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/*
* bitstream.c
*
* 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.
*
*/
#include <stdlib.h>
#include <stdio.h>
#include <inttypes.h>
#include <bswap.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "ac3.h"
#include "ac3_internal.h"
#include "bitstream.h"
uint32_t bits_left = 0;
uint64_t current_word;
uint64_t *buffer_start = 0;
static inline uint64_t getdword (void)
{
return be2me_64 (*buffer_start++);
}
static inline void bitstream_fill_current (void)
{
//current_word = bswap_64 (*buffer_start++);
current_word = getdword ();
}
uint32_t bitstream_get_bh (uint32_t num_bits)
{
uint32_t result;
num_bits -= bits_left;
result = (current_word << (64 - bits_left)) >> (64 - bits_left);
bitstream_fill_current();
if(num_bits != 0)
result = (result << num_bits) | (current_word >> (64 - num_bits));
bits_left = 64 - num_bits;
return result;
}
void bitstream_init (uint8_t *start)
{
//initialize the start of the buffer
buffer_start = (uint64_t *) start;
bits_left = 0;
}
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