1344614 - Improve GMP clock from second to millisecond precision

Status: RESOLVED FIXED

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

Description

[Chris Pearce [:cpearce (Not reading bugmail)]]

The clock that GMP currently exposes to CDMs has second precision:

https://dxr.mozilla.org/mozilla-central/rev/8d026c60151005ad942e3d4389318fe28a0c8c54/dom/media/gmp/GMPPlatform.cpp#223

However the clock the Chromium exposes to CDMs has microsecond precision:

https://cs.chromium.org/chromium/src/media/cdm/cdm_adapter.cc?l=733&rcl=9a71b6540c7dce7068c4abe0317e740f504986fc
https://cs.chromium.org/chromium/src/base/time/time.cc?l=160&rcl=9a71b6540c7dce7068c4abe0317e740f504986fc

We have Chromium's base::Time in our source tree, so we should use that so that the clock we provide Widevine is as close to what Chrome provides it.

I'm not aware of this causing issues, AFAICT Widevine doesn't need super high precision timers, so we can let this ride the trains.

Comment 1

[Chris Pearce [:cpearce (Not reading bugmail)]]

Attachment: Bug 1344614 - Improve GMP clock precision to match Chromium's CDM clock.

The clock that GMP currently exposes to CDMs has second precision. Whereas the
clock that Chromium exposes to CDMs has microsecond precision. We should use
the same clock as Chromium does (since we have its code in our tree already) so
that our CDM harness is as compatible to Chromium as possible.

Review commit: https://reviewboard.mozilla.org/r/117430/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/117430/

Comment 2

[JW Wang [:jwwang] [:jw_wang]]

Comment on attachment 8843828 [details]
Bug 1344614 - Improve GMP clock precision to match Chromium's CDM clock.

https://reviewboard.mozilla.org/r/117430/#review119058

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e5cb10f268e5
Improve GMP clock precision to match Chromium's CDM clock. r=jwwang

Comment 4

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/e5cb10f268e5