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 40enum { 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 47enum { 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 58enum 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 78typedef struct FLACStreaminfo { 79 FLACSTREAMINFO 80} FLACStreaminfo; 81 82typedef 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 */ 99void avpriv_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s, 100 const uint8_t *buffer); 101 102/** 103 * Validate the FLAC extradata. 104 * @param[in] avctx codec context containing the extradata. 105 * @param[out] format extradata format. 106 * @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data. 107 * @return 1 if valid, 0 if not valid. 108 */ 109int avpriv_flac_is_extradata_valid(AVCodecContext *avctx, 110 enum FLACExtradataFormat *format, 111 uint8_t **streaminfo_start); 112 113#if LIBAVCODEC_VERSION_MAJOR < 56 114void avpriv_flac_parse_block_header(const uint8_t *block_header, 115 int *last, int *type, int *size); 116#endif 117 118/** 119 * Calculate an estimate for the maximum frame size based on verbatim mode. 120 * @param blocksize block size, in samples 121 * @param ch number of channels 122 * @param bps bits-per-sample 123 */ 124int ff_flac_get_max_frame_size(int blocksize, int ch, int bps); 125 126/** 127 * Validate and decode a frame header. 128 * @param avctx AVCodecContext to use as av_log() context 129 * @param gb GetBitContext from which to read frame header 130 * @param[out] fi frame information 131 * @param log_level_offset log level offset. can be used to silence error messages. 132 * @return non-zero on error, 0 if ok 133 */ 134int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb, 135 FLACFrameInfo *fi, int log_level_offset); 136 137void ff_flac_set_channel_layout(AVCodecContext *avctx); 138 139/** 140 * Parse the metadata block parameters from the header. 141 * @param[in] block_header header data, at least 4 bytes 142 * @param[out] last indicator for last metadata block 143 * @param[out] type metadata block type 144 * @param[out] size metadata block size 145 */ 146static av_always_inline void flac_parse_block_header(const uint8_t *block_header, 147 int *last, int *type, int *size) 148{ 149 int tmp = bytestream_get_byte(&block_header); 150 if (last) 151 *last = tmp & 0x80; 152 if (type) 153 *type = tmp & 0x7F; 154 if (size) 155 *size = bytestream_get_be24(&block_header); 156} 157 158#endif /* AVCODEC_FLAC_H */ 159