Queue Element use in Gstreamer Pipelines

Question

gst-launch-1.0 videotestsrc
! queue ! vp8enc ! rtpvp8pay
! application/x-rtp,media=video,encoding-name=VP8,payload=96
! webrtcbin name=sendrecv

In this pipeline I don't understand the need for queue element after videotestsrc ?

Can someone throw some light on the same ?

Answer 1

Its mostly for the buffering purpose. queue can hold the frames until vp8enc is done encoding current frame and ready to consume next one.

You read more about buffering in gstreamer here https://gstreamer.freedesktop.org/documentation/application-development/advanced/buffering.html?gi-language=c