Totem pauses and stutters during video playback even when CPU usage is low

The issue seems to persist regardless of which shell / desktop environment I use.

Workaround: Use 'gst-play-1.0' instead of 'totem'. It avoids the rendering glitches and has much lower CPU usage.

Status changed to 'Confirmed' because the bug affects multiple users.

This happens in full-screen mode for a window with client-side decorations using OpenGL. Another workaround is to use GNOME MPV without CSD or without OpenGL: https://bugzilla.gnome.org/show_bug.cgi?id=778766#c2

Re comment #2: With GNOME MPV, it doesn't happen on KDE Plasma for me even if both CSD and OpenGL are enabled.

I have this bug also in 3.18.1-1ubuntu4 in Xenial.

First experimental fix: https://git.launchpad.net/~vanvugt/ubuntu/+source/totem/commit/?id=02076c41f892e214d946457f944c6da3011307f1

Although I suspect we are linked to the wrong upstream bug so I won't mention it there.

This bug was fixed in the package totem - 3.25.90.1-0ubuntu2

---------------
totem (3.25.90.1-0ubuntu2) artful; urgency=medium

  * debian/patches/fix-bvw_update_tags-performance.patch:
    - bacon-video-widget.c: Reduce CPU usage and visible stuttering
      (LP: #1698282 and LP: #1698270).

 -- Daniel van Vugt <email address hidden> Mon, 21 Aug 2017 16:10:19 +0800

Does the fix apply in Xenial?

I don't see why not. Let's just wait until upstream has accepted the fix and I'll be more confident about applying the same to xenial.

OK, I have now encountered a few reasons for totem stuttering...

1. Excessive/faulty tags parsing (only seen in Big Buck Bunny videos?). Upstream has fixed the root cause:
  https://bugzilla.gnome.org/show_bug.cgi?id=786561
but we have also patched totem itself in Ubuntu to avoid the issue:
  https://launchpad.net/ubuntu/+source/totem/3.25.90.1-0ubuntu2

2. Excessive CPU usage of clutter-gtk particularly under Wayland -> bug 1698282

3. Insufficient buffering/parallelism in GStreamer. BBB tends to have a big stutter when the video bitrate spikes over 11Mbps. I'm not aware of any other reports of the problem though.

4. My experimental fixes for the high CPU usage of clutter-gtk in bug 1698282 reintroduces an old smoothness problem that only occurs under the default setting of CLUTTER_BACKEND=gdk (but not with CLUTTER_BACKEND=wayland or x11). I'll try to fix that somewhere between bug 1698282 and this one.

Smoothness issue 4 above I have tracked down to this clutter-gtk code:

-------------------------
static void
clutter_master_clock_gdk_update (GdkFrameClock *frame_clock,
                                 ClutterMasterClockGdk *master_clock)
{
  GList *stages, *l;

  _clutter_threads_acquire_lock ();

  /* Get the time to use for this frame */
  master_clock->cur_tick = gdk_frame_clock_get_frame_time (frame_clock);
-------------------------

The problem is not in clutter-gtk though. It's a general lack of precision in the GdkFrameClock logic. Despite my monitor running at around 60Hz, the GDK frame_time interval is erratic and mostly varies between 17 and 18 milliseconds. So the root cause is just poor timing logic in GDK.

I have an experimental fix already for gdk so probably don't need to propose changes to clutter-gtk any more.

Sorry, in comment #12 I mean "clutter" (in its gdk subdir), not "clutter-gtk".

Now looking into issue 3 from comment #11 again.

Every time the big stutter occurs it coincides with my PC's harddisk LED. Also, the same place in the video seems to be the first time the stream bitrate peaks over 10Mbps. So there seems to be some kind of cause and effect at this particularly detailed part of the video.

The stutter only occurs in totem though. No other gstreamer tool seems to exhibit the problem when playing the same video. Even using "gst-launch-1.0 playbin uri=file:///...." seems to not have the problem. So all evidence at the moment is suggesting the biggest stutter is somehow specific to the totem binary, and not gstreamer in general.

I've also just noticed a 5th source of stuttering; that is using clutterautovideosink in an X11 session. Will ignore that problem for now...

The part relevant to clutter-gtk is now released with bug 1698282. Although that doesn't contribute much to the visible stuttering for me, it could in theory for some systems.

Some simple system monitoring:
  cat /proc/`pidof totem`/io
reveals totem's biggest skip coincides with a disk _write_ of some sort.

That should be easy to track down but I'm just about out of time this week.

Here tis: https://bugzilla.gnome.org/show_bug.cgi?id=788926

A fix for bionic.

The attachment "totem-pl-parser_3.26.0-1ubuntu2.debdiff" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

This bug was fixed in the package totem-pl-parser - 3.26.0-1ubuntu2

---------------
totem-pl-parser (3.26.0-1ubuntu2) bionic; urgency=medium

  * totem-pl-parser-xspf.c: Avoid large stutters in video playback due to
    heavy (and unnecessary) disk syncing (LP: #1698270)

 -- Daniel van Vugt <email address hidden> Tue, 31 Oct 2017 17:07:46 +0800

I suspect there's another issue specific to Xorg that's causing stutter there, and not yet resolved. Although you won't see it till bug 1747744 is fixed :)

This bug was fixed in the package gtk+3.0 - 3.22.28-1ubuntu1

---------------
gtk+3.0 (3.22.28-1ubuntu1) bionic; urgency=medium

  * Merge with Debian. Remaining changes:
    + Install a settings.ini file to set our themes
    + Enable Mir backend
    + Update debian/libgtk-3-0.symbols
    + debian/control.in:
      - Build-depend on adwaita-icon-theme-full for icon name check test
    + debian/rules: Mark additional known test failures:
      - box-shadow-changes-modify-clip.ui
      - label-text-shadow-changes-modify-clip.ui
    + Ubuntu-specific patches:
      - 073_treeview_almost_fixed.patch
      - bzg_gtkcellrenderer_grabbing_modifier.patch
      - ubuntu_gtk_custom_menu_items.patch
      - print-dialog-show-options-of-remote-dnssd-printers.patch
      - uimanager-guard-against-nested-node-updates.patch
      - x-canonical-accel.patch
      - message-dialog-restore-traditional-look-on-unity.patch
      - 0001-gtk-reftest-Force-icon-theme-to-Adwaita.patch
      - restore_filechooser_typeaheadfind.patch
      - 0001-calendar-always-emit-day-selected-once.patch
      - 0001-gtkwindow-set-transparent-background-color.patch
      - ubuntu_fileselector_behaviour.patch
      - unity-border-radius.patch
      - unity-headerbar-maximized-mode.patch
      - gtksocket-unscale-before-sending-configurenotify.patch
      - no_content_hub.patch

gtk+3.0 (3.22.28-1) unstable; urgency=medium

  * New upstream release (LP: #1698270) (LP: #1714518)
  * Update Vcs fields for conversion to git
  * Add debian/gbp.conf
  * Bump Standards-Version to 4.1.3
  * Update Vcs fields for migration to https://salsa.debian.org/
  * Drop git_text-view-support-emoji-chooser.patch: Applied in new release

 -- Jeremy Bicha <email address hidden> Thu, 15 Feb 2018 10:15:34 -0500

This issue is still not fixed for Xorg. Not sure what package to target though...

I'm really not sure what changed to make 4K video so stuttery now in totem. The CPU is fairly low and goes through the roof only if I uninstall VAAPI. So VAAPI is working, and it works smoothly in mpv too.

Since I could last play 4K smoothly in totem there has been:
  * A mesa update 17.2 -> 18.0
  * A Xorg update 1.19.5 -> 1.19.6
  * Kernel updates
  * Hardware changes (I changed from a Haswell to Kaby Lake desktop)

I am also having stutter videos in Totem in Bionic. I am using old hardware from 2011. I am ready to give more debugging info when needed.

Progress! I think...
https://bugzilla.gnome.org/show_bug.cgi?id=795195

Maybe this is a better upstream bug:
https://bugzilla.gnome.org/show_bug.cgi?id=795325

Status changed to 'Confirmed' because the bug affects multiple users.

After gnome-twitch flatpak update (and some other "core" flatpak packages update) now I have same lags in gnome-twitch.
The bug comes from gnome. Just like most of bugs in Ubuntu and other distros.

I encounter probably the same bug in 18.04 and in 18.10.

I've opened a separate bug report because it might not be the exact issue:
https://bugs.launchpad.net/ubuntu/+source/gstreamer1.0/+bug/1818382