From d14ef2268f6b5ae9b9027d181db85dd1d08fe4ba Mon Sep 17 00:00:00 2001
From: Rafael Carvalho <rpaschoal@live.com>
Date: Tue, 7 Mar 2023 16:31:45 +1300
Subject: [PATCH] Add "BuildGifSnapshotArguments" method

---
 FFMpegCore/FFMpeg/SnapshotArgumentBuilder.cs | 25 ++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/FFMpegCore/FFMpeg/SnapshotArgumentBuilder.cs b/FFMpegCore/FFMpeg/SnapshotArgumentBuilder.cs
index 4456837..2645867 100644
--- a/FFMpegCore/FFMpeg/SnapshotArgumentBuilder.cs
+++ b/FFMpegCore/FFMpeg/SnapshotArgumentBuilder.cs
@@ -31,6 +31,31 @@ public static (FFMpegArguments, Action<FFMpegArgumentOptions> outputOptions) Bui
                 .Resize(size));
     }
 
+    public static (FFMpegArguments, Action<FFMpegArgumentOptions> outputOptions) BuildGifSnapshotArguments(
+        string input,
+        IMediaAnalysis source,
+        Size? size = null,
+        TimeSpan? captureTime = null,
+        TimeSpan? duration = null,
+        int? streamIndex = null,
+        int fps = 12)
+    {
+        var defaultGifOutputSize = new Size(480, -1);
+
+        captureTime ??= TimeSpan.FromSeconds(source.Duration.TotalSeconds / 3);
+        size = PrepareSnapshotSize(source, size) ?? defaultGifOutputSize;
+        streamIndex ??= source.PrimaryVideoStream?.Index
+                        ?? source.VideoStreams.FirstOrDefault()?.Index
+                        ?? 0;
+
+        return (FFMpegArguments
+                .FromFileInput(input, false, options => options
+                    .Seek(captureTime)
+                    .WithDuration(duration)),
+            options => options
+                .WithGifPalettArgument((int)streamIndex, size, fps));
+    }
+
     private static Size? PrepareSnapshotSize(IMediaAnalysis source, Size? wantedSize)
     {
         if (wantedSize == null || (wantedSize.Value.Height <= 0 && wantedSize.Value.Width <= 0) || source.PrimaryVideoStream == null)