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#include "mpg123.h"
#if 0
static void check_buffer_range(int size)
{
int pos = (bsi.wordpointer-bsbuf) + (size >> 3);
if( pos >= fsizeold) {
fprintf(stderr, "Pointer out of range (%d,%d)!\n", pos, fsizeold);
}
}
#endif
void mpg123_backbits(int number_of_bits)
{
bsi.bitindex -= number_of_bits;
bsi.wordpointer += (bsi.bitindex>>3);
bsi.bitindex &= 0x7;
}
int mpg123_getbitoffset(void)
{
return (-bsi.bitindex)&0x7;
}
int mpg123_getbyte(void)
{
#ifdef DEBUG_GETBITS
if(bsi.bitindex)
fprintf(stderr,"getbyte called unsynched!\n");
#endif
return *bsi.wordpointer++;
}
unsigned int mpg123_getbits(int number_of_bits)
{
unsigned long rval;
#ifdef DEBUG_GETBITS
fprintf(stderr, "g%d", number_of_bits);
#endif
if(!number_of_bits)
return 0;
#if 0
check_buffer_range(number_of_bits + bsi.bitindex);
#endif
{
rval = bsi.wordpointer[0];
rval <<= 8;
rval |= bsi.wordpointer[1];
rval <<= 8;
rval |= bsi.wordpointer[2];
rval <<= bsi.bitindex;
rval &= 0xffffff;
bsi.bitindex += number_of_bits;
rval >>= (24-number_of_bits);
bsi.wordpointer += (bsi.bitindex >> 3);
bsi.bitindex &= 7;
}
#ifdef DEBUG_GETBITS
fprintf(stderr,":%x ",rval);
#endif
return rval;
}
unsigned int mpg123_getbits_fast(int number_of_bits)
{
unsigned int rval;
#ifdef DEBUG_GETBITS
fprintf(stderr,"g%d",number_of_bits);
#endif
#if 0
check_buffer_range(number_of_bits+bsi.bitindex);
#endif
rval = (unsigned char) (bsi.wordpointer[0] << bsi.bitindex);
rval |= ((unsigned int) bsi.wordpointer[1] << bsi.bitindex) >> 8;
rval <<= number_of_bits;
rval >>= 8;
bsi.bitindex += number_of_bits;
bsi.wordpointer += (bsi.bitindex >> 3);
bsi.bitindex &= 7;
#ifdef DEBUG_GETBITS
fprintf(stderr,":%x ",rval);
#endif
return rval;
}
unsigned int mpg123_get1bit(void)
{
unsigned char rval;
#ifdef DEBUG_GETBITS
fprintf(stderr,"g%d",1);
#endif
#if 0
check_buffer_range(1+bsi.bitindex);
#endif
rval = *bsi.wordpointer << bsi.bitindex;
bsi.bitindex++;
bsi.wordpointer += (bsi.bitindex >> 3);
bsi.bitindex &= 7;
#ifdef DEBUG_GETBITS
fprintf(stderr,":%d ",rval >> 7);
#endif
return rval>>7;
}
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