I managed finally to make a patch for mp32ogg so that now also german umlaut are supported and the conversion doesn't just fail. Reproducible: Always Steps to Reproduce:
Created attachment 142086 [details, diff] The patch for umlaut
(In reply to comment #1) > Created an attachment (id=142086) [edit] > The patch for umlaut > I took the ubuntu-version and adapted it to the gentoo-version. The ubuntu-version also had some new features like manually set bitrate but this doesn't concern the umlaut so these changes aren't in the patch.
Created attachment 144895 [details, diff] The patch unified version
Fix is in the tree. Please wait a couple of hours, resync and have fun! ;-) Thanks.