.WPL File Format – Smart playlists

smartPlaylist

The dynamic part of the playlist. Parent: seq. Children: querySet and optionally filter.

<smartPlaylist version="1.0.0.0">
  <querySet>
    <sourceFilter type="smartFilterObject"
                  id="{4202947A-A563-4B05-A754-A1B4B5989849}"
                  name="Music in my library">
      <fragment name="Genre">
        <argument name="condition">Is</argument>
        <argument name="value">Rock</argument>
      </fragment>
    </sourceFilter>
  </querySet>
  <filter type="smartFilterObject"
          id="{BC5E21B0-504C-46F6-82BF-FB975C911AD6}"
          name="Microsoft Auto Playlist Filter -- Limits auto playlists by count, size or duration">
    <fragment name="Limit Number of Items">
      <argument name="number">25</argument>
    </fragment>
  </filter>
</smartPlaylist>

querySet

Says which items to select from the library, whatever the size of the result. No attributes. Parent: smartPlaylist. Child: sourceFilter.

sourceFilter

A filter object that selects items from one part of the library. Parent: querySet. Child: fragment.

One of Microsoft’s examples uses the name Windows Media Local Music Library Filter with the music GUID.

filter

Limits the result: it removes content the sourceFilter chose, and adds nothing. Parent: smartPlaylist. Child: fragment.

fragment

One condition. Parents: sourceFilter, filter. Child: argument.

Conditions are written as a condition string in parts: “Album Artist Is Joe” has the name Album Artist, the condition Is and the value Joe.

argument

One portion of a condition string. Its text is the value of that portion. Parent: fragment. No children.

Microsoft writes these names in both capitalised and lower-case forms across its examples (Condition and condition).

The conditions it lists are: Equals, Does Not Equal, Contains, Does Not Contain, Is Less Than, Is Greater Than, Is, Is Not, Is Before, Is Later Than, Is More Recent Than, Above, Below, Ascending, Descending, Random, Is At Least and Is No More Than. The fragment page additionally uses Is After, Older Than and More Recent Than.

Condition fragments

A fragment naming a media attribute holds two arguments: a condition and a value.

<fragment name="Album Artist">
  <argument name="Condition">Is</argument>
  <argument name="Value">Joe</argument>
</fragment>

The next table gives every metadata attribute, the conditions it accepts and the values it accepts.

Limits

Fragments that limit the size of the playlist belong in a filter.

<fragment name="Limit Total Size To">
  <argument name="Format">Megabytes</argument>
  <argument name="Number">5</argument>
</fragment>
<fragment name="Limit Total Duration To">
  <argument name="Format">Minutes</argument>
  <argument name="Number">20</argument>
</fragment>
<fragment name="Limit Number of Items">
  <argument name="Number">15</argument>
</fragment>

Playback order

A fragment named Randomize Playback Order holds no arguments and plays the list in random order.

A fragment named Sort By holds a Value argument, which is the attribute to sort on, and a Condition argument, which is Ascending, Descending or Random.

<fragment name="Sort By">
  <argument name="value">Title</argument>
  <argument name="condition">Ascending</argument>
</fragment>

Sorting must use an attribute that applies to the items being sorted. Music cannot be sorted by Actor, for example.