/* * bitstream.h * Copyright (C) 2000-2002 Michel Lespinasse * Copyright (C) 1999-2000 Aaron Holtzman * * This file is part of a52dec, a free ATSC A-52 stream decoder. * See http://liba52.sourceforge.net/ for updates. * * a52dec 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. * * a52dec 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 */ /* (stolen from the kernel) */ #ifdef WORDS_BIGENDIAN # define swab32(x) (x) #else # if 0 && 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 void a52_bitstream_set_ptr (a52_state_t * state, uint8_t * buf); uint32_t a52_bitstream_get_bh (a52_state_t * state, uint32_t num_bits); int32_t a52_bitstream_get_bh_2 (a52_state_t * state, uint32_t num_bits); static inline uint32_t bitstream_get (a52_state_t * state, uint32_t num_bits) { uint32_t result; if (num_bits < state->bits_left) { result = (state->current_word << (32 - state->bits_left)) >> (32 - num_bits); state->bits_left -= num_bits; return result; } return a52_bitstream_get_bh (state, num_bits); } static inline int32_t bitstream_get_2 (a52_state_t * state, uint32_t num_bits) { int32_t result; if (num_bits < state->bits_left) { result = (((int32_t)state->current_word) << (32 - state->bits_left)) >> (32 - num_bits); state->bits_left -= num_bits; return result; } return a52_bitstream_get_bh_2 (state, num_bits); }