diff options
author | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2022-01-03 12:35:39 +0100 |
---|---|---|
committer | Andreas Rheinhardt <andreas.rheinhardt@outlook.com> | 2022-01-06 08:28:02 +0100 |
commit | 2b541b8c1d8b214d39c5f86fe8dc3a2aebe08f6d (patch) | |
tree | a5ae6de87a523c167a9fe5a39dfbbc7261355d43 /libavcodec/put_golomb.h | |
parent | e228d7b0db7d6cb02a73bee6d3bf4f6ecf92d0bf (diff) |
avcodec/golomb: Factor writing golomb codes out
Most users only want to either read or write golomb codes, not both.
By splitting these headers one avoids having unnecesssary
(get|put)_hits.h inclusions.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Diffstat (limited to 'libavcodec/put_golomb.h')
-rw-r--r-- | libavcodec/put_golomb.h | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/libavcodec/put_golomb.h b/libavcodec/put_golomb.h new file mode 100644 index 0000000000..9ca911fc3c --- /dev/null +++ b/libavcodec/put_golomb.h @@ -0,0 +1,168 @@ +/* + * exp golomb vlc writing stuff + * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at> + * Copyright (c) 2004 Alex Beregszaszi + * + * 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 + */ + +/** + * @file + * @brief + * exp golomb vlc writing stuff + * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi + */ + +#ifndef AVCODEC_PUT_GOLOMB_H +#define AVCODEC_PUT_GOLOMB_H + +#include <stdint.h> +#include "put_bits.h" + +extern const uint8_t ff_ue_golomb_len[256]; + +/** + * write unsigned exp golomb code. 2^16 - 2 at most + */ +static inline void set_ue_golomb(PutBitContext *pb, int i) +{ + av_assert2(i >= 0); + av_assert2(i <= 0xFFFE); + + if (i < 256) + put_bits(pb, ff_ue_golomb_len[i], i + 1); + else { + int e = av_log2(i + 1); + put_bits(pb, 2 * e + 1, i + 1); + } +} + +/** + * write unsigned exp golomb code. 2^32-2 at most. + */ +static inline void set_ue_golomb_long(PutBitContext *pb, uint32_t i) +{ + av_assert2(i <= (UINT32_MAX - 1)); + + if (i < 256) + put_bits(pb, ff_ue_golomb_len[i], i + 1); + else { + int e = av_log2(i + 1); + put_bits64(pb, 2 * e + 1, i + 1); + } +} + +/** + * write truncated unsigned exp golomb code. + */ +static inline void set_te_golomb(PutBitContext *pb, int i, int range) +{ + av_assert2(range >= 1); + av_assert2(i <= range); + + if (range == 2) + put_bits(pb, 1, i ^ 1); + else + set_ue_golomb(pb, i); +} + +/** + * write signed exp golomb code. 16 bits at most. + */ +static inline void set_se_golomb(PutBitContext *pb, int i) +{ + i = 2 * i - 1; + if (i < 0) + i ^= -1; //FIXME check if gcc does the right thing + set_ue_golomb(pb, i); +} + +/** + * write unsigned golomb rice code (ffv1). + */ +static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit, + int esc_len) +{ + int e; + + av_assert2(i >= 0); + + e = i >> k; + if (e < limit) + put_bits(pb, e + k + 1, (1 << k) + av_mod_uintp2(i, k)); + else + put_bits(pb, limit + esc_len, i - limit + 1); +} + +/** + * write unsigned golomb rice code (jpegls). + */ +static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k, + int limit, int esc_len) +{ + int e; + + av_assert2(i >= 0); + + e = (i >> k) + 1; + if (e < limit) { + while (e > 31) { + put_bits(pb, 31, 0); + e -= 31; + } + put_bits(pb, e, 1); + if (k) + put_sbits(pb, k, i); + } else { + while (limit > 31) { + put_bits(pb, 31, 0); + limit -= 31; + } + put_bits(pb, limit, 1); + put_bits(pb, esc_len, i - 1); + } +} + +/** + * write signed golomb rice code (ffv1). + */ +static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit, + int esc_len) +{ + int v; + + v = -2 * i - 1; + v ^= (v >> 31); + + set_ur_golomb(pb, v, k, limit, esc_len); +} + +/** + * write signed golomb rice code (flac). + */ +static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k, + int limit, int esc_len) +{ + int v; + + v = -2 * i - 1; + v ^= (v >> 31); + + set_ur_golomb_jpegls(pb, v, k, limit, esc_len); +} + +#endif /* AVCODEC_PUT_GOLOMB_H */ |