A video I encoded myself in DXV does work too, so that's an option if you want to convert all your source material. These reports from the Wine testing database show them just playing the included DXV clips too, so my guess is that's all they tested:
https://appdb.winehq.org/objectManager. ... &iId=39557
None of the various methods of installing Windows Media Player did me any good for playing h264 mp4s. The closest I got was by using winetricks (available via apt) to install mf i.e. MediaFoundation, which Resolume is definitely going to need, based on the description here:
https://resolume.com/support/en/video
There are some "mediafoundation fixes" that gamers sometimes use to make Wine play videos better, but those didn't get me any further than regular winetricks mf. Once that was installed, I could see that Avenue was at least trying to load my mp4 file, rather than completely ignoring it, but then it crashed.
If we could disable the request to MediaFoundation and let ffmpeg handle it, that would be nice, but I'm not going to patch the binary to do that. I bet you could change just a few instructions, but that's too much like my day job to sound like any fun.
Giving up on Wine for now since I don't want to convert everything to DXV. But if you don't mind that, it's worth trying.