update recording mp4 args

Emby.Server.Implementations/LiveTv/EmbyTV/EncodedRecorder.cs

@@ -163,7 +163,7 @@ namespace Emby.Server.Implementations.LiveTv.EmbyTV
 
             var durationParam = " -t " + _mediaEncoder.GetTimeParameter(duration.Ticks);
             var inputModifiers = "-fflags +genpts -async 1 -vsync -1";
-            var commandLineArgs = "-i \"{0}\"{5} {2} -map_metadata -1 -threads 0 {3}{4} -y \"{1}\"";
+            var commandLineArgs = "-i \"{0}\"{5} {2} -map_metadata -1 -threads 0 {3}{4}{6} -y \"{1}\"";
 
             long startTimeTicks = 0;
             //if (mediaSource.DateLiveStreamOpened.HasValue)
@@ -193,7 +193,11 @@ namespace Emby.Server.Implementations.LiveTv.EmbyTV
 
             var subtitleArgs = CopySubtitles ? " -codec:s copy" : " -sn";
 
-            commandLineArgs = string.Format(commandLineArgs, inputTempFile, targetFile, videoArgs, GetAudioArgs(mediaSource), subtitleArgs, durationParam);
+            var outputParam = string.Equals(Path.GetExtension(targetFile), ".mp4", StringComparison.OrdinalIgnoreCase) ?
+                " -f mp4 -movflags frag_keyframe+empty_moov" :
+                string.Empty;
+
+            commandLineArgs = string.Format(commandLineArgs, inputTempFile, targetFile, videoArgs, GetAudioArgs(mediaSource), subtitleArgs, durationParam, outputParam);
 
             return inputModifiers + " " + commandLineArgs;
         }