1/*
2 * FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
3 * Copyright (c) 2008 Justin Ruggles
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 "get_bits.h"
32
33#define FLAC_STREAMINFO_SIZE   34
34#define FLAC_MAX_CHANNELS       8
35#define FLAC_MIN_BLOCKSIZE     16
36#define FLAC_MAX_BLOCKSIZE  65535
37#define FLAC_MIN_FRAME_SIZE    11
38
39enum {
40    FLAC_CHMODE_INDEPENDENT =  0,
41    FLAC_CHMODE_LEFT_SIDE   =  8,
42    FLAC_CHMODE_RIGHT_SIDE  =  9,
43    FLAC_CHMODE_MID_SIDE    = 10,
44};
45
46enum {
47    FLAC_METADATA_TYPE_STREAMINFO = 0,
48    FLAC_METADATA_TYPE_PADDING,
49    FLAC_METADATA_TYPE_APPLICATION,
50    FLAC_METADATA_TYPE_SEEKTABLE,
51    FLAC_METADATA_TYPE_VORBIS_COMMENT,
52    FLAC_METADATA_TYPE_CUESHEET,
53    FLAC_METADATA_TYPE_PICTURE,
54    FLAC_METADATA_TYPE_INVALID = 127
55};
56
57enum FLACExtradataFormat {
58    FLAC_EXTRADATA_FORMAT_STREAMINFO  = 0,
59    FLAC_EXTRADATA_FORMAT_FULL_HEADER = 1
60};
61
62#define FLACCOMMONINFO \
63    int samplerate;         /**< sample rate                             */\
64    int channels;           /**< number of channels                      */\
65    int bps;                /**< bits-per-sample                         */\
66
67/**
68 * Data needed from the Streaminfo header for use by the raw FLAC demuxer
69 * and/or the FLAC decoder.
70 */
71#define FLACSTREAMINFO \
72    FLACCOMMONINFO \
73    int max_blocksize;      /**< maximum block size, in samples          */\
74    int max_framesize;      /**< maximum frame size, in bytes            */\
75    int64_t samples;        /**< total number of samples                 */\
76
77typedef struct FLACStreaminfo {
78    FLACSTREAMINFO
79} FLACStreaminfo;
80
81typedef struct FLACFrameInfo {
82    FLACCOMMONINFO
83    int blocksize;          /**< block size of the frame                 */
84    int ch_mode;            /**< channel decorrelation mode              */
85    int64_t frame_or_sample_num;    /**< frame number or sample number   */
86    int is_var_size;                /**< specifies if the stream uses variable
87                                         block sizes or a fixed block size;
88                                         also determines the meaning of
89                                         frame_or_sample_num             */
90} FLACFrameInfo;
91
92/**
93 * Parse the Streaminfo metadata block
94 * @param[out] avctx   codec context to set basic stream parameters
95 * @param[out] s       where parsed information is stored
96 * @param[in]  buffer  pointer to start of 34-byte streaminfo data
97 */
98void avpriv_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
99                                  const uint8_t *buffer);
100
101/**
102 * Validate the FLAC extradata.
103 * @param[in]  avctx codec context containing the extradata.
104 * @param[out] format extradata format.
105 * @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
106 * @return 1 if valid, 0 if not valid.
107 */
108int avpriv_flac_is_extradata_valid(AVCodecContext *avctx,
109                                   enum FLACExtradataFormat *format,
110                                   uint8_t **streaminfo_start);
111
112/**
113 * Parse the metadata block parameters from the header.
114 * @param[in]  block_header header data, at least 4 bytes
115 * @param[out] last indicator for last metadata block
116 * @param[out] type metadata block type
117 * @param[out] size metadata block size
118 */
119void avpriv_flac_parse_block_header(const uint8_t *block_header,
120                                    int *last, int *type, int *size);
121
122/**
123 * Calculate an estimate for the maximum frame size based on verbatim mode.
124 * @param blocksize block size, in samples
125 * @param ch number of channels
126 * @param bps bits-per-sample
127 */
128int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
129
130/**
131 * Validate and decode a frame header.
132 * @param      avctx AVCodecContext to use as av_log() context
133 * @param      gb    GetBitContext from which to read frame header
134 * @param[out] fi    frame information
135 * @param      log_level_offset  log level offset. can be used to silence error messages.
136 * @return non-zero on error, 0 if ok
137 */
138int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
139                                FLACFrameInfo *fi, int log_level_offset);
140#endif /* AVCODEC_FLAC_H */
141