FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/mjpegenc.h
Date: 2021-09-24 20:55:06
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Lines: 4 4 100.0%
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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 9028 static inline void put_marker(PutBitContext *p, enum JpegMarker code)
102 {
103 9028 put_bits(p, 8, 0xff);
104 9028 put_bits(p, 8, code);
105 9028 }
106
107 int ff_mjpeg_encode_init(MpegEncContext *s);
108 void ff_mjpeg_encode_close(MpegEncContext *s);
109 void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]);
110 int ff_mjpeg_encode_stuffing(MpegEncContext *s);
111
112 #endif /* AVCODEC_MJPEGENC_H */
113