[Webkit-unassigned] [Bug 215314] Distorted audio when using createMediaElementSource

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=215314

Luigi Pulcini <luigi at luigipulcini.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |luigi at luigipulcini.com

--- Comment #3 from Luigi Pulcini <luigi at luigipulcini.com> ---
As I mentioned in https://bugs.webkit.org/show_bug.cgi?id=211394, this behavior in connection to the use of the CreateMediaElementSource method seems to be related to a resampling problem when there is a mismatch between the sample rate of the audio file being played and the one of the user's device (which is in no way controllable by the developer).

The following video clearly demonstrates the different behavior between Chrome 86 (86.0.4240.198) and Safari 14.0 (15610.1.28.1.9, 15610) under MacOS 10.15.7.
https://youtu.be/KYtb-FnjbpQ

The test page shown in the video can be found at the following address: https://www.waveplayer.info/createmediaelementsource-test/

Regardless of the sample rate and the bitrate of the audio file being played back, my tests seem to conclude that the audio distortion is less likely to occur while downsampling rather than upsampling. So, if the audio context is created with the device set to 96 kHz, then switching the device sample rate to a smaller value doesn't affect the audio. By contrast, setting the sample rate of the device to a smaller value (e.g. 44.1 kHz) and then switching to a greater value is more likely to introduce the resampling distortion.

None of these behaviors occur in any other browser or device.
It is just Safari and iOS.

I hope this helps to clarify.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20201129/bf517dca/attachment-0001.htm>