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Diffstat (limited to 'media/ffvpx/libavcodec/unary.h')
-rw-r--r-- | media/ffvpx/libavcodec/unary.h | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/unary.h b/media/ffvpx/libavcodec/unary.h new file mode 100644 index 0000000000..d57f9f70c5 --- /dev/null +++ b/media/ffvpx/libavcodec/unary.h @@ -0,0 +1,69 @@ +/* + * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at> + * + * 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 "get_bits.h" + +/** + * Get unary code of limited length + * @param gb GetBitContext + * @param[in] stop The bitstop value (unary code of 1's or 0's) + * @param[in] len Maximum length + * @return unary 0 based code index. This is also the length in bits of the + * code excluding the stop bit. + * (in case len=1) + * 1 0 + * 0 1 + * (in case len=2) + * 1 0 + * 01 1 + * 00 2 + * (in case len=3) + * 1 0 + * 01 1 + * 001 2 + * 000 3 + */ +static inline int get_unary(GetBitContext *gb, int stop, int len) +{ + int i; + + for(i = 0; i < len && get_bits1(gb) != stop; i++); + return i; +} + +/** + * Get unary code terminated by a 0 with a maximum length of 33 + * @param gb GetBitContext + * @return Unary length/index + */ +static inline int get_unary_0_33(GetBitContext *gb) +{ + return get_unary(gb, 0, 33); +} + +static inline int get_unary_0_9(GetBitContext *gb) +{ + return get_unary(gb, 0, 9); +} + +#endif /* AVCODEC_UNARY_H */ |