[gst-devel] is it possible dynamically change framerate in a running pipeline?

[Tim-Philipp Müller]

On Sat, 2010-01-09 at 21:23 +0100, Farkas Levente wrote:

Hi,

> is it possible dynamically change a running pipeline's framerate while 
> it's in RUNNING state?

Yes.

> or should we've to set to READY, set the 
> framerate and set back to RUNNING?

No.

> since if've to change it to READY 
> then we loose a few frame during the state transmission which wouldn't 
> be useful in case of using a grabber card.
> or gstreamer not able to change the capabilities in an already 
> negotiated pipeline?

It depends a bit on the elements involved, but there's no problem in
principle with changing the framerate on the fly. The framerate field in
the caps is at best indicative, what matters more are timestamps on
buffers (and the initial newsegment event). Some elements (e.g.
theoraenc) will not react well if you change the input framerate, but
most elements won't really care and just process things based on the
timestamps.

Cheers
 -Tim