156 lines
5.3 KiB
C
Executable File
156 lines
5.3 KiB
C
Executable File
/*
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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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* @return negative error code on faiure or >= 0 on success
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*/
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int ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s,
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const uint8_t *buffer);
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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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