251 lines
7.6 KiB
Factor
251 lines
7.6 KiB
Factor
! Copyright (C) 2020 .
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! See http://factorcode.org/license.txt for BSD license.
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USING: alien.syntax math io.encodings.binary kernel io io.files locals endian bit-arrays math.intervals combinators math.order sequences io.streams.peek io.binary namespaces accessors byte-arrays ;
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USING: prettyprint ;
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USING: flac.metadata.private flac.metadata ;
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QUALIFIED: bitstreams
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IN: flac.decoder
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ALIAS: read-bit bitstreams:read
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ALIAS: peek-bits bitstreams:peek
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CONSTANT: sync-code 16382
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ERROR: sync-code-error ;
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ERROR: invalid-channel-assignment ;
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ERROR: reserved-block-size ;
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ERROR: invalid-sample-rate ;
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ERROR: invalid-subframe-type ;
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ERROR: invalid-subframe-sync ;
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ENUM: flac-channel-assignment
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channels-mono
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channels-left/right
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channels-left/right/center
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channels-left/right/left-surround/right-surround
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channels-left/right/center/left-surround/right-surround
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channels-left/right/center/lfe/left-surround/right-surround
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channels-left/right/center/lfe/center-surround/side-left/side-right
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channels-left/right/center/lfe/left-surround/right-surround/side-left/side-right
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channels-left
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channels-right
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channels-mid ;
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ENUM: flac-frame-number-type
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frame-number-type-frame
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frame-number-type-sample ;
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ENUM: flac-subframe-type
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subframe-type-constant
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subframe-type-verbatim
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subframe-type-fixed
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subframe-type-lpc ;
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ENUM: flac-entropy-coding-method
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entropy-coding-partioned-rice
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entropy-coding-partioned-rice2 ;
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TUPLE: flac-subframe
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{ type maybe{ subframe-type-constant
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subframe-type-verbatim
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subframe-type-fixed
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subframe-type-lpc } }
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{ wasted-bits integer }
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{ data byte-array } ;
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TUPLE: frame-header
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{ number-type maybe{ frame-number-type-frame frame-number-type-sample } }
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{ blocksize integer }
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{ sample-rate integer }
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{ channels integer }
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{ channel-assignment maybe{ channels-mono
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channels-left/right
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channels-left/right/center
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channels-left/right/left-surround/right-surround
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channels-left/right/center/left-surround/right-surround
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channels-left/right/center/lfe/left-surround/right-surround
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channels-left/right/center/lfe/center-surround/side-left/side-right
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channels-left/right/center/lfe/left-surround/right-surround/side-left/side-right
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channels-left
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channels-right
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channels-mid } }
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{ bits-per-sample integer }
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{ frame|sample-number integer }
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{ crc integer } ;
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TUPLE: frame-footer
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{ crc integer } ;
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TUPLE: flac-frame
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{ header frame-header }
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{ subframes sequence }
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{ footer frame-footer } ;
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: 0xxxxxxx? ( n -- ? ) 0x80 bitand 0x80 = not ;
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: 110xxxxx? ( n -- ? ) dup [ 0xc0 bitand 0xc0 = ] [ 0x20 bitand 0x20 = not ] bi* and ;
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: 1110xxxx? ( n -- ? ) dup [ 0xe0 bitand 0xe0 = ] [ 0x10 bitand 0x10 = not ] bi* and ;
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: 11110xxx? ( n -- ? ) dup [ 0xf0 bitand 0xf0 = ] [ 0x08 bitand 0x08 = not ] bi* and ;
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: 111110xx? ( n -- ? ) dup [ 0xf8 bitand 0xf8 = ] [ 0x04 bitand 0x04 = not ] bi* and ;
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: 1111110x? ( n -- ? ) dup [ 0xfc bitand 0xfc = ] [ 0x02 bitand 0x02 = not ] bi* and ;
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: 11111110? ( n -- ? ) dup [ 0xfe bitand 0xfe = ] [ 0x01 bitand 0x01 = not ] bi* and ;
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:: remaining-bytes ( n -- n )
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{
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{ [ n 110xxxxx? ] [ 1 ] }
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{ [ n 1110xxxx? ] [ 2 ] }
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{ [ n 11110xxx? ] [ 3 ] }
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{ [ n 111110xx? ] [ 4 ] }
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{ [ n 1111110x? ] [ 5 ] }
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{ [ n 11111110? ] [ 6 ] }
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} cond ;
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! : remaining-bytes ( n -- n )
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! {
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! { [ dup 110xxxxx? ] [ drop 1 ] }
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! { [ dup 1110xxxx? ] [ drop 2 ] }
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! { [ dup 11110xxx? ] [ drop 3 ] }
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! { [ dup 111110xx? ] [ drop 4 ] }
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! { [ dup 1111110x? ] [ drop 5 ] }
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! { [ dup 11111110? ] [ drop 6 ] }
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! } cond ;
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:: decode-utf8-uint ( frame-length bitstream -- n )
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frame-length 7 -
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bitstream read-bit
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frame-length <iota>
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[
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drop
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2 bitstream read-bit drop
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6 shift 6 bitstream read-bit bitor
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] each ;
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: read-utf8-uint ( -- n )
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1 read dup
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be> 0xxxxxxx?
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[ be> ]
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[
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dup be> remaining-bytes read
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B{ } append-as be>
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] if ;
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: decode-block-size ( n -- n )
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{
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{ [ dup 0b0000 = ] [ drop reserved-block-size ] }
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{ [ dup 0b0001 = ] [ drop 192 ] }
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{ [ dup 0b0010 0b0101 between? ] [ 2 - 2^ 567 * ] }
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{ [ dup 0b0110 0b0111 between? ] [ ] }
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{ [ dup 0b1000 0b1111 between? ] [ 8 - 2^ 256 * ] }
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} cond ;
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: decode-bits-per-sample ( n -- n )
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{
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{ 0b000 [ -99 ] }
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{ 0b001 [ 8 ] }
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{ 0b010 [ 12 ] }
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{ 0b011 [ -99 ] }
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{ 0b100 [ 16 ] }
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{ 0b101 [ 20 ] }
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{ 0b110 [ 24 ] }
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{ 0b111 [ -99 ] }
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} case ;
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: decode-sample-rate ( n -- n )
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{
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{ 0b0000 [ -99 ] }
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{ 0b0001 [ 88200 ] }
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{ 0b0010 [ 17640 ] }
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{ 0b0011 [ 19200 ] }
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{ 0b0100 [ 8000 ] }
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{ 0b0101 [ 16000 ] }
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{ 0b0110 [ 22050 ] }
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{ 0b0111 [ 24000 ] }
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{ 0b1000 [ 32000 ] }
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{ 0b1001 [ 44100 ] }
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{ 0b1010 [ 48000 ] }
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{ 0b1011 [ 96000 ] }
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{ 0b1100 [ 1 read be> 1000 * ] }
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{ 0b1101 [ 2 read be> ] }
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{ 0b1110 [ 2 read be> 10 * ] }
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{ 0b1111 [ invalid-sample-rate ] }
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} case ;
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: decode-channels ( n -- channels channel-assignment )
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dup
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{
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{ [ dup 0b0000 0b0111 between? ] [ 1 + ] }
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{ [ 0b1000 0b1010 between? ] [ 2 ] }
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[ invalid-channel-assignment ]
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} cond swap
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<flac-channel-assignment> ;
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:: decode-header ( bitstream -- frame-header )
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[
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14 bitstream read-bit drop ! ignore sync
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1 bitstream read-bit drop ! reserved
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1 bitstream read-bit
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4 bitstream read-bit
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4 bitstream read-bit
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4 bitstream read-bit
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3 bitstream read-bit
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1 bitstream read-bit drop ! ignore magic sync
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read-utf8-uint
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[
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{
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[ <flac-frame-number-type> ]
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[ decode-block-size ]
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[ decode-sample-rate ]
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[ decode-channels ]
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[ decode-bits-per-sample ]
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} spread
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] dip
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1 read be>
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] with-big-endian
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frame-header boa ;
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:: decode-subframe-type ( n -- type )
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{
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{ [ n 0 = ] [ 0 ] }
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{ [ n 1 = ] [ 1 ] }
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{ [ n 8 >= n 12 <= and ] [ 2 ] }
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{ [ n 32 >= ] [ 3 ] }
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[ invalid-subframe-type ]
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} cond <flac-subframe-type> ;
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:: decode-subframe ( bitstream -- subframe )
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1 bitstream read-bit 1 = [ invalid-subframe-sync ] when
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6 bitstream read-bit decode-subframe-type
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1 bitstream read-bit ! TODO: wasted-bits: 0 for now..
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B{ }
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flac-subframe boa ;
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! TODO: actually decode based on subframe type
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! TODO: handle wasted bits assuming 1 byte for now :/
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: read-subframe ( frame-header channel -- subframe )
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drop drop
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1 read bitstreams:<msb0-bit-reader> decode-subframe ;
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: read-subframes ( frame-header -- seq )
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dup channels>> swap <repetition> [ read-subframe ] map-index ;
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: read-frame-header ( -- frame-header )
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4 read bitstreams:<msb0-bit-reader> decode-header ;
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: read-frame ( -- frame )
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read-frame-header
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dup read-subframes
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frame-footer new
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flac-frame boa ;
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: decode-file ( filename -- something )
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binary
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[
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read-flac-magic [ not-a-flac-file ] unless
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read-stream-info .
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skip-metadata
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! 51448296 seek-absolute seek-input
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read-frame
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contents .
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] with-file-reader ;
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