[gstreamer-bugs] [Bug 578500] v4l2src caps

GStreamer (bugzilla.gnome.org) bugzilla-daemon at bugzilla.gnome.org
Tue Apr 14 08:13:22 PDT 2009

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  GStreamer | gst-plugins-good | Ver: 0.10.21

Tim-Philipp Müller changed:

           What    |Removed                     |Added
             Status|UNCONFIRMED                 |NEEDINFO

------- Comment #5 from Tim-Philipp Müller  2009-04-14 15:13 UTC -------
> Following the above recommendation I reformulate the report as follows:
>   ... 
> 2) The following pipeline failed in negociating caps while it exists compatible
> caps on each element pairs.
> $ gst-launch-0.10  v4l2src ! ffmpegcolorspace ! video/x-raw-rgb ! xvimagesink
>     ...
> ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Could not
> negotiate format

This is not a bug. It is a perfectly normal/expected failure. See my second
comment above.

> 3) Hint: the same pipeline ending with element ximagesink or fakesink in place
> of xvimagesink succeeds.

This is also as expected (ximagesink supports only RGB, and fakesink will
accept anything) and does not indicate a bug in the above pipeline.

> The same is true if we force fully defined caps between ffmpeg & ximagesink as
> follows:
> $ gst-launch-0.10 --gst-debug=v4l2src:3 v4l2src ! ffmpegcolorspace !
> video/x-raw-rgb,width=320,height=240,bpp=32,depth=24,endianness=4321,red_mask=65280,green_mask=16711680,blue_mask=-16777216
> ! xvimagesink

Are you saying this pipeline with *xvimagesink* succeeds? (note that you write
'ffmpeg & ximagesink' but the pipeline actually contains an xvimagesink).

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