# AdaptiveTrackSelection.Factory

Artifact: [androidx.media3:media3-exoplayer](https://developer.android.com/jetpack/androidx/releases/media3) [View Source](https://cs.android.com/search?q=file:androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.java+class:androidx.media3.exoplayer.trackselection.AdaptiveTrackSelection.Factory)

*** ** * ** ***


```
public class AdaptiveTrackSelection.Factory implements ExoTrackSelection.Factory
```

<br />

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Factory for `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection` instances.

## Summary

| ### Public constructors |
|---|
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#Factory()()` Creates an adaptive track selection factory with default parameters. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#Factory(int,int,int,float)( int minDurationForQualityIncreaseMs, int maxDurationForQualityDecreaseMs, int minDurationToRetainAfterDiscardMs, float bandwidthFraction )` Creates an adaptive track selection factory. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#Factory(int,int,int,float,float,androidx.media3.common.util.Clock)( int minDurationForQualityIncreaseMs, int maxDurationForQualityDecreaseMs, int minDurationToRetainAfterDiscardMs, float bandwidthFraction, float bufferedFractionToLiveEdgeForQualityIncrease, https://developer.android.com/reference/androidx/media3/common/util/Clock clock )` Creates an adaptive track selection factory. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#Factory(int,int,int,int,int,float)( int minDurationForQualityIncreaseMs, int maxDurationForQualityDecreaseMs, int minDurationToRetainAfterDiscardMs, int maxWidthToDiscard, int maxHeightToDiscard, float bandwidthFraction )` Creates an adaptive track selection factory. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#Factory(int,int,int,int,int,float,float,androidx.media3.common.util.Clock)( int minDurationForQualityIncreaseMs, int maxDurationForQualityDecreaseMs, int minDurationToRetainAfterDiscardMs, int maxWidthToDiscard, int maxHeightToDiscard, float bandwidthFraction, float bufferedFractionToLiveEdgeForQualityIncrease, https://developer.android.com/reference/androidx/media3/common/util/Clock clock )` Creates an adaptive track selection factory. |

| ### Public methods |
|---|---|
| `final ExoTrackSelection[]` | `@https://developer.android.com/reference/androidx/media3/common/util/NullableType https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#createTrackSelections(androidx.media3.exoplayer.trackselection.ExoTrackSelection.Definition[],androidx.media3.exoplayer.upstream.BandwidthMeter,androidx.media3.exoplayer.source.MediaSource.MediaPeriodId,androidx.media3.common.Timeline)( @https://developer.android.com/reference/androidx/media3/common/util/NullableType ExoTrackSelection.Definition[] definitions, https://developer.android.com/reference/androidx/media3/exoplayer/upstream/BandwidthMeter bandwidthMeter, https://developer.android.com/reference/androidx/media3/exoplayer/source/MediaSource.MediaPeriodId mediaPeriodId, https://developer.android.com/reference/androidx/media3/common/Timeline timeline )` Creates track selections for the provided `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/ExoTrackSelection.Definition`. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory` | `@https://checkerframework.org/api/com/google/errorprone/annotations/CanIgnoreReturnValue.html https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#setTrackFormatComparator(java.util.Comparator<androidx.media3.common.Format>)(https://developer.android.com/reference/java/util/Comparator.html<https://developer.android.com/reference/androidx/media3/common/Format> trackFormatComparator)` Sets the comparator used to order formats in adaptive track selections. |

| ### Protected methods |
|---|---|
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection` | `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory#createAdaptiveTrackSelection(androidx.media3.common.TrackGroup,int[],int,androidx.media3.exoplayer.upstream.BandwidthMeter,com.google.common.collect.ImmutableList<androidx.media3.exoplayer.trackselection.AdaptiveTrackSelection.AdaptationCheckpoint>)( https://developer.android.com/reference/androidx/media3/common/TrackGroup group, int[] tracks, int type, https://developer.android.com/reference/androidx/media3/exoplayer/upstream/BandwidthMeter bandwidthMeter, https://guava.dev/releases/snapshot-android/api/docs/com/google/common/collect/ImmutableList.html<https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.AdaptationCheckpoint> adaptationCheckpoints )` Creates a single adaptive selection for the given group, bandwidth meter and tracks. |

## Public constructors

### Factory

```
public Factory()
```

Creates an adaptive track selection factory with default parameters.

### Factory

```
public Factory(
    int minDurationForQualityIncreaseMs,
    int maxDurationForQualityDecreaseMs,
    int minDurationToRetainAfterDiscardMs,
    float bandwidthFraction
)
```

Creates an adaptive track selection factory.

| Parameters |
|---|---|
| `int minDurationForQualityIncreaseMs` | The minimum duration of buffered data required for the selected track to switch to one of higher quality. |
| `int maxDurationForQualityDecreaseMs` | The maximum duration of buffered data required for the selected track to switch to one of lower quality. |
| `int minDurationToRetainAfterDiscardMs` | When switching to a video track of higher quality, the selection may indicate that media already buffered at the lower quality can be discarded to speed up the switch. This is the minimum duration of media that must be retained at the lower quality. It must be at least ` minDurationForQualityIncreaseMs`. |
| `float bandwidthFraction` | The fraction of the available bandwidth that the selection should consider available for use. Setting to a value less than 1 is recommended to account for inaccuracies in the bandwidth estimator. |

### Factory

```
public Factory(
    int minDurationForQualityIncreaseMs,
    int maxDurationForQualityDecreaseMs,
    int minDurationToRetainAfterDiscardMs,
    float bandwidthFraction,
    float bufferedFractionToLiveEdgeForQualityIncrease,
    Clock clock
)
```

Creates an adaptive track selection factory.

| Parameters |
|---|---|
| `int minDurationForQualityIncreaseMs` | The minimum duration of buffered data required for the selected track to switch to one of higher quality. |
| `int maxDurationForQualityDecreaseMs` | The maximum duration of buffered data required for the selected track to switch to one of lower quality. |
| `int minDurationToRetainAfterDiscardMs` | When switching to a video track of higher quality, the selection may indicate that media already buffered at the lower quality can be discarded to speed up the switch. This is the minimum duration of media that must be retained at the lower quality. It must be at least ` minDurationForQualityIncreaseMs`. |
| `float bandwidthFraction` | The fraction of the available bandwidth that the selection should consider available for use. Setting to a value less than 1 is recommended to account for inaccuracies in the bandwidth estimator. |
| `float bufferedFractionToLiveEdgeForQualityIncrease` | For live streaming, the fraction of the duration from current playback position to the live edge that has to be buffered before the selected track can be switched to one of higher quality. This parameter is only applied when the playback position is closer to the live edge than ` minDurationForQualityIncreaseMs`, which would otherwise prevent switching to a higher quality from happening. |
| `https://developer.android.com/reference/androidx/media3/common/util/Clock clock` | A `https://developer.android.com/reference/androidx/media3/common/util/Clock`. |

### Factory

```
public Factory(
    int minDurationForQualityIncreaseMs,
    int maxDurationForQualityDecreaseMs,
    int minDurationToRetainAfterDiscardMs,
    int maxWidthToDiscard,
    int maxHeightToDiscard,
    float bandwidthFraction
)
```

Creates an adaptive track selection factory.

| Parameters |
|---|---|
| `int minDurationForQualityIncreaseMs` | The minimum duration of buffered data required for the selected track to switch to one of higher quality. |
| `int maxDurationForQualityDecreaseMs` | The maximum duration of buffered data required for the selected track to switch to one of lower quality. |
| `int minDurationToRetainAfterDiscardMs` | When switching to a video track of higher quality, the selection may indicate that media already buffered at the lower quality can be discarded to speed up the switch. This is the minimum duration of media that must be retained at the lower quality. It must be at least ` minDurationForQualityIncreaseMs`. |
| `int maxWidthToDiscard` | The maximum video width that the selector may discard from the buffer to speed up switching to a higher quality. |
| `int maxHeightToDiscard` | The maximum video height that the selector may discard from the buffer to speed up switching to a higher quality. |
| `float bandwidthFraction` | The fraction of the available bandwidth that the selection should consider available for use. Setting to a value less than 1 is recommended to account for inaccuracies in the bandwidth estimator. |

### Factory

```
public Factory(
    int minDurationForQualityIncreaseMs,
    int maxDurationForQualityDecreaseMs,
    int minDurationToRetainAfterDiscardMs,
    int maxWidthToDiscard,
    int maxHeightToDiscard,
    float bandwidthFraction,
    float bufferedFractionToLiveEdgeForQualityIncrease,
    Clock clock
)
```

Creates an adaptive track selection factory.

| Parameters |
|---|---|
| `int minDurationForQualityIncreaseMs` | The minimum duration of buffered data required for the selected track to switch to one of higher quality. |
| `int maxDurationForQualityDecreaseMs` | The maximum duration of buffered data required for the selected track to switch to one of lower quality. |
| `int minDurationToRetainAfterDiscardMs` | When switching to a video track of higher quality, the selection may indicate that media already buffered at the lower quality can be discarded to speed up the switch. This is the minimum duration of media that must be retained at the lower quality. It must be at least ` minDurationForQualityIncreaseMs`. |
| `int maxWidthToDiscard` | The maximum video width that the selector may discard from the buffer to speed up switching to a higher quality. |
| `int maxHeightToDiscard` | The maximum video height that the selector may discard from the buffer to speed up switching to a higher quality. |
| `float bandwidthFraction` | The fraction of the available bandwidth that the selection should consider available for use. Setting to a value less than 1 is recommended to account for inaccuracies in the bandwidth estimator. |
| `float bufferedFractionToLiveEdgeForQualityIncrease` | For live streaming, the fraction of the duration from current playback position to the live edge that has to be buffered before the selected track can be switched to one of higher quality. This parameter is only applied when the playback position is closer to the live edge than ` minDurationForQualityIncreaseMs`, which would otherwise prevent switching to a higher quality from happening. |
| `https://developer.android.com/reference/androidx/media3/common/util/Clock clock` | A `https://developer.android.com/reference/androidx/media3/common/util/Clock`. |

## Public methods

### createTrackSelections

```
@NullableType
public final ExoTrackSelection[] createTrackSelections(
    @NullableType ExoTrackSelection.Definition[] definitions,
    BandwidthMeter bandwidthMeter,
    MediaSource.MediaPeriodId mediaPeriodId,
    Timeline timeline
)
```

Creates track selections for the provided `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/ExoTrackSelection.Definition`.

Implementations that create at most one adaptive track selection may use `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/TrackSelectionUtil#createTrackSelectionsForDefinitions(androidx.media3.exoplayer.trackselection.ExoTrackSelection.Definition[],androidx.media3.exoplayer.trackselection.TrackSelectionUtil.AdaptiveTrackSelectionFactory)`.

| Parameters |
|---|---|
| `@https://developer.android.com/reference/androidx/media3/common/util/NullableType ExoTrackSelection.Definition[] definitions` | A `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/ExoTrackSelection.Definition` array. May include null values. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/upstream/BandwidthMeter bandwidthMeter` | A `https://developer.android.com/reference/androidx/media3/exoplayer/upstream/BandwidthMeter` which can be used to select tracks. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/source/MediaSource.MediaPeriodId mediaPeriodId` | The `https://developer.android.com/reference/androidx/media3/exoplayer/source/MediaSource.MediaPeriodId` of the period for which tracks are to be selected. |
| `https://developer.android.com/reference/androidx/media3/common/Timeline timeline` | The `https://developer.android.com/reference/androidx/media3/common/Timeline` holding the period for which tracks are to be selected. |

| Returns |
|---|---|
| `ExoTrackSelection[]` | The created selections. Must have the same length as `definitions` and may include null values. |

### setTrackFormatComparator

```
@CanIgnoreReturnValue
public AdaptiveTrackSelection.Factory setTrackFormatComparator(Comparator<Format> trackFormatComparator)
```

Sets the comparator used to order formats in adaptive track selections. The comparator order controls which formats are considered first during adaptation.

The default is `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/BaseTrackSelection#DEFAULT_FORMAT_COMPARATOR()`, which decides the priority based on the bitrate.

| Parameters |
|---|---|
| `https://developer.android.com/reference/java/util/Comparator.html<https://developer.android.com/reference/androidx/media3/common/Format> trackFormatComparator` | Comparator used to order selected formats. |

| Returns |
|---|---|
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.Factory` | This factory, for convenience. |

## Protected methods

### createAdaptiveTrackSelection

```
protected AdaptiveTrackSelection createAdaptiveTrackSelection(
    TrackGroup group,
    int[] tracks,
    int type,
    BandwidthMeter bandwidthMeter,
    ImmutableList<AdaptiveTrackSelection.AdaptationCheckpoint> adaptationCheckpoints
)
```

Creates a single adaptive selection for the given group, bandwidth meter and tracks.

| Parameters |
|---|---|
| `https://developer.android.com/reference/androidx/media3/common/TrackGroup group` | The `https://developer.android.com/reference/androidx/media3/common/TrackGroup`. |
| `int[] tracks` | The indices of the selected tracks in the track group. |
| `int type` | The type that will be returned from `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/TrackSelection#getType()`. |
| `https://developer.android.com/reference/androidx/media3/exoplayer/upstream/BandwidthMeter bandwidthMeter` | A `https://developer.android.com/reference/androidx/media3/exoplayer/upstream/BandwidthMeter` which can be used to select tracks. |
| `https://guava.dev/releases/snapshot-android/api/docs/com/google/common/collect/ImmutableList.html<https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.AdaptationCheckpoint> adaptationCheckpoints` | The `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection.AdaptationCheckpoint` that can be used to calculate available bandwidth for this selection. |

| Returns |
|---|---|
| `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection` | An `https://developer.android.com/reference/androidx/media3/exoplayer/trackselection/AdaptiveTrackSelection` for the specified tracks. |