/* * 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 uint32_t __i386_swab32(uint32_t x) { __asm__("bswap %0" : "=r" (x) : "0" (x)); return x; } # else # define swab32(x)\ ((((uint8_t*)&x)[0] << 24) | (((uint8_t*)&x)[1] << 16) | \ (((uint8_t*)&x)[2] << 8) | (((uint8_t*)&x)[3])) # endif #endif extern uint32_t bits_left; extern uint32_t current_word; void bitstream_set_ptr (uint8_t * buf); uint32_t bitstream_get_bh(uint32_t num_bits); static inline uint32_t bitstream_get(uint32_t num_bits) { uint32_t 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); }