mirror of https://git.ffmpeg.org/ffmpeg.git
126 lines
3.9 KiB
C
126 lines
3.9 KiB
C
/*
|
|
* HEVC Annex B format parser
|
|
*
|
|
* Copyright (C) 2012 - 2013 Guillaume Martres
|
|
*
|
|
* This file is part of Libav.
|
|
*
|
|
* Libav is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* Libav is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with Libav; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#include "libavutil/common.h"
|
|
|
|
#include "parser.h"
|
|
#include "hevc.h"
|
|
|
|
#define START_CODE 0x000001 ///< start_code_prefix_one_3bytes
|
|
|
|
/**
|
|
* Find the end of the current frame in the bitstream.
|
|
* @return the position of the first byte of the next frame, or END_NOT_FOUND
|
|
*/
|
|
static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
|
|
int buf_size)
|
|
{
|
|
int i;
|
|
ParseContext *pc = s->priv_data;
|
|
|
|
for (i = 0; i < buf_size; i++) {
|
|
int nut;
|
|
|
|
pc->state64 = (pc->state64 << 8) | buf[i];
|
|
|
|
if (((pc->state64 >> 3 * 8) & 0xFFFFFF) != START_CODE)
|
|
continue;
|
|
|
|
nut = (pc->state64 >> 2 * 8 + 1) & 0x3F;
|
|
// Beginning of access unit
|
|
if ((nut >= NAL_VPS && nut <= NAL_AUD) || nut == NAL_SEI_PREFIX ||
|
|
(nut >= 41 && nut <= 44) || (nut >= 48 && nut <= 55)) {
|
|
if (pc->frame_start_found) {
|
|
pc->frame_start_found = 0;
|
|
return i - 5;
|
|
}
|
|
} else if (nut <= NAL_RASL_R ||
|
|
(nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT)) {
|
|
int first_slice_segment_in_pic_flag = buf[i] >> 7;
|
|
if (first_slice_segment_in_pic_flag) {
|
|
if (!pc->frame_start_found) {
|
|
pc->frame_start_found = 1;
|
|
s->key_frame = nut >= NAL_BLA_W_LP && nut <= NAL_CRA_NUT;
|
|
} else { // First slice of next frame found
|
|
pc->frame_start_found = 0;
|
|
return i - 5;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return END_NOT_FOUND;
|
|
}
|
|
|
|
static int hevc_parse(AVCodecParserContext *s, AVCodecContext *avctx,
|
|
const uint8_t **poutbuf, int *poutbuf_size,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
int next;
|
|
ParseContext *pc = s->priv_data;
|
|
|
|
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
|
|
next = buf_size;
|
|
} else {
|
|
next = hevc_find_frame_end(s, buf, buf_size);
|
|
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
|
|
*poutbuf = NULL;
|
|
*poutbuf_size = 0;
|
|
return buf_size;
|
|
}
|
|
}
|
|
|
|
*poutbuf = buf;
|
|
*poutbuf_size = buf_size;
|
|
return next;
|
|
}
|
|
|
|
// Split after the parameter sets at the beginning of the stream if they exist.
|
|
static int hevc_split(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
|
|
{
|
|
int i;
|
|
uint32_t state = -1;
|
|
int has_ps = 0;
|
|
|
|
for (i = 0; i < buf_size; i++) {
|
|
state = (state << 8) | buf[i];
|
|
if (((state >> 8) & 0xFFFFFF) == START_CODE) {
|
|
int nut = (state >> 1) & 0x3F;
|
|
if (nut >= NAL_VPS && nut <= NAL_PPS)
|
|
has_ps = 1;
|
|
else if (has_ps)
|
|
return i - 3;
|
|
else // no parameter set at the beginning of the stream
|
|
return 0;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
AVCodecParser ff_hevc_parser = {
|
|
.codec_ids = { AV_CODEC_ID_HEVC },
|
|
.priv_data_size = sizeof(ParseContext),
|
|
.parser_parse = hevc_parse,
|
|
.parser_close = ff_parse_close,
|
|
.split = hevc_split,
|
|
};
|