fix motion element timing (#2430)

ErsatzTV.Infrastructure/Streaming/Graphics/GraphicsElement.cs

@@ -8,12 +8,13 @@ public abstract class GraphicsElement : IGraphicsElement
 {
     public int ZIndex { get; protected set; }
 
-    public bool IsFailed { get; set; }
+    public bool IsFinished { get; set; }
 
     public abstract Task InitializeAsync(
         Resolution squarePixelFrameSize,
         Resolution frameSize,
         int frameRate,
+        TimeSpan seek,
         CancellationToken cancellationToken);
 
     public abstract ValueTask<Option<PreparedElementImage>> PrepareImage(

ErsatzTV.Infrastructure/Streaming/Graphics/GraphicsEngine.cs

@@ -86,6 +86,7 @@ public class GraphicsEngine(
                     context.SquarePixelFrameSize,
                     context.FrameSize,
                     context.FrameRate,
+                    context.Seek,
                     cancellationToken)));
 
         long frameCount = 0;
@@ -122,7 +123,7 @@ public class GraphicsEngine(
 
                 // prepare images outside mutate to allow async image generation
                 var preparedElementImages = new List<PreparedElementImage>();
-                foreach (IGraphicsElement element in elements.Where(e => !e.IsFailed).OrderBy(e => e.ZIndex))
+                foreach (IGraphicsElement element in elements.Where(e => !e.IsFinished).OrderBy(e => e.ZIndex))
                 {
                     try
                     {
@@ -137,7 +138,7 @@ public class GraphicsEngine(
                     }
                     catch (Exception ex)
                     {
-                        element.IsFailed = true;
+                        element.IsFinished = true;
                         logger.LogWarning(
                             ex,
                             "Failed to draw graphics element of type {Type}; will disable for this content",

ErsatzTV.Infrastructure/Streaming/Graphics/IGraphicsElement.cs

@@ -6,12 +6,13 @@ public interface IGraphicsElement
 {
     int ZIndex { get; }
 
-    bool IsFailed { get; set; }
+    bool IsFinished { get; set; }
 
     Task InitializeAsync(
         Resolution squarePixelFrameSize,
         Resolution frameSize,
         int frameRate,
+        TimeSpan seek,
         CancellationToken cancellationToken);
 
     ValueTask<Option<PreparedElementImage>> PrepareImage(

ErsatzTV.Infrastructure/Streaming/Graphics/Image/ImageElement.cs

@@ -15,6 +15,7 @@ public class ImageElement(ImageGraphicsElement imageGraphicsElement, ILogger log
         Resolution squarePixelFrameSize,
         Resolution frameSize,
         int frameRate,
+        TimeSpan seek,
         CancellationToken cancellationToken)
     {
         try
@@ -51,7 +52,7 @@ public class ImageElement(ImageGraphicsElement imageGraphicsElement, ILogger log
         }
         catch (Exception ex)
         {
-            IsFailed = true;
+            IsFinished = true;
             logger.LogWarning(ex, "Failed to initialize image element; will disable for this content");
         }
     }

ErsatzTV.Infrastructure/Streaming/Graphics/Image/WatermarkElement.cs

@@ -32,6 +32,7 @@ public class WatermarkElement : ImageElementBase
         Resolution squarePixelFrameSize,
         Resolution frameSize,
         int frameRate,
+        TimeSpan seek,
         CancellationToken cancellationToken)
     {
         try
@@ -80,7 +81,7 @@ public class WatermarkElement : ImageElementBase
         }
         catch (Exception ex)
         {
-            IsFailed = true;
+            IsFinished = true;
             _logger.LogWarning(ex, "Failed to initialize watermark element; will disable for this content");
         }
     }

ErsatzTV.Infrastructure/Streaming/Graphics/Motion/MotionElement.cs

@@ -1,4 +1,5 @@
 using System.Buffers;
+using System.Globalization;
 using System.IO.Pipelines;
 using CliWrap;
 using ErsatzTV.Core;
@@ -55,17 +56,32 @@ public class MotionElement(
         Resolution squarePixelFrameSize,
         Resolution frameSize,
         int frameRate,
+        TimeSpan seek,
         CancellationToken cancellationToken)
     {
         try
         {
+            _startTime = TimeSpan.FromSeconds(motionElement.StartSeconds ?? 0);
+            ProbeResult probeResult = await ProbeMotionElement(frameSize);
+            var overlayDuration = probeResult.Duration;
+
+            // already past the time when this is supposed to play; don't do any more work
+            if (_startTime + overlayDuration < seek)
+            {
+                IsFinished = true;
+                return;
+            }
+
             var pipe = new Pipe();
             _pipeReader = pipe.Reader;
 
-            _startTime = TimeSpan.FromSeconds(motionElement.StartSeconds ?? 0);
+            var overlaySeekTime = TimeSpan.Zero;
+            if (_startTime < seek)
+            {
+                overlaySeekTime = seek - _startTime;
+            }
 
-            SizeAndDecoder sizeAndDecoder = await ProbeMotionElement(frameSize);
-            Resolution sourceSize = sizeAndDecoder.Size;
+            Resolution sourceSize = probeResult.Size;
 
             int scaledWidth = sourceSize.Width;
             int scaledHeight = sourceSize.Height;
@@ -118,23 +134,30 @@ public class MotionElement(
 
             List<string> arguments = ["-nostdin", "-hide_banner", "-nostats", "-loglevel", "error"];
 
-            foreach (string decoder in sizeAndDecoder.Decoder)
+            foreach (string decoder in probeResult.Decoder)
             {
                 arguments.AddRange(["-c:v", decoder]);
             }
 
+            if (overlaySeekTime > TimeSpan.Zero)
+            {
+                arguments.AddRange(["-ss", overlaySeekTime.TotalSeconds.ToString(CultureInfo.InvariantCulture)]);
+            }
+
             arguments.AddRange(
             [
                 "-i", motionElement.VideoPath,
             ]);
 
+            var videoFilter = $"fps={frameRate}";
             if (motionElement.Scale)
             {
-                arguments.AddRange(["-vf", $"scale={targetSize.Width}:{targetSize.Height}"]);
+                videoFilter += $",scale={targetSize.Width}:{targetSize.Height}";
             }
 
             arguments.AddRange(
             [
+                "-vf", videoFilter,
                 "-f", "image2pipe",
                 "-pix_fmt", "bgra",
                 "-vcodec", "rawvideo",
@@ -157,7 +180,7 @@ public class MotionElement(
         }
         catch (Exception ex)
         {
-            IsFailed = true;
+            IsFinished = true;
             logger.LogWarning(ex, "Failed to initialize motion element; will disable for this content");
         }
     }
@@ -169,7 +192,7 @@ public class MotionElement(
         TimeSpan channelTime,
         CancellationToken cancellationToken)
     {
-        if (contentTime < _startTime || _isFinished)
+        if (_isFinished || contentTime < _startTime)
         {
             return Option<PreparedElementImage>.None;
         }
@@ -225,7 +248,7 @@ public class MotionElement(
         }
     }
 
-    private async Task<SizeAndDecoder> ProbeMotionElement(Resolution frameSize)
+    private async Task<ProbeResult> ProbeMotionElement(Resolution frameSize)
     {
         try
         {
@@ -249,9 +272,10 @@ public class MotionElement(
                         };
                     }
 
-                    return new SizeAndDecoder(
+                    return new ProbeResult(
                         new Resolution { Width = mediaVersion.Width, Height = mediaVersion.Height },
-                        decoder);
+                        decoder,
+                        mediaVersion.Duration);
                 }
             }
         }
@@ -260,8 +284,8 @@ public class MotionElement(
             // do nothing
         }
 
-        return new SizeAndDecoder(frameSize, Option<string>.None);
+        return new ProbeResult(frameSize, Option<string>.None, TimeSpan.Zero);
     }
 
-    private record SizeAndDecoder(Resolution Size, Option<string> Decoder);
+    private record ProbeResult(Resolution Size, Option<string> Decoder, TimeSpan Duration);
 }

ErsatzTV.Infrastructure/Streaming/Graphics/Subtitle/SubtitleElement.cs

@@ -56,6 +56,7 @@ public class SubtitleElement(
         Resolution squarePixelFrameSize,
         Resolution frameSize,
         int frameRate,
+        TimeSpan seek,
         CancellationToken cancellationToken)
     {
         try
@@ -112,7 +113,7 @@ public class SubtitleElement(
         }
         catch (Exception ex)
         {
-            IsFailed = true;
+            IsFinished = true;
             logger.LogWarning(ex, "Failed to initialize subtitle element; will disable for this content");
         }
     }

ErsatzTV.Infrastructure/Streaming/Graphics/Text/TextElement.cs

@@ -3,8 +3,6 @@ using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Graphics;
 using Microsoft.Extensions.Logging;
 using NCalc;
-using Scriban;
-using Scriban.Runtime;
 using SkiaSharp;
 using RichTextKit = Topten.RichTextKit;
 
@@ -35,6 +33,7 @@ public partial class TextElement(
         Resolution squarePixelFrameSize,
         Resolution frameSize,
         int frameRate,
+        TimeSpan seek,
         CancellationToken cancellationToken)
     {
         try
@@ -92,7 +91,7 @@ public partial class TextElement(
         }
         catch (Exception ex)
         {
-            IsFailed = true;
+            IsFinished = true;
             logger.LogWarning(ex, "Failed to initialize text element; will disable for this content");
         }