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
32#define FLAC_STREAMINFO_SIZE   34
33#define FLAC_MAX_CHANNELS       8
34#define FLAC_MIN_BLOCKSIZE     16
35#define FLAC_MAX_BLOCKSIZE  65535
36
37enum {
38    FLAC_CHMODE_INDEPENDENT =  0,
39    FLAC_CHMODE_LEFT_SIDE   =  8,
40    FLAC_CHMODE_RIGHT_SIDE  =  9,
41    FLAC_CHMODE_MID_SIDE    = 10,
42};
43
44enum {
45    FLAC_METADATA_TYPE_STREAMINFO = 0,
46    FLAC_METADATA_TYPE_PADDING,
47    FLAC_METADATA_TYPE_APPLICATION,
48    FLAC_METADATA_TYPE_SEEKTABLE,
49    FLAC_METADATA_TYPE_VORBIS_COMMENT,
50    FLAC_METADATA_TYPE_CUESHEET,
51    FLAC_METADATA_TYPE_PICTURE,
52    FLAC_METADATA_TYPE_INVALID = 127
53};
54
55enum FLACExtradataFormat {
56    FLAC_EXTRADATA_FORMAT_STREAMINFO  = 0,
57    FLAC_EXTRADATA_FORMAT_FULL_HEADER = 1
58};
59
60#define FLACCOMMONINFO \
61    int samplerate;         /**< sample rate                             */\
62    int channels;           /**< number of channels                      */\
63    int bps;                /**< bits-per-sample                         */\
64
65/**
66 * Data needed from the Streaminfo header for use by the raw FLAC demuxer
67 * and/or the FLAC decoder.
68 */
69#define FLACSTREAMINFO \
70    FLACCOMMONINFO \
71    int max_blocksize;      /**< maximum block size, in samples          */\
72    int max_framesize;      /**< maximum frame size, in bytes            */\
73    int64_t samples;        /**< total number of samples                 */\
74
75typedef struct FLACStreaminfo {
76    FLACSTREAMINFO
77} FLACStreaminfo;
78
79typedef struct FLACFrameInfo {
80    FLACCOMMONINFO
81    int blocksize;          /**< block size of the frame                 */
82    int ch_mode;            /**< channel decorrelation mode              */
83} FLACFrameInfo;
84
85/**
86 * Parse the Streaminfo metadata block
87 * @param[out] avctx   codec context to set basic stream parameters
88 * @param[out] s       where parsed information is stored
89 * @param[in]  buffer  pointer to start of 34-byte streaminfo data
90 */
91void ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
92                              const uint8_t *buffer);
93
94/**
95 * Validate the FLAC extradata.
96 * @param[in]  avctx codec context containing the extradata.
97 * @param[out] format extradata format.
98 * @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
99 * @return 1 if valid, 0 if not valid.
100 */
101int ff_flac_is_extradata_valid(AVCodecContext *avctx,
102                               enum FLACExtradataFormat *format,
103                               uint8_t **streaminfo_start);
104
105/**
106 * Parse the metadata block parameters from the header.
107 * @param[in]  block_header header data, at least 4 bytes
108 * @param[out] last indicator for last metadata block
109 * @param[out] type metadata block type
110 * @param[out] size metadata block size
111 */
112void ff_flac_parse_block_header(const uint8_t *block_header,
113                                int *last, int *type, int *size);
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 */
121int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
122
123#endif /* AVCODEC_FLAC_H */
124