X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=synfig-core%2Ftags%2Fsynfig_0_61_03%2Fsynfig-core%2Fsrc%2Fmodules%2Fmod_libavcodec%2Flibavcodec%2Fliba52%2Fbitstream.c;fp=synfig-core%2Ftags%2Fsynfig_0_61_03%2Fsynfig-core%2Fsrc%2Fmodules%2Fmod_libavcodec%2Flibavcodec%2Fliba52%2Fbitstream.c;h=89b69cff03559d10379fe81fe6c703de4de9e809;hb=2362dce2bb8c6a5fd5f3bd049975c3d89411f5d3;hp=0000000000000000000000000000000000000000;hpb=6f41e88a004056081fbf3e45c4eb9780cc08cd91;p=synfig.git diff --git a/synfig-core/tags/synfig_0_61_03/synfig-core/src/modules/mod_libavcodec/libavcodec/liba52/bitstream.c b/synfig-core/tags/synfig_0_61_03/synfig-core/src/modules/mod_libavcodec/libavcodec/liba52/bitstream.c new file mode 100644 index 0000000..89b69cf --- /dev/null +++ b/synfig-core/tags/synfig_0_61_03/synfig-core/src/modules/mod_libavcodec/libavcodec/liba52/bitstream.c @@ -0,0 +1,91 @@ +/* + * bitstream.c + * Copyright (C) 2000-2003 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 + */ +#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; +}