Getting sample rate / sample format/ channels cound of playbin in python

[Pavel Hofman]

Hi Tim,

 >
 > The signal gives you the pad. From the pad you can query the caps with
 > something like
 >
 >   caps = pad.get_current_caps()
 >
 > and then from the caps you can get the rate/channel fields from the
 > first caps structure:
 >
 >   rate = caps[0]['rate']
 >   chans = caps[0]['channels']
Thanks a lot. Actually I was able to find examples of getting the rate 
from the pad -> caps, but I cannot find/do not know how to get the 
correct pad from the gst 1.0 playbin (playbin2 ). May I ask you for help 
with this?

 >
 > If you don't actually need to play the file you can also use the
 > GstDiscoverer API from the pbutils library instead.

Very good to know. For this I am using Python audio tools 
http://audiotools.sourceforge.net/ but perhaps standardizing on 
gstreamer would be an advantage.>

 > With playbin3 this is slightly nicer, you get a STREAM_COLLECTION
 > message on the bus with the streams and can query the info (caps etc.)
 > from the stream object instead.

I will take a look at playbin3, my project needs no backward 
compatibility. Is playbin3 stable enough?

I very much appreciate your help, thanks a lot.

Pavel.