diff options
Diffstat (limited to 'mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MaskingMediaSource.java')
| -rw-r--r-- | mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MaskingMediaSource.java | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MaskingMediaSource.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MaskingMediaSource.java new file mode 100644 index 0000000000..8c867a8c26 --- /dev/null +++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/MaskingMediaSource.java @@ -0,0 +1,353 @@ +/* + * Copyright (C) 2019 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +package org.mozilla.thirdparty.com.google.android.exoplayer2.source; + +import android.util.Pair; +import androidx.annotation.Nullable; +import org.mozilla.thirdparty.com.google.android.exoplayer2.C; +import org.mozilla.thirdparty.com.google.android.exoplayer2.Timeline; +import org.mozilla.thirdparty.com.google.android.exoplayer2.Timeline.Window; +import org.mozilla.thirdparty.com.google.android.exoplayer2.source.MediaSourceEventListener.EventDispatcher; +import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.Allocator; +import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.TransferListener; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util; +import java.io.IOException; + +/** + * A {@link MediaSource} that masks the {@link Timeline} with a placeholder until the actual media + * structure is known. + */ +public final class MaskingMediaSource extends CompositeMediaSource<Void> { + + private final MediaSource mediaSource; + private final boolean useLazyPreparation; + private final Timeline.Window window; + private final Timeline.Period period; + + private MaskingTimeline timeline; + @Nullable private MaskingMediaPeriod unpreparedMaskingMediaPeriod; + @Nullable private EventDispatcher unpreparedMaskingMediaPeriodEventDispatcher; + private boolean hasStartedPreparing; + private boolean isPrepared; + + /** + * Creates the masking media source. + * + * @param mediaSource A {@link MediaSource}. + * @param useLazyPreparation Whether the {@code mediaSource} is prepared lazily. If false, all + * manifest loads and other initial preparation steps happen immediately. If true, these + * initial preparations are triggered only when the player starts buffering the media. + */ + public MaskingMediaSource(MediaSource mediaSource, boolean useLazyPreparation) { + this.mediaSource = mediaSource; + this.useLazyPreparation = useLazyPreparation; + window = new Timeline.Window(); + period = new Timeline.Period(); + timeline = MaskingTimeline.createWithDummyTimeline(mediaSource.getTag()); + } + + /** Returns the {@link Timeline}. */ + public Timeline getTimeline() { + return timeline; + } + + @Override + public void prepareSourceInternal(@Nullable TransferListener mediaTransferListener) { + super.prepareSourceInternal(mediaTransferListener); + if (!useLazyPreparation) { + hasStartedPreparing = true; + prepareChildSource(/* id= */ null, mediaSource); + } + } + + @Nullable + @Override + public Object getTag() { + return mediaSource.getTag(); + } + + @Override + @SuppressWarnings("MissingSuperCall") + public void maybeThrowSourceInfoRefreshError() throws IOException { + // Do nothing. Source info refresh errors will be thrown when calling + // MaskingMediaPeriod.maybeThrowPrepareError. + } + + @Override + public MaskingMediaPeriod createPeriod( + MediaPeriodId id, Allocator allocator, long startPositionUs) { + MaskingMediaPeriod mediaPeriod = + new MaskingMediaPeriod(mediaSource, id, allocator, startPositionUs); + if (isPrepared) { + MediaPeriodId idInSource = id.copyWithPeriodUid(getInternalPeriodUid(id.periodUid)); + mediaPeriod.createPeriod(idInSource); + } else { + // We should have at most one media period while source is unprepared because the duration is + // unset and we don't load beyond periods with unset duration. We need to figure out how to + // handle the prepare positions of multiple deferred media periods, should that ever change. + unpreparedMaskingMediaPeriod = mediaPeriod; + unpreparedMaskingMediaPeriodEventDispatcher = + createEventDispatcher(/* windowIndex= */ 0, id, /* mediaTimeOffsetMs= */ 0); + unpreparedMaskingMediaPeriodEventDispatcher.mediaPeriodCreated(); + if (!hasStartedPreparing) { + hasStartedPreparing = true; + prepareChildSource(/* id= */ null, mediaSource); + } + } + return mediaPeriod; + } + + @Override + public void releasePeriod(MediaPeriod mediaPeriod) { + ((MaskingMediaPeriod) mediaPeriod).releasePeriod(); + if (mediaPeriod == unpreparedMaskingMediaPeriod) { + Assertions.checkNotNull(unpreparedMaskingMediaPeriodEventDispatcher).mediaPeriodReleased(); + unpreparedMaskingMediaPeriodEventDispatcher = null; + unpreparedMaskingMediaPeriod = null; + } + } + + @Override + public void releaseSourceInternal() { + isPrepared = false; + hasStartedPreparing = false; + super.releaseSourceInternal(); + } + + @Override + protected void onChildSourceInfoRefreshed( + Void id, MediaSource mediaSource, Timeline newTimeline) { + if (isPrepared) { + timeline = timeline.cloneWithUpdatedTimeline(newTimeline); + } else if (newTimeline.isEmpty()) { + timeline = + MaskingTimeline.createWithRealTimeline( + newTimeline, Window.SINGLE_WINDOW_UID, MaskingTimeline.DUMMY_EXTERNAL_PERIOD_UID); + } else { + // Determine first period and the start position. + // This will be: + // 1. The default window start position if no deferred period has been created yet. + // 2. The non-zero prepare position of the deferred period under the assumption that this is + // a non-zero initial seek position in the window. + // 3. The default window start position if the deferred period has a prepare position of zero + // under the assumption that the prepare position of zero was used because it's the + // default position of the DummyTimeline window. Note that this will override an + // intentional seek to zero for a window with a non-zero default position. This is + // unlikely to be a problem as a non-zero default position usually only occurs for live + // playbacks and seeking to zero in a live window would cause BehindLiveWindowExceptions + // anyway. + newTimeline.getWindow(/* windowIndex= */ 0, window); + long windowStartPositionUs = window.getDefaultPositionUs(); + if (unpreparedMaskingMediaPeriod != null) { + long periodPreparePositionUs = unpreparedMaskingMediaPeriod.getPreparePositionUs(); + if (periodPreparePositionUs != 0) { + windowStartPositionUs = periodPreparePositionUs; + } + } + Object windowUid = window.uid; + Pair<Object, Long> periodPosition = + newTimeline.getPeriodPosition( + window, period, /* windowIndex= */ 0, windowStartPositionUs); + Object periodUid = periodPosition.first; + long periodPositionUs = periodPosition.second; + timeline = MaskingTimeline.createWithRealTimeline(newTimeline, windowUid, periodUid); + if (unpreparedMaskingMediaPeriod != null) { + MaskingMediaPeriod maskingPeriod = unpreparedMaskingMediaPeriod; + maskingPeriod.overridePreparePositionUs(periodPositionUs); + MediaPeriodId idInSource = + maskingPeriod.id.copyWithPeriodUid(getInternalPeriodUid(maskingPeriod.id.periodUid)); + maskingPeriod.createPeriod(idInSource); + } + } + isPrepared = true; + refreshSourceInfo(this.timeline); + } + + @Nullable + @Override + protected MediaPeriodId getMediaPeriodIdForChildMediaPeriodId( + Void id, MediaPeriodId mediaPeriodId) { + return mediaPeriodId.copyWithPeriodUid(getExternalPeriodUid(mediaPeriodId.periodUid)); + } + + @Override + protected boolean shouldDispatchCreateOrReleaseEvent(MediaPeriodId mediaPeriodId) { + // Suppress create and release events for the period created while the source was still + // unprepared, as we send these events from this class. + return unpreparedMaskingMediaPeriod == null + || !mediaPeriodId.equals(unpreparedMaskingMediaPeriod.id); + } + + private Object getInternalPeriodUid(Object externalPeriodUid) { + return externalPeriodUid.equals(MaskingTimeline.DUMMY_EXTERNAL_PERIOD_UID) + ? timeline.replacedInternalPeriodUid + : externalPeriodUid; + } + + private Object getExternalPeriodUid(Object internalPeriodUid) { + return timeline.replacedInternalPeriodUid.equals(internalPeriodUid) + ? MaskingTimeline.DUMMY_EXTERNAL_PERIOD_UID + : internalPeriodUid; + } + + /** + * Timeline used as placeholder for an unprepared media source. After preparation, a + * MaskingTimeline is used to keep the originally assigned dummy period ID. + */ + private static final class MaskingTimeline extends ForwardingTimeline { + + public static final Object DUMMY_EXTERNAL_PERIOD_UID = new Object(); + + private final Object replacedInternalWindowUid; + private final Object replacedInternalPeriodUid; + + /** + * Returns an instance with a dummy timeline using the provided window tag. + * + * @param windowTag A window tag. + */ + public static MaskingTimeline createWithDummyTimeline(@Nullable Object windowTag) { + return new MaskingTimeline( + new DummyTimeline(windowTag), Window.SINGLE_WINDOW_UID, DUMMY_EXTERNAL_PERIOD_UID); + } + + /** + * Returns an instance with a real timeline, replacing the provided period ID with the already + * assigned dummy period ID. + * + * @param timeline The real timeline. + * @param firstWindowUid The window UID in the timeline which will be replaced by the already + * assigned {@link Window#SINGLE_WINDOW_UID}. + * @param firstPeriodUid The period UID in the timeline which will be replaced by the already + * assigned {@link #DUMMY_EXTERNAL_PERIOD_UID}. + */ + public static MaskingTimeline createWithRealTimeline( + Timeline timeline, Object firstWindowUid, Object firstPeriodUid) { + return new MaskingTimeline(timeline, firstWindowUid, firstPeriodUid); + } + + private MaskingTimeline( + Timeline timeline, Object replacedInternalWindowUid, Object replacedInternalPeriodUid) { + super(timeline); + this.replacedInternalWindowUid = replacedInternalWindowUid; + this.replacedInternalPeriodUid = replacedInternalPeriodUid; + } + + /** + * Returns a copy with an updated timeline. This keeps the existing period replacement. + * + * @param timeline The new timeline. + */ + public MaskingTimeline cloneWithUpdatedTimeline(Timeline timeline) { + return new MaskingTimeline(timeline, replacedInternalWindowUid, replacedInternalPeriodUid); + } + + /** Returns the wrapped timeline. */ + public Timeline getTimeline() { + return timeline; + } + + @Override + public Window getWindow(int windowIndex, Window window, long defaultPositionProjectionUs) { + timeline.getWindow(windowIndex, window, defaultPositionProjectionUs); + if (Util.areEqual(window.uid, replacedInternalWindowUid)) { + window.uid = Window.SINGLE_WINDOW_UID; + } + return window; + } + + @Override + public Period getPeriod(int periodIndex, Period period, boolean setIds) { + timeline.getPeriod(periodIndex, period, setIds); + if (Util.areEqual(period.uid, replacedInternalPeriodUid)) { + period.uid = DUMMY_EXTERNAL_PERIOD_UID; + } + return period; + } + + @Override + public int getIndexOfPeriod(Object uid) { + return timeline.getIndexOfPeriod( + DUMMY_EXTERNAL_PERIOD_UID.equals(uid) ? replacedInternalPeriodUid : uid); + } + + @Override + public Object getUidOfPeriod(int periodIndex) { + Object uid = timeline.getUidOfPeriod(periodIndex); + return Util.areEqual(uid, replacedInternalPeriodUid) ? DUMMY_EXTERNAL_PERIOD_UID : uid; + } + } + + /** Dummy placeholder timeline with one dynamic window with a period of indeterminate duration. */ + private static final class DummyTimeline extends Timeline { + + @Nullable private final Object tag; + + public DummyTimeline(@Nullable Object tag) { + this.tag = tag; + } + + @Override + public int getWindowCount() { + return 1; + } + + @Override + public Window getWindow(int windowIndex, Window window, long defaultPositionProjectionUs) { + return window.set( + Window.SINGLE_WINDOW_UID, + tag, + /* manifest= */ null, + /* presentationStartTimeMs= */ C.TIME_UNSET, + /* windowStartTimeMs= */ C.TIME_UNSET, + /* isSeekable= */ false, + // Dynamic window to indicate pending timeline updates. + /* isDynamic= */ true, + /* isLive= */ false, + /* defaultPositionUs= */ 0, + /* durationUs= */ C.TIME_UNSET, + /* firstPeriodIndex= */ 0, + /* lastPeriodIndex= */ 0, + /* positionInFirstPeriodUs= */ 0); + } + + @Override + public int getPeriodCount() { + return 1; + } + + @Override + public Period getPeriod(int periodIndex, Period period, boolean setIds) { + return period.set( + /* id= */ 0, + /* uid= */ MaskingTimeline.DUMMY_EXTERNAL_PERIOD_UID, + /* windowIndex= */ 0, + /* durationUs = */ C.TIME_UNSET, + /* positionInWindowUs= */ 0); + } + + @Override + public int getIndexOfPeriod(Object uid) { + return uid == MaskingTimeline.DUMMY_EXTERNAL_PERIOD_UID ? 0 : C.INDEX_UNSET; + } + + @Override + public Object getUidOfPeriod(int periodIndex) { + return MaskingTimeline.DUMMY_EXTERNAL_PERIOD_UID; + } + } +} |