From e25b669cc45358f64c900123ea6826c141aa70b8 Mon Sep 17 00:00:00 2001
From: Jason Dove <1695733+jasongdove@users.noreply.github.com>
Date: Sun, 7 Sep 2025 09:20:11 -0500
Subject: [PATCH] fix scaling content in certain locales (#2389)

---
 CHANGELOG.md                              |   1 +
 ErsatzTV.FFmpeg.Tests/MediaStreamTests.cs | 110 ++++++++++++++++++++++
 ErsatzTV.FFmpeg/MediaStream.cs            |   8 +-
 3 files changed, 117 insertions(+), 2 deletions(-)
 create mode 100644 ErsatzTV.FFmpeg.Tests/MediaStreamTests.cs

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1aeb1d604..fddde1e5f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - `local_infile=ON` is required when using MySQL (for bulk inserts when building playouts)
   - ETV will set this automatically when it has permission
   - When ETV does not have permission, startup will fail with logged instructions on how to configure MySql
+- Fix scaling content in locales that don't use period as a decimal separator (e.g. `,`)
 
 ### Changed
 - **BREAKING CHANGE**: change how `Scripted Schedule` system works
diff --git a/ErsatzTV.FFmpeg.Tests/MediaStreamTests.cs b/ErsatzTV.FFmpeg.Tests/MediaStreamTests.cs
new file mode 100644
index 000000000..9e732e25d
--- /dev/null
+++ b/ErsatzTV.FFmpeg.Tests/MediaStreamTests.cs
@@ -0,0 +1,110 @@
+using ErsatzTV.FFmpeg.Format;
+using LanguageExt;
+using NUnit.Framework;
+using Shouldly;
+
+namespace ErsatzTV.FFmpeg.Tests;
+
+[TestFixture]
+public class MediaStreamTests
+{
+    [Test]
+    [SetCulture("it-IT")]
+    public void SAR_0_0_DAR_4_3_Should_Not_Use_Comma_it_IT()
+    {
+        var mediaStream = new VideoStream(
+            0,
+            "h264",
+            "main",
+            Option<IPixelFormat>.None,
+            ColorParams.Default,
+            FrameSize.Unknown,
+            "0:0",
+            "4:3",
+            Option<string>.None,
+            false,
+            ScanKind.Progressive);
+
+        mediaStream.SampleAspectRatio.ShouldBe("1.333333333333:1");
+    }
+
+    [Test]
+    [SetCulture("en-US")]
+    public void SAR_0_0_DAR_4_3_Should_Not_Use_Comma_en_US()
+    {
+        var mediaStream = new VideoStream(
+            0,
+            "h264",
+            "main",
+            Option<IPixelFormat>.None,
+            ColorParams.Default,
+            FrameSize.Unknown,
+            "0:0",
+            "4:3",
+            Option<string>.None,
+            false,
+            ScanKind.Progressive);
+
+        mediaStream.SampleAspectRatio.ShouldBe("1.333333333333:1");
+    }
+
+    [Test]
+    [SetCulture("en-US")]
+    public void SAR_1_1_DAR_16_9_Should_Not_Use_Comma_en_US()
+    {
+        var mediaStream = new VideoStream(
+            0,
+            "h264",
+            "main",
+            Option<IPixelFormat>.None,
+            ColorParams.Default,
+            FrameSize.Unknown,
+            "1:1",
+            "16:9",
+            Option<string>.None,
+            false,
+            ScanKind.Progressive);
+
+        mediaStream.SampleAspectRatio.ShouldBe("1:1");
+    }
+
+    [Test]
+    [SetCulture("en-US")]
+    public void SAR_32_27_DAR_16_9_Should_Not_Use_Comma_en_US()
+    {
+        var mediaStream = new VideoStream(
+            0,
+            "h264",
+            "main",
+            Option<IPixelFormat>.None,
+            ColorParams.Default,
+            FrameSize.Unknown,
+            "32:27",
+            "16:9",
+            Option<string>.None,
+            false,
+            ScanKind.Progressive);
+
+        mediaStream.SampleAspectRatio.ShouldBe("32:27");
+    }
+
+    [Test]
+    [SetCulture("en-US")]
+    public void SAR_1point5_3point5_DAR_16_9_Should_Not_Use_Comma_en_US()
+    {
+        var mediaStream = new VideoStream(
+            0,
+            "h264",
+            "main",
+            Option<IPixelFormat>.None,
+            ColorParams.Default,
+            FrameSize.Unknown,
+            "1.5:3.5",
+            "16:9",
+            Option<string>.None,
+            false,
+            ScanKind.Progressive);
+
+        mediaStream.SampleAspectRatio.ShouldBe("1.5:3.5");
+    }
+}
diff --git a/ErsatzTV.FFmpeg/MediaStream.cs b/ErsatzTV.FFmpeg/MediaStream.cs
index efe498321..a64f2aa63 100644
--- a/ErsatzTV.FFmpeg/MediaStream.cs
+++ b/ErsatzTV.FFmpeg/MediaStream.cs
@@ -52,14 +52,18 @@ public record VideoStream(
                 }
 
                 double res = FrameSize.Width / (double)FrameSize.Height;
-                return $"{dar}:{res}";
+                var formattedDar = string.Format(CultureInfo.InvariantCulture, dar % 1 == 0 ? "{0:F0}" : "{0:0.############}", dar);
+                var formattedRes = string.Format(CultureInfo.InvariantCulture, res % 1 == 0 ? "{0:F0}" : "{0:0.############}", res);
+                return $"{formattedDar}:{formattedRes}";
             }
 
             {
                 string[] split = MaybeSampleAspectRatio.Split(':');
                 var num = double.Parse(split[0], CultureInfo.InvariantCulture);
                 var den = double.Parse(split[1], CultureInfo.InvariantCulture);
-                return $"{num}:{den}";
+                var formattedNum = string.Format(CultureInfo.InvariantCulture, num % 1 == 0 ? "{0:F0}" : "{0:0.############}", num);
+                var formattedDen = string.Format(CultureInfo.InvariantCulture, den % 1 == 0 ? "{0:F0}" : "{0:0.############}", den);
+                return $"{formattedNum}:{formattedDen}";
             }
         }
     }