Example of how to mimic the iOS equivalent of AVAssetWriterInput and CISourceOverCompositing

In iOS, one can take a sample buffer, modify it with CISourceOverCompositing and then use the result to feed AVAssetWriterInput.

That allows them to easily do things like add overlays to video. Since such functionality still does not exist in the MediaRecorder, an example of how to do this with what exists today would be very beneficial (just do a Google search on Android Video Watermark/Overlay/etc....it's a commonly requested topic with no good answers).

Start by reviewing the existing media-samples and the Android MediaRecorder capabilities relevant to the requested workflow. Compare the iOS AVAssetWriterInput and CISourceOverCompositing approach described here with available Android media APIs; done means a sample clearly demonstrates adding an overlay or watermark to recorded video.

Written by the indexing model from the issue text.