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Commit c48dd4f3 by olly Committed by Oliver Woodman
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Use FormatEvaluator for HLS. 

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=114743795
parent a7adcce0
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Showing with 118 additions and 79 deletions
library/src/main/java/com/google/android/exoplayer/chunk/FormatEvaluator.java
...@@ -28,8 +28,10 @@ public interface FormatEvaluator { ...@@ -28,8 +28,10 @@ public interface FormatEvaluator {
/** /**
* Enables the evaluator. * Enables the evaluator.
*
* @param formats The formats from which to select, ordered by decreasing bandwidth.
*/ */
void enable(); void enable(Format[] formats);
/** /**
* Disables the evaluator. * Disables the evaluator.
...@@ -39,22 +41,27 @@ public interface FormatEvaluator { ...@@ -39,22 +41,27 @@ public interface FormatEvaluator {
/** /**
* Update the supplied evaluation. * Update the supplied evaluation.
* <p> * <p>
* When the method is invoked, {@code evaluation} will contain the currently selected * When invoked, {@code evaluation} must contain the currently selected format (null for an
* format (null for the first evaluation), the most recent trigger (TRIGGER_INITIAL for the * initial evaluation), the most recent trigger (@link Chunk#TRIGGER_INITIAL} for an initial
* first evaluation) and the current queue size. The implementation should update these * evaluation) and the size of {@code queue}. The invocation will update the format and trigger,
* fields as necessary. * and may also reduce {@link Evaluation#queueSize} to indicate that chunks should be discarded
* <p> * from the end of the queue to allow re-buffering in a different format. The evaluation will
* The trigger should be considered "sticky" for as long as a given representation is selected, * always retain the first chunk in the queue, if there is one.
* and so should only be changed if the representation is also changed.
* *
* @param queue A read only representation of the currently buffered {@link MediaChunk}s. * @param queue A read only representation of currently buffered chunks. Must not be empty unless
* @param playbackPositionUs The current playback position. * the evaluation is at the start of playback or immediately follows a seek. All but the first
* @param formats The formats from which to select, ordered by decreasing bandwidth. * chunk may be discarded. A caller may pass a singleton list containing only the most
* @param evaluation The evaluation. * recently buffered chunk in the case that it does not support discarding of chunks.
* @param playbackPositionUs The current playback position in microseconds.
* @param switchingOverlapUs If switching format requires downloading overlapping media then this
* is the duration of the required overlap in microseconds. 0 otherwise.
* @param blacklistFlags An array whose length is equal to the number of available formats. A
* {@code true} element indicates that a format is currently blacklisted and should not be
* selected by the evaluation. At least one element must be {@code false}.
* @param evaluation The evaluation to be updated.
*/ */
// TODO: Pass more useful information into this method, and finalize the interface. void evaluate(List<? extends MediaChunk> queue, long playbackPositionUs,
void evaluate(List<? extends MediaChunk> queue, long playbackPositionUs, Format[] formats, long switchingOverlapUs, boolean[] blacklistFlags, Evaluation evaluation);
Evaluation evaluation);
/** /**
* A format evaluation. * A format evaluation.
...@@ -62,9 +69,9 @@ public interface FormatEvaluator { ...@@ -62,9 +69,9 @@ public interface FormatEvaluator {
public static final class Evaluation { public static final class Evaluation {
/** /**
* The desired size of the queue. * The selected format.
*/ */
public int queueSize; public Format format;
/** /**
* The sticky reason for the format selection. * The sticky reason for the format selection.
...@@ -72,46 +79,33 @@ public interface FormatEvaluator { ...@@ -72,46 +79,33 @@ public interface FormatEvaluator {
public int trigger; public int trigger;
/** /**
* The selected format. * The desired size of the queue.
*/ */
public Format format; public int queueSize;
public Evaluation() { public Evaluation() {
trigger = Chunk.TRIGGER_INITIAL; trigger = Chunk.TRIGGER_INITIAL;
} }
}
/** /**
* Always selects the first format. * Clears {@link #format} and sets {@link #trigger} to {@link Chunk#TRIGGER_INITIAL}.
*/ */
public static final class FixedEvaluator implements FormatEvaluator { public void clear() {
format = null;
@Override trigger = Chunk.TRIGGER_INITIAL;
public void enable() {
// Do nothing.
}
@Override
public void disable() {
// Do nothing.
}
@Override
public void evaluate(List<? extends MediaChunk> queue, long playbackPositionUs,
Format[] formats, Evaluation evaluation) {
evaluation.format = formats[0];
} }
} }
/** /**
* Selects randomly between the available formats. * Selects randomly between the available formats, excluding those that are blacklisted.
*/ */
public static final class RandomEvaluator implements FormatEvaluator { public static final class RandomEvaluator implements FormatEvaluator {
private final Random random; private final Random random;
private Format[] formats;
public RandomEvaluator() { public RandomEvaluator() {
this.random = new Random(); this.random = new Random();
} }
...@@ -124,20 +118,39 @@ public interface FormatEvaluator { ...@@ -124,20 +118,39 @@ public interface FormatEvaluator {
} }
@Override @Override
public void enable() { public void enable(Format[] formats) {
// Do nothing. this.formats = formats;
} }
@Override @Override
public void disable() { public void disable() {
// Do nothing. formats = null;
} }
@Override @Override
public void evaluate(List<? extends MediaChunk> queue, long playbackPositionUs, public void evaluate(List<? extends MediaChunk> queue, long playbackPositionUs,
Format[] formats, Evaluation evaluation) { long switchingOverlapUs, boolean[] blacklistFlags, Evaluation evaluation) {
Format newFormat = formats[random.nextInt(formats.length)]; // Count the number of non-blacklisted formats.
if (evaluation.format != null && !evaluation.format.equals(newFormat)) { int nonBlacklistedFormatCount = 0;
for (int i = 0; i < blacklistFlags.length; i++) {
if (!blacklistFlags[i]) {
nonBlacklistedFormatCount++;
}
}
int formatIndex = random.nextInt(nonBlacklistedFormatCount);
if (nonBlacklistedFormatCount != formats.length) {
// Adjust the format index to account for blacklisted formats.
nonBlacklistedFormatCount = 0;
for (int i = 0; i < blacklistFlags.length; i++) {
if (!blacklistFlags[i] && formatIndex == nonBlacklistedFormatCount++) {
formatIndex = i;
break;
}
}
}
Format newFormat = formats[formatIndex];
if (evaluation.format != null && evaluation.format != newFormat) {
evaluation.trigger = Chunk.TRIGGER_ADAPTIVE; evaluation.trigger = Chunk.TRIGGER_ADAPTIVE;
} }
evaluation.format = newFormat; evaluation.format = newFormat;
...@@ -163,13 +176,14 @@ public interface FormatEvaluator { ...@@ -163,13 +176,14 @@ public interface FormatEvaluator {
public static final float DEFAULT_BANDWIDTH_FRACTION = 0.75f; public static final float DEFAULT_BANDWIDTH_FRACTION = 0.75f;
private final BandwidthMeter bandwidthMeter; private final BandwidthMeter bandwidthMeter;
private final int maxInitialBitrate; private final int maxInitialBitrate;
private final long minDurationForQualityIncreaseUs; private final long minDurationForQualityIncreaseUs;
private final long maxDurationForQualityDecreaseUs; private final long maxDurationForQualityDecreaseUs;
private final long minDurationToRetainAfterDiscardUs; private final long minDurationToRetainAfterDiscardUs;
private final float bandwidthFraction; private final float bandwidthFraction;
private Format[] formats;
/** /**
* @param bandwidthMeter Provides an estimate of the currently available bandwidth. * @param bandwidthMeter Provides an estimate of the currently available bandwidth.
*/ */
...@@ -211,22 +225,26 @@ public interface FormatEvaluator { ...@@ -211,22 +225,26 @@ public interface FormatEvaluator {
} }
@Override @Override
public void enable() { public void enable(Format[] formats) {
// Do nothing. this.formats = formats;
} }
@Override @Override
public void disable() { public void disable() {
// Do nothing. formats = null;
} }
@Override @Override
public void evaluate(List<? extends MediaChunk> queue, long playbackPositionUs, public void evaluate(List<? extends MediaChunk> queue, long playbackPositionUs,
Format[] formats, Evaluation evaluation) { long switchingOverlapUs, boolean[] blacklistFlags, Evaluation evaluation) {
long bufferedDurationUs = queue.isEmpty() ? 0 long bufferedDurationUs = queue.isEmpty() ? 0
: queue.get(queue.size() - 1).endTimeUs - playbackPositionUs; : queue.get(queue.size() - 1).endTimeUs - playbackPositionUs;
if (switchingOverlapUs > 0) {
bufferedDurationUs = Math.max(0, bufferedDurationUs - switchingOverlapUs);
}
Format current = evaluation.format; Format current = evaluation.format;
Format ideal = determineIdealFormat(formats, bandwidthMeter.getBitrateEstimate()); Format ideal = determineIdealFormat(formats, blacklistFlags,
bandwidthMeter.getBitrateEstimate());
boolean isHigher = ideal != null && current != null && ideal.bitrate > current.bitrate; boolean isHigher = ideal != null && current != null && ideal.bitrate > current.bitrate;
boolean isLower = ideal != null && current != null && ideal.bitrate < current.bitrate; boolean isLower = ideal != null && current != null && ideal.bitrate < current.bitrate;
if (isHigher) { if (isHigher) {
...@@ -267,17 +285,22 @@ public interface FormatEvaluator { ...@@ -267,17 +285,22 @@ public interface FormatEvaluator {
/** /**
* Compute the ideal format ignoring buffer health. * Compute the ideal format ignoring buffer health.
*/ */
private Format determineIdealFormat(Format[] formats, long bitrateEstimate) { private Format determineIdealFormat(Format[] formats, boolean[] blacklistFlags,
long bitrateEstimate) {
int lowestBitrateNonBlacklistedIndex = 0;
long effectiveBitrate = bitrateEstimate == BandwidthMeter.NO_ESTIMATE long effectiveBitrate = bitrateEstimate == BandwidthMeter.NO_ESTIMATE
? maxInitialBitrate : (long) (bitrateEstimate * bandwidthFraction); ? maxInitialBitrate : (long) (bitrateEstimate * bandwidthFraction);
for (int i = 0; i < formats.length; i++) { for (int i = 0; i < formats.length; i++) {
Format format = formats[i]; Format format = formats[i];
if (!blacklistFlags[i]) {
if (format.bitrate <= effectiveBitrate) { if (format.bitrate <= effectiveBitrate) {
return format; return format;
} else {
lowestBitrateNonBlacklistedIndex = i;
}
} }
} }
// We didn't manage to calculate a suitable format. Return the lowest quality format. return formats[lowestBitrateNonBlacklistedIndex];
return formats[formats.length - 1];
} }
} }
......
library/src/main/java/com/google/android/exoplayer/dash/DashChunkSource.java
...@@ -131,6 +131,7 @@ public class DashChunkSource implements ChunkSource { ...@@ -131,6 +131,7 @@ public class DashChunkSource implements ChunkSource {
// Properties of enabled tracks. // Properties of enabled tracks.
private Format[] enabledFormats; private Format[] enabledFormats;
private boolean[] adaptiveFormatBlacklistFlags;
/** /**
* @param manifestFetcher A fetcher for the manifest. * @param manifestFetcher A fetcher for the manifest.
...@@ -266,7 +267,8 @@ public class DashChunkSource implements ChunkSource { ...@@ -266,7 +267,8 @@ public class DashChunkSource implements ChunkSource {
} }
Arrays.sort(enabledFormats, new DecreasingBandwidthComparator()); Arrays.sort(enabledFormats, new DecreasingBandwidthComparator());
if (enabledFormats.length > 1) { if (enabledFormats.length > 1) {
adaptiveFormatEvaluator.enable(); adaptiveFormatEvaluator.enable(enabledFormats);
adaptiveFormatBlacklistFlags = new boolean[tracks.length];
} }
processManifest(manifestFetcher.getManifest()); processManifest(manifestFetcher.getManifest());
} }
...@@ -311,7 +313,8 @@ public class DashChunkSource implements ChunkSource { ...@@ -311,7 +313,8 @@ public class DashChunkSource implements ChunkSource {
evaluation.queueSize = queue.size(); evaluation.queueSize = queue.size();
if (evaluation.format == null || !lastChunkWasInitialization) { if (evaluation.format == null || !lastChunkWasInitialization) {
if (enabledFormats.length > 1) { if (enabledFormats.length > 1) {
adaptiveFormatEvaluator.evaluate(queue, playbackPositionUs, enabledFormats, evaluation); adaptiveFormatEvaluator.evaluate(queue, playbackPositionUs, 0, adaptiveFormatBlacklistFlags,
evaluation);
} else { } else {
evaluation.format = enabledFormats[0]; evaluation.format = enabledFormats[0];
evaluation.trigger = Chunk.TRIGGER_MANUAL; evaluation.trigger = Chunk.TRIGGER_MANUAL;
...@@ -479,7 +482,7 @@ public class DashChunkSource implements ChunkSource { ...@@ -479,7 +482,7 @@ public class DashChunkSource implements ChunkSource {
adaptiveFormatEvaluator.disable(); adaptiveFormatEvaluator.disable();
} }
periodHolders.clear(); periodHolders.clear();
evaluation.format = null; evaluation.clear();
availableRange = null; availableRange = null;
fatalError = null; fatalError = null;
enabledFormats = null; enabledFormats = null;
......
library/src/main/java/com/google/android/exoplayer/smoothstreaming/SmoothStreamingChunkSource.java
...@@ -81,6 +81,7 @@ public class SmoothStreamingChunkSource implements ChunkSource { ...@@ -81,6 +81,7 @@ public class SmoothStreamingChunkSource implements ChunkSource {
// Properties of enabled tracks. // Properties of enabled tracks.
private Format[] enabledFormats; private Format[] enabledFormats;
private boolean[] adaptiveFormatBlacklistFlags;
private IOException fatalError; private IOException fatalError;
...@@ -171,7 +172,8 @@ public class SmoothStreamingChunkSource implements ChunkSource { ...@@ -171,7 +172,8 @@ public class SmoothStreamingChunkSource implements ChunkSource {
} }
Arrays.sort(enabledFormats, new DecreasingBandwidthComparator()); Arrays.sort(enabledFormats, new DecreasingBandwidthComparator());
if (enabledFormats.length > 1) { if (enabledFormats.length > 1) {
adaptiveFormatEvaluator.enable(); adaptiveFormatEvaluator.enable(enabledFormats);
adaptiveFormatBlacklistFlags = new boolean[tracks.length];
} }
} }
...@@ -221,7 +223,8 @@ public class SmoothStreamingChunkSource implements ChunkSource { ...@@ -221,7 +223,8 @@ public class SmoothStreamingChunkSource implements ChunkSource {
evaluation.queueSize = queue.size(); evaluation.queueSize = queue.size();
if (enabledFormats.length > 1) { if (enabledFormats.length > 1) {
adaptiveFormatEvaluator.evaluate(queue, playbackPositionUs, enabledFormats, evaluation); adaptiveFormatEvaluator.evaluate(queue, playbackPositionUs, 0, adaptiveFormatBlacklistFlags,
evaluation);
} else { } else {
evaluation.format = enabledFormats[0]; evaluation.format = enabledFormats[0];
evaluation.trigger = Chunk.TRIGGER_MANUAL; evaluation.trigger = Chunk.TRIGGER_MANUAL;
...@@ -316,7 +319,7 @@ public class SmoothStreamingChunkSource implements ChunkSource { ...@@ -316,7 +319,7 @@ public class SmoothStreamingChunkSource implements ChunkSource {
if (enabledFormats.length > 1) { if (enabledFormats.length > 1) {
adaptiveFormatEvaluator.disable(); adaptiveFormatEvaluator.disable();
} }
evaluation.format = null; evaluation.clear();
fatalError = null; fatalError = null;
} }
......
library/src/main/java/com/google/android/exoplayer/upstream/DefaultBandwidthMeter.java
...@@ -30,15 +30,21 @@ public final class DefaultBandwidthMeter implements BandwidthMeter { ...@@ -30,15 +30,21 @@ public final class DefaultBandwidthMeter implements BandwidthMeter {
public static final int DEFAULT_MAX_WEIGHT = 2000; public static final int DEFAULT_MAX_WEIGHT = 2000;
private static final int ELAPSED_MILLIS_FOR_ESTIMATE = 2000;
private static final int BYTES_TRANSFERRED_FOR_ESTIMATE = 512 * 1024;
private final Handler eventHandler; private final Handler eventHandler;
private final EventListener eventListener; private final EventListener eventListener;
private final Clock clock; private final Clock clock;
private final SlidingPercentile slidingPercentile; private final SlidingPercentile slidingPercentile;
private long bytesAccumulator;
private long startTimeMs;
private long bitrateEstimate;
private int streamCount; private int streamCount;
private long sampleStartTimeMs;
private long sampleBytesTransferred;
private long totalElapsedTimeMs;
private long totalBytesTransferred;
private long bitrateEstimate;
public DefaultBandwidthMeter() { public DefaultBandwidthMeter() {
this(null, null); this(null, null);
...@@ -73,34 +79,38 @@ public final class DefaultBandwidthMeter implements BandwidthMeter { ...@@ -73,34 +79,38 @@ public final class DefaultBandwidthMeter implements BandwidthMeter {
@Override @Override
public synchronized void onTransferStart() { public synchronized void onTransferStart() {
if (streamCount == 0) { if (streamCount == 0) {
startTimeMs = clock.elapsedRealtime(); sampleStartTimeMs = clock.elapsedRealtime();
} }
streamCount++; streamCount++;
} }
@Override @Override
public synchronized void onBytesTransferred(int bytes) { public synchronized void onBytesTransferred(int bytes) {
bytesAccumulator += bytes; sampleBytesTransferred += bytes;
} }
@Override @Override
public synchronized void onTransferEnd() { public synchronized void onTransferEnd() {
Assertions.checkState(streamCount > 0); Assertions.checkState(streamCount > 0);
long nowMs = clock.elapsedRealtime(); long nowMs = clock.elapsedRealtime();
int elapsedMs = (int) (nowMs - startTimeMs); int sampleElapsedTimeMs = (int) (nowMs - sampleStartTimeMs);
if (elapsedMs > 0) { totalElapsedTimeMs += sampleElapsedTimeMs;
float bitsPerSecond = (bytesAccumulator * 8000) / elapsedMs; totalBytesTransferred += sampleBytesTransferred;
slidingPercentile.addSample((int) Math.sqrt(bytesAccumulator), bitsPerSecond); if (sampleElapsedTimeMs > 0) {
float bandwidthEstimateFloat = slidingPercentile.getPercentile(0.5f); float bitsPerSecond = (sampleBytesTransferred * 8000) / sampleElapsedTimeMs;
bitrateEstimate = Float.isNaN(bandwidthEstimateFloat) ? NO_ESTIMATE slidingPercentile.addSample((int) Math.sqrt(sampleBytesTransferred), bitsPerSecond);
: (long) bandwidthEstimateFloat; if (totalElapsedTimeMs >= ELAPSED_MILLIS_FOR_ESTIMATE
notifyBandwidthSample(elapsedMs, bytesAccumulator, bitrateEstimate); || totalBytesTransferred >= BYTES_TRANSFERRED_FOR_ESTIMATE) {
} float bitrateEstimateFloat = slidingPercentile.getPercentile(0.5f);
streamCount--; bitrateEstimate = Float.isNaN(bitrateEstimateFloat) ? NO_ESTIMATE
if (streamCount > 0) { : (long) bitrateEstimateFloat;
startTimeMs = nowMs; }
} }
bytesAccumulator = 0; notifyBandwidthSample(sampleElapsedTimeMs, sampleBytesTransferred, bitrateEstimate);
if (--streamCount > 0) {
sampleStartTimeMs = nowMs;
}
sampleBytesTransferred = 0;
} }
private void notifyBandwidthSample(final int elapsedMs, final long bytes, final long bitrate) { private void notifyBandwidthSample(final int elapsedMs, final long bytes, final long bitrate) {
......
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