more nvidia fixes (#661)

* dont use mpeg2_cuvid with interlaced content

* fix nvidia scaling when padding is not needed

ErsatzTV.FFmpeg/Decoder/AvailableDecoders.cs

@@ -23,6 +23,10 @@ public static class AvailableDecoders
                 (HardwareAccelerationMode.Nvenc, VideoFormat.H264, PixelFormat.YUV420P10LE or PixelFormat.YUV444P10LE)
                     => new DecoderH264(),
 
+                // mpeg2_cuvid seems to have issues when yadif_cuda is used, so just use software decoding
+                (HardwareAccelerationMode.Nvenc, VideoFormat.Mpeg2Video, _) when desiredState.Deinterlaced =>
+                    new DecoderMpeg2Video(),
+
                 (HardwareAccelerationMode.Nvenc, VideoFormat.H264, _) => new DecoderH264Cuvid(),
                 (HardwareAccelerationMode.Nvenc, VideoFormat.Mpeg2Video, _) => new DecoderMpeg2Cuvid(
                     desiredState.Deinterlaced),

ErsatzTV.FFmpeg/Filter/Cuda/ScaleCudaFilter.cs

@@ -37,7 +37,13 @@ public class ScaleCudaFilter : BaseFilter
                     format = $":format={pixelFormat.FFmpegName}";
                 }
 
-                scale = $"scale_cuda={targetSize}:force_original_aspect_ratio=1{format}";
+                string aspectRatio = string.Empty;
+                if (_scaledSize != _paddedSize)
+                {
+                    aspectRatio = ":force_original_aspect_ratio=1";
+                }
+
+                scale = $"scale_cuda={targetSize}{aspectRatio}{format}";
             }
 
             // TODO: this might not always upload to hardware, so NextState could be inaccurate