A publisher captures an audio-video stream from the sources you specify. More...

Inherits IDisposable.

Detailed Description

A publisher captures an audio-video stream from the sources you specify.

Use the Publisher.Builder class to create a Publisher instance. You can then publish the audio-video stream to an Vonage Video API session by calling the Session.Publish(Publisher) method.

The Publisher class implements the System.IDisposable interface. Be sure to call the Dispose() method of the Publisher object to release its resources when you no longer need the object (for example, when the Publisher is removed or when the app or window is closing).

Member Enumeration Documentation

VideoReason

Defines values for the VideoEventArgs.Reason and VideoEventArgs.Reason properties.

Member Function Documentation

Dispose()

Disposes of the Publisher object's resources.

Note that the Publisher's resources are not disposed of when you call the Session.Publish(Publisher) method. When you call Session.Publish(Publisher), the resources of the Publisher object are retained so that you can reuse it (to Publish again to the session).

GetRtcStatsReport()

Gets the RTC stats report for the publisher. This is an asynchronous operation. When the stats are available, the RtcStatsReport message is sent.

Also see AudioStatsUpdated, VideoStatsUpdated, and Subscriber.GetRtcStatsReport().

Property Documentation

MaxVideoBitrate

The maximum video bitrate for the publisher's video stream (in bits per second).

This property sets an explicit upper limit on the publisher’s video bitrate. Setting this property to 0 clears any manual cap and reverts to the default preset-based adaptive bitrate behavior with no explicit limit.

Reading this property returns the currently configured maximum bitrate in bps. If no manual bitrate has been set, or if a bitrate preset is active, the value is 0.

A value of 0 indicates that no explicit bitrate limit is applied and the stream operates under adaptive preset rules to optimize quality.

PublishVideo

VideoBitratePreset

The video bitrate preset strategy applied to the publisher's video stream.

This property configures a predefined bitrate strategy to balance video quality and bandwidth usage. Preset configurations and manual bitrate settings are mutually exclusive. Setting the MaxVideoBitrate property overrides any preset and automatically changes this property to VideoBitratePreset.Custom.

Reading this property returns the currently active preset. If a custom bitrate has been manually set, the value will be VideoBitratePreset.Custom.

The default value is VideoBitratePreset.Default.

Note: The VideoBitratePreset.Custom value cannot be set directly.

For details, see Publisher Max Bitrate.

Event Documentation

NetworkConditionChanged

Occurs when network condition changes are detected on the publisher side.

This event is triggered when significant network condition changes occur, providing media link statistics along with the reason for the change.

VideoDisabled

Called when the publisher stops sending video.

Check the reason property of the event arguments for the reason why the video stopped.

VideoDisableWarning

Called when the publisher determines that the network congestion level has degraded and the video will be disabled if the congestion degrades further.

If the network degrades further, the Publisher disables the video and sends the AudioFallback message. If the stream quality improves, the Publisher sends the VideoDisableWarningLifted event.

This method is mainly called when the connection quality degrades.

VideoDisableWarningLifted

Called when the publisher determines that the network congestion level has improved to the point at which the video being disabled is not an immediate risk.

This method is mainly called when the connection quality improves.

VideoEnabled

Called when the publisher's video stream resumes (after video was disabled).

Check the reason property of the event arguments for the reason why the video was enabled.

VideoQualityChanged

Occurs when there is a change in the quality state of the publisher's video stream.

This event provides updated video statistics and a reason code indicating why the quality change occurred.

The VideoReason value specifies the cause of the event and follows this priority order: bandwidth degradation, CPU degradation, other quality degradation reasons, codec changes, and resolution or layer changes.

This event differs from the VideoDisabled and VideoEnabled events in that it reports quality-related changes rather than simple on/off state changes. The VideoDisabled and VideoEnabled events indicate when the publisher’s video track is turned off or on (for example, due to audio fallback or stream property updates). In contrast, VideoQualityChanged provides diagnostic insights into quality degradation causes—such as CPU or bandwidth limitations—and may be raised even when the video remains enabled.

Applications can use this event to monitor video quality and respond accordingly, such as updating UI indicators or notifying users of performance issues.