path: root/libavcodec/dirac_vlc.h (plain)
blob: 42ae41b00a7c9e3d82dfad28666634ce8d9704e9

1	/*
2	* Copyright (C) 2016 Open Broadcast Systems Ltd.
3	* Author 2016 Rostislav Pehlivanov <rpehlivanov@obe.tv>
4	*
5	* This file is part of FFmpeg.
6	*
7	* FFmpeg is free software; you can redistribute it and/or
8	* modify it under the terms of the GNU Lesser General Public
9	* License as published by the Free Software Foundation; either
10	* version 2.1 of the License, or (at your option) any later version.
11	*
12	* FFmpeg is distributed in the hope that it will be useful,
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15	* Lesser General Public License for more details.
16	*
17	* You should have received a copy of the GNU Lesser General Public
18	* License along with FFmpeg; if not, write to the Free Software
19	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*/
21
22	#ifndef AVCODEC_DIRAC_VLC_H
23	#define AVCODEC_DIRAC_VLC_H
24
25	#include "libavutil/avutil.h"
26
27	/* Can be 32 bits wide for some performance gain on some machines, but it will
28	* incorrectly decode very long coefficients (usually only 1 or 2 per frame) */
29	typedef uint64_t residual;
30
31	#define LUT_BITS 8
32
33	/* Exactly 64 bytes */
34	typedef struct DiracGolombLUT {
35	residual preamble, leftover;
36	int32_t ready[LUT_BITS];
37	int32_t preamble_bits, leftover_bits, ready_num;
38	int8_t need_s, sign;
39	} DiracGolombLUT;
40
41	av_cold int ff_dirac_golomb_reader_init(DiracGolombLUT **lut_ctx);
42
43	int ff_dirac_golomb_read_32bit(DiracGolombLUT *lut_ctx, const uint8_t *buf,
44	int bytes, uint8_t *dst, int coeffs);
45
46	int ff_dirac_golomb_read_16bit(DiracGolombLUT *lut_ctx, const uint8_t *buf,
47	int bytes, uint8_t *_dst, int coeffs);
48
49	av_cold void ff_dirac_golomb_reader_end(DiracGolombLUT **lut_ctx);
50
51	#endif /* AVCODEC_DIRAC_VLC_H */
52