allow clearing (omitting) video profile setting (#1706)

ErsatzTV.Core/FFmpeg/FFmpegLibraryProcessService.cs

@@ -998,7 +998,7 @@ public class FFmpegLibraryProcessService : IFFmpegProcessService
         };
 
     private static Option<string> GetVideoProfile(string videoFormat, string videoProfile) =>
-        (videoFormat, videoProfile.ToLowerInvariant()) switch
+        (videoFormat, (videoProfile ?? string.Empty).ToLowerInvariant()) switch
         {
             (VideoFormat.H264, VideoProfile.Main) => VideoProfile.Main,
             (VideoFormat.H264, VideoProfile.High) => VideoProfile.High,

ErsatzTV/Pages/FFmpegEditor.razor

@@ -63,7 +63,8 @@
                                     <MudSelect Label="Profile"
                                                @bind-Value="_model.VideoProfile"
                                                For="@(() => _model.VideoProfile)"
-                                               Disabled="@(_model.VideoFormat != FFmpegProfileVideoFormat.H264 || (_model.HardwareAcceleration != HardwareAccelerationKind.Nvenc && _model.HardwareAcceleration != HardwareAccelerationKind.Qsv && _model.HardwareAcceleration != HardwareAccelerationKind.None))">
+                                               Disabled="@(_model.VideoFormat != FFmpegProfileVideoFormat.H264 || (_model.HardwareAcceleration != HardwareAccelerationKind.Nvenc && _model.HardwareAcceleration != HardwareAccelerationKind.Qsv && _model.HardwareAcceleration != HardwareAccelerationKind.None))"
+                                               Clearable="true">
                                         <MudSelectItem Value="@VideoProfile.Main">main</MudSelectItem>
                                         <MudSelectItem Value="@VideoProfile.High">high</MudSelectItem>
                                     </MudSelect>