search

meetecho / janus-gateway

Janus WebRTC Server
https://janus.conf.meetecho.com
GNU General Public License v3.0
8.17k stars 2.47k forks source link

replaceVideo/replaceAudio not working on iOS Safari #1550

Closed jsdir closed 5 years ago

jsdir commented 5 years ago

Using media.replaceAudio or media.replaceVideo is failing on iOS Safari since none of the conditions required for using RTCRtpSender.replaceTrack (Firefox or Chrome >= 72) are met.

Instead, iOS Safari defaults to the following logic, which causes the RTCPeerConnection to send a second track for that media type without removing the first track.

https://github.com/meetecho/janus-gateway/blob/6075610ff3bbad37a79c432030b1d669907521fb/html/janus.js#L1560-L1561

This caused to gateway to fail with the following messages, which I figured to mean that the gateway expects only one track of each media type:

[WARN] [9003469785803948] Not video and not audio? dropping (SSRC 2603143779)...
[WARN] [9003469785803948] Not video and not audio? dropping (SSRC 2603143779)..

I've modified janus.js to check for the presence of RTCRtpSender.replaceTrack instead of the browser versions, and that seems to fix device switching on iOS Safari.

Does it make more sense in cases like these to directly check for the availability of the API on the browser instead of using conditionals requiring specific browser types and versions?

lminiero commented 5 years ago

Just checking for the presence of RTCRtpSender.replaceTrack will not work. There are browsers (e.g., some older versions of Chrome that are probably still around) that had the method, but it didn't do anything: in that case, the feature would just fail.

We can modify the check we have so that if it's Safari, we use replaceTrack as well. I'd like to be sure all versions of Safari supported this, though: do you know if they only added it later on?

lminiero commented 5 years ago

Eventually decided to change the code to use replaceTrack in Safari too.

lminiero commented 5 years ago

Improved the check, as I wasn't 100% sure replaceTrack was available in all Safari instances or only TP. Please let me know if you have feedback or you can verify this introduces regressions (can't check myself, sorry).