Fast track extractions if there is no subtitles (#548)

transcoder/src/codec.go

@@ -91,6 +91,10 @@ func GetMimeCodec(stream *ffprobe.Stream) *string {
 
 		return &ret
 
+	case "mp3":
+		ret := "mp4a.40.34"
+		return &ret
+
 	case "opus":
 		ret := "Opus"
 		return &ret
@@ -107,6 +111,10 @@ func GetMimeCodec(stream *ffprobe.Stream) *string {
 		ret := "fLaC"
 		return &ret
 
+	case "alac":
+		ret := "alac"
+		return &ret
+
 	default:
 		log.Printf("No known mime format for: %s", stream.CodecName)
 		return nil

transcoder/src/extract.go

@@ -29,6 +29,12 @@ func Extract(path string, sha string) (<-chan struct{}, error) {
 		os.MkdirAll(attachment_path, 0o644)
 		os.MkdirAll(subs_path, 0o755)
 
+		// If there is no subtitles, there is nothing to extract (also fonts would be useless).
+		if len(info.Subtitles) == 0 {
+			close(ret)
+			return
+		}
+
 		cmd := exec.Command(
 			"ffmpeg",
 			"-dump_attachment:t", "",