/*** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding** Copyright (C) 2003-2005 M. Bakker, Nero 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.**** The "appropriate copyright message" mentioned in section 2c of the GPLv2** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"**** Commercial non-GPL licensing of this software is possible.** For more info contact Nero AG through Mpeg4AAClicense@nero.com.**** $Id: bits.c,v 1.44 2007/11/01 12:33:29 menno Exp $**/ #include "common.h"#include "structs.h" #include "bits.h" /* reads only n bytes from the stream instead of the standard 4 */static /*INLINE*/ uint32_t getdword_n(void *mem, int n){    uint8_t* m8 = (uint8_t*)mem;    switch (n)    {    case 3:        return ((uint32_t)m8[2] << 8) | ((uint32_t)m8[1] << 16) | ((uint32_t)m8[0] << 24);    case 2:        return ((uint32_t)m8[1] << 16) | ((uint32_t)m8[0] << 24);    case 1:        return (uint32_t)m8[0] << 24;    default:        return 0;    }} /* initialize buffer, call once before first getbits or showbits */void faad_initbits(bitfile *ld, const void *_buffer, const uint32_t buffer_size){    uint32_t tmp;     if (ld == NULL)        return;     if (buffer_size == 0 || _buffer == NULL)    {        ld->error = 1;        return;    }     ld->buffer = _buffer;     ld->buffer_size = buffer_size;    ld->bytes_left  = buffer_size;     if (ld->bytes_left >= 4)    {        tmp = getdword((uint32_t*)ld->buffer);        ld->bytes_left -= 4;    } else {        tmp = getdword_n((uint32_t*)ld->buffer, ld->bytes_left);        ld->bytes_left = 0;    }    ld->bufa = tmp;     if (ld->bytes_left >= 4)    {        tmp = getdword((uint32_t*)ld->buffer + 1);        ld->bytes_left -= 4;    } else {        tmp = getdword_n((uint32_t*)ld->buffer + 1, ld->bytes_left);        ld->bytes_left = 0;    }    ld->bufb = tmp;     ld->start = (uint32_t*)ld->buffer;    ld->tail = ((uint32_t*)ld->buffer + 2);     ld->bits_left = 32;     ld->error = 0;} void faad_endbits(bitfile *ld){    (void)ld;} uint32_t faad_get_processed_bits(bitfile *ld){    return (uint32_t)(8 * (4*(ld->tail - ld->start) - 4) - (ld->bits_left));} uint8_t faad_byte_align(bitfile *ld){    int remainder = (32 - ld->bits_left) & 0x7;     if (remainder)    {        faad_flushbits(ld, 8 - remainder);        return (uint8_t)(8 - remainder);    }    return 0;} void faad_flushbits_ex(bitfile *ld, uint32_t bits){    uint32_t tmp;     ld->bufa = ld->bufb;    if (ld->bytes_left >= 4)    {        tmp = getdword(ld->tail);        ld->bytes_left -= 4;    } else {        tmp = getdword_n(ld->tail, ld->bytes_left);        ld->bytes_left = 0;    }    ld->bufb = tmp;    ld->tail++;    ld->bits_left += (32 - bits);    //ld->bytes_left -= 4;//    if (ld->bytes_left == 0)//        ld->no_more_reading = 1;//    if (ld->bytes_left < 0)//        ld->error = 1;} #ifdef DRM/* rewind to beginning */void faad_rewindbits(bitfile *ld){    uint32_t tmp;     ld->bytes_left = ld->buffer_size;     if (ld->bytes_left >= 4)    {        tmp = getdword((uint32_t*)&ld->start[0]);        ld->bytes_left -= 4;    } else {        tmp = getdword_n((uint32_t*)&ld->start[0], ld->bytes_left);        ld->bytes_left = 0;    }    ld->bufa = tmp;     if (ld->bytes_left >= 4)    {        tmp = getdword((uint32_t*)&ld->start[1]);        ld->bytes_left -= 4;    } else {        tmp = getdword_n((uint32_t*)&ld->start[1], ld->bytes_left);        ld->bytes_left = 0;    }    ld->bufb = tmp;     ld->bits_left = 32;    ld->tail = &ld->start[2];}#endif /* reset to a certain point */void faad_resetbits(bitfile *ld, uint32_t bits){    uint32_t tmp;    uint32_t words = bits >> 5;    uint32_t remainder = bits & 0x1F;     if (ld->buffer_size < words * 4)        ld->bytes_left = 0;    else        ld->bytes_left = ld->buffer_size - words*4;     if (ld->bytes_left >= 4)    {        tmp = getdword(&ld->start[words]);        ld->bytes_left -= 4;    } else {        tmp = getdword_n(&ld->start[words], ld->bytes_left);        ld->bytes_left = 0;    }    ld->bufa = tmp;     if (ld->bytes_left >= 4)    {        tmp = getdword(&ld->start[words+1]);        ld->bytes_left -= 4;    } else {        tmp = getdword_n(&ld->start[words+1], ld->bytes_left);        ld->bytes_left = 0;    }    ld->bufb = tmp;     ld->bits_left = 32 - remainder;    ld->tail = &ld->start[words+2];     /* recheck for reading too many bytes */    ld->error = 0;//    if (ld->bytes_left == 0)//        ld->no_more_reading = 1;//    if (ld->bytes_left < 0)//        ld->error = 1;} uint8_t *faad_getbitbuffer(bitfile *ld, uint32_t bits                       DEBUGDEC){    int i;    unsigned int temp;    int bytes = bits >> 3;    int remainder = bits & 0x7;     uint8_t *buffer = (uint8_t*)faad_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 = faad_getbits(ld, remainder DEBUGVAR(print,var,dbg)) << (8-remainder);         buffer[bytes] = (uint8_t)temp;    }     return buffer;} #ifdef DRM/* return the original data buffer */void *faad_origbitbuffer(bitfile *ld){    return (void*)ld->start;} /* return the original data buffer size */uint32_t faad_origbitbuffer_size(bitfile *ld){    return ld->buffer_size;}#endif #if 0/* 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);    ld->bufa = tmp;     tmp = getdword((uint32_t*)buffer + index - 1);    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_left = ld->buffer_size;    ld->error = 0;}#endif /* EOF */