57 lines
1.2 KiB
Go
57 lines
1.2 KiB
Go
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package ximalaya
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import (
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"bytes"
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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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type Decoder struct {
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rd io.ReadSeeker
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offset int
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audio io.Reader
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}
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func NewDecoder(rd io.ReadSeeker) common.Decoder {
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return &Decoder{rd: rd}
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}
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func (d *Decoder) Validate() error {
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encryptedHeader := make([]byte, x2mHeaderSize)
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if _, err := io.ReadFull(d.rd, encryptedHeader); err != nil {
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return fmt.Errorf("ximalaya read header: %w", err)
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}
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{ // try to decode with x2m
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header := decryptX2MHeader(encryptedHeader)
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if _, ok := common.SniffAll(header); ok {
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d.audio = io.MultiReader(bytes.NewReader(header), d.rd)
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return nil
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}
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}
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{ // try to decode with x3m
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// not read file again, since x2m and x3m have the same header size
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header := decryptX3MHeader(encryptedHeader)
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if _, ok := common.SniffAll(header); ok {
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d.audio = io.MultiReader(bytes.NewReader(header), d.rd)
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return nil
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}
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}
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return fmt.Errorf("ximalaya: unknown format")
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}
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func (d *Decoder) Read(p []byte) (n int, err error) {
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return d.audio.Read(p)
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}
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func init() {
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common.RegisterDecoder("x2m", false, NewDecoder)
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common.RegisterDecoder("x3m", false, NewDecoder)
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common.RegisterDecoder("xm", false, NewDecoder)
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}
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