mpv/libfaad2/bits.c

174 lines
4.1 KiB
C

/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program 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 of the License, or
** (at your option) any later version.
**
** This program 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 this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
**
** $Id: bits.c,v 1.22 2003/07/29 08:20:12 menno Exp $
**/
#include "common.h"
#include "structs.h"
#include <stdlib.h>
#include <string.h>
#include "bits.h"
/* initialize buffer, call once before first getbits or showbits */
void faad_initbits(bitfile *ld, void *_buffer, uint32_t buffer_size)
{
uint32_t tmp;
ld->buffer = malloc((buffer_size+12)*sizeof(uint8_t));
memset(ld->buffer, 0, (buffer_size+12)*sizeof(uint8_t));
memcpy(ld->buffer, _buffer, buffer_size*sizeof(uint8_t));
ld->buffer_size = buffer_size;
tmp = getdword((uint32_t*)ld->buffer);
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
ld->bufa = tmp;
tmp = getdword((uint32_t*)ld->buffer + 1);
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
ld->bufb = tmp;
ld->start = (uint32_t*)ld->buffer;
ld->tail = ((uint32_t*)ld->buffer + 2);
ld->bits_left = 32;
ld->bytes_used = 0;
ld->no_more_reading = 0;
ld->error = 0;
}
void faad_endbits(bitfile *ld)
{
if (ld)
if (ld->buffer) free(ld->buffer);
}
uint32_t faad_get_processed_bits(bitfile *ld)
{
return 8 * (4*(ld->tail - ld->start) - 4) - (ld->bits_left);
}
uint8_t faad_byte_align(bitfile *ld)
{
uint8_t remainder = (uint8_t)((32 - ld->bits_left) % 8);
if (remainder)
{
faad_flushbits(ld, 8 - remainder);
return (8 - remainder);
}
return 0;
}
/* rewind to beginning */
void faad_rewindbits(bitfile *ld)
{
uint32_t tmp;
tmp = ld->start[0];
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
ld->bufa = tmp;
tmp = ld->start[1];
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
ld->bufb = tmp;
ld->bits_left = 32;
ld->tail = &ld->start[2];
ld->bytes_used = 0;
ld->no_more_reading = 0;
}
uint8_t *faad_getbitbuffer(bitfile *ld, uint32_t bits
DEBUGDEC)
{
uint16_t i;
uint8_t temp;
uint16_t bytes = (uint16_t)bits / 8;
uint8_t remainder = (uint8_t)bits % 8;
uint8_t *buffer = (uint8_t*)malloc((bytes+1)*sizeof(uint8_t));
for (i = 0; i < bytes; i++)
{
buffer[i] = (uint8_t)faad_getbits(ld, 8 DEBUGVAR(print,var,dbg));
}
if (remainder)
{
temp = (uint8_t)faad_getbits(ld, remainder DEBUGVAR(print,var,dbg)) << (8-remainder);
buffer[bytes] = temp;
}
return buffer;
}
/* reversed bit reading routines, used for RVLC and HCR */
void faad_initbits_rev(bitfile *ld, void *buffer,
uint32_t bits_in_buffer)
{
uint32_t tmp;
int32_t index;
ld->buffer_size = bit2byte(bits_in_buffer);
index = (bits_in_buffer+31)/32 - 1;
ld->start = (uint32_t*)buffer + index - 2;
tmp = getdword((uint32_t*)buffer + index);
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
ld->bufa = tmp;
tmp = getdword((uint32_t*)buffer + index - 1);
#ifndef ARCH_IS_BIG_ENDIAN
BSWAP(tmp);
#endif
ld->bufb = tmp;
ld->tail = (uint32_t*)buffer + index;
ld->bits_left = bits_in_buffer % 32;
if (ld->bits_left == 0)
ld->bits_left = 32;
ld->bytes_used = 0;
ld->no_more_reading = 0;
ld->error = 0;
}