MCU / ROOM name

Rafael Ribeiro · Jul 29, 2020

Hello!

What is the difference from MCU / Simple mixer?

We notice that MCU audio & video is fluid and good quality.
We notice that MIXER without #room on name - just a mixer adding inputs, has few troubles with image and sound quality.

Is there anything related? Is the #room making a difference?

Max · Jul 30, 2020

Good day.
The difference is in realtime settings.
When realtime mixer enabled (this is default settings in latest builds since 5.2.607)

Code:

mixer_realtime=true

the mixer bufferizes incoming stream for smooth playback, but does not wait for stream resurrection if it has a problems (packet loss, bandwidth isuues and so on). So mixer output stream continues, only problem participant freezes.
When realtime mixer is disabled

Code:

mixer_realtime=false

previous implemetation works. In this case, the mixer waits for all participants even if their streams has quality problems. Non-realtime mixer has some tweaks to improve quality, but it is very sensitive to incoming stream parameters. This can lead to mixer freezes and out of sync problems.
The stream can be added to any of mixer types by special #mixer_name or by REST API, no difference at this point.
May be the out of sync problem that you reported in this thread relates to non realtime mixer. Please switch to realtime, disable all the tweaks like video buffering and check.

Rafael Ribeiro · Jul 30, 2020

Hello Max!

We just copied settings from our MCU server to our MIX server.
Same servers settings @Google.

The MCU have improved performance than mixer output.

Differences:

1-) On MCU, we publish by API and use #room on name - and on mixer, we publish by API without #room
2-) On Mixer we inject RTMP stream as INTRO VIDEO .... MCU always has only speakers.

Can RTMP cause this?
Can missing #room @injection streams cause thist?

Max · Jul 31, 2020

Rafael Ribeiro said:
Can RTMP cause this?
Can missing #room @injection streams cause thist?

RTMP can cause out of sync in mixer output stream if incoming stream has out of sync. Anyway,it does not depend on mixer API used.
Please clarify how do you publish the same stream to MCU server and to MIX server: WebRTC, RTMP?
Please check how the stream is playing from MIX server before adding to mixer. If stream is published by RTMP, there can be out of sync before the mixer.
Also please collect two reports from those two servers when the same stream is published to MCU and to MIX, and send us using this link.

About the streaming structure. How much streams have to be published to one mixer on MIX sersver? If only two streams per mixer (participant and its desktop), the mixer seems excessive for it. In this case, both streams can be just played simultaneously on the page.

Rafael Ribeiro · Jul 31, 2020

Hello Max!

We will provide the report.

We are working on this way:

Server A -> receive webcams & desktops from WebRTC.

On streamer.js we add 2 PULLs.

JavaScript:

function pull(nomedostream){
    
            console.log("Inside PULL");
    
            var resultpull;

            fetchUrl = apiurl + "pull/pull";
            const options = {
                method: "POST",
                headers: {
                    "Content-Type": "application/json"
                },
                body: JSON.stringify({
                    "uri": "wss://WCSSERVER--B:8443",
                    "localStreamName": nomedostream,
                    "remoteStreamName": nomedostream
                }),
            }

            

            resultpull = fetch(fetchUrl, options);
    
            console.log(nomedostream);
    
    
    
}

function pullmcu(nomedostream){
    
            var salaid = field("salaid");
    
            console.log("Inside PULL MCU");
    
            var resultpull;

            fetchUrl = apiurlservermcu + "pull/pull";
            const options = {
                method: "POST",
                headers: {
                    "Content-Type": "application/json"
                },
                body: JSON.stringify({
                    "uri": "wss://WCSSERVER--C:8443",
                    "localStreamName": nomedostream + "#room-" + salaid,
                    "remoteStreamName": nomedostream
                }),
            }

            

            resultpull = fetch(fetchUrl, options);
    
            console.log(nomedostream);
    
    
    
}

On this way, we pull the same stream for server MCU where users are automatic added to the room and we pull to our MIXER server where the "operator" can publish or remove from Mixer from our control panel - using API.

Rafael Ribeiro · Aug 2, 2020

Hello Max!

We have copied our MCU settings (flashphoner.properties file) to our MIXER and change entire application from our side, to convert Mixer output to MCU ... open a room #room-XX ... and streams like streamname#room-XX.

We notice 90% of improvements of quality.
Go deeper, we found a situation:

If background image is enabled, mixer frozzen ...
We just comment out background image line.

We notice 95% of improvements of quality.
Now, we go deeper and enable

#mixer_display_stream_name=true #Yes, commented
mixer_debug_mode=true

We solve all problems!

Our conclusion at this time is:

MCU only really works if a room is automatically created by user join streamname#room-XX and we can experience a REAL MCU usage.
We have some issues with background image (like reenderization?)

Starting the mixer before and add participants by API do not provide the same experience / result.

Max · Aug 3, 2020

We raised the ticket WCS-2829 to check this issues.
Please provide the following:
- actual settings both for MCU and MIXER server
- background image to reproduce mixer freeze
- reports from both servers
Also please note that /pull/pull query pulls WebRTC stream from server defined in uri to local server. Your code sample seems like you pull stream from server B to A and from server C to A. Maybe, you should use /pull/push instead:

JavaScript:

function pull(nomedostream){
   
            console.log("Inside PULL");
   
            var resultpull;
            /// Push stream from server A to B
            fetchUrl = apiurl + "pull/push";
            const options = {
                method: "POST",
                headers: {
                    "Content-Type": "application/json"
                },
                body: JSON.stringify({
                    "uri": "wss://WCSSERVER--B:8443",
                    "localStreamName": nomedostream,
                    "remoteStreamName": nomedostream
                }),
            }

           

            resultpull = fetch(fetchUrl, options);
   
            console.log(nomedostream);
   
}

function pullmcu(nomedostream){
   
            var salaid = field("salaid");
   
            console.log("Inside PULL MCU");
   
            var resultpull;
            /// Push stream from server A to C
            fetchUrl = apiurlservermcu + "pull/push";
            const options = {
                method: "POST",
                headers: {
                    "Content-Type": "application/json"
                },
                body: JSON.stringify({
                    "uri": "wss://WCSSERVER--C:8443",
                    "remoteStreamName": nomedostream + "#room-" + salaid,
                    "localStreamName": nomedostream
                }),
            }

           

            resultpull = fetch(fetchUrl, options);
   
            console.log(nomedostream);
       
}

Rafael Ribeiro · Aug 3, 2020

Hello Max!
The fetch URL are differents on each function.

I will prepare the files.

Thanks to investigate!

Max · Aug 5, 2020

Good day.
We reproduced your case. The tests shows that mixer can freeze on encoding 720p output stream. The possible workarounds are:
- use more powerful hardware for mixer servers
- use 480p for mixer output stream

Code:

mixer_video_width=852
mixer_video_height=480

We are checking for mixer code optimizing ways and let you know about results in this topic.

Rafael Ribeiro · Aug 5, 2020

Hello Max,

As I said, once we change the method, not start mixer by API and input participants like streamname#room-ID, solve the problem, then, its not hardware or resolution.

We are working on server
1-standard-16 (16 vCPUs, 60 GB de memória)

Only for mixer .. i think is enought .. to 5 participants + 1 screen.

Max · Aug 6, 2020

Rafael Ribeiro said:
As I said, once we change the method, not start mixer by API and input participants like streamname#room-ID, solve the problem, then, its not hardware or resolution.

Our tests don't confirm that. We still need the reports from those two servers when the same stream is published to MCU and to MIX. Please collect them and send using this link.

Rafael Ribeiro said:
We are working on server
1-standard-16 (16 vCPUs, 60 GB de memória)
Only for mixer .. i think is enought .. to 5 participants + 1 screen.

The problem is one mixer uses only one CPU core now. So VPS should provide maximum perfomance per 1 vCPU.

Max · Aug 27, 2020

Good day.
We investigated the issue and found that mixer perfomance is significally decreasing when background picture is used. This affects both realtime and non realtime mixers.
We fixed the issue in build 5.2.748, please update and check.

MCU / ROOM name

Rafael Ribeiro

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Max

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Rafael Ribeiro

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Max

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Rafael Ribeiro

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Rafael Ribeiro

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Max

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Rafael Ribeiro

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Max

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Rafael Ribeiro

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Max

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Max

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