Rearchitected transcoding to treat codecs and encoders as separate concepts.

core/transcoder/encoder_v4l2m2m.go

@@ -0,0 +1,69 @@
+package transcoder
+
+import log "github.com/sirupsen/logrus"
+
+// V4l2m2mEncoder uses Video4Linux memory-to-memory hardware encoding.
+type V4l2m2mEncoder struct{}
+
+func (e *V4l2m2mEncoder) Name() string {
+	return "v4l2m2m"
+}
+
+func (e *V4l2m2mEncoder) DisplayName() string {
+	return "Video4Linux"
+}
+
+func (e *V4l2m2mEncoder) GlobalFlags() []string {
+	return nil
+}
+
+func (e *V4l2m2mEncoder) PixelFormat() string {
+	return "nv21"
+}
+
+func (e *V4l2m2mEncoder) Scaler() string {
+	return ""
+}
+
+func (e *V4l2m2mEncoder) ExtraFilters() string {
+	return ""
+}
+
+func (e *V4l2m2mEncoder) ExtraArguments() []string {
+	return nil
+}
+
+func (e *V4l2m2mEncoder) VariantFlags(v *HLSVariant) []string {
+	return nil
+}
+
+func (e *V4l2m2mEncoder) SupportedVideoCodecs() []string {
+	return []string{videoCodecH264}
+}
+
+func (e *V4l2m2mEncoder) FFmpegEncoderForCodec(codec string) string {
+	switch codec {
+	case videoCodecH264:
+		return "h264_v4l2m2m"
+	default:
+		log.Warnf("v4l2m2m encoder does not support codec %q, falling back to h264_v4l2m2m", codec)
+		return "h264_v4l2m2m"
+	}
+}
+
+func (e *V4l2m2mEncoder) GetPresetForLevel(l int) string {
+	presetMapping := map[int]string{
+		0: "ultrafast",
+		1: "superfast",
+		2: "veryfast",
+		3: "faster",
+		4: "fast",
+	}
+	preset, ok := presetMapping[l]
+	if !ok {
+		defaultPreset := presetMapping[1]
+		log.Errorf("Invalid level for v4l preset %d, defaulting to %s", l, defaultPreset)
+		return defaultPreset
+	}
+	return preset
+}