<html><head></head><body><div>On Fri, 2021-09-24 at 12:59 +0200, Marianna Smidth Buschle via gstreamer-devel wrote:</div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"><div>I have a use case where I have N live sources (v4l2src) from which I can <br></div><div>select to be the output.<br></div><div><br></div><div>I also need to be able to make a replay (seek from a filesrc).<br></div><div><br></div><div>My question is how to properly handle the mixing of the live and <br></div><div>non-live sources since the timestamps don't match.<br></div><div><br></div><div>The filesrc starts from zero (or the seeking point) and the live sources <br></div><div>have a running-time based on the clock.</div></blockquote><div><br></div><div>This is actually simpler than what you wrote. What you would do is to call gst_pad_set_offset() on the source pad of the non-live streams that you want to connect to the mixer.</div><div>That would then make sure to update the running time accordingly.</div><div><br></div><div>The offset would in the simplest case be the current running time when connecting the non-live stream.</div><div>You can get that from the current pipeline clock's time minus the current pipeline's base time.</div><div><br></div><div>Alternatively you might want to add some more time to that to schedule the non-live stream into the future, or do more complicated calculations to schedule the start of the stream to a specific time.</div><div><br></div><div><br></div><div>Note that after a (flushing) seek the running time starts again at 0, so you might need to re-offset here after a seek.</div><blockquote type="cite" style="margin:0 0 0 .8ex; border-left:2px #729fcf solid;padding-left:1ex"></blockquote><div><br></div><div><span><pre>-- <br></pre><div data-evo-paragraph="" class="" style="width: 71ch;" data-evo-signature-plain-text-mode="">Sebastian Dröge, Centricular Ltd · <a href="http://www.centricular.com">https://www.centricular.com</a></div><div data-evo-paragraph="" class="" style="width: 71ch;"><br></div></span></div></body></html>