1
0
forked from um/cli

Sniff Output Audio Extension

This commit is contained in:
Emmm Monster 2021-05-16 12:18:19 +08:00
parent f9686bbfc4
commit c1c43d2a41
No known key found for this signature in database
GPG Key ID: C98279C83FB50DB9
4 changed files with 55 additions and 7 deletions

44
algo/common/sniff.go Normal file
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@ -0,0 +1,44 @@
package common
import "bytes"
type Sniffer func(header []byte) bool
var snifferRegistry = map[string]Sniffer{
".m4a": SnifferM4A,
".ogg": SnifferOGG,
".flac": SnifferFLAC,
".wav": SnifferWAV,
".wma": SnifferWMA,
".mp3": SnifferMP3,
}
func SniffAll(header []byte) (string, bool) {
for ext, sniffer := range snifferRegistry {
if sniffer(header) {
return ext, true
}
}
return "", false
}
func SnifferM4A(header []byte) bool {
return len(header) >= 8 && bytes.Equal([]byte("ftyp"), header[4:8])
}
func SnifferOGG(header []byte) bool {
return bytes.HasPrefix(header, []byte("OggS"))
}
func SnifferFLAC(header []byte) bool {
return bytes.HasPrefix(header, []byte("fLaC"))
}
func SnifferMP3(header []byte) bool {
return bytes.HasPrefix(header, []byte("ID3"))
}
func SnifferWAV(header []byte) bool {
return bytes.HasPrefix(header, []byte("RIFF"))
}
func SnifferWMA(header []byte) bool {
return bytes.HasPrefix(header, []byte("\x30\x26\xb2\x75\x8e\x66\xcf\x11\xa6\xd9\x00\xaa\x00\x62\xce\x6c"))
}

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@ -38,8 +38,6 @@ var (
0x92, 0x62, 0xf3, 0x74, 0xa1, 0x9f, 0xf4, 0xa0,
0x1d, 0x3f, 0x5b, 0xf0, 0x13, 0x0e, 0x09, 0x3d,
0xf9, 0xbc, 0x00, 0x11}
headerFlac = []byte{'f', 'L', 'a', 'C'}
headerOgg = []byte{'O', 'g', 'g', 'S'}
)
var key256MappingAll [][]int //[idx256][idx128]idx44
var key256Mapping128to44 map[int]int

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@ -3,6 +3,7 @@ package qmc
import (
"bytes"
"errors"
"github.com/unlock-music/cli/algo/common"
"github.com/unlock-music/cli/internal/logging"
"go.uber.org/zap"
)
@ -116,7 +117,7 @@ func detectMflac256Mask(input []byte) (*Key256Mask, error) {
if err != nil {
continue
}
if bytes.Equal(headerFlac, q.Decrypt(input[:len(headerFlac)])) {
if common.SnifferFLAC(q.Decrypt(input[:4])) {
rtErr = nil
break
}
@ -164,7 +165,7 @@ func detectMgg256Mask(input []byte) (*Key256Mask, error) {
if err != nil {
return nil, err
}
if bytes.Equal(headerOgg, q.Decrypt(input[:len(headerOgg)])) {
if common.SnifferOGG(q.Decrypt(input[:4])) {
return q, nil
}
return nil, ErrDetectMggMask

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@ -117,14 +117,19 @@ func tryDecFile(inputFile string, outputDir string, allDec []common.NewDecoderFu
return errors.New("failed while decoding: " + err.Error())
}
outData := dec.GetAudioData()
outExt := dec.GetAudioExt()
if outExt == "" {
outExt = ".mp3"
if ext, ok := common.SniffAll(outData); ok {
outExt = ext
} else {
outExt = ".mp3"
}
}
filenameOnly := strings.TrimSuffix(filepath.Base(inputFile), filepath.Ext(inputFile))
outPath := filepath.Join(outputDir, filenameOnly+"."+outExt)
err = os.WriteFile(outPath, dec.GetAudioData(), 0644)
outPath := filepath.Join(outputDir, filenameOnly+outExt)
err = os.WriteFile(outPath, outData, 0644)
if err != nil {
return err
}