<div dir="ltr"><div class="gmail_quote"><div>I faced similar issues a while back. A search in the group for something like "audiomixer gaps" should pull up the related posts.</div><div> </div><div>If memory serves, I found that using "adder" instead of "audiomixer" eliminated the gaps. As did setting a non-zero latency in the audiomixer properties. However, in my case, the latency value only seemed to have any effect at all if I also placed a queue after the audiomixer.</div><div> </div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"> Message: 1 Date: Tue, 5 Jan 2021 09:37:25 -0500 From: Guillaume Cartier <<a href="mailto:gucartier@gmail.com" target="_blank">gucartier@gmail.com</a>> To: Discussion of the development of and with GStreamer <<a href="mailto:gstreamer-devel@lists.freedesktop.org" target="_blank">gstreamer-devel@lists.freedesktop.org</a>> Subject: Re: Gstreamer audio mixer issue Message-ID: <CAN4e_LmOgJ6_q4yQOSaaL2jD_LZi80hjM=PJR1rC=<a href="mailto:4qeGFabqQ@mail.gmail.com" target="_blank">4qeGFabqQ@mail.gmail.com</a>> Content-Type: text/plain; charset="utf-8" Hi dananjaya, we are also using GStreamer for a project that involves mixing multiple live sources together. For us, the audiomixer would very often generate what we called "gritches" that upon looking at the output in Audacity were revealed to be small silence gaps in the output. Reading the source code and playing with it has led to the gst_aggregator_pad_has_space function that has a test that I believe is incorrect (in all humbleness being fairly new to GStreamer) : if (self->priv->latency == 0) return FALSE; I think this test should only apply in the non-live case, but in any case the good news is that by setting latency to any value in our audiomixer element (even 1), this has solved most of our problems. PS: You could also replace audiomixer with liveadder which is a subclass of audiomixer that by default sets latency to 30ms. On Tue, Jan 5, 2021 at 6:51 AM dananjaya <<a href="mailto:pulzappcheck890@gmail.com" target="_blank">pulzappcheck890@gmail.com</a>> wrote: > Hi, > I am trying the below pipeline to capture 2 1080p usb video streams while > previewing, with 2 usb audio sources mixed together. > > The issue is, the audio mixed and captured is containing lots of artifacts > such as click sounds. How can I resolve this issue. > > gst-launch-1.0 -e mp4mux name=mux ! filesink location=feed1mp1080HS.mp4 > v4l2src device=/dev/video1 ! tee name=t1 t1. ! queue ! video/x-raw, > width=1920, height=1080, framerate=30/1 ! nvvidconv ! queue ! nvv4l2h264enc > maxperf-enable=1 bitrate=4000000 profile=4 ! queue ! h264parse ! queue ! > mux.video_0 audiomixer name=mixer ! audioconvert ! voaacenc ! aacparse ! > mux.audio_0 pulsesrc > device="alsa_input.usb-VXIS_Inc_ezcap_U3_capture-02.analog-stereo" ! queue > ! > audio/x-raw,width=16,depth=16,rate=44100,channel=1 ! queue ! mixer.sink_0 > pulsesrc > > device="alsa_input.usb-C-Media_Electronics_Inc._USB_Advanced_Audio_Device-00.analog-stereo" > ! queue ! audio/x-raw,width=16,depth=16,rate=44100,channel=1 ! queue ! > mixer.sink_1 t1. ! queue ! video/x-raw, width=1920, height=1080, > framerate=30/1 ! nvvidconv ! queue ! > "video/x-raw(memory:NVMM),width=959,height=540,framerate=30/1,format=NV12" > ! > queue ! nvoverlaysink overlay-x=0 overlay-y=270 overlay-w=959 overlay-h=540 > overlay=1 v4l2src device=/dev/video2 ! tee name=t2 t2. ! queue ! > video/x-raw, width=1920, height=1080, framerate=30/1 ! nvvidconv ! queue ! > nvv4l2h264enc maxperf-enable=1 bitrate=4000000 profile=4 ! queue ! > h264parse > ! queue ! mp4mux ! filesink location=feed2mp1080HS.mp4 t2. ! queue ! > video/x-raw, width=1920, height=1080, framerate=30/1 ! nvvidconv ! queue ! > "video/x-raw(memory:NVMM),width=960,height=540,framerate=30/1,format=NV12" > ! > queue ! nvoverlaysink overlay-x=960 overlay-y=270 overlay-w=960 > overlay-h=540 overlay=2 > > Thanks in advance > > > </blockquote></div></div>