Unfortunately, I am unable to corroborate the vlc log and xvinfo output
from your bug report. It seems VLC does not "see" the XVideo adapters at
all. Normally, it should print plenty of messages in the log if it could
not use a specific adapter, unless the X server returns protocol errors.
Please make sure that xvideo-adaptors is set to -1. I guess this won't
work. Then I'm afraid the only option is to step through the VLC code to
figure out what is failing in xcb_xv.c (I don't have the same hardware, so
I cannot do it myself).
pkg-multimedia-maintainers mailing list