diff --git a/FFMpegCore/FFMpeg/FFMpeg.cs b/FFMpegCore/FFMpeg/FFMpeg.cs
index 4e7d47a..bceea02 100644
--- a/FFMpegCore/FFMpeg/FFMpeg.cs
+++ b/FFMpegCore/FFMpeg/FFMpeg.cs
@@ -254,9 +254,11 @@ public static bool PosterWithAudio(string image, string audio, string output)
 
             return FFMpegArguments
                 .FromFileInput(image, false, options => options
-                    .Loop(1))
+                    .Loop(1)
+                    .ForceFormat("image2"))
                 .AddFileInput(audio)
                 .OutputToFile(output, true, options => options
+                    .ForcePixelFormat("yuv420p")
                     .WithVideoCodec(VideoCodec.LibX264)
                     .WithConstantRateFactor(21)
                     .WithAudioBitrate(AudioQuality.Normal)