Seven Du said:

the codec doesn't change resolution, the source does. so if you record a conference to send rtmp, change the conference canvas size. or you can try explicitly set the size e.g. record {vw=320,vh=240}rtmp://url... attach a log if it still not working.

We initially tried to set the rtmp resolution via "video-canvas-size" in conference.conf.xml... Dialplan snippet: <action application="record_session" data="{modname=mod_av}rtmp://${ipOfPeerInCluster}:5150/viewOfUser/${idOfClientSession}"/> <action application="conference_set_auto_outcall" data="['conference_member_flags=endconf,jitterbuffer_msec=5p:100p']sofia/gateway/asterisk/${example_destination}"/> <action application="conference" data="${example_destination}@example_conference+flags{endconf|mintwo}"/> conference.conf.xml snippet: <profile name="example_conference"> <param name="domain" value="$${domain}"/> <param name="rate" value="8000"/> <param name="channels" value="2"/> <param name="interval" value="20"/> <param name="energy-level" value="0"/> <param name="caller-controls" value="none"/> <param name="caller-id-name" value="$${outbound_caller_name}"/> <param name="caller-id-number" value="$${outbound_caller_id}"/> <param name="comfort-noise" value="false"/> <param name="conference-flags" value="video-floor-only|rfc-4579|livearray-sync|minimize-video-encoding"/> <param name="video-mode" value="mux"/> <param name="video-layout-name" value="1x1"/> <param name="video-canvas-size" value="320x240"/> <param name="video-canvas-bgcolor" value="#333333"/> <param name="video-layout-bgcolor" value="#000000"/> <param name="video-codec-bandwidth" value="1mb"/> <param name="video-fps" value="15"/> <param name="max-members" value="2"/> <!-- <param name="terminate-on-silence" value="5"/> --> <param name="endconf-grace-time" value="5"/> </profile> ...and then we tried the av.conf.xml change that I already mentioned. I'm not sure I need {modname=mod_av} in front of my rtmp url, but in case I do, I adopted your suggestion in this way: New change to dialplan snippet: <action application="record_session" data="{modname=mod_av,vw=320,vh=240}rtmp://${ipOfPeerInCluster}:5150/viewOfUser/${idOfClientSession}"/> ...And it worked! I wonder why this works and the conference.conf.xml setting doesn't. Thanks!