nb_nals; i++) {
321 H2645NAL *nal = &pkt.nals[i];
324 ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps);
329 ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
335 av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
342 ff_h2645_packet_uninit(&pkt);
346 /* There are (invalid) samples in the wild with mp4-style extradata, where the
347 * parameter sets are stored unescaped (i.e. as RBSP).
348 * This function catches the parameter set decoding failure and tries again
349 * after escaping it */
350 static int decode_extradata_ps_mp4(const uint8_t *buf, int buf_size, H264ParamSets *ps,
351 int err_recognition, void *logctx)
355 ret = decode_extradata_ps(buf, buf_size, ps, 1, logctx);
356 if (ret < 0 && !(err_recognition & AV_EF_EXPLODE)) {
359 uint8_t *escaped_buf;
360 int escaped_buf_size;
362 av_log(logctx, AV_LOG_WARNING,
363 "SPS decoding failure, trying again after escaping the NAL\n");
365 if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3)
366 return AVERROR(ERANGE);
367 escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE;
368 escaped_buf = av_mallocz(escaped_buf_size);
370 return AVERROR(ENOMEM);
372 bytestream2_init(&gbc, buf, buf_size);
373 bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size);
375 while (bytestream2_get_bytes_left(&gbc)) {
376 if (bytestream2_get_bytes_left(&gbc) >= 3 &&
377 bytestream2_peek_be24(&gbc) <= 3) {
378 bytestream2_put_be24(&pbc, 3);
379 bytestream2_skip(&gbc, 2);
381 bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
384 escaped_buf_size = bytestream2_tell_p(&pbc);
385 AV_WB16(escaped_buf, escaped_buf_size - 2);
387 ret = decode_extradata_ps(escaped_buf, escaped_buf_size, ps, 1, logctx);
388 av_freep(&escaped_buf);
396 int ff_h264_decode_extradata(const uint8_t *data, int size, H264ParamSets *ps,
397 int *is_avc, int *nal_length_size,
398 int err_recognition, void *logctx)
404 const uint8_t *p = data;
409 av_log(logctx, AV_LOG_ERROR, "avcC %d too short\n", size);
410 return AVERROR_INVALIDDATA;
413 // Decode sps from avcC
414 cnt = *(p + 5) & 0x1f; // Number of sps
416 for (i = 0; i < cnt; i++) {
417 nalsize = AV_RB16(p) + 2;
418 if (p - data + nalsize > size)
419 return AVERROR_INVALIDDATA;
420 ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
422 av_log(logctx, AV_LOG_ERROR,
423 "Decoding sps %d from avcC failed\n", i);
428 // Decode pps from avcC
429 cnt = *(p++); // Number of pps
430 for (i = 0; i < cnt; i++) {
431 nalsize = AV_RB16(p) + 2;
432 if (p - data + nalsize > size)
433 return AVERROR_INVALIDDATA;
434 ret = decode_extradata_ps_mp4(p, nalsize, ps, err_recognition, logctx);
436 av_log(logctx, AV_LOG_ERROR,
437 "Decoding pps %d from avcC failed\n", i);
442 // Store right nal length size that will be used to parse all other nals
443 *nal_length_size = (data[4] & 0x03) + 1;
446 ret = decode_extradata_ps(data, size, ps, 0, logctx);