2 * HEVC Annex B format parser
4 * Copyright (C) 2012 - 2013 Guillaume Martres
6 * This file is part of Libav.
8 * Libav 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 * Libav 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 Libav; 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 #define START_CODE 0x000001 ///< start_code_prefix_one_3bytes
31 #define IS_IRAP_NAL(nal) (nal->type >= 16 && nal->type <= 23)
33 typedef struct HEVCParserContext {
42 static int hevc_parse_slice_header(AVCodecParserContext *s, HEVCNAL *nal,
43 AVCodecContext *avctx)
45 HEVCParserContext *ctx = s->priv_data;
46 GetBitContext *gb = &nal->gb;
52 get_bits1(gb); // first slice in pic
54 get_bits1(gb); // no output of prior pics
56 pps_id = get_ue_golomb_long(gb);
57 if (pps_id >= MAX_PPS_COUNT || !ctx->ps.pps_list[pps_id]) {
58 av_log(avctx, AV_LOG_ERROR, "PPS id out of range: %d\n", pps_id);
59 return AVERROR_INVALIDDATA;
61 pps = (HEVCPPS*)ctx->ps.pps_list[pps_id]->data;
62 sps = (HEVCSPS*)ctx->ps.sps_list[pps->sps_id]->data;
64 /* export the stream parameters */
65 s->coded_width = sps->width;
66 s->coded_height = sps->height;
67 s->width = sps->output_width;
68 s->height = sps->output_height;
69 s->format = sps->pix_fmt;
70 avctx->profile = sps->ptl.general_ptl.profile_idc;
71 avctx->level = sps->ptl.general_ptl.level_idc;
73 /* ignore the rest for now*/
78 static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
79 int buf_size, AVCodecContext *avctx)
81 HEVCParserContext *ctx = s->priv_data;
84 ret = ff_hevc_split_packet(&ctx->pkt, buf, buf_size, avctx, 0, 0);
88 for (i = 0; i < ctx->pkt.nb_nals; i++) {
89 HEVCNAL *nal = &ctx->pkt.nals[i];
91 /* ignore everything except parameter sets and VCL NALUs */
93 case NAL_VPS: ff_hevc_decode_nal_vps(&nal->gb, avctx, &ctx->ps); break;
94 case NAL_SPS: ff_hevc_decode_nal_sps(&nal->gb, avctx, &ctx->ps, 1); break;
95 case NAL_PPS: ff_hevc_decode_nal_pps(&nal->gb, avctx, &ctx->ps); break;
111 case NAL_RASL_R: hevc_parse_slice_header(s, nal, avctx); break;
119 * Find the end of the current frame in the bitstream.
120 * @return the position of the first byte of the next frame, or END_NOT_FOUND
122 static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
125 HEVCParserContext *ctx = s->priv_data;
126 ParseContext *pc = &ctx->pc;
129 for (i = 0; i < buf_size; i++) {
132 pc->state64 = (pc->state64 << 8) | buf[i];
134 if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
137 nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;
138 // Beginning of access unit
139 if ((nut >= NAL_VPS && nut <= NAL_AUD) || nut == NAL_SEI_PREFIX ||
140 (nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
141 if (pc->frame_start_found) {
142 pc->frame_start_found = 0;
145 } else if (nut <= NAL_RASL_R ||
146 (nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT)) {
147 int first_slice_segment_in_pic_flag = buf[i] >> 7;
148 if (first_slice_segment_in_pic_flag) {
149 if (!pc->frame_start_found) {
150 pc->frame_start_found = 1;
151 s->key_frame = nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT;
152 } else { // First slice of next frame found
153 pc->frame_start_found = 0;
160 return END_NOT_FOUND;
163 static int hevc_parse(AVCodecParserContext *s, AVCodecContext *avctx,
164 const uint8_t **poutbuf, int *poutbuf_size,
165 const uint8_t *buf, int buf_size)
169 HEVCParserContext *ctx = s->priv_data;
170 ParseContext *pc = &ctx->pc;
172 if (avctx->extradata && !ctx->parsed_extradata) {
173 parse_nal_units(s, avctx->extradata, avctx->extradata_size, avctx);
174 ctx->parsed_extradata = 1;
177 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
180 next = hevc_find_frame_end(s, buf, buf_size);
181 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
188 parse_nal_units(s, buf, buf_size, avctx);
191 *poutbuf_size = buf_size;
195 // Split after the parameter sets at the beginning of the stream if they exist.
196 static int hevc_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
202 for (i = 0; i < buf_size; i++) {
203 state = (state << 8) | buf[i];
204 if (((state >> 8) & 0xFFFFFF) == START_CODE) {
205 int nut = (state >> 1) & 0x3F;
206 if (nut >= NAL_VPS && nut <= NAL_PPS)
210 else // no parameter set at the beginning of the stream
217 static void hevc_parser_close(AVCodecParserContext *s)
219 HEVCParserContext *ctx = s->priv_data;
222 for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.vps_list); i++)
223 av_buffer_unref(&ctx->ps.vps_list[i]);
224 for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.sps_list); i++)
225 av_buffer_unref(&ctx->ps.sps_list[i]);
226 for (i = 0; i < FF_ARRAY_ELEMS(ctx->ps.pps_list); i++)
227 av_buffer_unref(&ctx->ps.pps_list[i]);
229 for (i = 0; i < ctx->pkt.nals_allocated; i++)
230 av_freep(&ctx->pkt.nals[i].rbsp_buffer);
231 av_freep(&ctx->pkt.nals);
232 ctx->pkt.nals_allocated = 0;
234 av_freep(&ctx->pc.buffer);
237 AVCodecParser ff_hevc_parser = {
238 .codec_ids = { AV_CODEC_ID_HEVC },
239 .priv_data_size = sizeof(HEVCParserContext),
240 .parser_parse = hevc_parse,
241 .parser_close = hevc_parser_close,