2 * HEVC Annex B format parser
4 * Copyright (C) 2012 - 2013 Guillaume Martres
6 * This file is part of FFmpeg.
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.
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.
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
23 #include "libavutil/common.h"
29 #include "h2645_parse.h"
33 #define START_CODE 0x000001 ///< start_code_prefix_one_3bytes
35 #define IS_IRAP_NAL(nal) (nal->type >= 16 && nal->type <= 23)
36 #define IS_IDR_NAL(nal) (nal->type == HEVC_NAL_IDR_W_RADL || nal->type == HEVC_NAL_IDR_N_LP)
38 typedef struct HEVCParserContext {
52 static int hevc_parse_slice_header(AVCodecParserContext *s, H2645NAL *nal,
53 AVCodecContext *avctx)
55 HEVCParserContext *ctx = s->priv_data;
56 HEVCParamSets *ps = &ctx->ps;
57 HEVCSEIContext *sei = &ctx->sei;
58 SliceHeader *sh = &ctx->sh;
59 GetBitContext *gb = &nal->gb;
61 int i, num = 0, den = 0;
63 sh->first_slice_in_pic_flag = get_bits1(gb);
64 s->picture_structure = sei->picture_timing.picture_struct;
65 s->field_order = sei->picture_timing.picture_struct;
67 if (IS_IRAP_NAL(nal)) {
69 sh->no_output_of_prior_pics_flag = get_bits1(gb);
72 sh->pps_id = get_ue_golomb(gb);
73 if (sh->pps_id >= HEVC_MAX_PPS_COUNT || !ps->pps_list[sh->pps_id]) {
74 av_log(avctx, AV_LOG_ERROR, "PPS id out of range: %d\n", sh->pps_id);
75 return AVERROR_INVALIDDATA;
77 ps->pps = (HEVCPPS*)ps->pps_list[sh->pps_id]->data;
79 if (ps->pps->sps_id >= HEVC_MAX_SPS_COUNT || !ps->sps_list[ps->pps->sps_id]) {
80 av_log(avctx, AV_LOG_ERROR, "SPS id out of range: %d\n", ps->pps->sps_id);
81 return AVERROR_INVALIDDATA;
83 if (ps->sps != (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data) {
84 ps->sps = (HEVCSPS*)ps->sps_list[ps->pps->sps_id]->data;
85 ps->vps = (HEVCVPS*)ps->vps_list[ps->sps->vps_id]->data;
87 ow = &ps->sps->output_window;
89 s->coded_width = ps->sps->width;
90 s->coded_height = ps->sps->height;
91 s->width = ps->sps->width - ow->left_offset - ow->right_offset;
92 s->height = ps->sps->height - ow->top_offset - ow->bottom_offset;
93 s->format = ps->sps->pix_fmt;
94 avctx->profile = ps->sps->ptl.general_ptl.profile_idc;
95 avctx->level = ps->sps->ptl.general_ptl.level_idc;
97 if (ps->vps->vps_timing_info_present_flag) {
98 num = ps->vps->vps_num_units_in_tick;
99 den = ps->vps->vps_time_scale;
100 } else if (ps->sps->vui.vui_timing_info_present_flag) {
101 num = ps->sps->vui.vui_num_units_in_tick;
102 den = ps->sps->vui.vui_time_scale;
105 if (num != 0 && den != 0)
106 av_reduce(&avctx->framerate.den, &avctx->framerate.num,
109 if (!sh->first_slice_in_pic_flag) {
110 int slice_address_length;
112 if (ps->pps->dependent_slice_segments_enabled_flag)
113 sh->dependent_slice_segment_flag = get_bits1(gb);
115 sh->dependent_slice_segment_flag = 0;
117 slice_address_length = av_ceil_log2_c(ps->sps->ctb_width *
118 ps->sps->ctb_height);
119 sh->slice_segment_addr = get_bitsz(gb, slice_address_length);
120 if (sh->slice_segment_addr >= ps->sps->ctb_width * ps->sps->ctb_height) {
121 av_log(avctx, AV_LOG_ERROR, "Invalid slice segment address: %u.\n",
122 sh->slice_segment_addr);
123 return AVERROR_INVALIDDATA;
126 sh->dependent_slice_segment_flag = 0;
128 if (sh->dependent_slice_segment_flag)
129 return 0; /* break; */
131 for (i = 0; i < ps->pps->num_extra_slice_header_bits; i++)
132 skip_bits(gb, 1); // slice_reserved_undetermined_flag[]
134 sh->slice_type = get_ue_golomb(gb);
135 if (!(sh->slice_type == HEVC_SLICE_I || sh->slice_type == HEVC_SLICE_P ||
136 sh->slice_type == HEVC_SLICE_B)) {
137 av_log(avctx, AV_LOG_ERROR, "Unknown slice type: %d.\n",
139 return AVERROR_INVALIDDATA;
141 s->pict_type = sh->slice_type == HEVC_SLICE_B ? AV_PICTURE_TYPE_B :
142 sh->slice_type == HEVC_SLICE_P ? AV_PICTURE_TYPE_P :
145 if (ps->pps->output_flag_present_flag)
146 sh->pic_output_flag = get_bits1(gb);
148 if (ps->sps->separate_colour_plane_flag)
149 sh->colour_plane_id = get_bits(gb, 2);
151 if (!IS_IDR_NAL(nal)) {
152 sh->pic_order_cnt_lsb = get_bits(gb, ps->sps->log2_max_poc_lsb);
153 s->output_picture_number = ctx->poc = ff_hevc_compute_poc(ps->sps, ctx->pocTid0, sh->pic_order_cnt_lsb, nal->type);
155 s->output_picture_number = ctx->poc = 0;
157 if (nal->temporal_id == 0 &&
158 nal->type != HEVC_NAL_TRAIL_N &&
159 nal->type != HEVC_NAL_TSA_N &&
160 nal->type != HEVC_NAL_STSA_N &&
161 nal->type != HEVC_NAL_RADL_N &&
162 nal->type != HEVC_NAL_RASL_N &&
163 nal->type != HEVC_NAL_RADL_R &&
164 nal->type != HEVC_NAL_RASL_R)
165 ctx->pocTid0 = ctx->poc;
167 return 1; /* no need to evaluate the rest */
171 * Parse NAL units of found picture and decode some basic information.
173 * @param s parser context.
174 * @param avctx codec context.
175 * @param buf buffer with field/frame data.
176 * @param buf_size size of the buffer.
178 static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
179 int buf_size, AVCodecContext *avctx)
181 HEVCParserContext *ctx = s->priv_data;
182 HEVCParamSets *ps = &ctx->ps;
183 HEVCSEIContext *sei = &ctx->sei;
184 int is_global = buf == avctx->extradata;
187 /* set some sane default values */
188 s->pict_type = AV_PICTURE_TYPE_I;
190 s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
192 ff_hevc_reset_sei(sei);
194 ret = ff_h2645_packet_split(&ctx->pkt, buf, buf_size, avctx, 0, 0,
195 AV_CODEC_ID_HEVC, 1);
199 for (i = 0; i < ctx->pkt.nb_nals; i++) {
200 H2645NAL *nal = &ctx->pkt.nals[i];
201 GetBitContext *gb = &nal->gb;
205 ff_hevc_decode_nal_vps(gb, avctx, ps);
208 ff_hevc_decode_nal_sps(gb, avctx, ps, 1);
211 ff_hevc_decode_nal_pps(gb, avctx, ps);
213 case HEVC_NAL_SEI_PREFIX:
214 case HEVC_NAL_SEI_SUFFIX:
215 ff_hevc_decode_nal_sei(gb, avctx, sei, ps, nal->type);
217 case HEVC_NAL_TRAIL_N:
218 case HEVC_NAL_TRAIL_R:
221 case HEVC_NAL_STSA_N:
222 case HEVC_NAL_STSA_R:
223 case HEVC_NAL_BLA_W_LP:
224 case HEVC_NAL_BLA_W_RADL:
225 case HEVC_NAL_BLA_N_LP:
226 case HEVC_NAL_IDR_W_RADL:
227 case HEVC_NAL_IDR_N_LP:
228 case HEVC_NAL_CRA_NUT:
229 case HEVC_NAL_RADL_N:
230 case HEVC_NAL_RADL_R:
231 case HEVC_NAL_RASL_N:
232 case HEVC_NAL_RASL_R:
235 av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit: %d\n", nal->type);
236 return AVERROR_INVALIDDATA;
239 ret = hevc_parse_slice_header(s, nal, avctx);
245 /* didn't find a picture! */
247 av_log(avctx, AV_LOG_ERROR, "missing picture in access unit\n");
252 * Find the end of the current frame in the bitstream.
253 * @return the position of the first byte of the next frame, or END_NOT_FOUND
255 static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
258 HEVCParserContext *ctx = s->priv_data;
259 ParseContext *pc = &ctx->pc;
262 for (i = 0; i < buf_size; i++) {
265 pc->state64 = (pc->state64 << 8) | buf[i];
267 if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
270 nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;
271 // Beginning of access unit
272 if ((nut >= HEVC_NAL_VPS && nut <= HEVC_NAL_EOB_NUT) || nut == HEVC_NAL_SEI_PREFIX ||
273 (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
274 if (pc->frame_start_found) {
275 pc->frame_start_found = 0;
278 } else if (nut <= HEVC_NAL_RASL_R ||
279 (nut >= HEVC_NAL_BLA_W_LP && nut <= HEVC_NAL_CRA_NUT)) {
280 int first_slice_segment_in_pic_flag = buf[i] >> 7;
281 if (first_slice_segment_in_pic_flag) {
282 if (!pc->frame_start_found) {
283 pc->frame_start_found = 1;
284 } else { // First slice of next frame found
285 pc->frame_start_found = 0;
292 return END_NOT_FOUND;
295 static int hevc_parse(AVCodecParserContext *s, AVCodecContext *avctx,
296 const uint8_t **poutbuf, int *poutbuf_size,
297 const uint8_t *buf, int buf_size)
300 HEVCParserContext *ctx = s->priv_data;
301 ParseContext *pc = &ctx->pc;
303 if (avctx->extradata && !ctx->parsed_extradata) {
304 parse_nal_units(s, avctx->extradata, avctx->extradata_size, avctx);
305 ctx->parsed_extradata = 1;
308 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
311 next = hevc_find_frame_end(s, buf, buf_size);
312 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
319 parse_nal_units(s, buf, buf_size, avctx);
322 *poutbuf_size = buf_size;
326 // Split after the parameter sets at the beginning of the stream if they exist.
327 static int hevc_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
329 const uint8_t *ptr = buf, *end = buf + buf_size;
337 ptr = avpriv_find_start_code(ptr, end, &state);
338 if ((state >> 8) != START_CODE)
340 nut = (state >> 1) & 0x3F;
341 if (nut == HEVC_NAL_VPS)
343 else if (nut == HEVC_NAL_SPS)
345 else if (nut == HEVC_NAL_PPS)
347 else if ((nut != HEVC_NAL_SEI_PREFIX || has_pps) &&
348 nut != HEVC_NAL_AUD) {
349 if (has_vps && has_sps) {
350 while (ptr - 4 > buf && ptr[-5] == 0)
352 return ptr - 4 - buf;
359 static void hevc_parser_close(AVCodecParserContext *s)
361 HEVCParserContext *ctx = s->priv_data;
364 for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.vps_list); i++)
365 av_buffer_unref(&ctx->ps.vps_list[i]);
366 for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.sps_list); i++)
367 av_buffer_unref(&ctx->ps.sps_list[i]);
368 for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.pps_list); i++)
369 av_buffer_unref(&ctx->ps.pps_list[i]);
373 ff_h2645_packet_uninit(&ctx->pkt);
374 ff_hevc_reset_sei(&ctx->sei);
376 av_freep(&ctx->pc.buffer);
379 AVCodecParser ff_hevc_parser = {
380 .codec_ids = { AV_CODEC_ID_HEVC },
381 .priv_data_size = sizeof(HEVCParserContext),
382 .parser_parse = hevc_parse,
383 .parser_close = hevc_parser_close,