@Override
protected void doSomeWork(long positionUs, long elapsedRealtimeUs) throws ExoPlaybackException {
currentPositionUs = positionUs;
try {
source.continueBuffering(positionUs);
} catch (IOException e) {
throw new ExoPlaybackException(e);
}
if (parserHelper.isParsing()) {
return;
}
Subtitle dequeuedSubtitle = null;
if (subtitle == null) {
try {
dequeuedSubtitle = parserHelper.getAndClearResult();
} catch (IOException e) {
throw new ExoPlaybackException(e);
}
}
if (subtitle == null && dequeuedSubtitle != null) {
// We've dequeued a new subtitle. Sync the event index and update the subtitle.
subtitle = dequeuedSubtitle;
syncNextEventIndex(positionUs);
textRendererNeedsUpdate = true;
} else if (subtitle != null) {
// We're iterating through the events in a subtitle. Set textRendererNeedsUpdate if we
// advance to the next event.
long nextEventTimeUs = getNextEventTime();
while (nextEventTimeUs <= positionUs) {
nextSubtitleEventIndex++;
nextEventTimeUs = getNextEventTime();
textRendererNeedsUpdate = true;
}
if (nextEventTimeUs == Long.MAX_VALUE) {
// We've finished processing the subtitle.
subtitle = null;
}
}
// We don't have a subtitle. Try and read the next one from the source, and if we succeed then
// sync and set textRendererNeedsUpdate.
if (!inputStreamEnded && subtitle == null) {
try {
SampleHolder sampleHolder = parserHelper.getSampleHolder();
sampleHolder.clearData();
int result = source.readData(trackIndex, positionUs, formatHolder, sampleHolder, false);
if (result == SampleSource.SAMPLE_READ && !sampleHolder.decodeOnly) {
parserHelper.startParseOperation();
textRendererNeedsUpdate = false;
} else if (result == SampleSource.END_OF_STREAM) {
inputStreamEnded = true;
}
} catch (IOException e) {
throw new ExoPlaybackException(e);
}
}
// Update the text renderer if we're both playing and textRendererNeedsUpdate is set.
if (textRendererNeedsUpdate && getState() == TrackRenderer.STATE_STARTED) {
textRendererNeedsUpdate = false;
if (subtitle == null) {
clearTextRenderer();
} else {
updateTextRenderer(positionUs);
}
}
}
