feat: show errors over next fallback by default (#3016)

CHANGELOG.md

@@ -21,6 +21,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - Optimize anamorphic pipelines by only performing one scale instead of two
   - Optimize tonemapping pipelines by downscaling before tonemapping when possible
   - Optimize QSV pipelines by merging consecutive vpp_qsv filters as much as possible (e.g. tonemap, scale and format using a single filter)
+  - Show error messages over black/silence fallback streams by default
+    - To disable, create the file `next/channel-config-overlays/default.json` in ETV's config folder with the contents `{"fallback":{"show_error":false}}`
 
 ### Fixed
 - Next engine:

ErsatzTV.Application/Streaming/ChannelConfigConverter.cs

@@ -159,6 +159,10 @@ public class ChannelConfigConverter(IConfigElementRepository configElementReposi
                 Audio = audioNormalization,
                 Video = videoNormalization,
                 Subtitle = subtitleNormalization
+            },
+            Fallback = new Fallback
+            {
+                ShowError = true
             }
         };
     }

ErsatzTV.Core/Next/Config/ChannelConfig.cs

@@ -22,6 +22,10 @@ namespace ErsatzTV.Core.Next.Config
 
     public partial class ChannelConfig
     {
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+        [JsonPropertyName("fallback")]
+        public Fallback? Fallback { get; set; }
+
         [JsonPropertyName("ffmpeg")]
         public Ffmpeg Ffmpeg { get; set; }
 
@@ -32,6 +36,21 @@ namespace ErsatzTV.Core.Next.Config
         public Playout Playout { get; set; }
     }
 
+    /// <summary>
+    /// Controls the content that replaces scheduled content when there is nothing to play
+    /// (a gap in the playout) or when the scheduled item fails
+    /// </summary>
+    public partial class Fallback
+    {
+        /// <summary>
+        /// Burn the reason for the fallback into the fallback video; this is always burned,
+        /// regardless of the normalization subtitle mode
+        /// </summary>
+        [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+        [JsonPropertyName("show_error")]
+        public bool? ShowError { get; set; }
+    }
+
     public partial class Ffmpeg
     {
         [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]