Bug 229601

Summary: Audio stutters when playing a m3u8 file during WebRTC conference
Product: WebKit Reporter: Sheng Yunzhou <yunzhou>
Component: MediaAssignee: Nobody <webkit-unassigned>
Status: RESOLVED CONFIGURATION CHANGED    
Severity: Normal CC: bfulgham, webkit-bug-importer, youennf
Priority: P2 Keywords: InRadar
Version: Safari 14   
Hardware: iPhone / iPad   
OS: iOS 14   

Description Sheng Yunzhou 2021-08-26 23:51:34 PDT
Hi,

We have encountered an issue that during a WebRTC conference, when a m3u8 format file is played using default <video> element, the beginning of the audio is stuttering for about 20 seconds, before it starts to play smoothly. The output of the video's sound is from top speaker.

However, if a mp4 format file is played, it's smooth from beginning without any stuttering. The output of the video's sound is from bottom loudspeaker.

If only a m3u8 format file is played without WebRTC conference, it plays smoothly.

Tested iOS versions:
- iPhone Xs Max on iOS 14.7.1
- iPad 7th Generation on iOS 14.7.1

To reproduce this issue:
- Start a WebRTC call with only yourself in it
- On the same page, play a video in m3u8 format, and verify if the audio stutters in the beginning

Sample app for issue reproduction: https://static.inspify.io/playground/ios_webrtc_audio/index.html
- Click on Join Meeting button
- Approve camera / microphone permission from public Jitsi
- No need to join conference room, while you can see your own video, play the video on top of the page
- Verify if audio is stuttering at the beginning
Comment 1 youenn fablet 2021-08-30 23:24:39 PDT
Hi Sheng, have you tried on latest iOS 15 betas?
It seems to work for me there.
Comment 2 Sheng Yunzhou 2021-08-31 22:17:18 PDT
Hello Youenn, I've just tried on iOS 15 on an iPad and the issue seems to be fixed.
Comment 3 Radar WebKit Bug Importer 2021-09-02 23:52:19 PDT
<rdar://problem/82711412>