[gst-devel] gst-launch test..

Rob Kramer robk at starhub.net.sg
Mon Jul 21 07:27:02 CEST 2003


Thanks for your answer!

On Monday 21 July 2003 15:55, Ronald Bultje wrote:
> 0.6.x:
> gst-launch filesrc location=bla.vob ! mpegdemux name=demux video_00! {
> queue ! mpeg2dec ! xvideosink }


[rob] ~> gst-launch filesrc location=/cdrom/bmwshort.vob ! mpegdemux 
name=demux video_00! { queue ! mpeg2dec ! xvideosink }
INFO (20142: 0) Initializing GStreamer Core Library version 0.6.2
INFO (20142: 0) CPU features: (00000000) MMX SSE
INFO (20142: 0) registry: loaded user_registry in 0.375432 seconds
ERROR: pipeline could not be constructed: Could not get a pad video_00 from 
element demux

[rob] ~> l /cdrom/bmwshort.vob
-r--r--r--    1 root     root     125492480 2003-02-19 11:05 

Could this be caused if for example my movie file isn't really a .vob, but a 
mpeg1 stream or something? Or should it play that just as well?

> > I can't seem to find documentation on the gst-launch grammar, besides the
> > bit in the manual. Where does 'video_00' come from, for example?
> gst-launch is a test tool, nothing more. A really important one, but
> still only a test tool. Not an end-user application. For real work, you
> want to write XML pipelines via gst-editor or write a full-fledged
> application. ;).

Sure, I wanted to use it to learn more about gstreamer's architecture and use. 
The whole pipeline dataflow design is quite wonderful, it reminds me of a DSP 
suite I used years ago (called Khoros).

> video_00 is a padname that's generated in mpegdemux if any video stream
> is seen. If there's two videostreams, the second would be video_01.
> Audio is audio_xx, etc.

Ah, thanks. I guess I should re-read the docs on dynamic pads etc.



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