Onimusha: Warlords doesn't even use H264 and has several other problems. None of these games need H264 to be explicitly exposed, they only need compressed output.
This is also only making my work on upstreaming Proton changes more difficult and I don't really understand what you are trying to achieve here.
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https://gitlab.winehq.org/wine/wine/-/merge_requests/5988#note_75084
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v6: winegstreamer: Respect video format padding for input buffers too.
winegstreamer: Normalize video processor and color converter apertures.
winegstreamer: Normalize both input and output media types stride at once.
winegstreamer: Use video info stride in buffer meta rather than videoflip.
winegstreamer: Keep the input caps on the transform.
winegstreamer: Use a new wg_video_buffer_pool class to add buffer meta.
winegstreamer: Only use pool and set buffer meta for raw video frames.
https://gitlab.winehq.org/wine/wine/-/merge_requests/5972