Add first draft of keyframe extraction for Matroska

src/Jellyfin.MediaEncoding.Keyframes/KeyframeData.cs

@@ -0,0 +1,28 @@
+using System.Collections.Generic;
+
+namespace Jellyfin.MediaEncoding.Keyframes
+{
+    public class KeyframeData
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="KeyframeData"/> class.
+        /// </summary>
+        /// <param name="totalDuration">The total duration of the video stream in ticks.</param>
+        /// <param name="keyframeTicks">The video keyframes in ticks.</param>
+        public KeyframeData(long totalDuration, IReadOnlyList<long> keyframeTicks)
+        {
+            TotalDuration = totalDuration;
+            KeyframeTicks = keyframeTicks;
+        }
+
+        /// <summary>
+        /// Gets the total duration of the stream in ticks.
+        /// </summary>
+        public long TotalDuration { get; }
+
+        /// <summary>
+        /// Gets the keyframes in ticks.
+        /// </summary>
+        public IReadOnlyList<long> KeyframeTicks { get; }
+    }
+}