Silverlight Player doesn't play video smoothly

Question

Hi all,

I'm having a problem with silverlight player when playing a smoothstreaming video (ismv). When the camera is moving fast some parts of the movie appear distorted (horizontal blocks). It seams like some horizontal parts of the movie are milliseconds delayed. This strange effect does not occur if I open the ismv file using the windows media player. If I pause the movie the image is ok also.

The original movie is in MPEG-TS format, the codec is H264/AVC and resolution is 1920x1080 (interlaced). I'm using Expression Encoder 3 to generate ismv files. The output format is VC1 - VBR Constrained. The best resolution is 1280x720, bit rate is 3,8Mbps and the lowest is 640 x 360, bit rate is 600kbps.

This strange effect is appearing both in the highest resolution and in the lowest.

I already try to use VC1 - CBR, H.264 - CBR and the results are the same. I also try to use Expression Encoder 2 SP1 and VC1 - CBR and the result is same.

I'm using the WindowsMediaPlayer.xap (with SmoothStreaming.xap included) for Silverlight 3 but I also try the SmoothStreamingBlackGlass.xap of Silverlight 2 and the result is the same.

Can anyone tell me what I might doing wrong?

Note: I'm encoding the movies using the Expression Encoder native codecs. But I've already tried to use external H264 codecs and the result is the same.

Regards,

Nuno Neto

Answer 1

I can't claim to be familiar with the media player controls that you mention, but I have seen a similar effect when playing video when the hosted Silverlight object is in windowless mode.

You may want to check the <object> or <asp:Silverlight> tag that is hosting your media player and try explicitly setting the "windowless" parameter to "false".

For more information on the parameter, please see:

• MSDN Documentation
• Silverlight SDK Blog Post
• Silverlight Performance Tips (about mid-way down the list)

Hope that helps.