mirror of
https://github.com/wader/fq.git
synced 2024-11-23 18:56:52 +03:00
113 lines
3.5 KiB
Go
113 lines
3.5 KiB
Go
package flac
|
|
|
|
// TODO: 24 bit picture length truncate warning
|
|
|
|
import (
|
|
"github.com/wader/fq/format"
|
|
"github.com/wader/fq/format/registry"
|
|
"github.com/wader/fq/pkg/decode"
|
|
"github.com/wader/fq/pkg/ranges"
|
|
)
|
|
|
|
var flacPicture []*decode.Format
|
|
var vorbisCommentFormat []*decode.Format
|
|
|
|
func init() {
|
|
registry.MustRegister(&decode.Format{
|
|
Name: format.FLAC_METADATABLOCK,
|
|
Description: "FLAC metadatablock",
|
|
DecodeFn: metadatablockDecode,
|
|
Dependencies: []decode.Dependency{
|
|
{Names: []string{format.FLAC_PICTURE}, Formats: &flacPicture},
|
|
{Names: []string{format.VORBIS_COMMENT}, Formats: &vorbisCommentFormat},
|
|
},
|
|
})
|
|
}
|
|
|
|
const (
|
|
MetadataBlockStreaminfo = 0
|
|
MetadataBlockPadding = 1
|
|
MetadataBlockApplication = 2
|
|
MetadataBlockSeektable = 3
|
|
MetadataBlockVorbisComment = 4
|
|
MetadataBlockCuesheet = 5
|
|
MetadataBlockPicture = 6
|
|
)
|
|
|
|
var metadataBlockNames = map[uint]string{
|
|
MetadataBlockStreaminfo: "Streaminfo",
|
|
MetadataBlockPadding: "Padding",
|
|
MetadataBlockApplication: "Application",
|
|
MetadataBlockSeektable: "Seektable",
|
|
MetadataBlockVorbisComment: "Vorbis comment",
|
|
MetadataBlockCuesheet: "Cuesheet",
|
|
MetadataBlockPicture: "Picture",
|
|
}
|
|
|
|
func metadatablockDecode(d *decode.D, in interface{}) interface{} {
|
|
mb := format.FlacMetadatablockOut{}
|
|
|
|
mb.IsLastBlock = d.FieldBool("last_block")
|
|
typ := d.FieldUFn("type", func() (uint64, decode.DisplayFormat, string) {
|
|
t := d.U7()
|
|
name := "Unknown"
|
|
if s, ok := metadataBlockNames[uint(t)]; ok {
|
|
name = s
|
|
}
|
|
return t, decode.NumberDecimal, name
|
|
})
|
|
length := d.FieldU24("length")
|
|
|
|
switch typ {
|
|
case MetadataBlockStreaminfo:
|
|
d.FieldU16("minimum_block_size")
|
|
d.FieldU16("maximum_block_size")
|
|
d.FieldU24("minimum_frame_size")
|
|
d.FieldU24("maximum_frame_size")
|
|
sampleRate := d.FieldU("sample_rate", 20)
|
|
// <3> (number of channels)-1. FLAC supports from 1 to 8 channels
|
|
d.FieldUFn("channels", func() (uint64, decode.DisplayFormat, string) { return d.U3() + 1, decode.NumberDecimal, "" })
|
|
// <5> (bits per sample)-1. FLAC supports from 4 to 32 bits per sample. Currently the reference encoder and decoders only support up to 24 bits per sample.
|
|
bitPerSample := d.FieldUFn("bits_per_sample", func() (uint64, decode.DisplayFormat, string) {
|
|
return d.U5() + 1, decode.NumberDecimal, ""
|
|
})
|
|
totalSamplesInStream := d.FieldU("total_samples_in_stream", 36)
|
|
md5Range := ranges.Range{Start: d.Pos(), Len: 16 * 8}
|
|
d.FieldBitBufLen("md5", 16*8)
|
|
|
|
mb.StreamInfo = format.FlacMetadatablockStreamInfo{
|
|
SampleRate: sampleRate,
|
|
BitPerSample: bitPerSample,
|
|
TotalSamplesInStream: totalSamplesInStream,
|
|
MD5Range: md5Range,
|
|
}
|
|
mb.HasStreamInfo = true
|
|
case MetadataBlockVorbisComment:
|
|
d.FieldFormatLen("comment", int64(length*8), vorbisCommentFormat, nil)
|
|
case MetadataBlockPicture:
|
|
d.FieldFormatLen("picture", int64(length*8), flacPicture, nil)
|
|
case MetadataBlockSeektable:
|
|
seektableCount := length / 18
|
|
d.FieldArrayFn("seekpoints", func(d *decode.D) {
|
|
for i := uint64(0); i < seektableCount; i++ {
|
|
d.FieldStructFn("seekpoint", func(d *decode.D) {
|
|
d.FieldUFn("sample_number", func() (uint64, decode.DisplayFormat, string) {
|
|
n := d.U64()
|
|
d := ""
|
|
if n == 0xffffffffffffffff {
|
|
d = "Placeholder"
|
|
}
|
|
return n, decode.NumberDecimal, d
|
|
})
|
|
d.FieldU64("offset")
|
|
d.FieldU16("number_of_samples")
|
|
})
|
|
}
|
|
})
|
|
default:
|
|
d.FieldBitBufLen("data", int64(length*8))
|
|
}
|
|
|
|
return mb
|
|
}
|