diff --git a/algo/qmc/key_mmkv.go b/algo/qmc/key_mmkv.go
index 3dff9eb..24b51cb 100644
--- a/algo/qmc/key_mmkv.go
+++ b/algo/qmc/key_mmkv.go
@@ -80,6 +80,35 @@ func readKeyFromMMKV(file string, logger *zap.Logger) ([]byte, error) {
 	return deriveKey(buf)
 }
 
+func OpenMMKV(vaultPath string, vaultKey string, logger *zap.Logger) error {
+	filePath, fileName := filepath.Split(vaultPath)
+	mgr, err := mmkv.NewManager(filepath.Dir(filePath))
+	if err != nil {
+		return fmt.Errorf("init mmkv manager: %w", err)
+	}
+
+	streamKeyVault, err = mgr.OpenVaultCrypto(fileName, vaultKey)
+	if err != nil {
+		return fmt.Errorf("open mmkv vault: %w", err)
+	}
+
+	logger.Debug("mmkv vault opened", zap.Strings("keys", streamKeyVault.Keys()))
+	return nil
+}
+
+func readKeyFromMMKVCustom(mid string) ([]byte, error) {
+	if streamKeyVault == nil {
+		return nil, fmt.Errorf("mmkv vault not loaded")
+	}
+
+	// get ekey from mmkv vault
+	eKey, err := streamKeyVault.GetBytes(mid)
+	if err != nil {
+		return nil, fmt.Errorf("get eKey error: %w", err)
+	}
+	return deriveKey(eKey)
+}
+
 func getRelativeMMKVDir(file string) (string, error) {
 	mmkvDir := filepath.Join(filepath.Dir(file), "../mmkv")
 	if _, err := os.Stat(mmkvDir); err != nil {
diff --git a/algo/qmc/qmc.go b/algo/qmc/qmc.go
index d6c084d..310e642 100644
--- a/algo/qmc/qmc.go
+++ b/algo/qmc/qmc.go
@@ -5,13 +5,12 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"go.uber.org/zap"
 	"io"
 	"runtime"
 	"strconv"
 	"strings"
 
-	"go.uber.org/zap"
-
 	"unlock-music.dev/cli/algo/common"
 	"unlock-music.dev/cli/internal/sniff"
 )
@@ -145,6 +144,18 @@ func (d *Decoder) searchKey() (err error) {
 		return d.readRawMetaQTag()
 	case "STag":
 		return errors.New("qmc: file with 'STag' suffix doesn't contains media key")
+	case "cex\x00":
+		footer := qqMusicTagMusicEx{}
+		audioLen, err := footer.Read(d.raw)
+		if err != nil {
+			return err
+		}
+		d.audioLen = int(audioLen)
+		d.decodedKey, err = readKeyFromMMKVCustom(footer.mediafile)
+		if err != nil {
+			return err
+		}
+		return nil
 	default:
 		size := binary.LittleEndian.Uint32(suffixBuf)
 
diff --git a/algo/qmc/qmc_footer_musicex.go b/algo/qmc/qmc_footer_musicex.go
new file mode 100644
index 0000000..444c2aa
--- /dev/null
+++ b/algo/qmc/qmc_footer_musicex.go
@@ -0,0 +1,65 @@
+package qmc
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+type qqMusicTagMusicEx struct {
+	songid        uint32 // Song ID
+	unknown_1     uint32 // unused & unknown
+	unknown_2     uint32 // unused & unknown
+	mid           string // Media ID
+	mediafile     string // real file name
+	unknown_3     uint32 // unused; uninitialized memory?
+	sizeof_struct uint32 // 19.57: fixed value: 0xC0
+	version       uint32 // 19.57: fixed value: 0x01
+	tag_magic     []byte // fixed value "musicex\0" (8 bytes)
+}
+
+func (tag *qqMusicTagMusicEx) Read(raw io.ReadSeeker) (int64, error) {
+	_, err := raw.Seek(-16, io.SeekEnd)
+	if err != nil {
+		return 0, fmt.Errorf("musicex seek error: %w", err)
+	}
+
+	footerBuf := make([]byte, 4)
+	footerBuf, err = io.ReadAll(io.LimitReader(raw, 4))
+	if err != nil {
+		return 0, fmt.Errorf("get musicex error: %w", err)
+	}
+	footerLen := int64(binary.LittleEndian.Uint32(footerBuf))
+
+	audioLen, err := raw.Seek(-footerLen, io.SeekEnd)
+	buf, err := io.ReadAll(io.LimitReader(raw, audioLen))
+	if err != nil {
+		return 0, err
+	}
+
+	tag.songid = binary.LittleEndian.Uint32(buf[0:4])
+	tag.unknown_1 = binary.LittleEndian.Uint32(buf[4:8])
+	tag.unknown_2 = binary.LittleEndian.Uint32(buf[8:12])
+
+	for i := 0; i < 30; i++ {
+		u := binary.LittleEndian.Uint16(buf[12+i*2 : 12+(i+1)*2])
+		if u == 0 {
+			break
+		}
+		tag.mid += string(u)
+	}
+	for i := 0; i < 50; i++ {
+		u := binary.LittleEndian.Uint16(buf[72+i*2 : 72+(i+1)*2])
+		if u == 0 {
+			break
+		}
+		tag.mediafile += string(u)
+	}
+
+	tag.unknown_3 = binary.LittleEndian.Uint32(buf[173:177])
+	tag.sizeof_struct = binary.LittleEndian.Uint32(buf[177:181])
+	tag.version = binary.LittleEndian.Uint32(buf[181:185])
+	tag.tag_magic = buf[185:193]
+
+	return audioLen, nil
+}
diff --git a/cmd/um/main.go b/cmd/um/main.go
index 8402142..4b74ce7 100644
--- a/cmd/um/main.go
+++ b/cmd/um/main.go
@@ -5,6 +5,9 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"github.com/fsnotify/fsnotify"
+	"github.com/urfave/cli/v2"
+	"go.uber.org/zap"
 	"io"
 	"os"
 	"os/signal"
@@ -15,15 +18,11 @@ import (
 	"strings"
 	"time"
 
-	"github.com/fsnotify/fsnotify"
-	"github.com/urfave/cli/v2"
-	"go.uber.org/zap"
-
 	"unlock-music.dev/cli/algo/common"
 	_ "unlock-music.dev/cli/algo/kgm"
 	_ "unlock-music.dev/cli/algo/kwm"
 	_ "unlock-music.dev/cli/algo/ncm"
-	_ "unlock-music.dev/cli/algo/qmc"
+	"unlock-music.dev/cli/algo/qmc"
 	_ "unlock-music.dev/cli/algo/tm"
 	_ "unlock-music.dev/cli/algo/xiami"
 	_ "unlock-music.dev/cli/algo/ximalaya"
@@ -50,6 +49,8 @@ func main() {
 		Flags: []cli.Flag{
 			&cli.StringFlag{Name: "input", Aliases: []string{"i"}, Usage: "path to input file or dir", Required: false},
 			&cli.StringFlag{Name: "output", Aliases: []string{"o"}, Usage: "path to output dir", Required: false},
+			&cli.StringFlag{Name: "vault-file", Aliases: []string{"db"}, Usage: "数据库文件位置 (请确保crc文件在同目录下)", Required: false},
+			&cli.StringFlag{Name: "vault-key", Aliases: []string{"key"}, Usage: "数据库密钥 (length 32)", Required: false},
 			&cli.BoolFlag{Name: "remove-source", Aliases: []string{"rs"}, Usage: "remove source file", Required: false, Value: false},
 			&cli.BoolFlag{Name: "skip-noop", Aliases: []string{"n"}, Usage: "skip noop decoder", Required: false, Value: true},
 			&cli.BoolFlag{Name: "update-metadata", Usage: "update metadata & album art from network", Required: false, Value: false},
@@ -130,6 +131,15 @@ func appMain(c *cli.Context) (err error) {
 		return errors.New("output should be a writable directory")
 	}
 
+	vaultPath := c.String("vault-file")
+	vaultKey := c.String("vault-key")
+	if vaultPath != "" && vaultKey != "" {
+		err := qmc.OpenMMKV(vaultPath, vaultKey, logger)
+		if err != nil {
+			return err
+		}
+	}
+
 	proc := &processor{
 		outputDir:       output,
 		skipNoopDecoder: c.Bool("skip-noop"),