[gst-devel] Gstreamer design questions

[lopez5 at gmx.de]

Hi all,
I have a few question about gstreamer and I would be happy if you
could give me some answers:

0.) Are the 'Application Development Manual 0.7.4.1' (manual.pdf) and
'Plugin Writer's Guide 0.7.4.1' (pwg.pdf) still up to date? If not,
what are the major points that have changed?

1.) 
http://www.freedesktop.org/~gstreamer/features/ : 
here it says: 

  'Pluggable scheduling system capable of dealing with most pipeline
  structures'

what does 'most' mean? In which cases will scheduling not work? Also,
there are a couple of emails in the archive complaining about bad
synchronization, what is the status with this because there is no
documentation about ?

2.)

http://www.freedesktop.org/~gstreamer/data/doc/gstreamer/head/manual/html/chapter-hello-world.html#section-hello-world
here it says:
 
  g_object_set (G_OBJECT (filesrc), "location", argv[1], NULL); 

Is this to only way to set up things on gstreamer elements? I mean, using
a string seams error-prone,. And, where are all these strings
documented? (ok, I can query them during run-time, but ...)

3.)

http://www.freedesktop.org/~gstreamer/data/doc/gstreamer/head/pwg/html/chapter-building-signals.html: 
here it says: 

  'Note, however, that the application needs to be aware of signals
  and their meaning, so if you're looking for a generic way for
  application- element interaction, signals are probably not what
  you're looking for.'

If signals are not the right way, what other way is
there?

4.)
http://www.freedesktop.org/~gstreamer/data/doc/gstreamer/head/pwg/html/chapter-advanced-events.html 
here it says: 

  'It is very important to understand how both of those methods work
  because if one element in the pipeline is not handling them
  correctly the whole event system of the pipeline is broken.'

Could you give some more details on this,
please.

5.)
http://www.freedesktop.org/~gstreamer/data/doc/gstreamer/head/pwg/html/section-events-definitions.html 
here it says: 

  'Events are stored in a GstEvent structure, which is simply a big C
  union with the types for each event in it.'

How can I add a custom event? Will I have to rebuild everything then?
Will I have to add code to each and every plug-in then?

6.) Chapter 24 and 25 of the Plugin Writer's Guide are
missing:
http://www.freedesktop.org/~gstreamer/data/doc/gstreamer/head/pwg/html/chapter-other-ntoone.html
http://www.freedesktop.org/~gstreamer/data/doc/gstreamer/head/pwg/html/chapter-other-nton.html

Does this mean that I currently cannot implement multiplexers with
gstreamer? 

If I can create a gstreamer pipeline that does audio/video
transcoding, i.e. demultiplex a/v -> transcode a/v -> multiplex a/v/ ,
what is the syntax for 'gst-launch' ?



Thanks! Martin.


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