Merge lp:~vanvugt/totem/fix-1698282 into lp:~ubuntu-desktop/totem/ubuntu

[Daniel van Vugt]

Reduce CPU usage and stuttery playback

For some reason bvw_update_tags gets called constantly even when none are
changing. And each call seems to trigger a clutter scene graph update.
So totem was spending 20-25% of its time in g_signal_emit and below updating the clutter scene graph and GTK widgets. With this fix, totem's
CPU usage drops by about a fifth and playback is much smoother (although
still not perfect).

This fixes the totem portion of LP: #1698282 and LP: #1698270, although
both bugs also need work done in clutter before they can be declared fully
resolved.

[Sebastien Bacher (seb128)]

Thanks Daniel

review: Approve

=== modified file 'debian/changelog'
--- debian/changelog	2017-08-13 23:37:49 +0000
+++ debian/changelog	2017-08-21 08:19:49 +0000
@@ -1,3 +1,10 @@
+totem (3.25.90.1-0ubuntu2) UNRELEASED; urgency=medium
+
+  * bacon-video-widget.c: Reduce CPU usage and visible stuttering
+    (LP: #1698282 and LP: #1698270).
+
+ -- Daniel van Vugt <[e-mail]>  Mon, 21 Aug 2017 16:10:19 +0800
+
 totem (3.25.90.1-0ubuntu1) artful; urgency=medium
 
   * New upstream release
 
=== added file 'debian/patches/fix-bvw_update_tags-performance.patch'
--- debian/patches/fix-bvw_update_tags-performance.patch	1970-01-01 00:00:00 +0000
+++ debian/patches/fix-bvw_update_tags-performance.patch	2017-08-21 08:19:49 +0000
@@ -0,0 +1,41 @@
+Description: Reduce CPU usage and stuttery playback
+ For some reason bvw_update_tags gets called constantly even when none are
+ changing. And each call seems to trigger a clutter scene graph update.
+ So totem was spending 20-25% of its time in g_signal_emit and below updating
+ the clutter scene graph and GTK widgets. With this fix, totem's CPU usage
+ drops by about a fifth and playback is much smoother (although still not
+ perfect).
+ .
+ This fixes the totem portion of LP: #1698282 and LP: #1698270, although
+ both bugs also need work done in clutter before they can be declared fully
+ resolved.
+Author: Daniel van Vugt <[e-mail]>
+Bug-Ubuntu: https://bugs.launchpad.net/bugs/1698282
+Forwarded: yes
+Last-Update: 2017-08-21
+
+diff --git a/src/backend/bacon-video-widget.c b/src/backend/bacon-video-widget.c
+index a8a5dbae..5808bd92 100644
+--- a/src/backend/bacon-video-widget.c
++++ b/src/backend/bacon-video-widget.c
+@@ -2063,12 +2063,15 @@ bvw_update_tags (BaconVideoWidget * bvw, GstTagList *tag_list, const gchar *type
+   GstTagList **cache = NULL;
+   GstTagList *result;
+ 
+-  GST_DEBUG ("Tags: %" GST_PTR_FORMAT, tag_list);
+-
+   /* all tags (replace previous tags, title/artist/etc. might change
+    * in the middle of a stream, e.g. with radio streams) */
+   result = gst_tag_list_merge (bvw->priv->tagcache, tag_list,
+                                    GST_TAG_MERGE_REPLACE);
++  if (gst_tag_list_is_equal (result, bvw->priv->tagcache)) {
++    gst_tag_list_unref (result);
++    return;
++  }
++  GST_DEBUG ("Tags: %" GST_PTR_FORMAT, tag_list);
+   if (bvw->priv->tagcache)
+     gst_tag_list_unref (bvw->priv->tagcache);
+   bvw->priv->tagcache = result;
+-- 
+2.11.0
+
 
=== modified file 'debian/patches/series'
--- debian/patches/series	2017-08-13 23:27:59 +0000
+++ debian/patches/series	2017-08-21 08:19:49 +0000
@@ -7,3 +7,4 @@
 0003-totem-movie-properties-Respect-gtk-dialogs-use-heade.patch
 ubuntu-make-zeitgeist-plugin-builtin.patch
 fix-lirc-detection.patch
+fix-bvw_update_tags-performance.patch