Bug 182653 – [GStreamer] Media controls slider does not work in webm video

• Component: Media
• Status: RESOLVED WORKSFORME

[Michael Catanzaro]

Media controls slider is broken in 2.19.90.

On https://ftp.fau.de/fosdem/2018/AW1.121/debugging_tools_memcheck.webm, you can drag the slider around and the displayed time changes, but your position in the video does not actually change.

[Michael Catanzaro]

See also: bug #182654

[Philippe Normand]

Works fine here with MiniBrowser from ToT.

Please provide a log: GST_DEBUG="3,webkit*:6"

[Charlie Turner]

This is a bit non-deterministic (see linked bug for more potential clues). Sometimes the seeking works OK, but the buffered display is often wrong. Sometimes I get the same issue as Michael, seek requests not doing anything.

I see lots of warnings like this,

0:00:01.092334649 91444 0x7fc11812b4f0 WARN      matroskareadcommon matroska-read-common.c:506:gst_matroska_read_common_parse_skip:<matroskademux0:sink> Unknown CueTrackPositions subelement 0xf0 - ignoring

And then a smattering of other odd bits,
0:00:01.092846580 91444 0x7fc11812b680 FIXME           videodecoder gstvideodecoder.c:928:gst_video_decoder_drain_out:<vp9dec0> Sub-class should implement drain()
...
0:00:01.158439637 91444 0x7fc0d804a450 WARN         audio-resampler audio-resampler.c:274:convert_taps_gint16_c: can't find exact taps
...
0:00:01.175487069 91444 0x7fc0d8049ca0 WARN                glwindow gstglwindow.c:285:gst_gl_window_new: Could not create window. user specified (null), creating dummy window
...
0:00:10.259229779 91444 0x7fc11812b680 FIXME           videodecoder gstvideodecoder.c:928:gst_video_decoder_drain_out:<vp9dec0> Sub-class should implement drain()
...
0:00:10.396547092 91444 0x7fc11812b680 WARN                  vpxdec gstvpxdec.c:574:gst_vpx_dec_open_codec:<vp9dec0> No keyframe, skipping

I'm running with WPE & dyz however.

[Michael Catanzaro]

Created attachment 333561 [details]
Gst debug log

[Philippe Normand]

Possibly fixed by bug #195631 ? Please check :)

[Michael Catanzaro]

There are no media controls in Ephy Tech Preview right now, bug #194367.

[Michael Catanzaro]

(In reply to Michael Catanzaro from comment #6)
> There are no media controls in Ephy Tech Preview right now, bug #194367.

It works fine in Fedora 30's Epiphany with WebKitGTK 2.23.91.

[Philippe Normand]

(In reply to Michael Catanzaro from comment #0)
> Media controls slider is broken in 2.19.90.
> 
> On https://ftp.fau.de/fosdem/2018/AW1.121/debugging_tools_memcheck.webm, you
> can drag the slider around and the displayed time changes, but your position
> in the video does not actually change.

Works as expected with MiniBrowser from trunk. Closing.

[Michael Catanzaro]

Unfortunately this is still broken in Ephy TP.

[Philippe Normand]

(In reply to Michael Catanzaro from comment #9)
> Unfortunately this is still broken in Ephy TP.

Ephy TP is not a webkit.org product. Unless proven otherwise, this is not a WebKit bug because the issue can't be reproduced with the MiniBrowser.

Please reopen only if/when it is clear this is a WebKit issue.

[Michael Catanzaro]

(In reply to Philippe Normand from comment #10)
> Ephy TP is not a webkit.org product.

https://webkit.org/downloads/ ?

The bug probably doesn't occur in the WebKit JHBuild environment because the JHBuild environment is crap and contains a bunch of old dependencies. If the fact that this bug exists in both Tech Preview *and* Fedora 30 isn't enough for you to consider it a valid bug, well I don't know, but I do know that WebKitGTK isn't a suitable dependency for Epiphany if it can't render media controls.

[Philippe Normand]

(In reply to Michael Catanzaro from comment #7)
> (In reply to Michael Catanzaro from comment #6)
> > There are no media controls in Ephy Tech Preview right now, bug #194367.
> 
> It works fine in Fedora 30's Epiphany with WebKitGTK 2.23.91.

"It works fine" means you see media controls?

If this issue really happens in Fedora's Epiphany with a recent version of WebKitGTK, please reopen :)

[Michael Catanzaro]

Oh, there are currently no media controls in Fedora 30. It broke in late March or early April (from bug #194367). That's a long time to go without media controls.

But really, Tech Preview is our only built product we have and our only plausible source of ground truth, to the extent that one should be required for reporting a bug. It should be enough. Using build-webkit's JHBuild, our results will be incomparable due to host dependencies, and moreover uninteresting due to very old dependencies in the JHBuild.

Regardless: we've gotten confused about the Bugzilla bugs. Bug #194367 is for missing media controls. This bug we're arguing in is for the slider not working when the media controls are present. It's impossible to evaluate whether this one is fixed due to bug #194367. So if you see a media controls slider and it works, I guess closing this might be appropriate.