How to reduce latency in Live Smooth Streaming?

Question

I use the Expression Encoder SDK to encode a live recording of my webcam, publish it to a web server that supports IIS 7.5 and Media Services 4, and view it using SmoothStreamingClient.

However, since I am aiming for a real-time conferencing solution, I need to drastically reduce the 20 second delay between local preview and remote playback.

I read in some places that you can configure Live Smooth Streaming to get a 2-second delay, but I did not find a tutorial explaining how to set up such a solution both on the encoding and on the providing and consuming sides.

This is the code I use to encode the captured video:

// Aquires audio and video devices EncoderDevice video = EncoderDevices.FindDevices(EncoderDeviceType.Video).Count > 0 ? EncoderDevices.FindDevices(EncoderDeviceType.Video)[0] : null; EncoderDevice audio = EncoderDevices.FindDevices(EncoderDeviceType.Audio).Count > 0 ? EncoderDevices.FindDevices(EncoderDeviceType.Audio)[0] : null; // Create a new device source. We use the first audio and video devices on the system job = new LiveJob(); LiveDeviceSource deviceSource = job.AddDeviceSource(video, audio); // sets preview window to winform panel hosted by xaml window deviceSource.PreviewWindow = new PreviewWindow(new HandleRef(prevWindow, prevWindow.GetHandle)); // Make this source the active one job.ActivateSource(deviceSource); job.ApplyPreset(LivePresets.VC1IISSmoothStreamingLowBandwidthStandard); PushBroadcastPublishFormat format = new PushBroadcastPublishFormat(); format.PublishingPoint = new Uri(path); // Adds the publishing format to the job job.PublishFormats.Add(format); job.StartEncoding(); 

Is there anything I can add to this code that will result in lower latency? If not, where can I configure the so-called "low latency support" that Smooth Streaming is supposed to provide?

Thanks in advance!

Answer 1

I believe that IIS only supports segment resizing for mobile streams. However, if you reduce the size of these segments and somehow imitate a mobile device, I’m sure that the latency will decrease.

You can also try to omit the segmented view in the advanced tab of the "Current vowel publishing points" section.

In general, it does not look like this feature is supported by IIS. My advice would be to look at another conferencing solution as you will never get less than 2 seconds of latency with HTTP streaming in the current state.