mpv/libmpdemux/parse_es.c

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//=================== MPEG-ES VIDEO PARSER =========================
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "config.h"
#include "mp_msg.h"
#include "help_mp.h"
#include "stream.h"
#include "demuxer.h"
#include "parse_es.h"
//static unsigned char videobuffer[MAX_VIDEO_PACKET_SIZE];
unsigned char* videobuffer=NULL;
int videobuf_len=0;
unsigned char videobuf_code[4];
int videobuf_code_len=0;
// sync video stream, and returns next packet code
int sync_video_packet(demux_stream_t *ds){
int skipped=0;
// we need enough bytes in the buffer:
while(videobuf_code_len<4){
#if 0
int c;
c=demux_getc(ds);if(c<0){ return 0;} // EOF
videobuf_code[videobuf_code_len++]=c;
#else
videobuf_code[videobuf_code_len++]=demux_getc(ds);
#endif
}
// sync packet:
while(1){
int c;
if(videobuf_code[0]==0 &&
videobuf_code[1]==0 &&
videobuf_code[2]==1) break; // synced
// shift buffer, drop first byte
++skipped;
videobuf_code[0]=videobuf_code[1];
videobuf_code[1]=videobuf_code[2];
videobuf_code[2]=videobuf_code[3];
c=demux_getc(ds);if(c<0){ return 0;} // EOF
videobuf_code[3]=c;
}
if(skipped) mp_dbg(MSGT_PARSEES,MSGL_DBG2,"videobuf: %d bytes skipped (next: 0x1%02X)\n",skipped,videobuf_code[3]);
return 0x100|videobuf_code[3];
}
// return: packet length
int read_video_packet(demux_stream_t *ds){
int packet_start;
// SYNC STREAM
// if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
// COPY STARTCODE:
packet_start=videobuf_len;
videobuffer[videobuf_len+0]=videobuf_code[0];
videobuffer[videobuf_len+1]=videobuf_code[1];
videobuffer[videobuf_len+2]=videobuf_code[2];
videobuffer[videobuf_len+3]=videobuf_code[3];
videobuf_len+=4;
// READ PACKET:
{ unsigned int head=-1;
while(videobuf_len<VIDEOBUFFER_SIZE){
int c=demux_getc(ds);
if(c<0) break; // EOF
videobuffer[videobuf_len++]=c;
#if 1
head<<=8;
if(head==0x100) break; // synced
head|=c;
#else
if(videobuffer[videobuf_len-4]==0 &&
videobuffer[videobuf_len-3]==0 &&
videobuffer[videobuf_len-2]==1) break; // synced
#endif
}
}
if(ds->eof){
videobuf_code_len=0; // EOF, no next code
return videobuf_len-packet_start;
}
videobuf_len-=4;
mp_dbg(MSGT_PARSEES,MSGL_DBG2,"videobuf: packet 0x1%02X len=%d (total=%d)\n",videobuffer[packet_start+3],videobuf_len-packet_start,videobuf_len);
// Save next packet code:
videobuf_code[0]=videobuffer[videobuf_len];
videobuf_code[1]=videobuffer[videobuf_len+1];
videobuf_code[2]=videobuffer[videobuf_len+2];
videobuf_code[3]=videobuffer[videobuf_len+3];
videobuf_code_len=4;
return videobuf_len-packet_start;
}
// return: next packet code
int skip_video_packet(demux_stream_t *ds){
// SYNC STREAM
// if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
videobuf_code_len=0; // force resync
// SYNC AGAIN:
return sync_video_packet(ds);
}