Right, but will we ever pass a non-NULL format for DMO objects?
I pass a non-NULL format in the lastest version in ProcessOutput(). It record the changed format returned by gstreamer.
Looking at that, I don't see what it achieves? We only pass the output format when recreating the wg_transform and in GetOutputSizeInfo(), but we don't recreate the wg_transform here, and in practice the width and height shouldn't change.