static void ext_user_data()
{
int code,ext_ID;
startcode();
while ((code = showbits(32))==EXT_START_CODE || code==USER_START_CODE)
{
if (code==EXT_START_CODE)
{
flushbits32();
ext_ID = getbits(4);
switch (ext_ID)
{
case SEQ_ID:
sequence_extension();
break;
case DISP_ID:
sequence_display_extension();
break;
case QUANT_ID:
quant_matrix_extension();
break;
case SEQSCAL_ID:
sequence_scalable_extension();
break;
case PANSCAN_ID:
picture_display_extension();
break;
case CODING_ID:
picture_coding_extension();
break;
case SPATSCAL_ID:
picture_spatial_scalable_extension();
break;
case TEMPSCAL_ID:
picture_temporal_scalable_extension();
break;
default:
fprintf(stderr,"reserved extension start code ID %d\n",ext_ID);
break;
}
startcode();
}
else
{
if (verbose)
printf("user data\n");
flushbits32();
startcode();
}
}
}
int getheader ()
{
unsigned int code, gob;
/* look for startcode */
startcode ();
code = getbits (PSC_LENGTH);
gob = getbits (5);
if (gob == SE_CODE)
return 0;
if (gob == 0)
{
if (trace)
{
fprintf (trace_file, "\nPSC: ");
printbits ((code << (5 + gob)), 22, 22);
}
getpicturehdr ();
if (syntax_arith_coding) /* reset decoder after receiving */
decoder_reset (); /* fixed length PSC string */
}
else
{
if (trace)
{
fprintf (trace_file, "\nGBSC: ");
printbits ((code << (5 + gob)), 22, 22);
}
}
return gob + 1;
}
static int gethdr()
{
unsigned int code;
for (;;)
{
/* look for startcode */
startcode();
code = getbits32();
switch (code)
{
case SEQ_START_CODE:
getseqhdr();
break;
case GOP_START_CODE:
getgophdr();
break;
case PICTURE_START_CODE:
getpicturehdr();
return 1;
break;
case SEQ_END_CODE:
return 0;
break;
default:
if (!quiet)
fprintf(stderr,"Unexpected startcode %08x (ignored)\n",code);
break;
}
}
}