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avcodec/flac: Move decoder+parser stuff into a new header, flac_parse.h

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(The FLAC parser currently ignores the streaminfo block;
therefore some of this is decoder-only. Given that the FLAC
parser should probably use the streaminfo block, this stuff
is moved to flac_parse.h.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
This commit is contained in:
Andreas Rheinhardt 2022-08-28 17:12:30 +02:00
parent f118b2aa46
commit 5089884e3c
5 changed files with 94 additions and 65 deletions
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1
libavcodec/flac.c
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@ -26,6 +26,7 @@
#include "get_bits.h"
#include "flac.h"
#include "flacdata.h"
#include "flac_parse.h"
static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 };

66
libavcodec/flac.h
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@ -1,5 +1,5 @@
/*
* FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
* FLAC (Free Lossless Audio Codec) common stuff
* Copyright (c) 2008 Justin Ruggles
*
* This file is part of FFmpeg.
@ -21,15 +21,13 @@
/**
* @file
* FLAC (Free Lossless Audio Codec) decoder/demuxer common functions
* FLAC (Free Lossless Audio Codec) common stuff
*/
#ifndef AVCODEC_FLAC_H
#define AVCODEC_FLAC_H
#include "avcodec.h"
#include "bytestream.h"
#include "get_bits.h"
#define FLAC_STREAMINFO_SIZE 34
#define FLAC_MAX_CHANNELS 8
@ -55,66 +53,6 @@ enum {
FLAC_METADATA_TYPE_INVALID = 127
};
/**
* Data needed from the Streaminfo header for use by the raw FLAC demuxer
* and/or the FLAC decoder.
*/
typedef struct FLACStreaminfo {
int samplerate; /**< sample rate */
int channels; /**< number of channels */
int bps; /**< bits-per-sample */
int max_blocksize; /**< maximum block size, in samples */
int max_framesize; /**< maximum frame size, in bytes */
int64_t samples; /**< total number of samples */
} FLACStreaminfo;
typedef struct FLACFrameInfo {
int samplerate; /**< sample rate */
int channels; /**< number of channels */
int bps; /**< bits-per-sample */
int blocksize; /**< block size of the frame */
int ch_mode; /**< channel decorrelation mode */
int64_t frame_or_sample_num; /**< frame number or sample number */
int is_var_size; /**< specifies if the stream uses variable
block sizes or a fixed block size;
also determines the meaning of
frame_or_sample_num */
} FLACFrameInfo;
/**
* Parse the Streaminfo metadata block
* @param[out] avctx codec context to set basic stream parameters
* @param[out] s where parsed information is stored
* @param[in] buffer pointer to start of 34-byte streaminfo data
*
* @return negative error code on faiure or >= 0 on success
*/
int ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
const uint8_t *buffer);
/**
* Validate the FLAC extradata.
* @param[in] avctx codec context containing the extradata.
* @param[out] format extradata format.
* @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
* @return 1 if valid, 0 if not valid.
*/
int ff_flac_is_extradata_valid(AVCodecContext *avctx,
uint8_t **streaminfo_start);
/**
* Validate and decode a frame header.
* @param avctx AVCodecContext to use as av_log() context
* @param gb GetBitContext from which to read frame header
* @param[out] fi frame information
* @param log_level_offset log level offset. can be used to silence error messages.
* @return non-zero on error, 0 if ok
*/
int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
FLACFrameInfo *fi, int log_level_offset);
void ff_flac_set_channel_layout(AVCodecContext *avctx, int channels);
/**
* Parse the metadata block parameters from the header.
* @param[in] block_header header data, at least 4 bytes

89
libavcodec/flac_parse.h Normal file
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@ -0,0 +1,89 @@
/*
* FLAC (Free Lossless Audio Codec) decoder/parser common functions
* Copyright (c) 2008 Justin Ruggles
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* FLAC (Free Lossless Audio Codec) decoder/parser common functions
*/
#ifndef AVCODEC_FLAC_PARSE_H
#define AVCODEC_FLAC_PARSE_H
#include "avcodec.h"
#include "get_bits.h"
typedef struct FLACStreaminfo {
int samplerate; /**< sample rate */
int channels; /**< number of channels */
int bps; /**< bits-per-sample */
int max_blocksize; /**< maximum block size, in samples */
int max_framesize; /**< maximum frame size, in bytes */
int64_t samples; /**< total number of samples */
} FLACStreaminfo;
typedef struct FLACFrameInfo {
int samplerate; /**< sample rate */
int channels; /**< number of channels */
int bps; /**< bits-per-sample */
int blocksize; /**< block size of the frame */
int ch_mode; /**< channel decorrelation mode */
int64_t frame_or_sample_num; /**< frame number or sample number */
int is_var_size; /**< specifies if the stream uses variable
block sizes or a fixed block size;
also determines the meaning of
frame_or_sample_num */
} FLACFrameInfo;
/**
* Parse the Streaminfo metadata block
* @param[out] avctx codec context to set basic stream parameters
* @param[out] s where parsed information is stored
* @param[in] buffer pointer to start of 34-byte streaminfo data
*
* @return negative error code on faiure or >= 0 on success
*/
int ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
const uint8_t *buffer);
/**
* Validate the FLAC extradata.
* @param[in] avctx codec context containing the extradata.
* @param[out] format extradata format.
* @param[out] streaminfo_start pointer to start of 34-byte STREAMINFO data.
* @return 1 if valid, 0 if not valid.
*/
int ff_flac_is_extradata_valid(AVCodecContext *avctx,
uint8_t **streaminfo_start);
/**
* Validate and decode a frame header.
* @param avctx AVCodecContext to use as av_log() context
* @param gb GetBitContext from which to read frame header
* @param[out] fi frame information
* @param log_level_offset log level offset. can be used to silence error messages.
* @return non-zero on error, 0 if ok
*/
int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
FLACFrameInfo *fi, int log_level_offset);
void ff_flac_set_channel_layout(AVCodecContext *avctx, int channels);
#endif /* AVCODEC_FLAC_PARSE_H */

2
libavcodec/flac_parser.c
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@ -36,7 +36,7 @@
#include "libavutil/crc.h"
#include "bytestream.h"
#include "parser.h"
#include "flac.h"
#include "flac_parse.h"
/** maximum number of adjacent headers that compare CRCs against each other */
#define FLAC_MAX_SEQUENTIAL_HEADERS 4

1
libavcodec/flacdec.c
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@ -44,6 +44,7 @@
#include "flac.h"
#include "flacdata.h"
#include "flacdsp.h"
#include "flac_parse.h"
#include "thread.h"
#include "unary.h"