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GetLiveLatency Method

Summary

Retrieves the latency used for streaming live streams.

Syntax

C++

public double GetLiveLatency(  
   int index 
)

Public Function GetLiveLatency( _ 
   ByVal index As Integer _ 
) As Double

public: 
double GetLiveLatency(  
   int index 
)

Parameters

index
0-based index of the source folder whose latency should be retrieved.

Return Value

The live latency (in seconds) of the specified source.

Remarks

The RTSP server treats growing DVR buffers as a live stream. When an RTSP client connects and requests playing a growing DVR buffer, the RTSP server starts playing from the current position in this live stream. For performance purposes, it starts a little bit behind the live stream. The amount by which it is behind the is called "live stream latency" and its amount is retrieved using this function. The live stream latency is a double value and is measured in seconds.

This function allows you to get the live stream latency for a source (if index is between 0 and SourceCount - 1) or for the server (if index is -1).

The default live stream latency is 0.5 (meaning the live stream is 0.5 seconds behind the live stream).

A DVR buffer is considered to be growing if it is still being written to by the DVR engine when an RTSP client requests it.

See the Introduction to the LEADTOOLS MPEG2 Transport Module topic for more information on DVR files.

If the source DVR buffer is using a compression compatible to the RTSP server, the streaming will start from the first key frame found before the "Live Stream Position" - "LiveLatency". This is done for performance purposes, because the streaming must start with a key frame.

Requirements

Target Platforms