libavcodec/flac.h

   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 libavcodec/flac.h
  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
  37 enum {
  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
  44 enum {
  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
  55 enum 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
  75 typedef struct FLACStreaminfo {
  76     FLACSTREAMINFO
  77 } FLACStreaminfo;
  78
  79 typedef 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  */
  91 void 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  */
 101 int 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  */
 112 void 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  */
 121 int ff_flac_get_max_frame_size(int blocksize, int ch, int bps);
 122
 123 #endif /* AVCODEC_FLAC_H */