Bug 197872 – [GStreamer][MSE] Video noticeably choppy

• Status: RESOLVED
• Resolution: WORKSFORME
• Component: Media

[Lionir]

https://www.youtube.com/watch?v=LXb3EKWsInQ (and other videos which require some level of horse power) will be quite noticeably choppy when compared to the same video on another browser.

Epiphany 3.33.1-cae625ba5
WebKitGTK 2.24.1

[Philippe Normand]

Playback performance highly depends on the GStreamer video decoder used, so we need to know which one is used. What's your GPU (hw, driver)? Is gstreamer-vaapi installed?

[Lionir]

(In reply to Philippe Normand from comment #1)
> Playback performance highly depends on the GStreamer video decoder used, so
> we need to know which one is used. What's your GPU (hw, driver)? Is
> gstreamer-vaapi installed?

I have a RX460 running Mesa 19, I'm not exactly sure of all the GStreamer video decoders I have but I use the flatpak which should have : vaapi, libav, plugins-bad, plugins-good, plugins-base, plugins-ugly.

[Philippe Normand]

*** This bug has been marked as a duplicate of bug 197752 ***

[Michael Catanzaro]

We don't have vaapi in the flatpak runtime anymore specifically because of bug #197752, so it's not going to be a duplicate unless he has an old runtime (unlikely).

[Lionir]

(In reply to Michael Catanzaro from comment #4)
> We don't have vaapi in the flatpak runtime anymore specifically because of
> bug #197752, so it's not going to be a duplicate unless he has an old
> runtime (unlikely).

I've updated to the latest again just now on everything so yes, it should be gone as you say and the issue is the same.

Could this be CPU-related if it's not actually being hardware accelerated? I do have an old Q6600 and the process is taking 30-40% CPU usage.

[Philippe Normand]

Can you make a log file and attach it here please?

GST_DEBUG="3,webkit*:6" GST_DEBUG_FILE=gst.log myapp ...

[Philippe Normand]

And also Epiphany disabling the most useful AC mode, is not helping :)

[Lionir]

Created attachment 369965 [details]
GST.log of the bug

[Philippe Normand]

So yeah, webkitvideosink is used instead of the GL sink, which degrades performance.

[Michael Catanzaro]

Need to -- at a minimum -- fix bug #193011 if you want Epiphany to start thinking about allowing AC mode. I'm also very discouraged by the lack of support I received in bug #192522. To allow AC mode, I need to be able to trust that we will respond to AC-related issues in a timely manner. History shows that is not likely.

[Philippe Normand]

Is this still an issue?

BTW, PSA: in 2.38 gstreamer-vaapi decoders will not be used, unless the WEBKIT_GST_ENABLE_LEGACY_VAAPI env var is set to 1. The new stateless va decoders will be used, supposing their rank is high enough, which can be ensured by setting this env var: GST_PLUGIN_FEATURE_RANK=vah264dec:MAX

[Philippe Normand]

Please give this a try with the new decoder has mentioned in previous comment. Feel free to re-open if the issue is still happening.