Transcoder: Audio Quality Enum

transcoder/src/audioquality.go

@@ -0,0 +1,60 @@
+package src
+
+import (
+	"net/http"
+
+	"github.com/labstack/echo/v4"
+)
+
+type AudioQuality string
+
+const (
+	K128      AudioQuality = "128k"
+	K192      AudioQuality = "192k"
+	K256      AudioQuality = "256k"
+	K320      AudioQuality = "320k"
+	M1        AudioQuality = "1411k" // AKA CD Quality (1,411mbps)
+	AOriginal AudioQuality = "original"
+)
+
+var AudioQualities = []AudioQuality{K128, K192, K256, K320, M1}
+
+func AudioQualityFromString(str string) (AudioQuality, error) {
+	if str == string(AOriginal) {
+		return AOriginal, nil
+	}
+
+	for _, quality := range AudioQualities {
+		if string(quality) == str {
+			return quality, nil
+		}
+	}
+	return AOriginal, echo.NewHTTPError(http.StatusBadRequest, "Invalid quality")
+}
+
+func (a AudioQuality) Bitrate() uint32 {
+	switch a {
+	case K128:
+		return 128_000
+	case K192:
+		return 192_000
+	case K256:
+		return 256_000
+	case K320:
+		return 320_000
+	case M1:
+		return 1_411_000
+	case AOriginal:
+		panic("Original quality must be handled specially")
+	}
+	panic("Invalid quality value")
+}
+
+func (audio *Audio) Quality() AudioQuality {
+	for _, quality := range AudioQualities {
+		if quality.Bitrate() >= audio.Bitrate {
+			return quality
+		}
+	}
+	return K128
+}