The control mechanism calculates the adjusted speed as {@code 1.0 + proportionalControlFactor * x (currentLiveOffsetSec - targetLiveOffsetSec)}. Unit speed (1.0f) is used, if the {@code - * currentLiveOffsetSec} is marginally close to {@code targetLiveOffsetSec}, i.e. {@code - * |currentLiveOffsetSec - targetLiveOffsetSec| <= MAXIMUM_LIVE_OFFSET_ERROR_US_FOR_UNIT_SPEED}. + * currentLiveOffsetSec} is closer to {@code targetLiveOffsetSec} than the value set with {@link + * Builder#setMaxLiveOffsetErrorMsForUnitSpeed(long)}. * *
The resulting speed is clamped to a minimum and maximum speed defined by the media, the * fallback values set with {@link Builder#setFallbackMinPlaybackSpeed(float)} and {@link @@ -63,13 +63,13 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC * The default {@link Builder#setMinUpdateIntervalMs(long) minimum interval} between playback * speed changes, in milliseconds. */ - public static final long DEFAULT_MIN_UPDATE_INTERVAL_MS = 500; + public static final long DEFAULT_MIN_UPDATE_INTERVAL_MS = 1_000; /** * The default {@link Builder#setProportionalControlFactor(float) proportional control factor} * used to adjust the playback speed. */ - public static final float DEFAULT_PROPORTIONAL_CONTROL_FACTOR = 0.05f; + public static final float DEFAULT_PROPORTIONAL_CONTROL_FACTOR = 0.1f; /** * The default increment applied to the target live offset each time the player is rebuffering, in @@ -84,10 +84,10 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC public static final float DEFAULT_MIN_POSSIBLE_LIVE_OFFSET_SMOOTHING_FACTOR = 0.999f; /** - * The maximum difference between the current live offset and the target live offset for which - * unit speed (1.0f) is used. + * The default maximum difference between the current live offset and the target live offset, in + * milliseconds, for which unit speed (1.0f) is used. */ - public static final long MAXIMUM_LIVE_OFFSET_ERROR_US_FOR_UNIT_SPEED = 5_000; + public static final long DEFAULT_MAX_LIVE_OFFSET_ERROR_MS_FOR_UNIT_SPEED = 20; /** Builder for a {@link DefaultLivePlaybackSpeedControl}. */ public static final class Builder { @@ -96,6 +96,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC private float fallbackMaxPlaybackSpeed; private long minUpdateIntervalMs; private float proportionalControlFactorUs; + private long maxLiveOffsetErrorUsForUnitSpeed; private long targetLiveOffsetIncrementOnRebufferUs; private float minPossibleLiveOffsetSmoothingFactor; @@ -105,6 +106,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC fallbackMaxPlaybackSpeed = DEFAULT_FALLBACK_MAX_PLAYBACK_SPEED; minUpdateIntervalMs = DEFAULT_MIN_UPDATE_INTERVAL_MS; proportionalControlFactorUs = DEFAULT_PROPORTIONAL_CONTROL_FACTOR / C.MICROS_PER_SECOND; + maxLiveOffsetErrorUsForUnitSpeed = C.msToUs(DEFAULT_MAX_LIVE_OFFSET_ERROR_MS_FOR_UNIT_SPEED); targetLiveOffsetIncrementOnRebufferUs = C.msToUs(DEFAULT_TARGET_LIVE_OFFSET_INCREMENT_ON_REBUFFER_MS); minPossibleLiveOffsetSmoothingFactor = DEFAULT_MIN_POSSIBLE_LIVE_OFFSET_SMOOTHING_FACTOR; @@ -173,6 +175,22 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC return this; } + /** + * Sets the maximum difference between the current live offset and the target live offset, in + * milliseconds, for which unit speed (1.0f) is used. + * + *
The default is {@link #DEFAULT_MAX_LIVE_OFFSET_ERROR_MS_FOR_UNIT_SPEED}. + * + * @param maxLiveOffsetErrorMsForUnitSpeed The maximum live offset error for which unit speed is + * used, in milliseconds. + * @return This builder, for convenience. + */ + public Builder setMaxLiveOffsetErrorMsForUnitSpeed(long maxLiveOffsetErrorMsForUnitSpeed) { + Assertions.checkArgument(maxLiveOffsetErrorMsForUnitSpeed > 0); + this.maxLiveOffsetErrorUsForUnitSpeed = C.msToUs(maxLiveOffsetErrorMsForUnitSpeed); + return this; + } + /** * Sets the increment applied to the target live offset each time the player is rebuffering, in * milliseconds. @@ -217,6 +235,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC fallbackMaxPlaybackSpeed, minUpdateIntervalMs, proportionalControlFactorUs, + maxLiveOffsetErrorUsForUnitSpeed, targetLiveOffsetIncrementOnRebufferUs, minPossibleLiveOffsetSmoothingFactor); } @@ -226,6 +245,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC private final float fallbackMaxPlaybackSpeed; private final long minUpdateIntervalMs; private final float proportionalControlFactor; + private final long maxLiveOffsetErrorUsForUnitSpeed; private final long targetLiveOffsetRebufferDeltaUs; private final float minPossibleLiveOffsetSmoothingFactor; @@ -249,12 +269,14 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC float fallbackMaxPlaybackSpeed, long minUpdateIntervalMs, float proportionalControlFactor, + long maxLiveOffsetErrorUsForUnitSpeed, long targetLiveOffsetRebufferDeltaUs, float minPossibleLiveOffsetSmoothingFactor) { this.fallbackMinPlaybackSpeed = fallbackMinPlaybackSpeed; this.fallbackMaxPlaybackSpeed = fallbackMaxPlaybackSpeed; this.minUpdateIntervalMs = minUpdateIntervalMs; this.proportionalControlFactor = proportionalControlFactor; + this.maxLiveOffsetErrorUsForUnitSpeed = maxLiveOffsetErrorUsForUnitSpeed; this.targetLiveOffsetRebufferDeltaUs = targetLiveOffsetRebufferDeltaUs; this.minPossibleLiveOffsetSmoothingFactor = minPossibleLiveOffsetSmoothingFactor; mediaConfigurationTargetLiveOffsetUs = C.TIME_UNSET; @@ -322,7 +344,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC adjustTargetLiveOffsetUs(liveOffsetUs); long liveOffsetErrorUs = liveOffsetUs - currentTargetLiveOffsetUs; - if (Math.abs(liveOffsetErrorUs) < MAXIMUM_LIVE_OFFSET_ERROR_US_FOR_UNIT_SPEED) { + if (Math.abs(liveOffsetErrorUs) < maxLiveOffsetErrorUsForUnitSpeed) { adjustedPlaybackSpeed = 1f; } else { float calculatedSpeed = 1f + proportionalControlFactor * liveOffsetErrorUs; diff --git a/library/core/src/test/java/com/google/android/exoplayer2/DefaultLivePlaybackSpeedControlTest.java b/library/core/src/test/java/com/google/android/exoplayer2/DefaultLivePlaybackSpeedControlTest.java index 2e2731b065..62ab1ee85a 100644 --- a/library/core/src/test/java/com/google/android/exoplayer2/DefaultLivePlaybackSpeedControlTest.java +++ b/library/core/src/test/java/com/google/android/exoplayer2/DefaultLivePlaybackSpeedControlTest.java @@ -512,7 +512,9 @@ public class DefaultLivePlaybackSpeedControlTest { @Test public void adjustPlaybackSpeed_liveOffsetWithinAcceptableErrorMargin_returnsUnitSpeed() { DefaultLivePlaybackSpeedControl defaultLivePlaybackSpeedControl = - new DefaultLivePlaybackSpeedControl.Builder().build(); + new DefaultLivePlaybackSpeedControl.Builder() + .setMaxLiveOffsetErrorMsForUnitSpeed(5) + .build(); defaultLivePlaybackSpeedControl.setLiveConfiguration( new LiveConfiguration( /* targetLiveOffsetMs= */ 2_000, @@ -523,16 +525,10 @@ public class DefaultLivePlaybackSpeedControlTest { float adjustedSpeedJustAboveLowerErrorMargin = defaultLivePlaybackSpeedControl.getAdjustedPlaybackSpeed( - /* liveOffsetUs= */ 2_000_000 - - DefaultLivePlaybackSpeedControl.MAXIMUM_LIVE_OFFSET_ERROR_US_FOR_UNIT_SPEED - + 1, - /* bufferedDurationUs= */ 1_000_000); + /* liveOffsetUs= */ 2_000_000 - 5_000 + 1, /* bufferedDurationUs= */ 1_000_000); float adjustedSpeedJustBelowUpperErrorMargin = defaultLivePlaybackSpeedControl.getAdjustedPlaybackSpeed( - /* liveOffsetUs= */ 2_000_000 - + DefaultLivePlaybackSpeedControl.MAXIMUM_LIVE_OFFSET_ERROR_US_FOR_UNIT_SPEED - - 1, - /* bufferedDurationUs= */ 1_000_000); + /* liveOffsetUs= */ 2_000_000 + 5_000 - 1, /* bufferedDurationUs= */ 1_000_000); assertThat(adjustedSpeedJustAboveLowerErrorMargin).isEqualTo(1f); assertThat(adjustedSpeedJustBelowUpperErrorMargin).isEqualTo(1f);