I tried this pipeline to mux audio and video streams captured from microphone and camera respectively. It works fine for sometime, but audio frames are dropped after sometime.

The video resolution is 2048x2048. When I am trying to capture video at 15 fps it works fine for about 2 mins. But as I increase the framerate, audio frames are dropped.

gst-launch-1.0 appsrc stream-type=0 is-live=TRUE caps="video/x-raw,format=RGB,width=2048,height=2048,framerate=30/1" ! queue ! x264enc bitrate=1000 tune=zerolatency speed-preset=1 ! flvmux name=mux ! filesink location='xyz.flv' ! alsasrc ! audioconvert ! audioresample ! voaacenc bitrate=64000 ! accparse ! audio/mpeg, mpegversion=4, stream-format=raw ! queue ! mux.

When I try to capture each of these streams individually, both are captured perfectly. But when I mux them using above pipeline, audio frames are dropped.