path: root/libavcodec/mjpegenc.h (plain)
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1	/*
2	* MJPEG encoder
3	* Copyright (c) 2000, 2001 Fabrice Bellard
4	* Copyright (c) 2003 Alex Beregszaszi
5	* Copyright (c) 2003-2004 Michael Niedermayer
6	*
7	* Support for external huffman table, various fixes (AVID workaround),
8	* aspecting, new decode_frame mechanism and apple mjpeg-b support
9	* by Alex Beregszaszi
10	*
11	* This file is part of FFmpeg.
12	*
13	* FFmpeg is free software; you can redistribute it and/or
14	* modify it under the terms of the GNU Lesser General Public
15	* License as published by the Free Software Foundation; either
16	* version 2.1 of the License, or (at your option) any later version.
17	*
18	* FFmpeg is distributed in the hope that it will be useful,
19	* but WITHOUT ANY WARRANTY; without even the implied warranty of
20	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21	* Lesser General Public License for more details.
22	*
23	* You should have received a copy of the GNU Lesser General Public
24	* License along with FFmpeg; if not, write to the Free Software
25	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26	*/
27
28	/**
29	* @file
30	* MJPEG encoder.
31	*/
32
33	#ifndef AVCODEC_MJPEGENC_H
34	#define AVCODEC_MJPEGENC_H
35
36	#include <stdint.h>
37
38	#include "mjpeg.h"
39	#include "mpegvideo.h"
40	#include "put_bits.h"
41
42	/**
43	* Buffer of JPEG frame data.
44	*
45	* Optimal Huffman table generation requires the frame data to be loaded into
46	* a buffer so that the tables can be computed.
47	* There are at most mb_width*mb_height*12*64 of these per frame.
48	*/
49	typedef struct MJpegHuffmanCode {
50	// 0=DC lum, 1=DC chrom, 2=AC lum, 3=AC chrom
51	uint8_t table_id; ///< The Huffman table id associated with the data.
52	uint8_t code; ///< The exponent.
53	uint16_t mant; ///< The mantissa.
54	} MJpegHuffmanCode;
55
56	/**
57	* Holds JPEG frame data and Huffman table data.
58	*/
59	typedef struct MJpegContext {
60	//FIXME use array [3] instead of lumi / chroma, for easier addressing
61	uint8_t huff_size_dc_luminance[12]; ///< DC luminance Huffman table size.
62	uint16_t huff_code_dc_luminance[12]; ///< DC luminance Huffman table codes.
63	uint8_t huff_size_dc_chrominance[12]; ///< DC chrominance Huffman table size.
64	uint16_t huff_code_dc_chrominance[12]; ///< DC chrominance Huffman table codes.
65
66	uint8_t huff_size_ac_luminance[256]; ///< AC luminance Huffman table size.
67	uint16_t huff_code_ac_luminance[256]; ///< AC luminance Huffman table codes.
68	uint8_t huff_size_ac_chrominance[256]; ///< AC chrominance Huffman table size.
69	uint16_t huff_code_ac_chrominance[256]; ///< AC chrominance Huffman table codes.
70
71	/** Storage for AC luminance VLC (in MpegEncContext) */
72	uint8_t uni_ac_vlc_len[64 * 64 * 2];
73	/** Storage for AC chrominance VLC (in MpegEncContext) */
74	uint8_t uni_chroma_ac_vlc_len[64 * 64 * 2];
75
76	// Default DC tables have exactly 12 values
77	uint8_t bits_dc_luminance[17]; ///< DC luminance Huffman bits.
78	uint8_t val_dc_luminance[12]; ///< DC luminance Huffman values.
79	uint8_t bits_dc_chrominance[17]; ///< DC chrominance Huffman bits.
80	uint8_t val_dc_chrominance[12]; ///< DC chrominance Huffman values.
81
82	// 8-bit JPEG has max 256 values
83	uint8_t bits_ac_luminance[17]; ///< AC luminance Huffman bits.
84	uint8_t val_ac_luminance[256]; ///< AC luminance Huffman values.
85	uint8_t bits_ac_chrominance[17]; ///< AC chrominance Huffman bits.
86	uint8_t val_ac_chrominance[256]; ///< AC chrominance Huffman values.
87
88	size_t huff_ncode; ///< Number of current entries in the buffer.
89	MJpegHuffmanCode *huff_buffer; ///< Buffer for Huffman code values.
90	} MJpegContext;
91
92	/**
93	* Enum for the Huffman encoding strategy.
94	*/
95	enum HuffmanTableOption {
96	HUFFMAN_TABLE_DEFAULT = 0, ///< Use the default Huffman tables.
97	HUFFMAN_TABLE_OPTIMAL = 1, ///< Compute and use optimal Huffman tables.
98	NB_HUFFMAN_TABLE_OPTION = 2
99	};
100
101	static inline void put_marker(PutBitContext *p, enum JpegMarker code)
102	{
103	put_bits(p, 8, 0xff);
104	put_bits(p, 8, code);
105	}
106
107	int ff_mjpeg_encode_init(MpegEncContext *s);
108	void ff_mjpeg_encode_picture_frame(MpegEncContext *s);
109	void ff_mjpeg_encode_close(MpegEncContext *s);
110	void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]);
111
112	#endif /* AVCODEC_MJPEGENC_H */
113