1260319 - MSE videos aren't being decoded through DXVA

Status: RESOLVED WORKSFORME

(Core :: Audio/Video: Playback, defect)

Description

[...]

User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:48.0) Gecko/20100101 Firefox/48.0
Build ID: 20160328030215

Steps to reproduce:

1. Run a trace log on DXVA Checker
2. Watch a video on YouTube
3. Stop the trace log


Actual results:

No DXVA events are reported whilst watching a video on YouTube with MSE enabled, thereby reducing decoding performance.

Toggling media.mediasource.enabled to false re-enables DXVA and shows events on the trace log. The video engine load in GPU-Z also shows activity whereas when MSE is enabled the video engine shows no activity.


Expected results:

Regressed on the 23/03/2016 Nightly

Comment 1

[Jean-Yves Avenard [:jya]]

This is not a MSE bug

Comment 2

[Jean-Yves Avenard [:jya]]

Most likely YouTube serves you VP9 which isn't hardware accelerated. What is "stats for nerds" showing when playing a video when you right click in the YouTube video?

Comment 3

[Jean-Yves Avenard [:jya]]

You're running 48. In 48 if your machine is fast enough vp9 with MSE is enabled. And YouTube serves vp9 by default

Comment 4

[...]

Yes, you're right. The videos are defaulting to webm/vp9 and my HD 4600 doesn't have the hardware decoder for VP9. Performance is still relatively good considering DXVA doesn't work, but will still have to toggle the webm pref to false.

Comment 5

[Jean-Yves Avenard [:jya]]

Unfortunately, at this stage you can't disable this. We have a bug for this pending review. 

But you'll find the VP9 is likely going to give you better results, and that power consumption is virtually the same as with h264. But on the other hand, as VP9 takes less bandwidth than h264; you'll typically can use a higher resolution as YouTube adaptative streaming is mostly linked to network bandwidth.