google chrome video lag

[Aleksandr Dolgaryev]

Hi,

first of all thanks for great work.

I have one problem though. Under some conditions I'm experiencing with google chrome video lag when using streaming plugin. Specifically when internet is bad and some packets are dropped google chrome starts to lag video up to 2-5 seconds, firefox in contrast keeps up and doesn't lag, even after IDR frame is received chrome continues to lag. Also one more observation: chrome starts to lag behind for 2-5 secs even in case internet is ok but on the same page there is a high JS activity, which is ok, but after JS code finished video continues to lag behind.

As I want to keep stream latency in bounds of 200-500 ms (which firefox delivers) I'd like to make chrome not to lag or at least "recover" after IDR frame. Is there a specific setting or trick for this?

I'm using janus commit 3cab7362d54d20c952a7b50d2c77e707d35c3f41, chrome version Version 66.0.3359.170 (also tried on canary with the same effect), stream settings are:

                type: 'rtp',

                audio: true,

                video: true,

                videopt: 96,

                videortpmap: 'H264/90000',

                videofmtp: 'profile-level-id=4de01f;packetization-mode=1',

                audiopt: 97,

                audiortpmap: 'opus/48000/2',

                audiofmtp: '97 stereo=1;sprop-stereo=1'

thanks in advance,

Aleksandr

[Lorenzo Miniero]

Have you tried enabling rfc4588 mode for retransmissions in the config file, and see if the delay improves that way?

L.

[Aleksandr Dolgaryev]

Yes, do not see the change in delay, it is still up to 5 secs in chrome, non existent in FF

[Lorenzo Miniero]

Can you try commenting this line and recompile to see if the lag is still affected?

https://github.com/meetecho/janus-gateway/blob/master/ice.c#L3409

This disables RTCP SR packets for video. Apparently in some cases it turned out to be the cause for delays, even though we haven't figured out why yet.

L.

[Aleksandr Dolgaryev]

This worked out pretty well! Thanks you saved my day, if you need any debug info to help fix this I'll gladly provide it. Please find below some stats for bad and good streams

[Diego Requena González]

I would like to test if I can fix audio and video syncs in my videorooms. Did you fixed this already? If not, please provide a reference to the line that must be commented out, because in new version v0.4.0, the link points to different line than the old one.

Best regards.

D.

[Bao Nguyen]

I applied this as well. Seemed to have fix the Chrome lag issue.

But new behavior I'm seeing very rarely RTP streams video or audio stalled out and recover after a few minutes. Anyone know anything in relation to that? I'm on Janus 0.3.1