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Issue metadata

Status: Duplicate
Merged: issue 835664
Owner: ----
Closed: Apr 2018
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Mac
Pri: 2
Type: Bug-Regression



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Web-MIDI-API: MidiOutput produces no hearable sound anymore

Reported by florian....@apsis.com, Apr 29 2018

Issue description

UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Steps to reproduce the problem:
1. send some midi messages to a midi device via MidiOutput::send 

What is the expected behavior?
That I hear some whatever I've send to the output :)

What went wrong?
No output hearable

Did this work before? Yes 65

Does this work in other browsers? Yes

Chrome version: 66.0.3359.139  Channel: stable
OS Version: OS X 10.13.4
Flash Version: 

I'm pretty sure that I haven't changed anything and that it worked last week before Chrome was updated to version 66 - my project still runs and produces hearable song in Samsung Internet browser (Android) which wasn't updated  -  so I guess something has changed in the new Chrome 66.
 
Labels: Needs-Bisect Needs-Triage-M66
Cc: krajshree@chromium.org
Labels: Triaged-ET Needs-Feedback
reporter@ - Thanks for filing the issue...!!

Could you please provide a sample test file/url to test the issue from TE-end. A screencast/ screen shot if provided will be much helpful in understanding the issue.
This will help us in triaging the issue further.

Thanks...!!
I've testet a bit more and it seems that MidiOutput::send works as expected if the optional timestamp is omitted or set to zero. As soon as I pass a timestamp > 0 it doesn't work anymore. 
To reproduce you'll need a midi-device to send the output to... 
All following ways work in Samsung Internet browser (Android) but not in 66...

I've found two ways to reproduce:
1.) Manual script (attached midiOutputSendIssue.js)
That script contains basic commands to send output with a delay of 500ms to MidiOutput (copied and slightly modified to send a middle C to all outputs from the Web-MIDI-Api documentation)

copy paste the content of attached midiOutputSendIssue.js into Chrome console -> if you're connected to a MIDI device you should hear a middle c after 500ms. Once executed you can trigger another middle-c to all output port by running `sendMiddleCToAllOutputs(midi, window.performance.now() + 500.0)` 

Since Chrome 66 I can't hear sound anymore when using a timestamp greater zero -> try`sendMiddleCToAllOutputs(midi, 0.0)` and surprisingly you hear a sound but not for a timestamp greater zero...

Another way to reproduce
2.) A website which uses midi-web-api

http://james-ingram-act-two.de/open-source/assistantPerformer/assistantPerformer.html
Choose pianola music score and when the score is loaded choose your output device and press the start butting. When the score sheet is shown press the button with the green circle to start playing the score via web-midi -> on my device I can't hear any output

I hope that helps

With kind regards


midiOutputSendIssue.js
2.1 KB View Download
Project Member

Comment 4 by sheriffbot@chromium.org, Apr 30 2018

Labels: -Needs-Feedback
Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Comment 5 by agoode@chromium.org, Apr 30 2018

Mergedinto: 835664
Status: Duplicate (was: Unconfirmed)

Comment 6 by agoode@chromium.org, Apr 30 2018

This should be released to devices in a week or so. See https://bugs.chromium.org/p/chromium/issues/detail?id=835664#c23

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