fix hls segmenter in some cultures (#582)

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix issue preventing some versions of ffmpeg (usually 4.4.x) from streaming MPEG-TS (Legacy) channels at all
   - The issue appears to be caused by using a thread count other than `1`
   - Thread count is now forced to `1` for all streaming modes other than HLS Segmenter
+- Fix bug with HLS Segmenter in cultures where `.` is a group/thousands separator
 
 ### Changed
 - Upgrade ffmpeg from 4.4 to 5.0 in all docker images

ErsatzTV.Core/FFmpeg/HlsPlaylistFilter.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Globalization;
 using System.Text;
 
 namespace ErsatzTV.Core.FFmpeg
@@ -55,7 +56,11 @@ namespace ErsatzTV.Core.FFmpeg
                     continue;
                 }
 
-                var duration = TimeSpan.FromSeconds(double.Parse(lines[i].TrimEnd(',').Split(':')[1]));
+                var duration = TimeSpan.FromSeconds(
+                    double.Parse(
+                        lines[i].TrimEnd(',').Split(':')[1],
+                        NumberStyles.Number,
+                        CultureInfo.InvariantCulture));
                 if (currentTime < filterBefore)
                 {
                     currentTime += duration;