# Configuration

The goal of this tutorial is to introduce Shaka's configuration system and the
concepts on which it is built.  More detail can be found in the API docs.

Shaka's Player object has a hierarchical configuration.  The overall player
config contains sub-configs for various parts of the system, such as manifests,
streaming, and DRM.

To see the current config, you can use `player.getConfiguration()`.  If you run
this without setting anything first, you get the default configuration.

Player also has a `configure()` method that takes a plain, anonymous object as
an argument.  Any fields you leave out of the config object will retain their
existing values, and any fields you explicitly set as `undefined` will be
reverted to their default value.

You can use the code from {@tutorial basic-usage} and try these examples in
the JS console:

```js
player.getConfiguration();

=> Object
     abr: Object
       bandwidthDowngradeTarget: 0.95
       bandwidthUpgradeTarget: 0.85
       defaultBandwidthEstimate: 500000
       enabled: true
       restrictions: Object
       switchInterval: 8
     abrFactory: Function
     drm: Object
       advanced: Object
       clearKeys: Object
       retryParameters: Object
         backoffFactor: 2
         baseDelay: 1000
         fuzzFactor: 0.5
         maxAttempts: 2
         timeout: 0
       servers: Object
     manifest: Object
       dash: Object
       hls: Object
       retryParameters: Object
     playRangeEnd: Infinity
     playRangeStart: 0
     preferredAudioLanguage: ""
     preferredTextLanguage: ""
     restrictions: Object
     streaming: Object
       bufferBehind: 30
       bufferingGoal: 10
       failureCallback: Function
       ignoreTextStreamFailures: false
       jumpLargeGaps: false
       rebufferingGoal: 2
       retryParameters: Object
       smallGapLimit: 0.5
       startAtSegmentBoundary: false


// set audio language preference to Canadian French:
player.configure({ preferredAudioLanguage: 'fr-CA' });
// NOTE: language preferences affect the next call to load()

// set text language preference to Greek and buffering goal to 2 minutes:
player.configure({
  preferredTextLanguage: 'el',
  streaming: {
    bufferingGoal: 120
  }
});

// check audio language preference, which is still Canadian French:
player.getConfiguration().preferredAudioLanguage

// check buffering goal, which is 2 minutes:
player.getConfiguration().streaming.bufferingGoal

// check rebuffering goal, which is still the default of 2 seconds:
player.getConfiguration().streaming.rebufferingGoal

// set the rebuffering goal to 15 seconds and revert buffering goal to default:
player.configure({
  streaming: {
    bufferingGoal: undefined,
    rebufferingGoal: 15
  }
});
```

Some of these fields have immediate effects (such as networking settings and
buffering settings) while some will not have any effect until the next call to
`load()` (such as DRM settings, manifest settings, and language settings).


#### Detailed API Docs

For more detail on individual configuration options, please see the API docs for
{@link shakaExtern.PlayerConfiguration} and {@link shaka.Player#configure}.


#### Continue the Tutorials

Next, check out {@tutorial network-and-buffering-config}.