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author | Diego 'Flameeyes' Pettenò <flameeyes@gmail.com> | 2006-12-02 01:19:48 +0000 |
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committer | Diego 'Flameeyes' Pettenò <flameeyes@gmail.com> | 2006-12-02 01:19:48 +0000 |
commit | 0ea721f7ce81357bc4ec6eea609cd50482c3d15b (patch) | |
tree | 25a0871cb3c06f9716acf9c204192d548f214048 /contrib/ffmpeg/libavcodec/liba52/bitstream.c | |
parent | d8ec380876e7f697ba609546d61757ab3f2d8715 (diff) | |
download | xine-lib-0ea721f7ce81357bc4ec6eea609cd50482c3d15b.tar.gz xine-lib-0ea721f7ce81357bc4ec6eea609cd50482c3d15b.tar.bz2 |
Start working on a branch where FFmpeg is not copied, patched and carved to be built with automake but instead imported inline and built using its own build system. This is an import of a slightly modified FFmpeg current tree. xine-lib builds, install and run fine with it, but there are of course plenty of things that needs to be fixed before it can even be considered for a 1.2.x series. Work will continue in the next days of course.
CVS patchset: 8397
CVS date: 2006/12/02 01:19:48
Diffstat (limited to 'contrib/ffmpeg/libavcodec/liba52/bitstream.c')
-rw-r--r-- | contrib/ffmpeg/libavcodec/liba52/bitstream.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavcodec/liba52/bitstream.c b/contrib/ffmpeg/libavcodec/liba52/bitstream.c new file mode 100644 index 000000000..f6b05c5e6 --- /dev/null +++ b/contrib/ffmpeg/libavcodec/liba52/bitstream.c @@ -0,0 +1,91 @@ +/* + * bitstream.c + * Copyright (C) 2000-2003 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ +#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; + state->current_word = 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; +} |