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