58 lines
1.3 KiB
Go
58 lines
1.3 KiB
Go
package tm
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import (
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"bytes"
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"errors"
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"fmt"
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"io"
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"unlock-music.dev/cli/algo/common"
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)
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var replaceHeader = []byte{0x00, 0x00, 0x00, 0x20, 0x66, 0x74, 0x79, 0x70}
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var magicHeader = []byte{0x51, 0x51, 0x4D, 0x55} //0x15, 0x1D, 0x1A, 0x21
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type Decoder struct {
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raw io.ReadSeeker // raw is the original file reader
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offset int
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audio io.Reader // audio is the decrypted audio data
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}
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func (d *Decoder) Validate() error {
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header := make([]byte, 8)
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if _, err := io.ReadFull(d.raw, header); err != nil {
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return fmt.Errorf("tm read header: %w", err)
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}
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if bytes.Equal(magicHeader, header[:len(magicHeader)]) { // replace m4a header
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d.audio = io.MultiReader(bytes.NewReader(replaceHeader), d.raw)
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return nil
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}
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if _, ok := common.SniffAll(header); ok { // not encrypted
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d.audio = io.MultiReader(bytes.NewReader(header), d.raw)
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return nil
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}
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return errors.New("tm: valid magic header")
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}
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func (d *Decoder) Read(buf []byte) (int, error) {
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return d.audio.Read(buf)
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}
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func NewTmDecoder(rd io.ReadSeeker) common.Decoder {
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return &Decoder{raw: rd}
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}
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func init() {
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// QQ Music IOS M4a (replace header)
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common.RegisterDecoder("tm2", false, NewTmDecoder)
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common.RegisterDecoder("tm6", false, NewTmDecoder)
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// QQ Music IOS Mp3 (not encrypted)
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common.RegisterDecoder("tm0", false, NewTmDecoder)
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common.RegisterDecoder("tm3", false, NewTmDecoder)
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}
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