Dynamically manipulating the pipeline while it is running

[yuryk]

Hello, everybody!
I need to do the following:

1. start a simple pipeline playing some long background music (bg.pcm in this case)
2. while it is playing, mix other (shorter) sounds into it (short.pcm) at some arbitrary times

For simplicity, of course, all files are in the same pcm format



i have tried the above pipeline, and it only plays the background, and only if i do not add any dynamic parts to it. Even if i only call gst_element_get_pad() to get the additional sink pad of the adder, the entire pipeline seems to not play.
I tried activating the pads and changing state of the dynamic part (i made it a bin with a ghost pad), still no good.

What's the correct way to achieve this?