From 28296f9c9e958b798c2947109ee479092c855721 Mon Sep 17 00:00:00 2001 From: Aurelien Jacobs Date: Sun, 26 Aug 2007 22:33:48 +0000 Subject: move get_unary() to its own file Originally committed as revision 10240 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/unary.h | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 libavcodec/unary.h (limited to 'libavcodec/unary.h') diff --git a/libavcodec/unary.h b/libavcodec/unary.h new file mode 100644 index 0000000000..195e69f906 --- /dev/null +++ b/libavcodec/unary.h @@ -0,0 +1,72 @@ +/* + * copyright (c) 2004 Michael Niedermayer + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVCODEC_UNARY_H +#define AVCODEC_UNARY_H + +#include "bitstream.h" + +/** + * Get unary code of limited length + * @todo FIXME Slow and ugly + * @param gb GetBitContext + * @param[in] stop The bitstop value (unary code of 1's or 0's) + * @param[in] len Maximum length + * @return Unary length/index + */ +static int get_unary(GetBitContext *gb, int stop, int len) +{ +#if 1 + int i; + + for(i = 0; i < len && get_bits1(gb) != stop; i++); + return i; +/* int i = 0, tmp = !stop; + + while (i != len && tmp != stop) + { + tmp = get_bits(gb, 1); + i++; + } + if (i == len && tmp != stop) return len+1; + return i;*/ +#else + unsigned int buf; + int log; + + OPEN_READER(re, gb); + UPDATE_CACHE(re, gb); + buf=GET_CACHE(re, gb); //Still not sure + if (stop) buf = ~buf; + + log= av_log2(-buf); //FIXME: -? + if (log < limit){ + LAST_SKIP_BITS(re, gb, log+1); + CLOSE_READER(re, gb); + return log; + } + + LAST_SKIP_BITS(re, gb, limit); + CLOSE_READER(re, gb); + return limit; +#endif +} + +#endif /* AVCODEC_UNARY_H */ -- cgit v1.2.3