Blank screenshots during video playback

I have a script which takes screenshot periodically to see whatever is displayed on the screen (mostly it's HTML based content) using LS2 API com.webos.surfacemanager/captureCompositorOutput method. And there's a bug that at the time some video is playing resulting screenshot is just a black image.
Testing showed that when displaying some other type of content like image or text this method works correctly.

Looking for an workaround or is there plans to fix this?

Current capture API implementation in compositor doesn't support to capture media. IMO, the media playback uses different layer than compositor layer.

captureCompositorOutput literally captures the output from the compositor. If something is not captured it means it is not a part of the compositor output. A typical example is the video which can be rendered in a different plane from what the compositor uses.

So there are no other means for capturing output of the plane which is used for rendering video?

There is no option to capture the video plane at the moment.