fix av1 software decoder priority (#1632)

CHANGELOG.md

@@ -45,6 +45,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix `Other Video`, `Song` and `Image` fallback metadata tags to always include parent folder (folder added to library) 
 - Allow playback of items with any positive duration, including less than one second
 - Fix VAAPI transcoding of OTA content containing A53 CC data
+- Fix AV1 software decoder priority (`libdav1d`, `libaom-av1`, `av1`)
 
 ### Changed
 - Log search index updates under scanner category at debug level, to indicate a potential cause for the UI being out of date

ErsatzTV.FFmpeg/Capabilities/FFmpegKnownDecoder.cs

@@ -9,6 +9,8 @@ public record FFmpegKnownDecoder
     public static readonly FFmpegKnownDecoder Mpeg4Cuvid = new("mpeg4_cuvid");
     public static readonly FFmpegKnownDecoder Vc1Cuvid = new("vc1_cuvid");
     public static readonly FFmpegKnownDecoder Vp9Cuvid = new("vp9_cuvid");
+    public static readonly FFmpegKnownDecoder Libdav1d = new("libdav1d");
+    public static readonly FFmpegKnownDecoder Libaomav1 = new("libaom-av1");
 
     private FFmpegKnownDecoder(string Name) => this.Name = Name;
 
@@ -23,6 +25,8 @@ public record FFmpegKnownDecoder
             Mpeg2Cuvid.Name,
             Mpeg4Cuvid.Name,
             Vc1Cuvid.Name,
-            Vp9Cuvid.Name
+            Vp9Cuvid.Name,
+            Libdav1d.Name,
+            Libaomav1.Name
         };
 }