work around nvidia green line (#2447)

CHANGELOG.md

@@ -46,7 +46,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
     - Text that already fits with the configured style will not be adjusted
 - Block schedules: add **experimental** `Break Content` to decos
   - Break content is similar to filler from classic schedules
-  - Break content is currently limited to placement `Break Start` (play before anything else in the block)
+  - Break content is currently limited to placement `Block Start` (play before anything else in the block)
     - Future work will add other placement options
   - Break content is currently limited to playlists (which do *not* pad - they simply play through the playlist one time)
     - Future work will add other collection options which will pad to the full block duration
@@ -64,6 +64,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix deco dead air fallback selection and duration on mirror channels
 - Fix fallback filler duration on mirror channels
 - Fix slow startup caused by check for overlapping playout items
+- Fix green line in *most* cases when overlaying content using NVIDIA acceleration
 
 ### Changed
 - Filler presets: use separate text fields for `hours`, `minutes` and `seconds` duration

ErsatzTV.FFmpeg/OutputOption/NvidiaGreenLineWorkaroundFilter.cs

@@ -0,0 +1,35 @@
+using ErsatzTV.FFmpeg.Format;
+
+namespace ErsatzTV.FFmpeg.OutputOption;
+
+public class NvidiaGreenLineWorkaroundFilter(string videoFormat, FrameSize frameSize) : OutputOption
+{
+    public override string[] OutputOptions
+    {
+        get
+        {
+            if (videoFormat is not (VideoFormat.Hevc or VideoFormat.H264))
+            {
+                return [];
+            }
+
+            int cropPixels = frameSize.Height switch
+            {
+                1080 => 8,
+                720 => 16,
+                _ => 0
+            };
+
+            if (cropPixels == 0)
+            {
+                return [];
+            }
+
+            return
+            [
+                "-bsf:v",
+                $"{videoFormat}_metadata=crop_bottom={cropPixels}"
+            ];
+        }
+    }
+}

ErsatzTV.FFmpeg/Pipeline/NvidiaPipelineBuilder.cs

@@ -329,6 +329,17 @@ public class NvidiaPipelineBuilder : SoftwarePipelineBuilder
             context,
             pipelineSteps);
 
+        if (ffmpegState.DecoderHardwareAccelerationMode is HardwareAccelerationMode.Nvenc &&
+            ffmpegState.EncoderHardwareAccelerationMode is HardwareAccelerationMode.Nvenc &&
+            (videoStream.FrameSize == desiredState.ScaledSize || (context is { HasSubtitleOverlay: true, HasGraphicsEngine: true } && desiredState.PaddedSize == desiredState.ScaledSize)) &&
+            (context.HasSubtitleOverlay || context.HasGraphicsEngine || context.HasWatermark))
+        {
+            pipelineSteps.Add(
+                new NvidiaGreenLineWorkaroundFilter(
+                    desiredState.VideoFormat,
+                    desiredState.CroppedSize.IfNone(desiredState.PaddedSize)));
+        }
+
         return new FilterChain(
             videoInputFile.FilterSteps,
             watermarkInputFile.Map(wm => wm.FilterSteps).IfNone([]),