Rearchitected transcoding to treat codecs and encoders as separate concepts.

core/transcoder/encoder_nvenc.go

@@ -0,0 +1,77 @@
+package transcoder
+
+import (
+	"fmt"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// NvencEncoder uses NVIDIA GPU hardware encoding.
+type NvencEncoder struct{}
+
+func (e *NvencEncoder) Name() string {
+	return "nvenc"
+}
+
+func (e *NvencEncoder) DisplayName() string {
+	return "NVIDIA NVENC"
+}
+
+func (e *NvencEncoder) GlobalFlags() []string {
+	return []string{
+		"-hwaccel", "cuda",
+	}
+}
+
+func (e *NvencEncoder) PixelFormat() string {
+	return pixelFormatYUV420P
+}
+
+func (e *NvencEncoder) Scaler() string {
+	return ""
+}
+
+func (e *NvencEncoder) ExtraFilters() string {
+	return ""
+}
+
+func (e *NvencEncoder) ExtraArguments() []string {
+	return nil
+}
+
+func (e *NvencEncoder) VariantFlags(v *HLSVariant) []string {
+	return []string{
+		fmt.Sprintf("-tune:v:%d", v.index), "ll",
+	}
+}
+
+func (e *NvencEncoder) SupportedVideoCodecs() []string {
+	return []string{videoCodecH264}
+}
+
+func (e *NvencEncoder) FFmpegEncoderForCodec(codec string) string {
+	switch codec {
+	case videoCodecH264:
+		return "h264_nvenc"
+	default:
+		log.Warnf("nvenc encoder does not support codec %q, falling back to h264_nvenc", codec)
+		return "h264_nvenc"
+	}
+}
+
+func (e *NvencEncoder) GetPresetForLevel(l int) string {
+	presetMapping := map[int]string{
+		0: "p1",
+		1: "p2",
+		2: "p3",
+		3: "p4",
+		4: "p5",
+	}
+	preset, ok := presetMapping[l]
+	if !ok {
+		defaultPreset := presetMapping[2]
+		log.Errorf("Invalid level for nvenc preset %d, defaulting to %s", l, defaultPreset)
+		return defaultPreset
+	}
+	return preset
+}