package tm import ( "bytes" "errors" "fmt" "io" "unlock-music.dev/cli/algo/common" "unlock-music.dev/cli/internal/sniff" ) 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 { raw io.ReadSeeker // raw is the original file reader offset int audio io.Reader // audio is the decrypted audio data } func (d *Decoder) Validate() error { header := make([]byte, 8) if _, err := io.ReadFull(d.raw, header); err != nil { return fmt.Errorf("tm read header: %w", err) } if bytes.Equal(magicHeader, header[:len(magicHeader)]) { // replace m4a header d.audio = io.MultiReader(bytes.NewReader(replaceHeader), d.raw) return nil } if _, ok := sniff.AudioExtension(header); ok { // not encrypted d.audio = io.MultiReader(bytes.NewReader(header), d.raw) return nil } return errors.New("tm: valid magic header") } func (d *Decoder) Read(buf []byte) (int, error) { return d.audio.Read(buf) } func NewTmDecoder(p *common.DecoderParams) common.Decoder { return &Decoder{raw: p.Reader} } func init() { // QQ Music IOS M4a (replace header) common.RegisterDecoder("tm2", false, NewTmDecoder) common.RegisterDecoder("tm6", false, NewTmDecoder) // QQ Music IOS Mp3 (not encrypted) common.RegisterDecoder("tm0", false, NewTmDecoder) common.RegisterDecoder("tm3", false, NewTmDecoder) }