Question about format capabilities

[Patrick Doyle]

When I run 'gst-inspect-1.0 ximagesink', I see the following:
...
Pad Templates:
  SINK template: 'sink'
    Availability: Always
    Capabilities:
      video/x-raw
              framerate: [ 0/1, 2147483647/1 ]
                  width: [ 1, 2147483647 ]
                 height: [ 1, 2147483647 ]
...

This tells me that xvimagesink takes video/x-raw frames at
(effectively) any frame rate and framesize.  But (as you note) that
doesn't tell me what specific image formats are support.  So I have
learned to do somthing like:

$ gst-launch-1.0 --gst-debug=CAPS:6 videotestsrc ! xvimagesink

When I look through the debug output produced by that, I see that
xvimagesink reports same set of capabilities (not surprisingly) and
that it doesn't restrict the image formats (which is what I learned
from gst-inspect-1.0).  Continuing through the debug output, I see
that videotestsrc and xvimagesink negotiate a UVYV format.  My
(limited) understanding of this negotiation process is that each side
is free to suggest the formats it supports and to choose from the
other side's list the format it would prefer to see.

--wpd


On Mon, Nov 10, 2014 at 9:02 AM, Francisco Velázquez
<francisco.javier at me.com> wrote:
> Dear GStreamer community,
>
> I am trying to figure out how to know what are the supported formats of
> ximagesink.
>
> I have GStreamer 1.4.3 in Mac OS X 10.10.
>
> `gst-inspect-1.0 ximagesink` shows no format information.
>
> You can see that
> http://cgit.freedesktop.org/gstreamer/gst-plugins-base/tree/sys/ximage/ximagesink.c:931
> does have a "format" descriptor, but that “format descriptor” is missing in
> http://cgit.freedesktop.org/gstreamer/gst-plugins-base/tree/docs/plugins/inspect/plugin-ximagesink.xml.
>
> Is the lack of format in the XML file intentional?
>
> How can one determine what are the supported formats of ximagesink without
> such description?
>
> Thank you,
>
> Francisco
>
>
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>