[gst-devel] GStreamer and audio and video bins

[Oscar Östlund]

Hi

I am pretty new on GStreamer. I am trying to setup an appliaction that  
uses this cool library.

I have a problem. This is the following setup I use:
pipeline:
   - filersrc
   - decodebin
   - videodin (type: bin)
     * ffmpegcolorspace
     * autovideosink
   - audiobin (type: bin)
     * audioconverter
     * autoaudiosink

So I create the audiobin et videobin first, and add them to the  
pipeline. Then create the filesrc and the decodebin. A callback is  
called on new-decoded-pad. This one links the audiobin's and the video  
bin's ghost pads to the decoder if appliacable. Then I set the state  
to playing and start the main loop.

If the file is Ogg/Vorbis, then it doesn't work. If I create the  
videobin but I don't add the videobin to the pipeline, it works fine.  
If on the other hand I create the videobin and then add it (even if it  
doesn't get linked), then everything works fine until I start the main  
loop. Then it just waits and doesn't play the music. It just open the  
viedo window and runs the mainloop but doesn't play anything. On the  
other hand, if the file is Ogg/Theora. Then everything works  
perfectly, in both situations.

Now I have a second problem. If I don't create the videobin, things  
work fine... as long as I add the audiobin to the pipeline not in the  
new-decoded-pad callback. My thought was that I wanted to add the  
video and audiobin to the pipeline only if needed. Apparently, I can't  
add them in the callback. Is that due to the fact that the callback is  
called in another thread (if it is) ??

Do you have any idea ?

Thank you for your help.

Oscar

PS I am running GStreamer on MacOSX.

PSS:
In the normal case, the bus gets a GST_MESSAGE_TAG, then a  
GST_MESSAGE_ASYNC_DONE and finally GST_MESSAGE_NEW_CLOCK
When I add the videobin to the pipeline, the bus receives the  
GST_MESSAGE_TAG but then nothing, just waits...