[gst-devel] Using gnonlin to extract time segments from a video file

[Edward Hervey]

Hi,

On Wed, 2009-02-11 at 23:52 -0200, Rodrigo Manhães wrote:
> Hi,
> 
> First of all, thanks for the replies!
> 
> I applied your instructions about the properties to some examples
> found on Internet, but didn't work. So, I created a video pipeline by
> myself and I'm facing problems on linking dynamic pads from
> gnlfilesource to both video and audio streams. As of GStreamer
> Documentation, decodebin emits one "new-decoded-pad" signal for each
> decoded stream. Neither gnlcomposition nor gnlfilesource accept a
> new-decoded-pad signal. How can I register a callback for these
> signals?

  'new-decoded-pad' is a convenience signal for new pads on decodebin.
The normal signal for new pads being added to an element is 'pad-added'.

   Edward

> 
> []'s
> Rodrigo
> 
> 
> 2009/2/10 Edward Hervey <bilboed at gmail.com>:
> > Hi,
> >
> >  For your use case apply the following properties if you want to cut D
> > seconds starting from A:
> >  # outside time-realm (what it will output)
> >  gnlsource.props.start = 0 # the output starts from 0 ...
> >  gnlsource.props.duration = D # ... and lasts D nanoseconds
> >  # inner time-realm (what you are extracting)
> >  gnlsource.props.media_start = A
> >  gnlsource.props.media_duration = D
> >
> >  One thing to take into account is that gnlfilesource will decode the
> > contents to raw audio/video (because it uses decodebin(2)). That means
> > you'll need encoders and muxer after your compositions.
> >
> >  As a side note, but I'm not sure whether you'll encounter this with
> > such a simple use-case, gnlfilesource has a few issues due to the queues
> > it uses internally. If you see the resulting file stopping before the
> > end, you will have to use a queue-less bin within a regular gnlsource.
> >  Since you're using python you can re-use such an element I created in
> > PiTiVi : SingleDecodeBin (git.pitivi.org ,
> > pitivi/elements/singledecodebin.py) and put that in a regular
> > 'gnlsource' along with the above properties.
> >
> >  I hope this helps.
> >
> >    Edward
> >
> > On Tue, 2009-02-10 at 01:32 -0200, Rodrigo Manhães wrote:
> >> Hi,
> >>
> >> I need to build a small command-line tool for extracting a time
> >> segment from a video file, creating another video file as result
> >> containing the desired segment. I've tried to do this creating a
> >> pipeline whose source is a gnlfilesource and the sink is a filesink
> >> and limiting the playback to the desired timebox.
> >>
> >> I got good results on this same goal for audio files. For video files,
> >> however, the gnlfilesource's properties for start and duration are
> >> ignored. Has gnonlin some limitation in this sense or the problem is
> >> in my code?
> >>
> >> I've tried to do the same thing with gstreamer without gnonlin and
> >> didn't get success.
> >>
> >> The language I'm using is Python.
> >>
> >> I thank any help or link for information.
> >>
> >> []'s
> >> Rodrigo
> >>
> >> ------------------------------------------------------------------------------
> >> Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
> >> software. With Adobe AIR, Ajax developers can use existing skills and code to
> >> build responsive, highly engaging applications that combine the power of local
> >> resources and data with the reach of the web. Download the Adobe AIR SDK and
> >> Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com
> >> _______________________________________________
> >> gstreamer-devel mailing list
> >> gstreamer-devel at lists.sourceforge.net
> >> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
> >
> >
> > ------------------------------------------------------------------------------
> > Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
> > software. With Adobe AIR, Ajax developers can use existing skills and code to
> > build responsive, highly engaging applications that combine the power of local
> > resources and data with the reach of the web. Download the Adobe AIR SDK and
> > Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com
> > _______________________________________________
> > gstreamer-devel mailing list
> > gstreamer-devel at lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/gstreamer-devel
> >
> 
> ------------------------------------------------------------------------------
> Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM)
> software. With Adobe AIR, Ajax developers can use existing skills and code to
> build responsive, highly engaging applications that combine the power of local
> resources and data with the reach of the web. Download the Adobe AIR SDK and
> Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/gstreamer-devel