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ffmpeg/libavcodec/parser.c

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/*
* Audio and Video frame extraction
* Copyright (c) 2003 Fabrice Bellard
* Copyright (c) 2003 Michael Niedermayer
*
* 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
*/
#include <string.h>
#include "parser.h"
#include "libavutil/mem.h"
static AVCodecParser *av_first_parser = NULL;
AVCodecParser* av_parser_next(AVCodecParser *p){
if(p) return p->next;
else return av_first_parser;
}
void av_register_codec_parser(AVCodecParser *parser)
{
parser->next = av_first_parser;
av_first_parser = parser;
}
AVCodecParserContext *av_parser_init(int codec_id)
{
AVCodecParserContext *s;
AVCodecParser *parser;
int ret;
if(codec_id == AV_CODEC_ID_NONE)
return NULL;
for(parser = av_first_parser; parser != NULL; parser = parser->next) {
if (parser->codec_ids[0] == codec_id ||
parser->codec_ids[1] == codec_id ||
parser->codec_ids[2] == codec_id ||
parser->codec_ids[3] == codec_id ||
parser->codec_ids[4] == codec_id)
goto found;
}
return NULL;
found:
s = av_mallocz(sizeof(AVCodecParserContext));
if (!s)
return NULL;
s->parser = parser;
s->priv_data = av_mallocz(parser->priv_data_size);
if (!s->priv_data) {
av_free(s);
return NULL;
}
s->fetch_timestamp=1;
s->pict_type = AV_PICTURE_TYPE_I;
if (parser->parser_init) {
ret = parser->parser_init(s);
if (ret != 0) {
av_free(s->priv_data);
av_free(s);
return NULL;
}
}
s->key_frame = -1;
s->convergence_duration = 0;
s->dts_sync_point = INT_MIN;
s->dts_ref_dts_delta = INT_MIN;
s->pts_dts_delta = INT_MIN;
return s;
}
void ff_fetch_timestamp(AVCodecParserContext *s, int off, int remove){
int i;
s->dts= s->pts= AV_NOPTS_VALUE;
s->pos= -1;
s->offset= 0;
for(i = 0; i < AV_PARSER_PTS_NB; i++) {
if ( s->cur_offset + off >= s->cur_frame_offset[i]
&& (s->frame_offset < s->cur_frame_offset[i] ||
(!s->frame_offset && !s->next_frame_offset)) // first field/frame
//check is disabled because mpeg-ts doesn't send complete PES packets
&& /*s->next_frame_offset + off <*/ s->cur_frame_end[i]){
s->dts= s->cur_frame_dts[i];
s->pts= s->cur_frame_pts[i];
s->pos= s->cur_frame_pos[i];
s->offset = s->next_frame_offset - s->cur_frame_offset[i];
if(remove)
s->cur_frame_offset[i]= INT64_MAX;
if(s->cur_offset + off < s->cur_frame_end[i])
break;
}
}
}
int av_parser_parse2(AVCodecParserContext *s,
AVCodecContext *avctx,
uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size,
int64_t pts, int64_t dts,
int64_t pos)
{
int index, i;
uint8_t dummy_buf[FF_INPUT_BUFFER_PADDING_SIZE];
if(!(s->flags & PARSER_FLAG_FETCHED_OFFSET)) {
s->next_frame_offset =
s->cur_offset = pos;
s->flags |= PARSER_FLAG_FETCHED_OFFSET;
}
if (buf_size == 0) {
/* padding is always necessary even if EOF, so we add it here */
memset(dummy_buf, 0, sizeof(dummy_buf));
buf = dummy_buf;
} else if (s->cur_offset + buf_size !=
s->cur_frame_end[s->cur_frame_start_index]) { /* skip remainder packets */
/* add a new packet descriptor */
i = (s->cur_frame_start_index + 1) & (AV_PARSER_PTS_NB - 1);
s->cur_frame_start_index = i;
s->cur_frame_offset[i] = s->cur_offset;
s->cur_frame_end[i] = s->cur_offset + buf_size;
s->cur_frame_pts[i] = pts;
s->cur_frame_dts[i] = dts;
s->cur_frame_pos[i] = pos;
}
if (s->fetch_timestamp){
s->fetch_timestamp=0;
s->last_pts = s->pts;
s->last_dts = s->dts;
s->last_pos = s->pos;
ff_fetch_timestamp(s, 0, 0);
}
/* WARNING: the returned index can be negative */
index = s->parser->parser_parse(s, avctx, (const uint8_t **)poutbuf, poutbuf_size, buf, buf_size);
/* update the file pointer */
if (*poutbuf_size) {
/* fill the data for the current frame */
s->frame_offset = s->next_frame_offset;
/* offset of the next frame */
s->next_frame_offset = s->cur_offset + index;
s->fetch_timestamp=1;
}
if (index < 0)
index = 0;
s->cur_offset += index;
return index;
}
/**
*
* @return 0 if the output buffer is a subset of the input, 1 if it is allocated and must be freed
* @deprecated use AVBitstreamFilter
*/
int av_parser_change(AVCodecParserContext *s,
AVCodecContext *avctx,
uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size, int keyframe){
if(s && s->parser->split){
if((avctx->flags & CODEC_FLAG_GLOBAL_HEADER) || (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER)){
int i= s->parser->split(avctx, buf, buf_size);
buf += i;
buf_size -= i;
}
}
/* cast to avoid warning about discarding qualifiers */
*poutbuf= (uint8_t *) buf;
*poutbuf_size= buf_size;
if(avctx->extradata){
if( (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER))
/*||(s->pict_type != AV_PICTURE_TYPE_I && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_NOKEY))*/
/*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
int size= buf_size + avctx->extradata_size;
*poutbuf_size= size;
*poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
return 1;
}
}
return 0;
}
void av_parser_close(AVCodecParserContext *s)
{
if(s){
if (s->parser->parser_close)
s->parser->parser_close(s);
av_free(s->priv_data);
av_free(s);
}
}
/*****************************************************/
/**
* Combine the (truncated) bitstream to a complete frame.
* @return -1 if no complete frame could be created, AVERROR(ENOMEM) if there was a memory allocation error
*/
int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
{
if(pc->overread){
av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
pc->overread, pc->state, next, pc->index, pc->overread_index);
av_dlog(NULL, "%X %X %X %X\n", (*buf)[0], (*buf)[1], (*buf)[2], (*buf)[3]);
}
/* Copy overread bytes from last frame into buffer. */
for(; pc->overread>0; pc->overread--){
pc->buffer[pc->index++]= pc->buffer[pc->overread_index++];
}
/* flush remaining if EOF */
if(!*buf_size && next == END_NOT_FOUND){
next= 0;
}
pc->last_index= pc->index;
/* copy into buffer end return */
if(next == END_NOT_FOUND){
void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, (*buf_size) + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
if(!new_buffer)
return AVERROR(ENOMEM);
pc->buffer = new_buffer;
memcpy(&pc->buffer[pc->index], *buf, *buf_size);
pc->index += *buf_size;
return -1;
}
*buf_size=
pc->overread_index= pc->index + next;
/* append to buffer */
if(pc->index){
void* new_buffer = av_fast_realloc(pc->buffer, &pc->buffer_size, next + pc->index + FF_INPUT_BUFFER_PADDING_SIZE);
if(!new_buffer)
return AVERROR(ENOMEM);
pc->buffer = new_buffer;
if(FF_INPUT_BUFFER_PADDING_SIZE > -next)
memcpy(&pc->buffer[pc->index], *buf, next + FF_INPUT_BUFFER_PADDING_SIZE );
pc->index = 0;
*buf= pc->buffer;
}
/* store overread bytes */
for(;next < 0; next++){
pc->state = (pc->state<<8) | pc->buffer[pc->last_index + next];
pc->state64 = (pc->state64<<8) | pc->buffer[pc->last_index + next];
pc->overread++;
}
if(pc->overread){
av_dlog(NULL, "overread %d, state:%X next:%d index:%d o_index:%d\n",
pc->overread, pc->state, next, pc->index, pc->overread_index);
av_dlog(NULL, "%X %X %X %X\n", (*buf)[0], (*buf)[1],(*buf)[2],(*buf)[3]);
}
return 0;
}
void ff_parse_close(AVCodecParserContext *s)
{
ParseContext *pc = s->priv_data;
av_freep(&pc->buffer);
}
/*************************/
int ff_mpeg4video_split(AVCodecContext *avctx,
const uint8_t *buf, int buf_size)
{
int i;
uint32_t state= -1;
for(i=0; i<buf_size; i++){
state= (state<<8) | buf[i];
if(state == 0x1B3 || state == 0x1B6)
return i-3;
}
return 0;
}
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