/**
* For live playbacks, determines the seek position that snaps playback to be {@code
* liveEdgeLatencyUs} behind the live edge of the provided manifest.
*
* @param manifest The manifest.
* @param liveEdgeLatencyUs The live edge latency, in microseconds.
* @return The seek position in microseconds.
*/
private static long getLiveSeekPosition(
SmoothStreamingManifest manifest, long liveEdgeLatencyUs) {
long liveEdgeTimestampUs = Long.MIN_VALUE;
for (int i = 0; i < manifest.streamElements.length; i++) {
StreamElement streamElement = manifest.streamElements[i];
if (streamElement.chunkCount > 0) {
long elementLiveEdgeTimestampUs =
streamElement.getStartTimeUs(streamElement.chunkCount - 1)
+ streamElement.getChunkDurationUs(streamElement.chunkCount - 1);
liveEdgeTimestampUs = Math.max(liveEdgeTimestampUs, elementLiveEdgeTimestampUs);
}
}
return liveEdgeTimestampUs - liveEdgeLatencyUs;
}
@Override
public void continueBuffering(long playbackPositionUs) {
if (manifestFetcher == null || !currentManifest.isLive || fatalError != null) {
return;
}
SmoothStreamingManifest newManifest = manifestFetcher.getManifest();
if (currentManifest != newManifest && newManifest != null) {
StreamElement currentElement = currentManifest.streamElements[enabledTrack.elementIndex];
int currentElementChunkCount = currentElement.chunkCount;
StreamElement newElement = newManifest.streamElements[enabledTrack.elementIndex];
if (currentElementChunkCount == 0 || newElement.chunkCount == 0) {
// There's no overlap between the old and new elements because at least one is empty.
currentManifestChunkOffset += currentElementChunkCount;
} else {
long currentElementEndTimeUs =
currentElement.getStartTimeUs(currentElementChunkCount - 1)
+ currentElement.getChunkDurationUs(currentElementChunkCount - 1);
long newElementStartTimeUs = newElement.getStartTimeUs(0);
if (currentElementEndTimeUs <= newElementStartTimeUs) {
// There's no overlap between the old and new elements.
currentManifestChunkOffset += currentElementChunkCount;
} else {
// The new element overlaps with the old one.
currentManifestChunkOffset += currentElement.getChunkIndex(newElementStartTimeUs);
}
}
currentManifest = newManifest;
needManifestRefresh = false;
}
if (needManifestRefresh
&& (SystemClock.elapsedRealtime()
> manifestFetcher.getManifestLoadStartTimestamp()
+ MINIMUM_MANIFEST_REFRESH_PERIOD_MS)) {
manifestFetcher.requestRefresh();
}
}
@Override
public final void getChunkOperation(
List<? extends MediaChunk> queue,
long seekPositionUs,
long playbackPositionUs,
ChunkOperationHolder out) {
if (fatalError != null) {
out.chunk = null;
return;
}
evaluation.queueSize = queue.size();
if (enabledTrack.isAdaptive()) {
adaptiveFormatEvaluator.evaluate(
queue, playbackPositionUs, enabledTrack.adaptiveFormats, evaluation);
} else {
evaluation.format = enabledTrack.fixedFormat;
evaluation.trigger = Chunk.TRIGGER_MANUAL;
}
Format selectedFormat = evaluation.format;
out.queueSize = evaluation.queueSize;
if (selectedFormat == null) {
out.chunk = null;
return;
} else if (out.queueSize == queue.size()
&& out.chunk != null
&& out.chunk.format.equals(selectedFormat)) {
// We already have a chunk, and the evaluation hasn't changed either the format or the size
// of the queue. Leave unchanged.
return;
}
// In all cases where we return before instantiating a new chunk, we want out.chunk to be null.
out.chunk = null;
StreamElement streamElement = currentManifest.streamElements[enabledTrack.elementIndex];
if (streamElement.chunkCount == 0) {
if (currentManifest.isLive) {
needManifestRefresh = true;
} else {
out.endOfStream = true;
}
return;
}
int chunkIndex;
if (queue.isEmpty()) {
if (live) {
seekPositionUs = getLiveSeekPosition(currentManifest, liveEdgeLatencyUs);
}
chunkIndex = streamElement.getChunkIndex(seekPositionUs);
} else {
MediaChunk previous = queue.get(out.queueSize - 1);
chunkIndex = previous.chunkIndex + 1 - currentManifestChunkOffset;
}
if (live && chunkIndex < 0) {
// This is before the first chunk in the current manifest.
fatalError = new BehindLiveWindowException();
return;
} else if (currentManifest.isLive) {
if (chunkIndex >= streamElement.chunkCount) {
// This is beyond the last chunk in the current manifest.
needManifestRefresh = true;
return;
} else if (chunkIndex == streamElement.chunkCount - 1) {
// This is the last chunk in the current manifest. Mark the manifest as being finished,
// but continue to return the final chunk.
needManifestRefresh = true;
}
} else if (chunkIndex >= streamElement.chunkCount) {
out.endOfStream = true;
return;
}
boolean isLastChunk = !currentManifest.isLive && chunkIndex == streamElement.chunkCount - 1;
long chunkStartTimeUs = streamElement.getStartTimeUs(chunkIndex);
long chunkEndTimeUs =
isLastChunk ? -1 : chunkStartTimeUs + streamElement.getChunkDurationUs(chunkIndex);
int currentAbsoluteChunkIndex = chunkIndex + currentManifestChunkOffset;
int manifestTrackIndex = getManifestTrackIndex(streamElement, selectedFormat);
int manifestTrackKey = getManifestTrackKey(enabledTrack.elementIndex, manifestTrackIndex);
Uri uri = streamElement.buildRequestUri(manifestTrackIndex, chunkIndex);
Chunk mediaChunk =
newMediaChunk(
selectedFormat,
uri,
null,
extractorWrappers.get(manifestTrackKey),
drmInitData,
dataSource,
currentAbsoluteChunkIndex,
chunkStartTimeUs,
chunkEndTimeUs,
evaluation.trigger,
mediaFormats.get(manifestTrackKey),
enabledTrack.adaptiveMaxWidth,
enabledTrack.adaptiveMaxHeight);
out.chunk = mediaChunk;
}