mirror of
https://github.com/mpv-player/mpv
synced 2024-12-15 03:15:52 +00:00
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
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//=================== VIDEO PARSER =========================
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#define MAX_VIDEO_PACKET_SIZE (224*1024+4)
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#define VIDEOBUFFER_SIZE 0x100000
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//static unsigned char videobuffer[MAX_VIDEO_PACKET_SIZE];
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static unsigned char* videobuffer=NULL;
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static int videobuf_len=0;
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static unsigned char videobuf_code[4];
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static int videobuf_code_len=0;
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// sync video stream, and returns next packet code
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int sync_video_packet(demux_stream_t *ds){
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int skipped=0;
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// we need enough bytes in the buffer:
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while(videobuf_code_len<4){
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#if 0
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int c;
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c=demux_getc(ds);if(c<0){ return 0;} // EOF
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videobuf_code[videobuf_code_len++]=c;
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#else
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videobuf_code[videobuf_code_len++]=demux_getc(ds);
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#endif
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}
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// sync packet:
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while(1){
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int c;
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if(videobuf_code[0]==0 &&
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videobuf_code[1]==0 &&
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videobuf_code[2]==1) break; // synced
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// shift buffer, drop first byte
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++skipped;
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videobuf_code[0]=videobuf_code[1];
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videobuf_code[1]=videobuf_code[2];
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videobuf_code[2]=videobuf_code[3];
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c=demux_getc(ds);if(c<0){ return 0;} // EOF
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videobuf_code[3]=c;
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}
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if(verbose>=2) if(skipped) printf("videobuf: %d bytes skipped\n",skipped);
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return 0x100|videobuf_code[3];
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}
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// return: packet length
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int read_video_packet(demux_stream_t *ds){
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int packet_start;
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// SYNC STREAM
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// if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
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// COPY STARTCODE:
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packet_start=videobuf_len;
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videobuffer[videobuf_len+0]=videobuf_code[0];
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videobuffer[videobuf_len+1]=videobuf_code[1];
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videobuffer[videobuf_len+2]=videobuf_code[2];
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videobuffer[videobuf_len+3]=videobuf_code[3];
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videobuf_len+=4;
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// READ PACKET:
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{ unsigned int head=-1;
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while(videobuf_len<VIDEOBUFFER_SIZE){
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int c=demux_getc(ds);
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if(c<0) break; // EOF
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videobuffer[videobuf_len++]=c;
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#if 1
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head<<=8;
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if(head==0x100) break; // synced
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head|=c;
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#else
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if(videobuffer[videobuf_len-4]==0 &&
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videobuffer[videobuf_len-3]==0 &&
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videobuffer[videobuf_len-2]==1) break; // synced
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#endif
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}
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}
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if(ds->eof){
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videobuf_code_len=0; // EOF, no next code
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return videobuf_len-packet_start;
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}
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videobuf_len-=4;
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if(verbose>=2) printf("videobuf: packet 0x1%02X len=%d\n",videobuffer[3],videobuf_len);
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// Save next packet code:
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videobuf_code[0]=videobuffer[videobuf_len];
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videobuf_code[1]=videobuffer[videobuf_len+1];
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videobuf_code[2]=videobuffer[videobuf_len+2];
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videobuf_code[3]=videobuffer[videobuf_len+3];
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videobuf_code_len=4;
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return videobuf_len-packet_start;
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}
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// return: next packet code
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int skip_video_packet(demux_stream_t *ds){
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// SYNC STREAM
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// if(!sync_video_packet(ds)) return 0; // cannot sync (EOF)
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videobuf_code_len=0; // force resync
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// SYNC AGAIN:
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return sync_video_packet(ds);
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}
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