Bug 190963 - On mobile Safari, mp3 audio spikes in volume after resuming from paused state
Summary: On mobile Safari, mp3 audio spikes in volume after resuming from paused state
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Web Audio (show other bugs)
Version: Safari 12
Hardware: iPhone / iPad iOS 11
: P2 Normal
Assignee: Nobody
Keywords: InRadar
Depends on:
Reported: 2018-10-26 09:22 PDT by stoldney.mcstoldneyson
Modified: 2019-01-23 14:18 PST (History)
2 users (show)

See Also:


Note You need to log in before you can comment on or make changes to this bug.
Description stoldney.mcstoldneyson 2018-10-26 09:22:11 PDT
I have a tag that I have loaded an mp3 into. When I play the mp3 when it is in paused state, the volume on iPad spikes much louder for a few seconds before returning to its prior volume level. The issue occurs in this sequence:

var sound = $("#AudioElement")[0];
sound.src = url;

// Later

// Later

I have reproduced this on iOS 11.2.5, 12.0, and 12.1.

The mp3s are encoded at 64Kbps/44100Hz in CBR formatting.

I think 1 of two things is happening here:

1. The audio when first played is being muted by Safari for some reason, and resuming the audio from paused state causes the volume to spike up to the global volume control for the device. IE, volume is spiking to what its supposed to be before being muted again by Safari.


2. The volume is not being muted by Safari on first play, and the spike in volume is just abnormal.
Comment 1 Radar WebKit Bug Importer 2018-10-29 17:40:57 PDT
Comment 2 stoldney.mcstoldneyson 2018-10-29 18:27:30 PDT
Jer Noble, I've noticed you've been assigned to this case as well. You can use the same login to the demo account I got for you in the other bug (190644) to reproduce. Select the same assessment from the menu and click the pause button in the lower left.
Comment 3 stoldney.mcstoldneyson 2018-11-28 09:33:23 PST
If possible, could I an update on this ticket, please?
Comment 4 stoldney.mcstoldneyson 2019-01-23 14:18:25 PST
I have tried a few workarounds to this issue, re-encoding the MP3s to different sample and bit rates. Here are the set of encodings I've tried (sample rate/bit rate):

I have also tried wavs encoded at 44100 bit rate. 

None of these resolved the issue. I am at loss for what else I can do different. And advice or help would be greatly appreciated.