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/*
* bitstream.h
*
* Copyright (C) Aaron Holtzman - Dec 1999
*
* This file is part of ac3dec, a free AC-3 audio decoder
*
* ac3dec is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* ac3dec is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNU Make; see the file COPYING. If not, write to
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
//My new and improved vego-matic endian swapping routine
//(stolen from the kernel)
#ifdef WORDS_BIGENDIAN
# define swab32(x) (x)
#else
# if defined (__i386__)
# define swab32(x) __i386_swab32(x)
static inline const uint_32 __i386_swab32(uint_32 x)
{
__asm__("bswap %0" : "=r" (x) : "0" (x));
return x;
}
# else
# define swab32(x)\
((((uint_8*)&x)[0] << 24) | (((uint_8*)&x)[1] << 16) | \
(((uint_8*)&x)[2] << 8) | (((uint_8*)&x)[3]))
# endif
#endif
extern uint_32 bits_left;
extern uint_32 current_word;
void bitstream_init(uint_8 *start);
uint_8 bitstream_get_byte(void);
uint_8 *bitstream_get_buffer_start(void);
void bitstream_buffer_frame(uint_32 frame_size);
uint_32 bitstream_get_bh(uint_32 num_bits);
static inline uint_32
bitstream_get(uint_32 num_bits)
{
uint_32 result;
if(num_bits < bits_left)
{
result = (current_word << (32 - bits_left)) >> (32 - num_bits);
bits_left -= num_bits;
return result;
}
return bitstream_get_bh(num_bits);
}
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