Blurry album art

[Michael Poker]

If I set the album art for a mp3 song and the picture has a very high resolution, it looks very sharp in vlc or other media players on my computer, but when I copy it to my mx4 and open it with the music app the album art looks a bit blurry.
A 1000*1000 px album art does not look like 1000*1000 on my meizu mx4, which has 1080p.
I hope, I described well enough what I expected and what I got.
Thank you for this great app 😃

[Victor Thompson (vthompson)]

Hi Michael, thanks for taking the time to file this bug and for helping to make Ubuntu better. I've added the Thumbnailer project to the bug report, as that is the application responsible for generating the thumbnail art.

[Michi Henning (michihenning)]

Hi Michael,

the thumbnailer keeps images up to 1920x1920 at their original size. Thumbnails are delivered to the application as JPG, so there can be some quality loss during format conversion, but it should almost always be unnoticeable or very minor. If a source image is in a format with an alpha channel (GIF, PNG, etc.) or is in SVG, the thumbnail is delivered to the application as PNG, to preserve transparency.

If you are seeing prominent scaling artefacts, it could be that the application has have asked for a thumbnail at a small size and then upscaled it for display. Alternatively, there might be a problem in the thumbnailer with image conversion.

To be sure, could you please attach the original song that exhibits this problem, together with an exact description of how you navigated to the blurry image in the music app? With that, we can have a look at why things are not looking right.

[James Henstridge (jamesh)]

Victor: are you sure this is a thumbnailer problem?

When playing around with music-app, the one place where large cover art is displayed is in the "now playing" screen. Looking at the source code, this corresponds to NowPlayingFullView.qml:

http://bazaar.launchpad.net/~music-app-dev/music-app/trunk/view/head:/app/components/NowPlayingFullView.qml

That code shows an intentionally blurred background image, with a CoverGrid over the top showing the album art. Looking at CoverGrid.qml, you're requesting thumbnails of at most 512x512:

http://bazaar.launchpad.net/~music-app-dev/music-app/trunk/view/head:/app/components/CoverGrid.qml#L68

On devices with high resolution screens like the Meizu MX4, this looks like it is going to be blowing up a down scaled version of the artwork.