1924887 - In the GMP Widevine process, log messages aren't captured in the firefox profiler

Status: REOPENED

(Core :: Audio/Video: GMP, defect, P3)

Description

[Alastor Wu [:alwu]]

See these two media profiles [1], they're from bug 1908340 (comment 7 and 9). We can see media logs in the content process, but can't see any log in the GMP process.

[1]
https://share.firefox.dev/4h80hwz
https://share.firefox.dev/3Y59mxr

Comment 1

[Jim Mathies [:jimm]]

This works but you have to disable the sandbox for some reason -

Open a command line console and browse to the install location for Firefox Nightly.
On Windows, enter 'set MOZ_DISABLE_GMP_SANDBOX=1'(return)
Launch Firefox using a clean profile from the command console (firefox.exe (return) or firefox.exe -p (return))
In the browser, open a tab and view about:logging
Enter 'timestamp,sync,GMP:5,EME:5' in the 'new log modules' text edit and click on 'Set Log Modules'
Under Output choose 'Logging to the Firefox Profiler' and check the 'Enable stack traces for log messages' checkbox.
Open an additional tab and visit a Widevine test site (Shaka Player Demo) or log into a streaming provider like Netflix.
In about:logging, click the 'Start Logging' button, then click the Firefox Profiler toolbar button to start recording. (The button should highlight when a recording is taking place.)
Return to the test site and play a stream past a point where the issue occurs.
Close the test tab, and click the Firefox Profiler toolbar button to stop recording.
Wait approximately 10 - 20 seconds for a new tab to open containing the profile.
Within the profiler tab click the 'upload local p[rofile' button on the upper right side of the tab. Once the upload is complete, a drop down menu will open displaying the URL of the profile. Select this text and copy it.
Share the URL of the profile for analysis with the engineer you are working with.

https://docs.google.com/document/d/1hPdnxL2iBlWParHPi_3LXtmSLKWoGgQHrqNI3k47PtU/edit#bookmark=id.ezylkjihmjnq

Comment 2

[Alastor Wu [:alwu]]

I feel that is something we should fix, despite of sandboxing. It's too complicated to ask users to follow those steps in order to capture the logs. Ideally, the about:logging should capture everything for us.