use a new filter

ErsatzTV.FFmpeg/Filter/Cuda/CudaSoftwareFallbackUploadFilter.cs

@@ -0,0 +1,9 @@
+namespace ErsatzTV.FFmpeg.Filter.Cuda;
+
+public class CudaSoftwareFallbackUploadFilter : BaseFilter
+{
+    public override string Filter => "hwupload";
+
+    public override FrameState NextState(FrameState currentState) =>
+        currentState with { FrameDataLocation = FrameDataLocation.Hardware };
+}

ErsatzTV.FFmpeg/Filter/Cuda/HardwareUploadCudaFilter.cs

@@ -1,11 +1,10 @@
-namespace ErsatzTV.FFmpeg.Filter;
+namespace ErsatzTV.FFmpeg.Filter.Cuda;
 
 public class HardwareUploadCudaFilter(FrameDataLocation frameDataLocation) : BaseFilter
 {
     public override string Filter => frameDataLocation switch
     {
         FrameDataLocation.Hardware => string.Empty,
-        FrameDataLocation.Unknown => "hwupload",
         _ => "hwupload_cuda"
     };
 

ErsatzTV.FFmpeg/Pipeline/NvidiaPipelineBuilder.cs

@@ -135,9 +135,12 @@ public class NvidiaPipelineBuilder : SoftwarePipelineBuilder
         {
             videoInputFile.AddOption(decoder);
 
+            // sometimes cuda fails to decode in hardware and falls back to software
+            // in that case, we need to upload to get the frame in hardware as expected
+            // this *should* no-op when frames are already in hardware
             if (ffmpegState.DecoderHardwareAccelerationMode is HardwareAccelerationMode.Nvenc)
             {
-                videoInputFile.FilterSteps.Add(new HardwareUploadCudaFilter(FrameDataLocation.Unknown));
+                videoInputFile.FilterSteps.Add(new CudaSoftwareFallbackUploadFilter());
             }
 
             return Some(decoder);