mirror of
https://github.com/wader/fq.git
synced 2024-12-26 15:02:28 +03:00
84 lines
1.9 KiB
Go
84 lines
1.9 KiB
Go
package mp3
|
|
|
|
// https://www.codeproject.com/Articles/8295/MPEG-Audio-Frame-Header
|
|
|
|
import (
|
|
"github.com/wader/fq/format"
|
|
"github.com/wader/fq/format/registry"
|
|
"github.com/wader/fq/pkg/decode"
|
|
)
|
|
|
|
func init() {
|
|
registry.MustRegister(decode.Format{
|
|
Name: format.XING,
|
|
Description: "Xing header",
|
|
DecodeFn: xingDecode,
|
|
})
|
|
}
|
|
|
|
func xingDecode(d *decode.D, in interface{}) interface{} {
|
|
// TODO: info has lame extension?
|
|
hasLameExtension := false
|
|
switch d.FieldUTF8("header", 4) {
|
|
case "Xing":
|
|
case "Info":
|
|
hasLameExtension = true
|
|
default:
|
|
d.Errorf("no xing header found")
|
|
}
|
|
|
|
qualityPresent := false
|
|
tocPresent := false
|
|
bytesPresent := false
|
|
framesPresent := false
|
|
d.FieldStruct("present_flags", func(d *decode.D) {
|
|
d.FieldU("unused", 28)
|
|
qualityPresent = d.FieldBool("quality")
|
|
tocPresent = d.FieldBool("toc")
|
|
bytesPresent = d.FieldBool("bytes")
|
|
framesPresent = d.FieldBool("frames")
|
|
})
|
|
|
|
if framesPresent {
|
|
d.FieldU32BE("frames")
|
|
}
|
|
if bytesPresent {
|
|
d.FieldU32BE("bytes")
|
|
}
|
|
if tocPresent {
|
|
d.FieldArray("toc", func(d *decode.D) {
|
|
for i := 0; i < 100; i++ {
|
|
d.FieldU8("entry")
|
|
}
|
|
})
|
|
}
|
|
if qualityPresent {
|
|
d.FieldU32BE("quality")
|
|
}
|
|
|
|
if hasLameExtension {
|
|
d.FieldStruct("lame_extension", func(d *decode.D) {
|
|
d.FieldUTF8("encoder", 9)
|
|
d.FieldU4("tag_revision")
|
|
d.FieldU4("vbr_method")
|
|
d.FieldU8("lowpass_filter") // TODO: /100
|
|
d.FieldU32("replay_gain_peak")
|
|
d.FieldU16("radio_replay_gain")
|
|
d.FieldU16("audiophile_replay_gain")
|
|
d.FieldU4("lame_flags")
|
|
d.FieldU4("lame_ath_type")
|
|
d.FieldU8("abr_vbr") // TODO:
|
|
d.FieldU12("encoder_delay") // TODO:
|
|
d.FieldU12("encoder_padding") // TODO:
|
|
d.FieldU8("misc") // TODO:
|
|
d.FieldU8("mp3_gain") // TODO:
|
|
d.FieldU16("preset") // TODO:
|
|
d.FieldU32("length")
|
|
d.FieldU16("music_crc") // TODO:
|
|
d.FieldU16("tag_crc") // TODO:
|
|
})
|
|
}
|
|
|
|
return nil
|
|
}
|