blob: 991ab43f3cc37ccd38142045a8e3fac2f52e6507
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 | static av_always_inline void flac_parse_block_header(const uint8_t *block_header, |
144 | int *last, int *type, int *size) |
145 | { |
146 | int tmp = bytestream_get_byte(&block_header); |
147 | if (last) |
148 | *last = tmp & 0x80; |
149 | if (type) |
150 | *type = tmp & 0x7F; |
151 | if (size) |
152 | *size = bytestream_get_be24(&block_header); |
153 | } |
154 | |
155 | #endif /* AVCODEC_FLAC_H */ |
156 |