Bug 199876

Summary: [GTK] webaudio tests fail despite seemingly producing the exact expected results
Product: WebKit Reporter: Alicia Boya García <aboya>
Component: WebKitGTKAssignee: Nobody <webkit-unassigned>
Status: RESOLVED FIXED    
Severity: Normal CC: bugs-noreply, pnormand
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Comparison of the waves, seemingly no difference none

Description Alicia Boya García 2019-07-17 12:27:00 PDT 
The following tests are failing on GTK since around r246107

webaudio/oscillator-custom.html
webaudio/oscillator-sawtooth.html
webaudio/oscillator-sine.html
webaudio/oscillator-square.html
webaudio/oscillator-triangle.html

Interestingly though, these are audio tests (instead of text tests or image tests), and the test tool claims a huge mismatch:

https://build.webkit.org/results/GTK%20Linux%2064-bit%20Release%20(Tests)/r247512%20(10978)/results.html

Sample #3622
< 9503
---
> 9504
Sample #7829
< 8243
---
> 8242
Sample #9686
< -6077
---
> -6076
Sample #11126
< -5946
---
> -5947
Sample #13515
< -62
---
> -63
Sample #15674
< 7894
[...]

But after taking both the actual and expected files, adding them to different tracks on Audacity, inverting one and playing the result, I couldn't hear anything. They look equal, sound equal, and the histogram shows them as pretty equal too.
Comment 1 Alicia Boya García 2019-07-17 12:33:33 PDT 
Created attachment 374317 [details]
Comparison of the waves, seemingly no difference
Comment 2 Philippe Normand 2019-07-23 09:37:56 PDT 
Most likely these need port specific expectations.
Comment 3 Philippe Normand 2020-10-26 06:19:58 PDT 
Rebaselined in r268972