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constant decoding sort of working

flac
Steve Ayerhart 2020-03-25 23:30:29 -05:00
parent 70439e2c6f
commit 776ab11a08
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GPG Key ID: 5BFD39C5359E967D
1 changed files with 34 additions and 29 deletions
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63
extra/flac/decoder/decoder.factor
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@ -46,15 +46,18 @@ ENUM: flac-entropy-coding-method
entropy-coding-partioned-rice
entropy-coding-partioned-rice2 ;
TUPLE: flac-subframe
{ type maybe{ subframe-type-constant
TUPLE: flac-subframe-header
{ subframe-type maybe{ subframe-type-constant
subframe-type-verbatim
subframe-type-fixed
subframe-type-lpc } }
{ wasted-bits integer }
{ wasted-bits integer } ;
TUPLE: flac-subframe
{ subframe-header flac-subframe-header }
{ data byte-array } ;
TUPLE: frame-header
TUPLE: flac-frame-header
{ number-type maybe{ frame-number-type-frame frame-number-type-sample } }
{ blocksize integer }
{ sample-rate integer }
@ -74,13 +77,13 @@ TUPLE: frame-header
{ frame|sample-number integer }
{ crc integer } ;
TUPLE: frame-footer
TUPLE: flac-frame-footer
{ crc integer } ;
TUPLE: flac-frame
{ header frame-header }
{ header flac-frame-header }
{ subframes sequence }
{ footer frame-footer } ;
{ footer flac-frame-footer } ;
: 0xxxxxxx? ( n -- ? ) 0x80 bitand 0x80 = not ;
: 110xxxxx? ( n -- ? ) dup [ 0xc0 bitand 0xc0 = ] [ 0x20 bitand 0x20 = not ] bi* and ;
@ -100,16 +103,6 @@ TUPLE: flac-frame
{ [ n 11111110? ] [ 6 ] }
} cond ;
! : remaining-bytes ( n -- n )
! {
! { [ dup 110xxxxx? ] [ drop 1 ] }
! { [ dup 1110xxxx? ] [ drop 2 ] }
! { [ dup 11110xxx? ] [ drop 3 ] }
! { [ dup 111110xx? ] [ drop 4 ] }
! { [ dup 1111110x? ] [ drop 5 ] }
! { [ dup 11111110? ] [ drop 6 ] }
! } cond ;
:: decode-utf8-uint ( frame-length bitstream -- n )
frame-length 7 -
bitstream read-bit
@ -201,7 +194,7 @@ TUPLE: flac-frame
] dip
1 read be>
] with-big-endian
frame-header boa ;
flac-frame-header boa ;
:: decode-subframe-type ( n -- type )
{
@ -212,30 +205,43 @@ TUPLE: flac-frame
[ invalid-subframe-type ]
} cond <flac-subframe-type> ;
:: decode-subframe ( bitstream -- subframe )
: read-constant-subframe ( bps -- data )
8 / read ;
:: decode-subframe-header ( bitstream -- subframe )
1 bitstream read-bit 1 = [ invalid-subframe-sync ] when
6 bitstream read-bit decode-subframe-type
1 bitstream read-bit ! TODO: wasted-bits: 0 for now..
B{ }
flac-subframe boa ;
flac-subframe-header boa ;
! TODO: actually decode based on subframe type
! TODO: handle wasted bits assuming 1 byte for now :/
: read-subframe ( frame-header channel -- subframe )
drop drop
1 read bitstreams:<msb0-bit-reader> decode-subframe ;
: read-subframe ( frame-header -- subframe )
1 read bitstreams:<msb0-bit-reader> decode-subframe-header dup
subframe-type>>
{
{ subframe-type-constant [ swap bits-per-sample>> read-constant-subframe ] }
{ subframe-type-verbatim [ drop "VERBATIM TODO" . B{ } ] }
{ subframe-type-fixed [ drop "FIXED TODO" . B{ } ] }
{ subframe-type-lpc [ drop "LPC TODO" . B{ } ] }
} case
flac-subframe boa ;
: read-subframes ( frame-header -- seq )
dup channels>> swap <repetition> [ read-subframe ] map-index ;
dup channels>> swap <repetition> [ read-subframe ] map ;
: read-frame-header ( -- frame-header )
4 read bitstreams:<msb0-bit-reader> decode-header ;
: read-frame-footer ( -- frame-footer )
2 read be> flac-frame-footer boa ;
: read-frame ( -- frame )
read-frame-header
dup read-subframes
frame-footer new
read-frame-footer
flac-frame boa ;
: decode-file ( filename -- something )
@ -245,6 +251,5 @@ TUPLE: flac-frame
read-stream-info .
skip-metadata
! 51448296 seek-absolute seek-input
read-frame
contents .
3 <iota> [ drop read-frame ] map
] with-file-reader ;