[music] User Interface is jerky/jumpy on Vivid

[Victor Thompson]

On the vivid channel, the music app performs poorly on the mako device. Scrolling in any view with cover art is incredibly jerky/jumpy. After the first flick to scroll down, the app will stop and freeze momentarily.

To reproduce on a mako device running vivid:
1. Navigate to the Songs or Albums tab. (Songs tab if the device does not have very many albums on it).
2. Flick upward to scroll down. Do this a few times.

Expected results: The result of Step #2 should be minimal lag/freezing of the app

Actual results: The app periodically freezes while scrolling.

[Victor Thompson (vthompson)]

I've turned on the performance relay and replaced the cover art in the views with blank art [1] [2]. With the overlay on the app typically renders frames in far over 16ms (see app_with_overlay.png). When the app is modified to not use the thumbnailer the app does not appear to freeze and seems to render frames within 16ms most of the time--or at least more often (see app_modified_with_overlay).

1 - lp:~vthompson/music-app/for-bug-1428944
2 - https://code.launchpad.net/~vthompson/music-app/for-bug-1428944

[Victor Thompson (vthompson)]

This is the app with the overlay added.

[Victor Thompson (vthompson)]

This is the app with the overlay added and modified to not use the thumbnailer service to display thumbnails.

[Victor Thompson (vthompson)]

It should be noted that the cover art images are being loaded asynchronously.

[Albert Astals Cid (aacid)]

Pretty sure this is a dupe of #1410260

Can you try the branch attached there to see if it solves your problem?

[Victor Thompson (vthompson)]

Yes it does. I'll make this as a dupe. Thank you so very much for pointing this out!