GNOME Bugzilla – Bug 168652
[v4lsrc] Doesn't link to alpha, unless a format is forced
Last modified: 2005-02-28 17:34:24 UTC
Command: gst-launch v4lsrc autoprobe=0 autoprobe-fps=0 ! video/x-raw-yuv,framerate=\(double\)10 ! alpha ! fakesink Expectation: The command would run, v4lsrc and alpha fixating to I420 between themselves. Result: WARN (0x8050918 - 308197:15:41.518887000) v4lsrc(25252) gstv4lsrc.c(678):gst_v4lsrc_src_link:<v4lsrc0> palette for fourcc AYUV is -1, refusing link ERROR: pipeline doesn't want to play. Ie, it doesn't even try to negotiate I420 (which is the only format supported by my webcam).
Well, duh, you are disabling autoprobing and thus it doesn't probe supported colorspaces and claims to support any. You should not do that unless you know what you are doing. ;). Stop-on-first-failure is policy, not a bug.