In version 3.8 of our Android SDK, we have introduced some changes to our API. This article details the main changes and how to handle them.
1. Buffer Levels
Before 3.7
Buffer levels where randomly set at player instantiation between a minimum and maximum target.
We had 2 ways to do so depending on the version of ExoPlayer.
Before ExoPlayer 2.8.0
It was required to change the instantiation of the default Exoplayer class DefaultLoadControl with this one:
DefaultLoadControl(
DefaultAllocator(true, C.DEFAULT_BUFFER_SEGMENT_SIZE),
DefaultLoadControl.DEFAULT_MIN_BUFFER_MS,
DnaClient.generateBufferTarget(
DefaultLoadControl.DEFAULT_MIN_BUFFER_MS,
DefaultLoadControl.DEFAULT_MAX_BUFFER_MS,
latencyInSec,
TimeUnit.SECONDS),
DefaultLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_AFTER_REBUFFER_MS,
DefaultLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_MS,
DefaultLoadControl.DEFAULT_TARGET_BUFFER_BYTES,
DefaultLoadControl.DEFAULT_PRIORITIZE_TIME_OVER_SIZE_THRESHOLDS)
From ExoPlayer 2.8.0
It was required to change the instantiation of the default Exoplayer builder DefaultLoadControl with this one:
DefaultLoadControl.Builder()
.setAllocator(DefaultAllocator(true, C.DEFAULT_BUFFER_SEGMENT_SIZE))
.setBufferDurationsMs(DefaultLoadControl.DEFAULT_MIN_BUFFER_MS,
DnaClient.generateBufferTarget(
DefaultLoadControl.DEFAULT_MIN_BUFFER_MS,
DefaultLoadControl.DEFAULT_MAX_BUFFER_MS,
latencyInSec,
TimeUnit.SECONDS),
DefaultLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_AFTER_REBUFFER_MS,
DefaultLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_MS)
.createDefaultLoadControl()
From 3.8
We now dynamically set the buffer targets to optimize DNA efficiency. It works for all ExoPlayer version.
In order to do so, we need to replace the DefaultLoadControl with a custom class.
The only changes made is the addition of this setter and getter
fun setMaxBufferTarget(target: Double) {
if (target.toLong() <= this.minBufferUs) return
this.maxBufferUs = TimeUnit.SECONDS.toMicros(target.toLong())
this.maxBufferMs = TimeUnit.SECONDS.toMillis(target.toLong()).toInt()
}
fun getMaxBufferTarget(): Double {
return TimeUnit.MICROSECONDS.toSeconds(this.maxBufferUs).toDouble()
}To make things easier we recommend to directly get the custom ExoLoadControl class from here.
Then, it is required to instantiation it in the PlayerActivity like so:
when {
this.loadControl != null -> return this.loadControl!!
latency <= 0 -> return ExoLoadControl.Builder().createDefaultLoadControl()
else -> {
val exoLoadControl = ExoLoadControl.Builder()
.setAllocator(DefaultAllocator(true, C.DEFAULT_BUFFER_SEGMENT_SIZE))
.setBufferDurationsMs(ExoLoadControl.DEFAULT_MIN_BUFFER_MS,
DnaClient.generateBufferTarget(
ExoLoadControl.DEFAULT_MIN_BUFFER_MS,
ExoLoadControl.DEFAULT_MAX_BUFFER_MS,
latency,
TimeUnit.SECONDS),
ExoLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_MS,
ExoLoadControl.DEFAULT_BUFFER_FOR_PLAYBACK_AFTER_REBUFFER_MS)
.createDefaultLoadControl()
this.loadControl = exoLoadControl
return exoLoadControl
}
}
2. Player Interactor
Before 3.7
The PlayerInteractor is how the SDK gets player specifics. The SDK needed the following information to work optimally:
- Looper
looper must return the looper used to create the player. It is mandatory from ExoPlayer 2.9.0 and above.
The recommended way is to use theapplicationLooperfunction (ExoPlayer doc) - Loaded TimeRanges
loadedTimeRanges must return a list of TimeRange (in milliseconds).
Each TimeRange represents a continuous interval of content present in the buffer. It is mandatory to return at least the TimeRange going from the playback time to the end of the buffered interval containing the playback time. - Current playback time
playbackTime must return the current time of the player in milliseconds.
import com.google.android.exoplayer2.SimpleExoPlayer
import com.google.android.exoplayer2.Timeline
import io.streamroot.dna.core.PlayerInteractor
import io.streamroot.dna.core.TimeRange
class ExoPlayerInteractor(
private val player: SimpleExoPlayer
) : PlayerInteractor {
//From ExoPlayer 2.9.0 and above
override fun looper(): Looper? = player.applicationLooper
override fun loadedTimeRanges(): MutableList<TimeRange> {
val shift = getCurrentWindowShift()
val rangeDurationMs = player.bufferedPosition - player.currentPosition
val timeRanges: MutableList<TimeRange> = ArrayList()
if (rangeDurationMs > 0) {
timeRanges.add(
TimeRange(
shift + player.currentPosition,
rangeDurationMs
)
)
}
return timeRanges
}
override fun playbackTime(): Long {
return getCurrentWindowShift() + player.currentPosition
}
private fun getCurrentWindowShift(): Long {
val current = player.currentTimeline
val timelineWindow = Timeline.Window()
var shift: Long = 0
if (player.currentWindowIndex < current?.windowCount!!) {
player.currentTimeline?.getWindow(player.currentWindowIndex, timelineWindow)
shift = timelineWindow.positionInFirstPeriodMs
}
return shift
}
}
From 3.8
The SDK now needs the following information to work optimally:
- Looper
looper must return the looper used to create the player. It is mandatory from ExoPlayer 2.9.0 and above.
The recommended way is to use theapplicationLooperfunction (ExoPlayer doc) - Loaded TimeRanges
loadedTimeRanges must return a list of TimeRange (in milliseconds).
Each TimeRange represents a continuous interval of content present in the buffer. It is mandatory to return at least the TimeRange going from the playback time to the end of the buffered interval containing the playback time. - Current playback time
playbackTime must return the current time of the player in milliseconds. - Buffer target
bufferTarget must return the target the player will try to buffer.
setBufferTarget allows us to dynamically change the buffer target of the player to optimize DNA performances.
import com.google.android.exoplayer2.SimpleExoPlayer
import com.google.android.exoplayer2.Timeline
import io.streamroot.dna.core.PlayerInteractor
import io.streamroot.dna.app.demo.player.exoplayer.ExoLoadControl
import io.streamroot.dna.core.TimeRange
import com.google.android.exoplayer2.LoadControl
class ExoPlayerInteractor(
private val player: SimpleExoPlayer,
val loadControl: LoadControl
) : PlayerInteractor {
//From ExoPlayer 2.9.0 and above
override fun looper(): Looper? = player.applicationLooper
override fun loadedTimeRanges(): MutableList<TimeRange> {
val shift = getCurrentWindowShift()
val rangeDurationMs = player.bufferedPosition - player.currentPosition
val timeRanges: MutableList<TimeRange> = ArrayList()
if (rangeDurationMs > 0) {
timeRanges.add(
TimeRange(
shift + player.currentPosition,
rangeDurationMs
)
)
}
return timeRanges
}
override fun playbackTime(): Long {
return getCurrentWindowShift() + player.currentPosition
}
private fun getCurrentWindowShift(): Long {
val current = player.currentTimeline
val timelineWindow = Timeline.Window()
var shift: Long = 0
if (player.currentWindowIndex < current?.windowCount!!) {
player.currentTimeline?.getWindow(player.currentWindowIndex, timelineWindow)
shift = timelineWindow.positionInFirstPeriodMs
}
return shift
}
override fun bufferTarget(): Double {
return if (loadControl is ExoLoadControl) {
this.loadControl.getMaxBufferTarget()
} else 0.0
}
override fun setBufferTarget(target: Double) {
if (loadControl is ExoLoadControl) {
loadControl.setMaxBufferTarget(target)
}
}
}
3. DNA Client instance creation
Before 3.7
DnaClient dnaClient = DnaClient.newBuilder()
.context(<Context>)
.playerInteractor(<PlayerInteractor>)
.latency(<Integer>)
.start(<Uri>);
From 3.8
DnaClient dnaClient = DnaClient.newBuilder()
.context(<Context>)
.playerInteractor(ExoPlayerInteractor(newPlayer, loadControl()))
.latency(<Integer>)
.start(<Uri>);