FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/flac.h
Date: 2021-09-22 05:58:22
Exec Total Coverage
Lines: 9 9 100.0%
Branches: 3 6 50.0%

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1 /*
2 * FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
3 * Copyright (c) 2008 Justin Ruggles
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 /**
23 * @file
24 * FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
25 */
26
27 #ifndef AVCODEC_FLAC_H
28 #define AVCODEC_FLAC_H
29
30 #include "avcodec.h"
31 #include "bytestream.h"
32 #include "get_bits.h"
33
34 #define FLAC_STREAMINFO_SIZE 34
35 #define FLAC_MAX_CHANNELS 8
36 #define FLAC_MIN_BLOCKSIZE 16
37 #define FLAC_MAX_BLOCKSIZE 65535
38 #define FLAC_MIN_FRAME_SIZE 11
39
40 enum {
41 FLAC_CHMODE_INDEPENDENT = 0,
42 FLAC_CHMODE_LEFT_SIDE = 1,
43 FLAC_CHMODE_RIGHT_SIDE = 2,
44 FLAC_CHMODE_MID_SIDE = 3,
45 };
46
47 enum {
48 FLAC_METADATA_TYPE_STREAMINFO = 0,
49 FLAC_METADATA_TYPE_PADDING,
50 FLAC_METADATA_TYPE_APPLICATION,
51 FLAC_METADATA_TYPE_SEEKTABLE,
52 FLAC_METADATA_TYPE_VORBIS_COMMENT,
53 FLAC_METADATA_TYPE_CUESHEET,
54 FLAC_METADATA_TYPE_PICTURE,
55 FLAC_METADATA_TYPE_INVALID = 127
56 };
57
58 enum FLACExtradataFormat {
59 FLAC_EXTRADATA_FORMAT_STREAMINFO = 0,
60 FLAC_EXTRADATA_FORMAT_FULL_HEADER = 1
61 };
62
63 #define FLACCOMMONINFO \
64 int samplerate; /**< sample rate */\
65 int channels; /**< number of channels */\
66 int bps; /**< bits-per-sample */\
67
68 /**
69 * Data needed from the Streaminfo header for use by the raw FLAC demuxer
70 * and/or the FLAC decoder.
71 */
72 #define FLACSTREAMINFO \
73 FLACCOMMONINFO \
74 int max_blocksize; /**< maximum block size, in samples */\
75 int max_framesize; /**< maximum frame size, in bytes */\
76 int64_t samples; /**< total number of samples */\
77
78 typedef struct FLACStreaminfo {
79 FLACSTREAMINFO
80 } FLACStreaminfo;
81
82 typedef struct FLACFrameInfo {
83 FLACCOMMONINFO
84 int blocksize; /**< block size of the frame */
85 int ch_mode; /**< channel decorrelation mode */
86 int64_t frame_or_sample_num; /**< frame number or sample number */
87 int is_var_size; /**< specifies if the stream uses variable
88 block sizes or a fixed block size;
89 also determines the meaning of
90 frame_or_sample_num */
91 } FLACFrameInfo;
92
93 /**
94 * Parse the Streaminfo metadata block
95 * @param[out] avctx codec context to set basic stream parameters
96 * @param[out] s where parsed information is stored
97 * @param[in] buffer pointer to start of 34-byte streaminfo data
98 *
99 * @return negative error code on faiure or >= 0 on success
100 */
101 int ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
102 const uint8_t *buffer);
103
104 /**
105 * Validate the FLAC extradata.
106 * @param[in] avctx codec context containing the extradata.
107 * @param[out] format extradata format.
108 * @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
109 * @return 1 if valid, 0 if not valid.
110 */
111 int ff_flac_is_extradata_valid(AVCodecContext *avctx,
112 enum FLACExtradataFormat *format,
113 uint8_t **streaminfo_start);
114
115 /**
116 * Calculate an estimate for the maximum frame size based on verbatim mode.
117 * @param blocksize block size, in samples
118 * @param ch number of channels
119 * @param bps bits-per-sample
120 */
121 int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
122
123 /**
124 * Validate and decode a frame header.
125 * @param avctx AVCodecContext to use as av_log() context
126 * @param gb GetBitContext from which to read frame header
127 * @param[out] fi frame information
128 * @param log_level_offset log level offset. can be used to silence error messages.
129 * @return non-zero on error, 0 if ok
130 */
131 int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
132 FLACFrameInfo *fi, int log_level_offset);
133
134 void ff_flac_set_channel_layout(AVCodecContext *avctx);
135
136 /**
137 * Parse the metadata block parameters from the header.
138 * @param[in] block_header header data, at least 4 bytes
139 * @param[out] last indicator for last metadata block
140 * @param[out] type metadata block type
141 * @param[out] size metadata block size
142 */
143 97 static av_always_inline void flac_parse_block_header(const uint8_t *block_header,
144 int *last, int *type, int *size)
145 {
146 97 int tmp = bytestream_get_byte(&block_header);
147
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97 if (last)
148 97 *last = tmp & 0x80;
149
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97 if (type)
150 97 *type = tmp & 0x7F;
151
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97 if (size)
152 97 *size = bytestream_get_be24(&block_header);
153 97 }
154
155 #endif /* AVCODEC_FLAC_H */
156