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libavcodec
flac.h
Go to the documentation of this file.
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/*
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* FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
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* Copyright (c) 2008 Justin Ruggles
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
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*/
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#ifndef AVCODEC_FLAC_H
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#define AVCODEC_FLAC_H
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#include "
avcodec.h
"
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#include "
bytestream.h
"
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#include "
get_bits.h
"
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#define FLAC_STREAMINFO_SIZE 34
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#define FLAC_MAX_CHANNELS 8
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#define FLAC_MIN_BLOCKSIZE 16
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#define FLAC_MAX_BLOCKSIZE 65535
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#define FLAC_MIN_FRAME_SIZE 11
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enum
{
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FLAC_CHMODE_INDEPENDENT
= 0,
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FLAC_CHMODE_LEFT_SIDE
= 1,
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FLAC_CHMODE_RIGHT_SIDE
= 2,
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FLAC_CHMODE_MID_SIDE
= 3,
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};
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enum
{
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FLAC_METADATA_TYPE_STREAMINFO
= 0,
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FLAC_METADATA_TYPE_PADDING
,
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FLAC_METADATA_TYPE_APPLICATION
,
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FLAC_METADATA_TYPE_SEEKTABLE
,
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FLAC_METADATA_TYPE_VORBIS_COMMENT
,
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FLAC_METADATA_TYPE_CUESHEET
,
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FLAC_METADATA_TYPE_PICTURE
,
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FLAC_METADATA_TYPE_INVALID
= 127
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};
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enum
FLACExtradataFormat
{
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FLAC_EXTRADATA_FORMAT_STREAMINFO
= 0,
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FLAC_EXTRADATA_FORMAT_FULL_HEADER
= 1
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};
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#define FLACCOMMONINFO \
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int samplerate;
/**< sample rate */
\
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int channels;
/**< number of channels */
\
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int bps;
/**< bits-per-sample */
\
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/**
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* Data needed from the Streaminfo header for use by the raw FLAC demuxer
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* and/or the FLAC decoder.
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*/
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#define FLACSTREAMINFO \
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FLACCOMMONINFO \
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int max_blocksize;
/**< maximum block size, in samples */
\
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int max_framesize;
/**< maximum frame size, in bytes */
\
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int64_t samples;
/**< total number of samples */
\
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typedef
struct
FLACStreaminfo
{
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FLACSTREAMINFO
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}
FLACStreaminfo
;
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typedef
struct
FLACFrameInfo
{
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FLACCOMMONINFO
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int
blocksize
;
/**< block size of the frame */
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int
ch_mode
;
/**< channel decorrelation mode */
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int64_t
frame_or_sample_num
;
/**< frame number or sample number */
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int
is_var_size
;
/**< specifies if the stream uses variable
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block sizes or a fixed block size;
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also determines the meaning of
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frame_or_sample_num */
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}
FLACFrameInfo
;
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/**
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* Parse the Streaminfo metadata block
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* @param[out] avctx codec context to set basic stream parameters
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* @param[out] s where parsed information is stored
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* @param[in] buffer pointer to start of 34-byte streaminfo data
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*/
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void
ff_flac_parse_streaminfo
(
AVCodecContext
*avctx,
struct
FLACStreaminfo
*
s
,
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const
uint8_t
*
buffer
);
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#if LIBAVCODEC_VERSION_MAJOR < 57
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void
avpriv_flac_parse_streaminfo
(
AVCodecContext
*avctx,
struct
FLACStreaminfo
*
s
,
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const
uint8_t
*
buffer
);
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int
avpriv_flac_is_extradata_valid
(
AVCodecContext
*avctx,
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enum
FLACExtradataFormat
*format,
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uint8_t
**streaminfo_start);
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#endif
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/**
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* Validate the FLAC extradata.
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* @param[in] avctx codec context containing the extradata.
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* @param[out] format extradata format.
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* @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
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* @return 1 if valid, 0 if not valid.
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*/
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int
ff_flac_is_extradata_valid
(
AVCodecContext
*avctx,
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enum
FLACExtradataFormat
*format,
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uint8_t
**streaminfo_start);
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/**
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* Calculate an estimate for the maximum frame size based on verbatim mode.
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* @param blocksize block size, in samples
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* @param ch number of channels
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* @param bps bits-per-sample
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*/
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int
ff_flac_get_max_frame_size
(
int
blocksize,
int
ch,
int
bps
);
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/**
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* Validate and decode a frame header.
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* @param avctx AVCodecContext to use as av_log() context
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* @param gb GetBitContext from which to read frame header
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* @param[out] fi frame information
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* @param log_level_offset log level offset. can be used to silence error messages.
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* @return non-zero on error, 0 if ok
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*/
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int
ff_flac_decode_frame_header
(
AVCodecContext
*avctx,
GetBitContext
*gb,
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FLACFrameInfo
*
fi
,
int
log_level_offset);
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void
ff_flac_set_channel_layout
(
AVCodecContext
*avctx);
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/**
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* Parse the metadata block parameters from the header.
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* @param[in] block_header header data, at least 4 bytes
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* @param[out] last indicator for last metadata block
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* @param[out] type metadata block type
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* @param[out] size metadata block size
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*/
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static
av_always_inline
void
flac_parse_block_header
(
const
uint8_t
*block_header,
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int
*last,
int
*
type
,
int
*
size
)
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{
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int
tmp = bytestream_get_byte(&block_header);
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if
(last)
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*last = tmp & 0x80;
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if
(type)
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*type = tmp & 0x7F;
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if
(size)
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*size = bytestream_get_be24(&block_header);
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}
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#endif
/* AVCODEC_FLAC_H */
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