diff options
Diffstat (limited to 'libfaad2/bits.c')
| -rw-r--r-- | libfaad2/bits.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/libfaad2/bits.c b/libfaad2/bits.c new file mode 100644 index 0000000000..00f9ad0090 --- /dev/null +++ b/libfaad2/bits.c @@ -0,0 +1,173 @@ +/* +** 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; +} |