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/*
* 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,
};
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