Multiple video.js recorder on a single page (iOS)

[tstrohmeier]

Description

In iOS only one recorder at a time can be used.

Steps to reproduce

Create 2 video.js recorder on a single page. Start the recording in one recorder then in the other recorder. The first recorder is going to continue recording but is black and has no video stream anymore.

Results

Expected

Use a shared stream in both recorders. "Global Stream" as mentioned here: https://webrtchacks.com/guide-to-safari-webrtc/

Actual

Only one recorder at a time is usable.

Additional Information

Please include any additional information necessary here. Including the following:

versions

videojs record

4.3.0

webm-wasm

0.4.1

browsers

iOS Safari v14

OSes

iOS 14.4

[thijstriemstra]

@tstrohmeier what version of iOS?

The first recorder is going to continue recording but is black and has no video stream anymore.

This actually sounds like this issue: #552

webm-wasm

also, I don't think this plugin works on iOS (never tested it personally). Can you try without this plugin?

[tstrohmeier]

@thijstriemstra Yes webm-wasm actually works on iPadOs v 14.4.
#552 is the reason why I use webm-wasm. The RecordRTC recorder seems to have an issue on iOS.

But this thicket is about an other problem/topic. iOS only allows one user media stream at a time. It would be good if you can use one stream in multiple recorder.

[thijstriemstra]

The RecordRTC recorder seems to have an issue on iOS.

No, as you can see in #552 it's Safari that has an issue with MediaRecorder IMO. webm-wasm plugin also uses RecordRTC.

But this thicket is about an other problem/topic. iOS only allows one user media stream at a time.

No I think it's the same issue. One user media stream in iOS is causing behavior your see in #552

It would be good if you can use one stream in multiple recorder.

It would be good but I don't see how to fix this, without having to make all kinds of workarounds just for Safari. I don't get paid for this work and spending all my time on Safari is just plain annoying, Apple isn't paying me or something. If it works correctly in all browsers, I would expect it to work in Safari as well, and if it doesn't it's a bug in Safari. As you can see in #552, the latest Safari preview release has fixed the issue and I am certain it will be fixed in iOS as well. Until then I welcome any pull requests but you might as well wait until Safari releases a new version and fix for this issue.

[tstrohmeier]

No, as you can see in #552 it's Safari that has an issue with MediaRecorder IMO.

I did not debug on iOS yet but on MacOS Safari v14 I can confirm that MediaRecorder does not exists:
ReferenceError: Can't find variable: MediaRecorder

webm-wasm plugin also uses RecordRTC.

I don't know. I just use the library. The benefit for me is that I can also control bit rate etc.

No I think it's the same issue. One user media stream in iOS is causing behavior your see in #552

Not really. As I wrote the webm-wasm plugin works for me in all browsers (Chrome, Firefox, Safari, Safari iOS).

The only issue I have is that iOS only allows one stream at the time and so I can only use one recorder at the time on iOS/iPadOS. This is expected behavior on iOS.
Here is a good description on it: https://webrtchacks.com/guide-to-safari-webrtc/ Headline: "New getUserMedia() request kills existing stream track" I also don't think that Apple will change this.

It would be good but I don't see how to fix this, without having to make all kinds of workarounds just for Safari. I don't get paid for this work and spending all my time on Safari is just plain annoying, Apple isn't paying me or something. If it works correctly in all browsers, I would expect it to work in Safari as well, and if it doesn't it's a bug in Safari. As you can see in #552, the latest Safari preview release has fixed the issue and I am certain it will be fixed in iOS as well. Until then I welcome any pull requests but you might as well wait until Safari releases a new version and fix for this issue.

I can understand you! I do not have many experience with WebRTC so I can not really help you.
Seems like Apple is doing it's own thing again. I just notice from reading a bit that iOS will never change this behavior and this is why the possibility of getter/setter for the underlying media stream would be a good thing for the future. This would allow to share it between different recorder instances.

[thijstriemstra]

I did not debug on iOS yet but on MacOS Safari v14 I can confirm that MediaRecorder does not exists:
ReferenceError: Can't find variable: MediaRecorder

It should be enabled by default. If not, use these instructions to enable it: https://www.educative.io/edpresso/how-to-enable-the-mediarecorder-api-for-safari Also see #552

[tstrohmeier]

@thijstriemstra Thank you.

[thijstriemstra]

I tested this with the updated multi example on iOS 14.5 on Mobile Safari 14.1 and when I start the video preview in the 2nd recorder it goes black like you described. It seems to work fine on desktop Safari 14.1.

The related webkit ticket is https://bugs.webkit.org/show_bug.cgi?id=179363 so I'm marking this as a known browser issue.