1
0
forked from um/cli
cli/algo/tm/tm.go
2020-12-26 15:03:34 +08:00

60 lines
1.0 KiB
Go

package tm
import (
"bytes"
"errors"
"github.com/umlock-music/cli/algo/common"
)
var replaceHeader = []byte{0x00, 0x00, 0x00, 0x20, 0x66, 0x74, 0x79, 0x70}
var magicHeader = []byte{0x51, 0x51, 0x4D, 0x55} //0x15, 0x1D, 0x1A, 0x21
type Decoder struct {
file []byte
audio []byte
headerMatch bool
audioExt string
}
func (d *Decoder) GetCoverImage() []byte {
return nil
}
func (d *Decoder) GetAudioData() []byte {
return d.audio
}
func (d *Decoder) GetAudioExt() string {
return d.audioExt
}
func (d *Decoder) GetMeta() common.Meta {
return nil
}
func NewDecoder(data []byte) *Decoder {
return &Decoder{file: data}
}
func (d *Decoder) Validate() error {
if len(d.file) < 8 {
return errors.New("invalid file size")
}
if !bytes.Equal(magicHeader, d.file[:4]) {
return errors.New("not a valid tm file")
}
d.headerMatch = true
return nil
}
func (d *Decoder) Decode() error {
d.audio = d.file
if d.headerMatch {
for i := 0; i < 8; i++ {
d.audio[i] = replaceHeader[i]
}
d.audioExt = "m4a"
}
return nil
}