Hardware-accelerated transcoding (#41)

* add qsv transcoding support

* add basic nvenc support

* add nvenc to docker-compose

* add vaapi hardware acceleration

* add vaapi driver to dockerfile

* raise ffmpeg log level

* lots of progress with nvenc, qsv and vaapi remain untested

* qsv fixes

* code cleanup

ErsatzTV.Core/Domain/FFmpegProfile.cs

@@ -6,6 +6,7 @@
         public string Name { get; set; }
         public int ThreadCount { get; set; }
         public bool Transcode { get; set; }
+        public HardwareAccelerationKind HardwareAcceleration { get; set; }
         public int ResolutionId { get; set; }
         public Resolution Resolution { get; set; }
         public bool NormalizeResolution { get; set; }

ErsatzTV.Core/Domain/HardwareAccelerationKind.cs

@@ -0,0 +1,10 @@
+namespace ErsatzTV.Core.Domain
+{
+    public enum HardwareAccelerationKind
+    {
+        None = 0,
+        Qsv = 1,
+        Nvenc = 2,
+        Vaapi = 3
+    }
+}