mirror of https://git.ffmpeg.org/ffmpeg.git
150 lines
4.1 KiB
C
150 lines
4.1 KiB
C
/*
|
|
* H.26L/H.264/AVC/JVT/14496-10/... parser
|
|
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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.
|
|
*
|
|
* FFmpeg 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 FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*
|
|
*/
|
|
|
|
/**
|
|
* @file h264_parser.c
|
|
* H.264 / AVC / MPEG4 part10 parser.
|
|
* @author Michael Niedermayer <michaelni@gmx.at>
|
|
*/
|
|
|
|
#include "parser.h"
|
|
#include "h264_parser.h"
|
|
|
|
#include <assert.h>
|
|
|
|
|
|
int ff_h264_find_frame_end(H264Context *h, const uint8_t *buf, int buf_size)
|
|
{
|
|
int i;
|
|
uint32_t state;
|
|
ParseContext *pc = &(h->s.parse_context);
|
|
//printf("first %02X%02X%02X%02X\n", buf[0], buf[1],buf[2],buf[3]);
|
|
// mb_addr= pc->mb_addr - 1;
|
|
state= pc->state;
|
|
if(state>13)
|
|
state= 7;
|
|
|
|
for(i=0; i<buf_size; i++){
|
|
if(state==7){
|
|
for(; i<buf_size; i++){
|
|
if(!buf[i]){
|
|
state=2;
|
|
break;
|
|
}
|
|
}
|
|
}else if(state<=2){
|
|
if(buf[i]==1) state^= 5; //2->7, 1->4, 0->5
|
|
else if(buf[i]) state = 7;
|
|
else state>>=1; //2->1, 1->0, 0->0
|
|
}else if(state<=5){
|
|
int v= buf[i] & 0x1F;
|
|
if(v==7 || v==8 || v==9){
|
|
if(pc->frame_start_found){
|
|
i++;
|
|
found:
|
|
pc->state=7;
|
|
pc->frame_start_found= 0;
|
|
return i-(state&5);
|
|
}
|
|
}else if(v==1 || v==2 || v==5){
|
|
if(pc->frame_start_found){
|
|
state+=8;
|
|
continue;
|
|
}else
|
|
pc->frame_start_found = 1;
|
|
}
|
|
state= 7;
|
|
}else{
|
|
if(buf[i] & 0x80)
|
|
goto found;
|
|
state= 7;
|
|
}
|
|
}
|
|
pc->state= state;
|
|
return END_NOT_FOUND;
|
|
}
|
|
|
|
static int h264_parse(AVCodecParserContext *s,
|
|
AVCodecContext *avctx,
|
|
const uint8_t **poutbuf, int *poutbuf_size,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
H264Context *h = s->priv_data;
|
|
ParseContext *pc = &h->s.parse_context;
|
|
int next;
|
|
|
|
if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
|
|
next= buf_size;
|
|
}else{
|
|
next= ff_h264_find_frame_end(h, buf, buf_size);
|
|
|
|
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
|
|
*poutbuf = NULL;
|
|
*poutbuf_size = 0;
|
|
return buf_size;
|
|
}
|
|
|
|
if(next<0 && next != END_NOT_FOUND){
|
|
assert(pc->last_index + next >= 0 );
|
|
ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
|
|
}
|
|
}
|
|
|
|
*poutbuf = buf;
|
|
*poutbuf_size = buf_size;
|
|
return next;
|
|
}
|
|
|
|
static int h264_split(AVCodecContext *avctx,
|
|
const uint8_t *buf, int buf_size)
|
|
{
|
|
int i;
|
|
uint32_t state = -1;
|
|
int has_sps= 0;
|
|
|
|
for(i=0; i<=buf_size; i++){
|
|
if((state&0xFFFFFF1F) == 0x107)
|
|
has_sps=1;
|
|
/* if((state&0xFFFFFF1F) == 0x101 || (state&0xFFFFFF1F) == 0x102 || (state&0xFFFFFF1F) == 0x105){
|
|
}*/
|
|
if((state&0xFFFFFF00) == 0x100 && (state&0xFFFFFF1F) != 0x107 && (state&0xFFFFFF1F) != 0x108 && (state&0xFFFFFF1F) != 0x109){
|
|
if(has_sps){
|
|
while(i>4 && buf[i-5]==0) i--;
|
|
return i-4;
|
|
}
|
|
}
|
|
if (i<buf_size)
|
|
state= (state<<8) | buf[i];
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
AVCodecParser h264_parser = {
|
|
{ CODEC_ID_H264 },
|
|
sizeof(H264Context),
|
|
NULL,
|
|
h264_parse,
|
|
ff_parse_close,
|
|
h264_split,
|
|
};
|