The quality of the video transmitted by WebRTC is very low on iOS Safari 15.4(only Offerer situation)

• Component: WebRTC
• Status: RESOLVED CONFIGURATION CHANGED

[yuki uchida]

# Overview
The quality of the video transmitted by WebRTC is very low on iOS Safari 15.4.
And, changing MediaStreamTrack.enabled eliminate　this problem.


## steps to reproduce
device A: iOS Safari
device B: Any(ChromeM101 on Mac and iPadOS(unknown version) was tested)

1. (device A&B) visit https://yasubaba.github.io/prodSkyWay/room_videoMute/
2. (device A&B) Accept permissions for camera and microphone.
3. (device A&B) join Room and start WebRTC Connection.
4. (device B) received Video is very low quality. (However, the image quality seems to be normal on webrtc internals.)
5. (device A) click `Video Mute/Unmute` 
6.  (device B) received Video is good quality. (However, But on webrtc internals it looks no different than step 4)


The mute procedure is very simple as follows
```
document.getElementById('js-videoEnabled').addEventListener('click', () => {
  localStream.getVideoTracks().forEach( track => {
    track.enabled = !track.enabled;
  });
})
```


## Actual Results
iOS Safari always send low quality video at first, but changing track.enabled is workaround.

## Expected Results
device B receive good quality Video.

## Hardware
iPhone11 iOS15.4

[yuki uchida]

(In reply to yuki uchida from comment #0)
> # Overview
> The quality of the video transmitted by WebRTC is very low on iOS Safari
> 15.4.
> And, changing MediaStreamTrack.enabled eliminate　this problem.
> 
> 
> ## steps to reproduce
> device A: iOS Safari
> device B: Any(ChromeM101 on Mac and iPadOS(unknown version) was tested)
> 
> 1. (device A&B) visit https://yasubaba.github.io/prodSkyWay/room_videoMute/
> 2. (device A&B) Accept permissions for camera and microphone.
> 3. (device A&B) join Room and start WebRTC Connection.
> 4. (device B) received Video is very low quality. (However, the image
> quality seems to be normal on webrtc internals.)
> 5. (device A) click `Video Mute/Unmute` 
> 6.  (device B) received Video is good quality. (However, But on webrtc
> internals it looks no different than step 4)
> 
> 
> The mute procedure is very simple as follows
> ```
> document.getElementById('js-videoEnabled').addEventListener('click', () => {
>   localStream.getVideoTracks().forEach( track => {
>     track.enabled = !track.enabled;
>   });
> })
> ```
> 
> 
> ## Actual Results
> iOS Safari always send low quality video at first, but changing
> track.enabled is workaround.
> 
> ## Expected Results
> device B receive good quality Video.
> 
> ## Hardware
> iPhone11 iOS15.4


Postscript.

This problem seems to occur only when iOS Safari is the Offerer. iOS Safari is the Answerer, Chrome receives a clean image from the beginning.


## steps to reproduce
device A: iOS Safari
device B: Any(ChromeM101 on Mac and iPadOS(unknown version) was tested)

1. (device A&B) visit https://yasubaba.github.io/prodSkyWay/room_videoMute/
2. (device A&B) Accept permissions for camera and microphone.
3. (device B) join Room and start WebRTC Connection.
4. (device A) join Room and start WebRTC Connection.(createOffer)
5. (device A&B)  WebRTC Connection start.
6. (device B) received Video is very low quality. (However, the image quality seems to be normal on webrtc-internals.)
7. (device A) click `Video Mute/Unmute` 
8 (device B) received Video is good quality. (However, But on webrtc-internals it looks no different than step 6)

[youenn fablet]

Can you try on latest iOS 15.5 beta to see whether that fixes your issue?

[Radar WebKit Bug Importer]

<rdar://problem/93171146>

[Kyle Foley]

15.5 beta fixes the Safari issue for me

[youenn fablet]

Marking as configuration changed