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author | Guenter Bartsch <guenter@users.sourceforge.net> | 2001-08-29 00:51:57 +0000 |
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committer | Guenter Bartsch <guenter@users.sourceforge.net> | 2001-08-29 00:51:57 +0000 |
commit | 6d13f53fb05950ca9475dbf6f786f6aeffd35b91 (patch) | |
tree | 466e105627f81a49d5dd40380554c5572086e75c /src/liba52/bitstream.c | |
parent | c593749af24848995d168d7714c3361daa1ada03 (diff) | |
download | xine-lib-6d13f53fb05950ca9475dbf6f786f6aeffd35b91.tar.gz xine-lib-6d13f53fb05950ca9475dbf6f786f6aeffd35b91.tar.bz2 |
update to liba52 v 0.7.0 including the dynamic range compensation feature (disabled by default, enable it in your .xinerc if you want it)
CVS patchset: 515
CVS date: 2001/08/29 00:51:57
Diffstat (limited to 'src/liba52/bitstream.c')
-rw-r--r-- | src/liba52/bitstream.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/src/liba52/bitstream.c b/src/liba52/bitstream.c new file mode 100644 index 000000000..30caa5ea3 --- /dev/null +++ b/src/liba52/bitstream.c @@ -0,0 +1,99 @@ +/* + * bitstream.c + * Copyright (C) 1999-2001 Aaron Holtzman <aholtzma@ess.engr.uvic.ca> + * + * This file is part of a52dec, a free ATSC A-52 stream decoder. + * + * 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 + +static uint32_t * buffer_start; + +uint32_t bits_left; +uint32_t current_word; + +void bitstream_set_ptr (uint8_t * buf) +{ + int align; + + align = (int)buf & 3; + buffer_start = (uint32_t *) (buf - align); + bits_left = 0; + bitstream_get (align * 8); +} + +static inline void +bitstream_fill_current() +{ + uint32_t tmp; + + tmp = *(buffer_start++); + 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 +bitstream_get_bh(uint32_t num_bits) +{ + uint32_t result; + + num_bits -= bits_left; + result = (current_word << (32 - bits_left)) >> (32 - bits_left); + + bitstream_fill_current(); + + if(num_bits != 0) + result = (result << num_bits) | (current_word >> (32 - num_bits)); + + bits_left = 32 - num_bits; + + return result; +} + +int32_t +bitstream_get_bh_2(uint32_t num_bits) +{ + int32_t result; + + num_bits -= bits_left; + result = (((int32_t)current_word) << (32 - bits_left)) >> (32 - bits_left); + + bitstream_fill_current(); + + if(num_bits != 0) + result = (result << num_bits) | (current_word >> (32 - num_bits)); + + bits_left = 32 - num_bits; + + return result; +} |