44 lines
1.7 KiB
Markdown
44 lines
1.7 KiB
Markdown
---
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title: Track selection
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---
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Track selection determines which of the available media tracks are played by the
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player. Track selection is the responsibility of a `TrackSelector`, an instance
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of which can be provided whenever an `ExoPlayer` is built.
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~~~
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DefaultTrackSelector trackSelector = new DefaultTrackSelector(context);
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ExoPlayer player =
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new ExoPlayer.Builder(context)
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.setTrackSelector(trackSelector)
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.build();
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~~~
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{: .language-java}
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`DefaultTrackSelector` is a flexible `TrackSelector` suitable for most use
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cases. When using a `DefaultTrackSelector`, it's possible to control which
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tracks it selects by modifying its `Parameters`. This can be done before or
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during playback. For example the following code tells the selector to restrict
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video track selections to SD, and to select a German audio track if there is
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one:
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~~~
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trackSelector.setParameters(
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trackSelector
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.buildUponParameters()
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.setMaxVideoSizeSd()
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.setPreferredAudioLanguage("deu"));
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~~~
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{: .language-java}
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This is an example of constraint based track selection, in which constraints are
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specified without knowledge of the tracks that are actually available. Many
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different types of constraint can be specified using `Parameters`. `Parameters`
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can also be used to select specific tracks from those that are available. See
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the [`DefaultTrackSelector`][], [`Parameters`][] and [`ParametersBuilder`][]
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documentation for more details.
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[`Parameters`]: {{ site.exo_sdk }}/trackselection/DefaultTrackSelector.Parameters.html
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[`ParametersBuilder`]: {{ site.exo_sdk }}/trackselection/DefaultTrackSelector.ParametersBuilder.html
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[`DefaultTrackSelector`]: {{ site.exo_sdk }}/trackselection/DefaultTrackSelector.html
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