GNOME Bugzilla – Bug 471823
[v4l2src] Fails to negotiate capabilities with Macbook Pro isight
Last modified: 2007-09-11 14:42:42 UTC
Running gst-launch-0.10 v4l2src ! video/x-raw-yuv,format=\(fourcc\)UYVY,width=320,height=240 ! ffmpegcolorspace ! ximagesink gives me a failure to negotiate capabilities error. Reverting http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/sys/v4l2/gstv4l2src.c?r1=1.80&r2=1.81 makes it work again. Restoring the old code path to gst_v4l2src_get_caps is sufficient, so I'm assuming that there's some breakage in how the caps are set up. I'm using the driver from http://files.i-nz.net/projects/linux-kernel/isight/uvcvideo-isight.tar.gz - I'll try to dump the caps from the two versions now.
Created attachment 94631 [details] Working code with GST_CAPS:5,GST_NEGOTIATION:5
Created attachment 94634 [details] Broken code with GST_CAPS:5,GST_NEGOTIATION:5
Seem like the framerate discovery code failed to find a framerate and ended up with an empty list of rates. I see two possible causes: broken driver or min/max framerates reported by the driver were equal. Does this patch commited to CVS fix it for you? * sys/v4l2/v4l2src_calls.c: (gst_v4l2src_probe_caps_for_format_and_size): Add some more debugging in the framerate function. Iterate stepwise framerate up to and _including_ the max and if nothing was added to the list, add a dummy 0/1 to 100/1 framerate so that we don't end up with an empty list. http://webcvs.freedesktop.org/gstreamer/gst-plugins-good/sys/v4l2/v4l2src_calls.c?r1=1.63&r2=1.64 If it still fails can you reopen and attach a log with GST_DEBUG=*v4l2*:5 ?
Not directly related to the problem reported, just thought I'd mention it since it's iSight-related: v4l2src works great for me now (Macbook Pro 3rd generation, gutsy kernel/drivers), but then it seems like it was only ever really broken for me with the v4l2src from the 0.10.6 -good release, and the error I get with that was different too (namely: Could not get buffers from device "/dev/video0"). That is with the drivers and driver versions as they ship in gutsy though, which might be different from the versions Matthew is using.
Wim, I need the following patch, but otherwise it works fine. Simple thinko in merging?
Created attachment 95138 [details] [review] Patch against cvs head to fix fraction init
Seems like it has always been wrong.. commited your patch to CVS now. Thanks for testing.
*** Bug 475424 has been marked as a duplicate of this bug. ***