If we could do "reconfigure and seek" like reader_SetOutputProps(). Then we don't need to recreate wg_parser. What do you think?
I don't believe that reconfigure is sufficient, no. My understanding is that it will not trigger decodebin to remove elements from the pipeline; it will only ask the existing elements to change what they are outputting. For a decoder, or a transcoder like videoconvert, this is sufficient to change the format from e.g. one RGB format to another, but I doubt it will be sufficient to change whether a decoder is in fact decoding or not.