mpv/demux_mpg.c

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// MPG/VOB file parser for DEMUXER v2.5 by A'rpi/ESP-team
static unsigned int read_mpeg_timestamp(stream_t *s,int c){
int d,e;
unsigned int pts;
d=stream_read_word(s);
e=stream_read_word(s);
if( ((c&1)!=1) || ((d&1)!=1) || ((e&1)!=1) ) return 0; // invalid pts
pts=(((c>>1)&7)<<30)|((d>>1)<<15)|(e>>1);
if(verbose>=3) printf("{%d}",pts);
return pts;
}
static char dvdaudio_table[256];
//static unsigned int packet_start_pos=0;
static int demux_mpg_read_packet(demuxer_t *demux,int id){
int d;
int len;
unsigned char c=0;
unsigned int pts=0;
unsigned int dts=0;
demux_stream_t *ds=NULL;
if(verbose>=3) printf("demux_read_packet: %X\n",id);
// if(id==0x1BA) packet_start_pos=stream_tell(demux->stream);
if(id<0x1BC || id>0x1FF) return -1;
if(id==0x1BE) return -1; // padding stream
if(id==0x1BF) return -1; // private2
len=stream_read_word(demux->stream);
if(verbose>=3) printf("PACKET len=%d",len);
if(len==0 || len>224*1024) return -2; // invalid packet !!!!!!
while(len>0){ // Skip stuFFing bytes
c=stream_read_char(demux->stream);--len;
if(c!=0xFF)break;
}
if((c>>6)==1){ // Read (skip) STD scale & size value
// printf(" STD_scale=%d",(c>>5)&1);
d=((c&0x1F)<<8)|stream_read_char(demux->stream);
len-=2;
// printf(" STD_size=%d",d);
c=stream_read_char(demux->stream);
}
// Read System-1 stream timestamps:
if((c>>4)==2){
pts=read_mpeg_timestamp(demux->stream,c);
len-=4;
} else
if((c>>4)==3){
pts=read_mpeg_timestamp(demux->stream,c);
c=stream_read_char(demux->stream);
if((c>>4)!=1) pts=0; //printf("{ERROR4}");
dts=read_mpeg_timestamp(demux->stream,c);
len-=4+1+4;
} else
if((c>>6)==2){
int pts_flags;
int hdrlen;
// System-2 (.VOB) stream:
if((c>>4)&3) printf("Warning! Encrypted VOB file! (DeCSS not (yet) supported)\n");
c=stream_read_char(demux->stream); pts_flags=c>>6;
c=stream_read_char(demux->stream); hdrlen=c;
len-=2;
if(verbose>=3) printf(" hdrlen=%d (len=%d)",hdrlen,len);
if(hdrlen>len){ printf("demux_mpg: invalid header length \n"); return -1;}
if(pts_flags==2){
c=stream_read_char(demux->stream);
pts=read_mpeg_timestamp(demux->stream,c);
len-=5;hdrlen-=5;
} else
if(pts_flags==3){
c=stream_read_char(demux->stream);
pts=read_mpeg_timestamp(demux->stream,c);
c=stream_read_char(demux->stream);
dts=read_mpeg_timestamp(demux->stream,c);
len-=10;hdrlen-=10;
}
len-=hdrlen;
if(hdrlen>0) stream_skip(demux->stream,hdrlen); // skip header bytes
//============== DVD Audio sub-stream ======================
if(id==0x1BD){
int aid=stream_read_char(demux->stream)&0x7F;--len;
ds=demux->audio;
if(ds->id==-1) ds->id=aid;
if(!dvdaudio_table[aid]){
dvdaudio_table[aid]=1;
printf("DVD Audio format: %s ID=%d%s\n",
((aid&0x70)==0x20)?"PCM":"AC3",aid,(ds->id==aid)?" CURRENT":"");
}
if(len<3) return -1; // invalid audio packet
if(ds->id!=aid){
// drop packet (not selected channel)
ds=NULL;
} else {
// READ Packet: Skip additional audio header data:
c=stream_read_char(demux->stream);
c=stream_read_char(demux->stream);
c=stream_read_char(demux->stream);
len-=3;
if(ds->type==-1){
// autodetect type
ds->type=((aid&0x70)==0x20)?2:3;
}
if(ds->type==2 && len>=2){
// read PCM header
int head;
head=stream_read_char(demux->stream); head=c<<8;
c=stream_read_char(demux->stream); head|=c; len-=2;
while(len>0 && head!=0x180){
head=c<<8;
c=stream_read_char(demux->stream);
head|=c;--len;
}
if(!len) printf("End of packet while searching for PCM header\n");
}
}
}
} else {
//if(c!=0x0f) printf(" {ERROR5,c=%d} \n",c);
}
if(verbose>=3) printf(" => len=%d\n",len);
if(len<=0 || len>224*1024) return -1; // Invalid packet size
if(id>=0x1C0 && id<=0x1DF){
// mpeg audio
int aid=id-0x1C0;
if(demux->audio->id==-1) demux->audio->id=aid;
if(demux->audio->id==aid){
ds=demux->audio;
if(ds->type==-1) ds->type=1;
}
} else
if(id>=0x1E0 && id<=0x1EF){
// mpeg video
int aid=id-0x1E0;
if(demux->video->id==-1) demux->video->id=aid;
if(demux->video->id==aid) ds=demux->video;
}
if(ds){
if(verbose>=2) printf("DEMUX_MPG: Read %d data bytes from packet %04X\n",len,id);
// printf("packet start = 0x%X \n",stream_tell(demux->stream)-packet_start_pos);
ds_read_packet(ds,demux->stream,len,pts/90000.0f,0);
return 1;
}
if(verbose>=2) printf("DEMUX_MPG: Skipping %d data bytes from packet %04X\n",len,id);
stream_skip(demux->stream,len);
return 0;
}
static int num_elementary_packets100=0;
static int num_elementary_packets101=0;
int demux_mpg_es_fill_buffer(demuxer_t *demux){
//if(demux->type==DEMUXER_TYPE_MPEG_ES)
// Elementary video stream
if(demux->stream->eof) return 0;
demux->filepos=stream_tell(demux->stream);
ds_read_packet(demux->video,demux->stream,4096,0,0);
return 1;
}
int demux_mpg_fill_buffer(demuxer_t *demux){
unsigned int head=0;
int skipped=0;
int max_packs=128;
int ret=0;
// System stream
do{
demux->filepos=stream_tell(demux->stream);
head=stream_read_dword(demux->stream);
while((head&0xffffff00)!=0x00000100){
if(stream_eof(demux->stream)) break;
head=(head<<8)|stream_read_char(demux->stream);
++skipped; ++demux->filepos;
}
if(stream_eof(demux->stream)) break;
// sure: head=0x000001XX
if(demux->synced==0){
if(head==0x1BA) demux->synced=1;
} else
if(demux->synced==1){
if(head==0x1BB || (head>=0x1C0 && head<=0x1EF)){
demux->synced=2;
if(verbose) printf("system stream synced at 0x%X (%d)!\n",demux->filepos,demux->filepos);
} else demux->synced=0;
} // else
if(demux->synced==2){
ret=demux_mpg_read_packet(demux,head);
if(!ret)
if(--max_packs==0){
demux->stream->eof=1;
printf("demux: file doesn't contain the selected audio or video stream\n");
return 0;
}
} else {
if(head>=0x100 && head<0x1B0){
if(head==0x100)
++num_elementary_packets100;
else
if(head==0x101) ++num_elementary_packets101;
if(verbose>=3) printf("Opps... elementary video packet found: %03X\n",head);
}
#if 1
if(num_elementary_packets100>50 && num_elementary_packets101>50
&& skipped>4000000){
if(verbose) printf("sync_mpeg_ps: seems to be ES stream...\n");
demux->stream->eof=1;
break;
}
#endif
}
} while(ret!=1);
if(verbose>=2) printf("demux: %d bad bytes skipped\n",skipped);
if(demux->stream->eof){
if(verbose>=2) printf("MPEG Stream reached EOF\n");
return 0;
}
return 1;
}