Building a pipeline to merge two audio tracks, use a video track, and add a watermark

[Ayron Jungren]

Hello,

I'm trying to build a pipeline that accepts three files as input (two
videos, and an alpha PNG). The pipeline needs to combine the two audio
tracks from the videos, use the video track of the first video file
(ignoring the video track of the second), and add in the alpha PNG as a
watermark. I've tried gst-launch but I can't seem to get the pipeline
right. I'm not against using the C API either, and I've read over the
documentation on fd.o, but I can't think of a good starting point to
build the right pipeline. Any assistance would be greatly appreciated.

Ayron Jungren