What is "Scan metadata" about ?

What it is:
Rather than looking up and automatically download covers for albums and images of performers "on request", you (or the administrator) can initiate a "scan" for these "metadata", so all images are stored and available locally on the AmpJuke server before being requested.

The automatic download process of album covers and performer images is referred to as "Scan metadata".


How it works:
When "Scan metadata" is started, AmpJuke attempts to find a cover for all albums in the database.
The same applies to all performers in the database.
If no cover or performer picture is found on the local AmpJuke server, an API-request is made to Microsoft's search-engine, Bing, and - if a suitable result is found, the image is stored.

Each album cover/performer image is retrieved using the Microsoft Bing API 2.0 and the best album cover or performer image to be used is determined using a "highscore" algorithm within AmpJuke.


How it's configured:
Configuration of "Scan metadata" is done prior to running it.
There are several related parameter divided into 3 groups, as follows:

General options.
Bing AppId: Is the AppId (sequence of letters/digits) you get when signing up for Bing Appid. You can sign up here (using a - required - Microsoft Live login): http://www.bing.com/developers/createapp.aspx.

You can enter the AppId in the appropriate field, or store/configure the Bing AppId by logging in and click "Configuration..." on the "Welcome" page.

Show details during scan+import: Is similar to the same setting used when doing a "Scan music".
Select the detail level that suits your preference.

Simulate import (don't change/alter anything): Aka. the option for sissies... Use it to simulate a "Scan metadata" operation.
Everything will happen like a normal scan, but nothing will actually be stored.

Album/performer options.
The settings are basically the same - the only difference is if we're dealing with automatic download of album covers or performer images.
The parameters are explained below using "Album options" as example.

Get album images: If checked, album images will be downloaded automatically, stored on the local AmpJuke server, and displayed later.
If this setting is left unchecked, no album images will be auto-downloaded.

Preferred dimensions (width,height): Is an integer describing the ideal size of the album images that should be auto-downloaded.
During testing, I found out that a value around 200 is best.

If no cover image is found, use a blank one: If checked, and if no album cover was found using the Bing API, use a "blank" cover instead.
Doing this will avoid a subsequent request to the API asking for the same cover later.

Delete album images without a reference: If checked, and if a cover is found on the local AmpJuke server that doesn't reference an album in the database, the file will be deleted.


Please note that album covers and performer images fetched automatically are used extensively in various parts of AmpJuke.
For example when users have any of the personal settings "Display small images", "Browse albums by cover" and/or "Browse performers by picture" turned on.

13-08-2010