I’m running leap 42.2, and I’ve got Chromium installed. I had a vendor tell me that I need chromium-ffmepgsumo to watch videos in Chromium. I’m running Chromium 55, while the last chromium-ffmpegsumo package is Chromium 54?
Chromium uses the system’s ffmpeg now. This also means that you don’t have to replace chromium-ffmpegsumo (the “crippled” version) with chromium-ffmpeg either to get full codec support. Just install the full ffmpeg (from Packman e.g.).
Did you install the full ffmpeg (and libav*) from Packman?
You need this for other media players too.
The version included in openSUSE lacks support for non-free codecs for legal reasons.