DashSegmentIndex.java
/*
* Copyright (C) 2016 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 androidx.media3.exoplayer.dash;
import androidx.media3.common.C;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.exoplayer.dash.manifest.RangedUri;
/** Indexes the segments within a media stream. */
@UnstableApi
public interface DashSegmentIndex {
int INDEX_UNBOUNDED = -1;
/**
* Returns {@code getFirstSegmentNum()} if the index has no segments or if the given media time is
* earlier than the start of the first segment. Returns {@code getFirstSegmentNum() +
* getSegmentCount() - 1} if the given media time is later than the end of the last segment.
* Otherwise, returns the segment number of the segment containing the given media time.
*
* @param timeUs The time in microseconds.
* @param periodDurationUs The duration of the enclosing period in microseconds, or {@link
* C#TIME_UNSET} if the period's duration is not yet known.
* @return The segment number of the corresponding segment.
*/
long getSegmentNum(long timeUs, long periodDurationUs);
/**
* Returns the start time of a segment.
*
* @param segmentNum The segment number.
* @return The corresponding start time in microseconds.
*/
long getTimeUs(long segmentNum);
/**
* Returns the duration of a segment.
*
* @param segmentNum The segment number.
* @param periodDurationUs The duration of the enclosing period in microseconds, or {@link
* C#TIME_UNSET} if the period's duration is not yet known.
* @return The duration of the segment, in microseconds.
*/
long getDurationUs(long segmentNum, long periodDurationUs);
/**
* Returns a {@link RangedUri} defining the location of a segment.
*
* @param segmentNum The segment number.
* @return The {@link RangedUri} defining the location of the data.
*/
RangedUri getSegmentUrl(long segmentNum);
/** Returns the segment number of the first defined segment in the index. */
long getFirstSegmentNum();
/**
* Returns the segment number of the first available segment in the index.
*
* @param periodDurationUs The duration of the enclosing period in microseconds, or {@link
* C#TIME_UNSET} if the period's duration is not yet known.
* @param nowUnixTimeUs The current time in milliseconds since the Unix epoch.
* @return The number of the first available segment.
*/
long getFirstAvailableSegmentNum(long periodDurationUs, long nowUnixTimeUs);
/**
* Returns the number of segments defined in the index, or {@link #INDEX_UNBOUNDED}.
*
* <p>An unbounded index occurs if a dynamic manifest uses SegmentTemplate elements without a
* SegmentTimeline element, and if the period duration is not yet known. In this case the caller
* can query the available segment using {@link #getFirstAvailableSegmentNum(long, long)} and
* {@link #getAvailableSegmentCount(long, long)}.
*
* @param periodDurationUs The duration of the enclosing period in microseconds, or {@link
* C#TIME_UNSET} if the period's duration is not yet known.
* @return The number of segments in the index, or {@link #INDEX_UNBOUNDED}.
*/
long getSegmentCount(long periodDurationUs);
/**
* Returns the number of available segments in the index.
*
* @param periodDurationUs The duration of the enclosing period in microseconds, or {@link
* C#TIME_UNSET} if the period's duration is not yet known.
* @param nowUnixTimeUs The current time in milliseconds since the Unix epoch.
* @return The number of available segments in the index.
*/
long getAvailableSegmentCount(long periodDurationUs, long nowUnixTimeUs);
/**
* Returns the time, in microseconds, at which a new segment becomes available, or {@link
* C#TIME_UNSET} if not applicable.
*
* @param periodDurationUs The duration of the enclosing period in microseconds, or {@link
* C#TIME_UNSET} if the period's duration is not yet known.
* @param nowUnixTimeUs The current time in milliseconds since the Unix epoch.
* @return The time, in microseconds, at which a new segment becomes available, or {@link
* C#TIME_UNSET} if not applicable.
*/
long getNextSegmentAvailableTimeUs(long periodDurationUs, long nowUnixTimeUs);
/**
* Returns true if segments are defined explicitly by the index.
*
* <p>If true is returned, each segment is defined explicitly by the index data, and all of the
* listed segments are guaranteed to be available at the time when the index was obtained.
*
* <p>If false is returned then segment information was derived from properties such as a fixed
* segment duration. If the presentation is dynamic, it's possible that only a subset of the
* segments are available.
*
* @return Whether segments are defined explicitly by the index.
*/
boolean isExplicit();
}