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 int huffman;
61 /* Force duplication of mjpeg matrices, useful for rtp streaming */
62 int force_duplicated_matrix;
63 //FIXME use array [3] instead of lumi / chroma, for easier addressing
64 uint8_t huff_size_dc_luminance[12]; ///< DC luminance Huffman table size.
65 uint16_t huff_code_dc_luminance[12]; ///< DC luminance Huffman table codes.
66 uint8_t huff_size_dc_chrominance[12]; ///< DC chrominance Huffman table size.
67 uint16_t huff_code_dc_chrominance[12]; ///< DC chrominance Huffman table codes.
68
69 uint8_t huff_size_ac_luminance[256]; ///< AC luminance Huffman table size.
70 uint16_t huff_code_ac_luminance[256]; ///< AC luminance Huffman table codes.
71 uint8_t huff_size_ac_chrominance[256]; ///< AC chrominance Huffman table size.
72 uint16_t huff_code_ac_chrominance[256]; ///< AC chrominance Huffman table codes.
73
74 /** Storage for AC luminance VLC (in MpegEncContext) */
75 uint8_t uni_ac_vlc_len[64 * 64 * 2];
76 /** Storage for AC chrominance VLC (in MpegEncContext) */
77 uint8_t uni_chroma_ac_vlc_len[64 * 64 * 2];
78
79 // Default DC tables have exactly 12 values
80 uint8_t bits_dc_luminance[17]; ///< DC luminance Huffman bits.
81 uint8_t val_dc_luminance[12]; ///< DC luminance Huffman values.
82 uint8_t bits_dc_chrominance[17]; ///< DC chrominance Huffman bits.
83 uint8_t val_dc_chrominance[12]; ///< DC chrominance Huffman values.
84
85 // 8-bit JPEG has max 256 values
86 uint8_t bits_ac_luminance[17]; ///< AC luminance Huffman bits.
87 uint8_t val_ac_luminance[256]; ///< AC luminance Huffman values.
88 uint8_t bits_ac_chrominance[17]; ///< AC chrominance Huffman bits.
89 uint8_t val_ac_chrominance[256]; ///< AC chrominance Huffman values.
90
91 size_t huff_ncode; ///< Number of current entries in the buffer.
92 MJpegHuffmanCode *huff_buffer; ///< Buffer for Huffman code values.
93 } MJpegContext;
94
95 /**
96 * Enum for the Huffman encoding strategy.
97 */
98 enum HuffmanTableOption {
99 HUFFMAN_TABLE_DEFAULT = 0, ///< Use the default Huffman tables.
100 HUFFMAN_TABLE_OPTIMAL = 1, ///< Compute and use optimal Huffman tables.
101 NB_HUFFMAN_TABLE_OPTION = 2
102 };
103
put_marker(PutBitContext * p,enum JpegMarker code)104 static inline void put_marker(PutBitContext *p, enum JpegMarker code)
105 {
106 put_bits(p, 8, 0xff);
107 put_bits(p, 8, code);
108 }
109
110 int ff_mjpeg_encode_init(MpegEncContext *s);
111 void ff_mjpeg_amv_encode_picture_header(MpegEncContext *s);
112 void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]);
113 int ff_mjpeg_encode_stuffing(MpegEncContext *s);
114
115 #endif /* AVCODEC_MJPEGENC_H */
116