RadMediaPlayer is a simple wrapper around the Silverlight MediaElement
control. To be honest, I am not very familiar with SMPTE but if Silverlight's MediaElement cannot read it, then RadMediaPlayer cannot read it as well. However, you mentioned that you are using a customized media element. Therefore, you can inherit RadMediaPlayer, edit its Style and replace the default MediaElement with your media element.
Capturing an image is not supported. As for markers, we have the concept of chapters in RadMediaPlayer which are essentially markers for the MediaElement control. You can take a look at this example
for further reference. Let me know what your thoughts are. I'd be glad to continue the discussion with you.
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