diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
index 62ae61e9a6..d63ea7502d 100644
--- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
+++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs
@@ -7482,8 +7482,18 @@ namespace MediaBrowser.Controller.MediaEncoding
             if (Path.GetExtension(outputPath.AsSpan()).Equals(".mp4", StringComparison.OrdinalIgnoreCase)
                 && state.BaseRequest.Context == EncodingContext.Streaming)
             {
-                // Comparison: https://github.com/jansmolders86/mediacenterjs/blob/master/lib/transcoding/desktop.js
-                format = " -f mp4 -movflags frag_keyframe+empty_moov+delay_moov";
+                // Use fragmented MP4 for adaptive streaming (HLS/DASH with segments)
+                // Use faststart for progressive downloads (better seeking and metadata)
+                if (!string.IsNullOrEmpty(state.Request.SegmentContainer))
+                {
+                    // Fragmented MP4 for HLS/DASH
+                    format = " -f mp4 -movflags frag_keyframe+empty_moov+delay_moov";
+                }
+                else
+                {
+                    // Progressive download - use faststart for proper seeking and duration
+                    format = " -f mp4 -movflags faststart";
+                }
             }
 
             var threads = GetNumberOfThreads(state, encodingOptions, videoCodec);