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/* |
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* bitstream.h |
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* Copyright (C) 2000-2002 Michel Lespinasse <walken@zoy.org> |
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* Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca> |
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* |
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* This file is part of a52dec, a free ATSC A-52 stream decoder. |
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* See http://liba52.sourceforge.net/ for updates. |
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* |
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* a52dec is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License as published by |
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* the Free Software Foundation; either version 2 of the License, or |
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* (at your option) any later version. |
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* |
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* a52dec is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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/* (stolen from the kernel) */ |
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#ifdef WORDS_BIGENDIAN |
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|
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# define swab32(x) (x) |
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|
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#else |
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|
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# if 0 && defined (__i386__) |
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|
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# define swab32(x) __i386_swab32(x) |
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static inline const uint32_t __i386_swab32(uint32_t x) |
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{ |
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__asm__("bswap %0" : "=r" (x) : "0" (x)); |
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return x; |
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} |
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|
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# else |
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|
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# define swab32(x)\ |
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((((uint8_t*)&x)[0] << 24) | (((uint8_t*)&x)[1] << 16) | \ |
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(((uint8_t*)&x)[2] << 8) | (((uint8_t*)&x)[3])) |
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|
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# endif |
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#endif |
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|
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void a52_bitstream_set_ptr (a52_state_t * state, uint8_t * buf); |
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uint32_t a52_bitstream_get_bh (a52_state_t * state, uint32_t num_bits); |
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int32_t a52_bitstream_get_bh_2 (a52_state_t * state, uint32_t num_bits); |
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|
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static inline uint32_t bitstream_get (a52_state_t * state, uint32_t num_bits) |
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{ |
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uint32_t result; |
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|
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if (num_bits < state->bits_left) { |
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result = (state->current_word << (32 - state->bits_left)) >> (32 - num_bits); |
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state->bits_left -= num_bits; |
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return result; |
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} |
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|
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return a52_bitstream_get_bh (state, num_bits); |
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} |
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|
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static inline int32_t bitstream_get_2 (a52_state_t * state, uint32_t num_bits) |
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{ |
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int32_t result; |
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|
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if (num_bits < state->bits_left) { |
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result = (((int32_t)state->current_word) << (32 - state->bits_left)) >> (32 - num_bits); |
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state->bits_left -= num_bits; |
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return result; |
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} |
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|
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return a52_bitstream_get_bh_2 (state, num_bits); |
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} |
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