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author | Diego 'Flameeyes' Pettenò <flameeyes@gmail.com> | 2007-05-31 20:00:05 +0200 |
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committer | Diego 'Flameeyes' Pettenò <flameeyes@gmail.com> | 2007-05-31 20:00:05 +0200 |
commit | 2470724b1c7705870c00c206e1dda663fd419238 (patch) | |
tree | a696adc1674b9f23a4a3d33b91366e0f530563a0 /contrib/a52dec/bitstream.c | |
parent | c043cbe458de70acbdb12afb97c20c6a00d416dd (diff) | |
download | xine-lib-2470724b1c7705870c00c206e1dda663fd419238.tar.gz xine-lib-2470724b1c7705870c00c206e1dda663fd419238.tar.bz2 |
Move liba52/a52dec sources inside contrib/a52dec.
--HG--
rename : src/liba52/a52.h => contrib/a52dec/a52.h
rename : src/liba52/a52_internal.h => contrib/a52dec/a52_internal.h
rename : src/liba52/bit_allocate.c => contrib/a52dec/bit_allocate.c
rename : src/liba52/bitstream.c => contrib/a52dec/bitstream.c
rename : src/liba52/bitstream.h => contrib/a52dec/bitstream.h
rename : src/liba52/crc.c => contrib/a52dec/crc.c
rename : src/liba52/diff_against_release.patch => contrib/a52dec/diff_against_release.patch
rename : src/liba52/downmix.c => contrib/a52dec/downmix.c
rename : src/liba52/imdct.c => contrib/a52dec/imdct.c
rename : src/liba52/parse.c => contrib/a52dec/parse.c
rename : src/liba52/tables.h => contrib/a52dec/tables.h
Diffstat (limited to 'contrib/a52dec/bitstream.c')
-rw-r--r-- | contrib/a52dec/bitstream.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/contrib/a52dec/bitstream.c b/contrib/a52dec/bitstream.c new file mode 100644 index 000000000..04e8ca6d0 --- /dev/null +++ b/contrib/a52dec/bitstream.c @@ -0,0 +1,95 @@ +/* + * bitstream.c + * Copyright (C) 2000-2002 Michel Lespinasse <walken@zoy.org> + * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca> + * + * 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 + */ + +#include "config.h" + +#include <inttypes.h> + +#include "a52.h" +#include "a52_internal.h" +#include "bitstream.h" + +#define BUFFER_SIZE 4096 + +void a52_bitstream_set_ptr (a52_state_t * state, uint8_t * buf) +{ + int align; + + align = (long)buf & 3; + state->buffer_start = (uint32_t *) (buf - align); + state->bits_left = 0; + bitstream_get (state, align * 8); +} + +static inline void bitstream_fill_current (a52_state_t * state) +{ + uint32_t tmp; + + tmp = *(state->buffer_start++); + state->current_word = swab32 (tmp); +} + +/* + * The fast paths for _get is in the + * bitstream.h header file so it can be inlined. + * + * The "bottom half" of this routine is suffixed _bh + * + * -ah + */ + +uint32_t a52_bitstream_get_bh (a52_state_t * state, uint32_t num_bits) +{ + uint32_t result; + + num_bits -= state->bits_left; + result = ((state->current_word << (32 - state->bits_left)) >> + (32 - state->bits_left)); + + bitstream_fill_current (state); + + if (num_bits != 0) + result = (result << num_bits) | (state->current_word >> (32 - num_bits)); + + state->bits_left = 32 - num_bits; + + return result; +} + +int32_t a52_bitstream_get_bh_2 (a52_state_t * state, uint32_t num_bits) +{ + int32_t result; + + num_bits -= state->bits_left; + result = ((((int32_t)state->current_word) << (32 - state->bits_left)) >> + (32 - state->bits_left)); + + bitstream_fill_current(state); + + if (num_bits != 0) + result = (result << num_bits) | (state->current_word >> (32 - num_bits)); + + state->bits_left = 32 - num_bits; + + return result; +} |