Made the service basically start working

Encoder/NvencExt.cs

@@ -0,0 +1,41 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Encoder;
+
+public enum NvencSpeed {
+    Default=0, 
+    Slow=1, 
+    Medium=2, 
+    Fast=3, 
+    p1=12,
+    p2=13,
+    p3=14,
+    p4=15,
+    p5=16,
+    p6=17,
+    p7=18,
+}
+
+public enum NvencTune {
+    hq=1,
+    uhq=5,
+    ll=2,
+    ull=3,
+    lossless=4,
+}
+
+class NvencSpeedPreset(NvencSpeed speed) : FFMpegCore.Arguments.IArgument {
+    public string Text { get { return $"-preset {speed.ToString().ToLower()}"; } }
+}
+
+class NvencTuneArgument(NvencTune tune) : FFMpegCore.Arguments.IArgument {
+    public string Text { get { return $"-tune {tune.ToString().ToLower()}"; } }
+}
+
+class NvencHighBitDepthArgument(bool enable) : FFMpegCore.Arguments.IArgument {
+    public string Text { get { return enable ? "-highbitdepth true" : string.Empty; } }
+}
+
+class NvencQPArgument([Range(-1, 255)]byte qp) : FFMpegCore.Arguments.IArgument {
+    public string Text { get { return $"-qp {qp}"; } }
+}