private TimeSpan CalculateDownloadTimeout(Segment segment)
{
if (!IsDynamic)
{
return(TimeSpan.MaxValue);
}
var timeout = timeBufferDepthDefault;
var averageThroughput = throughputHistory.GetAverageThroughput();
if (averageThroughput > 0 && currentRepresentation.Bandwidth.HasValue && segment.Period != null)
{
var bandwidth = currentRepresentation.Bandwidth.Value;
var duration = segment.Period.Duration.TotalSeconds;
var segmentSize = bandwidth * duration;
var calculatedTimeNeeded = TimeSpan.FromSeconds(segmentSize / averageThroughput * 1.5);
var docParams = currentStreams.GetDocumentParameters();
if (docParams == null)
{
throw new ArgumentNullException("currentStreams.GetDocumentParameters() returns null");
}
var manifestMinBufferDepth =
docParams.Document.MinBufferTime ?? TimeSpan.Zero;
timeout = calculatedTimeNeeded > manifestMinBufferDepth ? calculatedTimeNeeded : manifestMinBufferDepth;
}
return(timeout);
}
public void AdaptToNetConditions()
{
// Treat adaptive streaming as "non critical". If cannot be processed now due to lock, attempt
// will be done at next iteration.
if (!Monitor.TryEnter(switchStreamLock))
{
return;
}
try
{
if (DisableAdaptiveStreaming)
{
return;
}
if (currentStream == null && pendingStream == null)
{
return;
}
var streamToAdapt = pendingStream ?? currentStream;
if (streamToAdapt.Representation.Bandwidth.HasValue == false)
{
return;
}
var currentThroughput = throughputHistory.GetAverageThroughput();
if (Math.Abs(currentThroughput) < 0.1)
{
return;
}
Logger.Debug("Adaptation values:");
Logger.Debug(" current throughput: " + currentThroughput);
Logger.Debug(" current stream bandwidth: " + streamToAdapt.Representation.Bandwidth.Value);
// availableStreams is sorted array by descending bandwidth
var stream = availableStreams.FirstOrDefault(o =>
o.Representation.Bandwidth <= currentThroughput) ?? availableStreams.Last();
if (stream.Representation.Bandwidth == streamToAdapt.Representation.Bandwidth)
{
return;
}
Logger.Info("Changing stream to bandwidth: " + stream.Representation.Bandwidth);
pendingStream = stream;
}
finally
{
Monitor.Exit(switchStreamLock);
}
}
public void AdaptToNetConditions()
{
if (DisableAdaptiveStreaming)
{
return;
}
if (currentStream == null && pendingStream == null)
{
return;
}
var streamToAdapt = pendingStream ?? currentStream;
if (streamToAdapt.Representation.Bandwidth.HasValue == false)
{
return;
}
var currentThroughput = throughputHistory.GetAverageThroughput();
if (Math.Abs(currentThroughput) < 0.1)
{
return;
}
Logger.Debug("Adaptation values:");
Logger.Debug(" current throughput: " + currentThroughput);
Logger.Debug(" current stream bandwidth: " + streamToAdapt.Representation.Bandwidth.Value);
// availableStreams is sorted array by descending bandwidth
var stream = availableStreams.FirstOrDefault(o =>
o.Representation.Bandwidth <= currentThroughput) ?? availableStreams.Last();
if (stream.Representation.Bandwidth == streamToAdapt.Representation.Bandwidth)
{
return;
}
Logger.Info("Changing stream to bandwidth: " + stream.Representation.Bandwidth);
pendingStream = stream;
}