mirror of
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97 lines
2.7 KiB
Go
97 lines
2.7 KiB
Go
package flac
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// TODO: 24 bit picture length truncate warning
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// TODO: Cuesheet
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import (
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"fmt"
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"github.com/wader/fq/format"
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"github.com/wader/fq/format/registry"
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"github.com/wader/fq/pkg/decode"
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)
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var flacStreaminfoFormat decode.Group
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var flacPicture decode.Group
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var vorbisCommentFormat decode.Group
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func init() {
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registry.MustRegister(decode.Format{
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Name: format.FLAC_METADATABLOCK,
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Description: "FLAC metadatablock",
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DecodeFn: metadatablockDecode,
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Dependencies: []decode.Dependency{
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{Names: []string{format.FLAC_STREAMINFO}, Group: &flacStreaminfoFormat},
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{Names: []string{format.FLAC_PICTURE}, Group: &flacPicture},
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{Names: []string{format.VORBIS_COMMENT}, Group: &vorbisCommentFormat},
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},
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})
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}
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const (
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MetadataBlockStreaminfo = 0
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MetadataBlockPadding = 1
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MetadataBlockApplication = 2
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MetadataBlockSeektable = 3
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MetadataBlockVorbisComment = 4
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MetadataBlockCuesheet = 5
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MetadataBlockPicture = 6
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)
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var metadataBlockNames = decode.UToStr{
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MetadataBlockStreaminfo: "Streaminfo",
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MetadataBlockPadding: "Padding",
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MetadataBlockApplication: "Application",
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MetadataBlockSeektable: "Seektable",
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MetadataBlockVorbisComment: "Vorbis comment",
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MetadataBlockCuesheet: "Cuesheet",
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MetadataBlockPicture: "Picture",
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}
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func metadatablockDecode(d *decode.D, in interface{}) interface{} {
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var hasStreamInfo bool
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var streamInfo format.FlacStreamInfo
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isLastBlock := d.FieldBool("last_block")
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typ := d.FieldU7("type", d.MapUToStrSym(metadataBlockNames))
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length := d.FieldU24("length")
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switch typ {
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case MetadataBlockStreaminfo:
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flacStreaminfoOut, ok := d.Format(flacStreaminfoFormat, nil).(format.FlacStreaminfoOut)
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if !ok {
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panic(fmt.Sprintf("expected FlacStreaminfoOut, got %#+v", flacStreaminfoOut))
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}
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hasStreamInfo = true
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streamInfo = flacStreaminfoOut.StreamInfo
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case MetadataBlockVorbisComment:
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d.FieldFormatLen("comment", int64(length*8), vorbisCommentFormat, nil)
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case MetadataBlockPicture:
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d.FieldFormatLen("picture", int64(length*8), flacPicture, nil)
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case MetadataBlockSeektable:
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seektableCount := length / 18
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d.FieldArray("seekpoints", func(d *decode.D) {
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for i := uint64(0); i < seektableCount; i++ {
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d.FieldStruct("seekpoint", func(d *decode.D) {
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d.FieldU64("sample_number", d.MapUToScalar(decode.UToScalar{
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0xffff_ffff_ffff_ffff: {Description: "Placeholder"},
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}))
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d.FieldU64("offset")
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d.FieldU16("number_of_samples")
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})
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}
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})
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case MetadataBlockApplication:
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d.FieldUTF8("id", 4)
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d.FieldRawLen("data", int64((length-4)*8))
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default:
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d.FieldRawLen("data", int64(length*8))
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}
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return format.FlacMetadatablockOut{
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IsLastBlock: isLastBlock,
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HasStreamInfo: hasStreamInfo,
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StreamInfo: streamInfo,
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}
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}
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