Class LiveVideoCompositor

Namespace: VisioForge.Core.LiveVideoCompositorV2

Assembly: VisioForge.Core.dll

Real-time live video and audio compositor: mixes several inputs into one composition and routes it to any number of outputs, with inputs and outputs added and removed while the composition runs. Video mixing runs on the CPU, OpenGL or Direct3D 11 (Windows) depending on VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositorSettings.MixerType. Use it for live production, multi-camera switching and streaming.

public class LiveVideoCompositor : IDisposable, IAsyncDisposable

Remarks

This is version 2 of the compositor and the one to use in new code; the V1 type in VisioForge.Core.LiveVideoCompositor is obsolete. Each input and each output runs in its own MediaBlocks pipeline, bridged into the main mixing pipeline, so one failing source cannot stall the composition. The compositor is created from a VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositorSettings describing the composition frame size, frame rate and audio format.

Constructors

LiveVideoCompositor(LiveVideoCompositorSettings)

Initializes a new instance of the VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor class.

public LiveVideoCompositor(LiveVideoCompositorSettings settings)

Parameters

settings LiveVideoCompositorSettings: The configuration settings for the compositor.

Examples

var settings = new LiveVideoCompositorSettings(1920, 1080, new VideoFrameRate(30, 1))
{
    MixerType = LVCMixerType.OpenGL,
    AudioEnabled = true
};
var compositor = new LiveVideoCompositor(settings);

Remarks

This constructor creates the main pipeline, video mixer based on the specified mixer type, audio mixer if enabled, and all necessary infrastructure for managing inputs and outputs. The compositor is initialized but not started - call StartAsync() to begin processing.

Properties

Background

Gets or sets the background color of the compositor canvas.

public SKColor Background { get; set; }

Property Value

SKColor

Remarks

This color is visible in areas not covered by any video input. Changes to this property take effect immediately during playback when using transparent mixer background mode.

Settings

Gets the configuration settings for this Live Video Compositor instance.

public LiveVideoCompositorSettings Settings { get; }

Property Value

LiveVideoCompositorSettings

Remarks

These settings are immutable after the compositor is created. To change settings, create a new compositor instance with different settings. The audio settings - VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositorSettings.AudioEnabled, the audio format, sample rate and channel count - are captured by the constructor, so changing them on this object afterwards has no effect.

Video_Overlay_Enabled

Gets or sets a value indicating whether the video overlay manager is enabled.

public bool Video_Overlay_Enabled { get; set; }

Property Value

bool

Methods

Dispose(bool)

Releases the unmanaged resources used by the VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor and optionally releases the managed resources.

protected virtual void Dispose(bool disposing)

Parameters

disposing bool: true to release both managed and unmanaged resources; false to release only unmanaged resources.

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources. This is the public synchronous Dispose method, implementing the IDisposable interface.

public void Dispose()

DisposeAsync()

Asynchronously releases the unmanaged and managed resources used by the VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor. This method is part of the IAsyncDisposable pattern, allowing for asynchronous resource cleanup.

public ValueTask DisposeAsync()

Returns

ValueTask: A ValueTask that represents the asynchronous dispose operation.

DurationAsync()

Gets the current playback position of the compositor.

public Task<TimeSpan> DurationAsync()

Returns

Task<TimeSpan>: A Task<TResult> that completes with the current position.

Remarks

For live compositing, this typically represents the elapsed time since the compositor started. The position is determined by the main pipeline's clock.

~LiveVideoCompositor()

Finalizes an instance of the VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor class. This finalizer is called by the .NET runtime to release unmanaged resources if the VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor.Dispose method was not called explicitly.

protected ~LiveVideoCompositor()

GetAudioMixer()

Gets the audio mixer component of the compositor.

public AudioMixerBlock GetAudioMixer()

Returns

AudioMixerBlock: The VisioForge.Core.MediaBlocks.AudioProcessing.AudioMixerBlock that combines multiple audio inputs, or null if audio is disabled or the compositor is stopped.

Remarks

The audio mixer combines all audio inputs into a single output stream. It is only created if AudioEnabled is true in the settings, and only between StartAsync() and StopAsync() — see GetVideoMixer().

GetContext()

Gets the context object for this compositor.

public ContextX GetContext()

Returns

ContextX: The VisioForge.Core.GStreamer.ContextX instance used for logging and error handling.

Remarks

The context provides centralized logging and error management functionality for the compositor and all its components.

GetPipeline()

Gets the main processing pipeline of the compositor.

public MediaBlocksPipeline GetPipeline()

Returns

MediaBlocksPipeline: The main VisioForge.Core.MediaBlocks.MediaBlocksPipeline that manages the compositor's core processing.

Remarks

This pipeline contains the video mixer, audio mixer, effects processors, and output distribution. It is separate from the individual input and output pipelines.

GetVideoMixer()

Gets the video mixer component of the compositor.

public VideoMixerBlock GetVideoMixer()

Returns

VideoMixerBlock: The VisioForge.Core.MediaBlocks.VideoProcessing.VideoMixerBlock that combines multiple video inputs into a single output, or null while the compositor is stopped.

Remarks

The video mixer is the core component that performs the actual video composition. Its type (CPU, OpenGL, D3D11) is determined by the MixerType setting. It exists only between StartAsync() and StopAsync(): the composition graph is built on start and retired on stop, so the instance can be started again.

Input_AddAsync(LVCVideoInput)

Adds a video-only input to the compositor.

public Task<bool> Input_AddAsync(LVCVideoInput input)

Parameters

input LVCVideoInput: The video input to add.

Returns

Task<bool>: A Task<TResult> that completes with true if the input was added successfully; otherwise, false.

Remarks

On anything but true - a false and a throw alike - the input was not added and the wrapper is the caller's. Nothing the attempt installed survives: an add that had got far enough to build or start anything rolls all of it back and stops and disposes the input on the way out, while one refused before it touched the input at all - a null argument, a settings check - leaves it as it was. Either way the caller disposes it, and disposing an already-disposed one is harmless (LVCInput.Dispose is idempotent), so a caller that owns it through a finally needs no special case. A retry builds a fresh input rather than re-submitting this one.

An input whose video frame size is unknown - a width or height of 0 in its info - is refused with false, and the reason is raised through VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor.OnError. So is an input whose source cannot be connected, such as one with no video output, or is known to send no video through the output it has: an RTSP source or UniversalSourceBlock whose camera or file info was read, with no video stream, or a UniversalSourceBlock with video rendering off.

This method can be called before or after the compositor is started. If called after startup, the input is dynamically added to the running pipeline. The input's AutoStart property determines whether it begins processing immediately. Each input is assigned a unique ID for bridge connections.

Exceptions

InvalidOperationException: May occur if the maximum number of inputs is exceeded.

Input_AddAsync(LVCAudioInput)

Adds an audio-only input to the compositor.

public Task<bool> Input_AddAsync(LVCAudioInput input)

Parameters

input LVCAudioInput: The audio input to add.

Returns

Task<bool>: A Task<TResult> that completes with true if the input was added successfully; otherwise, false.

Remarks

An input whose source cannot be connected, such as one with no audio output, is refused with false, and the reason is raised through VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor.OnError. So is one whose source is known to send no audio through the output it has: an RTSPSourceBlock or RTSPRAWSourceBlock with AudioEnabled off, a file or an RTSP camera whose info was read, with no audio stream, or an NDI sender found to have no audio when it is probed here.

This method requires audio to be enabled in the compositor settings. Like video inputs, audio inputs can be added dynamically during playback. Each input is assigned a unique ID for bridge connections and mixed into the main audio output.

Exceptions

InvalidOperationException: Thrown when audio is disabled in compositor settings.

Input_AddAsync(LVCVideoAudioInput, bool)

Adds a combined video and audio input to the compositor.

public Task<bool> Input_AddAsync(LVCVideoAudioInput input, bool start = false)

Parameters

input LVCVideoAudioInput: The video/audio input to add.
start bool: If true, starts the input after adding; otherwise uses the input's AutoStart property. Default is false.

Returns

Task<bool>: A Task<TResult> that completes with true if the input was added successfully; otherwise, false.

Remarks

An input that renders video with an unknown frame size - a width or height of 0 in its video info - is refused with false, and the reason is raised through VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor.OnError. So is an input whose source cannot be connected, such as one with no output for a leg it has.

This method handles inputs that provide both video and audio streams. The video and audio components are processed separately but remain synchronized. Special handling is provided for file sources to ensure proper preloading when added to a running compositor. Both video and audio IDs are assigned from their respective pools; an input without an audio leg - no audio info, a UniversalSourceBlock or UniversalSourceBlockV2 with audio rendering off, an RTSPSourceBlock or RTSPRAWSourceBlock with AudioEnabled off, a file, or an RTSP camera whose info was read, with no audio stream, or a source with no audio output such as an NDI sender found to have no audio when it is probed - takes no audio ID and no audio slot. The same holds for video, except that an NDI source given video info always has a video leg. An NDI source is probed here, before its audio leg is decided. An input with neither leg is refused with false, and the reason is raised through VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor.OnError.

Input_Count()

Gets the total number of inputs currently added to the compositor.

public int Input_Count()

Returns

int: The number of inputs of all types (video, audio, and combined).

Remarks

This count includes all input types regardless of their current state (playing, paused, or stopped).

Input_Get(int)

Gets an input by its index in the input list.

public LVCInput Input_Get(int index)

Parameters

index int: The zero-based index of the input.

Returns

LVCInput: The VisioForge.Core.LiveVideoCompositorV2.LVCInput at the specified index; null if the index is out of range.

Remarks

This method returns the base input type. Cast the result to the specific input type (LVCVideoInput, LVCAudioInput, or LVCVideoAudioInput) as needed.

Input_Get(Guid)

Gets an input by its unique identifier.

public LVCInput Input_Get(Guid id)

Parameters

id Guid: The unique identifier of the input.

Returns

LVCInput: The VisioForge.Core.LiveVideoCompositorV2.LVCInput with the specified ID; null if not found.

Remarks

This is the preferred method for retrieving inputs as IDs are guaranteed to be unique and stable throughout the input's lifetime. The returned base type can be cast to the specific input type as needed.

Input_GetID(string)

Gets the unique identifier of an input by its name.

public Guid? Input_GetID(string name)

Parameters

name string: The name of the input to find.

Returns

Guid?: The Guid of the input if found; null if no input with the specified name exists.

Remarks

Input names are not required to be unique, so this method returns the first match found. For reliable identification, use the input's ID directly.

Input_GetName(Guid)

Gets the name of an input by its unique identifier.

public string Input_GetName(Guid id)

Parameters

id Guid: The unique identifier of the input.

Returns

string: The name of the input if found; null if no input with the specified ID exists.

Remarks

This method is useful for displaying input information in user interfaces or logs.

Input_RemoveAsync(Guid)

Removes an input from the compositor by its unique ID.

public Task<bool> Input_RemoveAsync(Guid id)

Parameters

id Guid: The unique identifier of the input to remove.

Returns

Task<bool>: A Task<TResult> that completes with true if the input was removed successfully; otherwise, false.

Remarks

This method can be called during playback to dynamically remove inputs. It properly:

Stops the input pipeline
Blocks and removes mixer pads
Cleans up bridge connections
Releases IDs back to the pool for reuse
Disposes of all resources The removal is performed safely without interrupting other inputs or the main pipeline.

Input_VideoAudio_Get(int)

Gets a video/audio input by its index in the input list.

public LVCVideoAudioInput Input_VideoAudio_Get(int index)

Parameters

index int: The zero-based index of the input.

Returns

LVCVideoAudioInput: The VisioForge.Core.LiveVideoCompositorV2.LVCVideoAudioInput at the specified index; null if the index is out of range or the input is not a video/audio type.

Remarks

This method performs type checking and will return null if the input at the specified index is not a combined video/audio input.

Input_VideoAudio_Get(Guid)

Gets a video/audio input by its unique identifier.

public LVCVideoAudioInput Input_VideoAudio_Get(Guid id)

Parameters

id Guid: The unique identifier of the input.

Returns

LVCVideoAudioInput: The VisioForge.Core.LiveVideoCompositorV2.LVCVideoAudioInput with the specified ID; null if not found or the input is not a video/audio type.

Remarks

This is the preferred method for retrieving inputs as IDs are guaranteed to be unique and stable throughout the input's lifetime.

Input_VideoStream_Get(LVCInput)

Gets the video mixer stream configuration for a specific input.

public VideoMixerStream Input_VideoStream_Get(LVCInput input)

Parameters

input LVCInput: The input to get the stream for.

Returns

VideoMixerStream: The VisioForge.Core.Types.X.VideoEffects.VideoMixerStream containing position, size, and other properties; null if the input is not found.

Remarks

Use this method to retrieve the current configuration of a video input stream, which can then be modified and updated using Input_VideoStream_Update().

It answers on a stopped compositor too, and returns the same object a run left behind: the stream survives a stop, so an input can be repositioned between StopAsync() and the next StartAsync(), which picks the change up as it rebuilds the mixer. Mutating the object is enough there — Input_VideoStream_Update() pushes to a live mixer and does nothing while the composition is stopped.

It returns null for an input without a video leg, and otherwise only before the input's first build. Up to that point the layout is the input's own Rectangle/ZOrder/ResizePolicy, which seed the stream; afterwards the stream is the layout and those properties are no longer read.

Input_VideoStream_Update(VideoMixerStream)

Updates the configuration of a video input stream in the mixer.

public void Input_VideoStream_Update(VideoMixerStream stream)

Parameters

stream VideoMixerStream: The stream configuration to update.

Examples

var stream = compositor.Input_VideoStream_Get(input);
if (stream != null)
{
    stream.Alpha = 0.5; // Set 50% transparency
    stream.Rectangle = new Rect(100, 100, 640, 480); // Reposition
    compositor.Input_VideoStream_Update(stream);
}

Remarks

Use this method to dynamically change properties of a video input during playback, such as position, size, opacity, or z-order. The stream object should be obtained from Input_VideoStream_Get() and modified before passing to this method.

It pushes the change to the running mixer, so it does nothing while the composition is stopped — there, mutating the object Input_VideoStream_Get() returned is the whole of it, and the next StartAsync() builds the mixer from it.

Output_AddAsync(LVCVideoOutput, bool)

Adds a video-only output to the compositor.

public Task<bool> Output_AddAsync(LVCVideoOutput output, bool start = false)

Parameters

output LVCVideoOutput: The video output to add.
start bool: If true, starts the output immediately; otherwise, it must be started manually. Default is false.

Returns

Task<bool>: A Task<TResult> that completes with true if the output was added successfully; otherwise, false.

Remarks

On anything but true - a false and a throw alike - the output was not added and the wrapper is the caller's. Nothing the attempt installed survives: an add that had got far enough to build or start anything rolls all of it back and stops and disposes the output on the way out, while one refused before it touched the output at all - a null argument, a settings check - leaves it as it was. Either way the caller disposes it, and disposing an already-disposed one is harmless (LVCOutput.Dispose is idempotent), so a caller that owns it through a finally needs no special case. A retry builds a fresh output rather than re-submitting this one.

This method can be called before or after the compositor is started. If called after startup, the output is dynamically added to the running pipeline using a tee element. The start parameter overrides the output's AutoStart property for immediate activation.

Output_AddAsync(LVCAudioOutput, bool)

Adds an audio-only output to the compositor.

public Task<bool> Output_AddAsync(LVCAudioOutput output, bool start = false)

Parameters

output LVCAudioOutput: The audio output to add.
start bool: If true, starts the output immediately; otherwise, it must be started manually. Default is false.

Returns

Task<bool>: A Task<TResult> that completes with true if the output was added successfully; otherwise, false.

Remarks

Audio outputs receive the mixed audio from all audio inputs. Multiple audio outputs can be active simultaneously, each receiving the same audio mix. This is useful for recording while streaming or monitoring.

A compositor with VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositorSettings.AudioEnabled set to false has no audio mix, so this method returns false there, before and after start alike.

Output_AddAsync(LVCVideoAudioOutput, bool)

Adds a combined video and audio output to the compositor.

public Task<bool> Output_AddAsync(LVCVideoAudioOutput output, bool start = false)

Parameters

output LVCVideoAudioOutput: The video/audio output to add.
start bool: If true, starts the output immediately; otherwise, it must be started manually. Default is false.

Returns

Task<bool>: A Task<TResult> that completes with true if the output was added successfully; otherwise, false.

Remarks

This method creates separate bridge connections for video and audio streams to the output. Both streams remain synchronized through the output pipeline. Common uses include recording files with both video and audio or streaming to services that require both components. With VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositorSettings.AudioEnabled set to false only the video bridge is created, and the output receives video alone.

Output_Audio_Get(int)

Gets an audio output by its index in the output list.

public LVCAudioOutput Output_Audio_Get(int index)

Parameters

index int: The zero-based index of the output.

Returns

LVCAudioOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCAudioOutput at the specified index; null if the index is out of range or the output is not an audio-only type.

Remarks

This method performs type checking and will return null if the output at the specified index is not an audio-only output.

Output_Audio_Get(Guid)

Gets an audio output by its unique identifier.

public LVCAudioOutput Output_Audio_Get(Guid id)

Parameters

id Guid: The unique identifier of the output.

Returns

LVCAudioOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCAudioOutput with the specified ID; null if not found or the output is not an audio-only type.

Remarks

This is the preferred method for retrieving outputs as IDs are guaranteed to be unique and stable throughout the output's lifetime.

Output_Count()

Gets the total number of outputs currently added to the compositor.

public int Output_Count()

Returns

int: The number of outputs of all types (video, audio, and combined).

Remarks

This count includes all output types regardless of their current state (active or inactive).

Output_Get(int)

Gets an output by its index in the output list.

public LVCOutput Output_Get(int index)

Parameters

index int: The zero-based index of the output.

Returns

LVCOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCOutput at the specified index; null if the index is out of range.

Remarks

This method returns the base output type. Cast the result to the specific output type (LVCVideoOutput, LVCAudioOutput, or LVCVideoAudioOutput) as needed.

Output_Get(Guid)

Gets an output by its unique identifier.

public LVCOutput Output_Get(Guid id)

Parameters

id Guid: The unique identifier of the output.

Returns

LVCOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCOutput with the specified ID; null if not found.

Remarks

This is the preferred method for retrieving outputs as IDs are guaranteed to be unique and stable throughout the output's lifetime. The returned base type can be cast to the specific output type as needed.

Output_Get(string) Deprecated

Use Output_Get(Guid id) instead for better performance and unique identification.

Gets an output by its name.

[Obsolete("Use Output_Get(Guid id) instead for better performance and unique identification.")]
public LVCOutput Output_Get(string name)

Parameters

name string: The name of the output to find.

Returns

LVCOutput: The first VisioForge.Core.LiveVideoCompositorV2.LVCOutput with the specified name; null if no output with the specified name exists.

Remarks

Output names are not required to be unique, so this method returns the first match found. This method is obsolete and may be removed in future versions.

Output_GetID(string)

Gets the unique identifier of an output by its name.

public Guid? Output_GetID(string name)

Parameters

name string: The name of the output to find.

Returns

Guid?: The Guid of the output if found; null if no output with the specified name exists.

Remarks

Output names are not required to be unique, so this method returns the first match found. For reliable identification, use the output's ID directly.

Output_GetName(Guid)

Gets the name of an output by its unique identifier.

public string Output_GetName(Guid id)

Parameters

id Guid: The unique identifier of the output.

Returns

string: The name of the output if found; null if no output with the specified ID exists.

Remarks

This method is useful for displaying output information in user interfaces or logs.

Output_RemoveAsync(Guid)

Removes an output from the compositor by its unique ID.

public Task<bool> Output_RemoveAsync(Guid id)

Parameters

id Guid: The unique identifier of the output to remove.

Returns

Task<bool>: A Task<TResult> that completes with true if the output was removed successfully; otherwise, false.

Remarks

This method stops the output pipeline gracefully and removes it from the compositor. For file outputs, this ensures proper file finalization. The output is disposed after removal.

Output_VideoAudio_Get(int)

Gets a video/audio output by its index in the output list.

public LVCVideoAudioOutput Output_VideoAudio_Get(int index)

Parameters

index int: The zero-based index of the output.

Returns

LVCVideoAudioOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCVideoAudioOutput at the specified index; null if the index is out of range or the output is not a video/audio type.

Remarks

This method performs type checking and will return null if the output at the specified index is not a combined video/audio output.

Output_VideoAudio_Get(Guid)

Gets a video/audio output by its unique identifier.

public LVCVideoAudioOutput Output_VideoAudio_Get(Guid id)

Parameters

id Guid: The unique identifier of the output.

Returns

LVCVideoAudioOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCVideoAudioOutput with the specified ID; null if not found or the output is not a video/audio type.

Remarks

This is the preferred method for retrieving outputs as IDs are guaranteed to be unique and stable throughout the output's lifetime.

Output_Video_Get(int)

Gets a video output by its index in the output list.

public LVCVideoOutput Output_Video_Get(int index)

Parameters

index int: The zero-based index of the output.

Returns

LVCVideoOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCVideoOutput at the specified index; null if the index is out of range or the output is not a video-only type.

Remarks

This method performs type checking and will return null if the output at the specified index is not a video-only output.

Output_Video_Get(Guid)

Gets a video output by its unique identifier.

public LVCVideoOutput Output_Video_Get(Guid id)

Parameters

id Guid: The unique identifier of the output.

Returns

LVCVideoOutput: The VisioForge.Core.LiveVideoCompositorV2.LVCVideoOutput with the specified ID; null if not found or the output is not a video-only type.

Remarks

This is the preferred method for retrieving outputs as IDs are guaranteed to be unique and stable throughout the output's lifetime.

SetLicenseCertificateAsync(byte[])

Loads a license certificate into this instance and activates it if the certificate requires activation.

public Task SetLicenseCertificateAsync(byte[] certificateData)

Parameters

certificateData byte[]: The bytes of a .vflicense certificate file issued by VisioForge.

Returns

Task: A task that completes once the certificate has been loaded and any required activation has run.

Remarks

This is the only public licensing API. The file-path and stream overloads and every license-key method were removed in 2026.5.2, so an application reads the .vflicense file itself and passes the bytes here. The certificate belongs to this instance: call it on every instance you create, before starting it -- licensing one instance does not license another. Without a certificate the instance runs in the 30-day trial.

StartAsync()

Starts the compositor and all configured inputs and outputs.

public Task<bool> StartAsync()

Returns

Task<bool>: A Task<TResult> that completes with true if startup was successful; otherwise, false.

Examples

var compositor = new LiveVideoCompositor(settings);
// Add inputs and outputs...
if (await compositor.StartAsync())
{
    Console.WriteLine("Compositor started successfully");
}

Remarks

This method performs the following operations:

Applies license keys to all pipelines
Builds the internal pipeline structure
Preloads all inputs and outputs for synchronized startup
Configures clock synchronization across all pipelines
Starts all components in the correct order

Inputs and outputs with AutoStart=true will begin processing immediately. Others must be started manually after the compositor is running.

StopAsync()

Stops the compositor and all active inputs and outputs.

public Task StopAsync()

Returns

Task: A Task representing the asynchronous stop operation.

Remarks

This method stops all components in the reverse order of startup:

Stops all inputs
Stops the main pipeline
Stops all outputs
Retires the composition graph, so the instance can be started again

File outputs are properly finalized to ensure valid output files. The compositor can be restarted: call StartAsync() again on the same instance, with the inputs and outputs it still holds, plus any added or removed while it was stopped. Note that the composition graph exists only between StartAsync() and StopAsync(), so GetVideoMixer() and GetAudioMixer() return null on a stopped compositor.

Video_Effects_AddOrUpdateAsync(BaseVideoEffect)

Adds a new video effect or updates an existing one on the composed output.

public Task Video_Effects_AddOrUpdateAsync(BaseVideoEffect effect)

Parameters

effect BaseVideoEffect: The video effect to add or update. If an effect with the same name exists, it will be updated.

Returns

Task: A Task representing the asynchronous operation.

Remarks

This method can be called during playback to dynamically add or modify effects. If the video effect manager is not initialized, this method will return without doing anything. A ResizeVideoEffect, crop effect or box cannot be added or updated through this call while the composition is running with at least one video output: the outputs were built for the frame size that reached them. The call is refused through VisioForge.Core.LiveVideoCompositorV2.LiveVideoCompositor.OnError, and the effect stays registered, so the next start applies it. Without outputs it applies live, as the renderer follows a frame-size change. Setting a property on an effect object that is already applied is not intercepted and takes effect live.

Video_Effects_AddOrUpdateAsync(BaseVideoEffect, int) Deprecated

The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_AddOrUpdateAsync(effect). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.

Adds a new video effect or updates an existing one on the composed output.

[Obsolete("The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_AddOrUpdateAsync(effect). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.")]
public Task Video_Effects_AddOrUpdateAsync(BaseVideoEffect effect, int channel)

Parameters

effect BaseVideoEffect: The video effect to add or update.
channel int: Ignored.

Returns

Task: A Task representing the asynchronous operation.

Video_Effects_Clear()

Removes all video effects from the composed output.

public void Video_Effects_Clear()

Remarks

A playing composition is paused for the clear and resumed afterwards. A composition left in Pause is cleared in place and stays paused. A frame-size effect present on a live composition refuses the clear - stop the composition first. A clear that cannot take the pause - the pipeline is already stopping - is reported and skipped. Before the first start, and after the composition has been stopped, the effects are only configuration and are removed without touching the pipeline state.

Video_Effects_Clear(int) Deprecated

The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_Clear(). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.

Removes all video effects from the composed output.

[Obsolete("The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_Clear(). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.")]
public void Video_Effects_Clear(int channel)

Parameters

channel int: Ignored.

Video_Effects_Get(string)

Retrieves a video effect by its name.

public IBaseVideoEffect Video_Effects_Get(string effectName)

Parameters

effectName string: The unique name of the effect to retrieve.

Returns

IBaseVideoEffect: The VisioForge.Core.Types.X.VideoEffects.IBaseVideoEffect instance if found; otherwise, null.

Remarks

Use this method to retrieve an effect instance for modification or inspection. If the video effect manager is not initialized, this method will return null.

Video_Effects_Get(string, int) Deprecated

The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_Get(effectName). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.

Retrieves a video effect by its name.

[Obsolete("The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_Get(effectName). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.")]
public IBaseVideoEffect Video_Effects_Get(string effectName, int channel)

Parameters

effectName string: The unique name of the effect to retrieve.
channel int: Ignored.

Returns

IBaseVideoEffect: The VisioForge.Core.Types.X.VideoEffects.IBaseVideoEffect instance if found; otherwise, null.

Video_Effects_RemoveAsync(BaseVideoEffect)

Removes a video effect from the composed output.

public Task Video_Effects_RemoveAsync(BaseVideoEffect effect)

Parameters

effect BaseVideoEffect: The video effect instance to remove.

Returns

Task: A Task representing the asynchronous operation.

Remarks

This method pauses the pipeline during effect removal to ensure smooth operation. The pipeline will automatically resume after the effect is removed. If the video effect manager or pipeline is not initialized, this method will return without doing anything. Before the first successful start, and after the composition has been stopped, the effect is removed as configuration without changing the pipeline state; the next start builds the composition from the effects that remain.

Video_Effects_RemoveAsync(string)

Removes a video effect from the composed output by its name.

public Task Video_Effects_RemoveAsync(string name)

Parameters

name string: The unique name of the effect to remove.

Returns

Task: A Task representing the asynchronous operation.

Remarks

This method first looks up the effect by name, then removes it if found. The pipeline is paused during removal and automatically resumed afterwards. If the effect is not found or the video effect manager is not initialized, this method will return without doing anything. Before the first successful start, and after the composition has been stopped, the effect is removed as configuration without changing the pipeline state; the next start builds the composition from the effects that remain.

Video_Effects_RemoveAsync(BaseVideoEffect, int) Deprecated

The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_RemoveAsync(effect). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.

Removes a video effect from the composed output.

[Obsolete("The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_RemoveAsync(effect). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.")]
public Task Video_Effects_RemoveAsync(BaseVideoEffect effect, int channel)

Parameters

effect BaseVideoEffect: The video effect instance to remove.
channel int: Ignored.

Returns

Task: A Task representing the asynchronous operation.

Video_Effects_RemoveAsync(string, int) Deprecated

The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_RemoveAsync(name). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.

Removes a video effect from the composed output by its name.

[Obsolete("The channel parameter has no meaning on V2: effects apply to the composed output. Use Video_Effects_RemoveAsync(name). For per-input effects, add a VideoEffectsBlock to LVCVideoInput.ProcessingVideoBlocks.")]
public Task Video_Effects_RemoveAsync(string name, int channel)

Parameters

name string: The unique name of the effect to remove.
channel int: Ignored.

Returns

Task: A Task representing the asynchronous operation.

Video_Overlay_Add(IOverlayManagerElement, int)

Adds a new overlay element to the video stream.

public void Video_Overlay_Add(IOverlayManagerElement overlay, int channel = 0)

Parameters

overlay IOverlayManagerElement: The overlay element to add, such as text, image, or shape overlay.
channel int: The channel number for multi-channel support. Currently not used but reserved for future use. Default is 0.

Remarks

The overlay will be rendered on top of the video according to its position and properties. Multiple overlays can be added and will be rendered in the order they were added.

Video_Overlay_Clear(int)

Removes all overlay elements from the video stream.

public void Video_Overlay_Clear(int channel = 0)

Parameters

channel int: The channel number for multi-channel support. Currently not used but reserved for future use. Default is 0.

Remarks

This method clears all overlays at once, leaving a clean video output without any overlays.

Video_Overlay_Remove(IOverlayManagerElement, int)

Removes a specific overlay element from the video stream.

public void Video_Overlay_Remove(IOverlayManagerElement overlay, int channel = 0)

Parameters

overlay IOverlayManagerElement: The overlay element to remove. Must be the same instance that was previously added.
channel int: The channel number for multi-channel support. Currently not used but reserved for future use. Default is 0.

Remarks

If the specified overlay is not found in the current overlay list, no action is taken.

Video_Overlay_RemoveAt(int, int)

Removes an overlay element at the specified index from the overlay list.

public void Video_Overlay_RemoveAt(int index, int channel = 0)

Parameters

index int: The zero-based index of the overlay to remove.
channel int: The channel number for multi-channel support. Currently not used but reserved for future use. Default is 0.

Exceptions

ArgumentOutOfRangeException: Thrown when the index is out of range of the overlay list.

Video_Overlay_Update(IOverlayManagerElement, int)

Updates an existing overlay element with new properties.

public void Video_Overlay_Update(IOverlayManagerElement overlay, int channel = 0)

Parameters

overlay IOverlayManagerElement: The overlay element with updated properties. Must be the same instance that was previously added.
channel int: The channel number for multi-channel support. Currently not used but reserved for future use. Default is 0.

Remarks

This method removes the existing overlay and re-adds it with the updated properties. This ensures that any changes to the overlay's properties (position, text, color, etc.) are immediately reflected in the video output.

OnAudioVUMeter

Occurs when new audio VU meter data is available.

public event EventHandler<VUMeterXEventArgs> OnAudioVUMeter

Event Type

EventHandler<VUMeterXEventArgs>

OnError

Occurs when an error happens during compositor operation.

public event EventHandler<ErrorsEventArgs> OnError

Event Type

EventHandler<ErrorsEventArgs>

Remarks

Subscribe to this event to receive notifications about errors in the compositor, inputs, outputs, or any processing pipelines. The event args contain details about the error source and description.

OnRenderStatistics

Occurs periodically with measured render statistics for the compositor output.

public event EventHandler<RenderStatisticsEventArgs> OnRenderStatistics

Event Type

EventHandler<RenderStatisticsEventArgs>

Remarks

Fires approximately every 500 ms on a threadpool thread while the compositor is running. Use it to detect when the compositor is falling behind the configured frame rate — a sustained VisioForge.Core.Types.Events.RenderStatisticsEventArgs.ActualFps below VisioForge.Core.Types.Events.RenderStatisticsEventArgs.ConfiguredFps indicates the pipeline cannot keep up with the configured load. Marshal to the UI thread before updating controls.

Table of Contents

Class LiveVideoCompositor

Inheritance

Implements

Inherited Members

Remarks

Constructors

LiveVideoCompositor(LiveVideoCompositorSettings)

Parameters

Examples

Remarks

Properties

Background

Property Value

Remarks

Settings

Property Value

Remarks

Video_Overlay_Enabled

Property Value

Methods

Dispose(bool)

Parameters

Dispose()

DisposeAsync()

Returns

DurationAsync()

Returns

Remarks

~LiveVideoCompositor()

GetAudioMixer()

Returns

Remarks

GetContext()

Returns

Remarks

GetPipeline()

Returns

Remarks

GetVideoMixer()

Returns

Remarks

Input_AddAsync(LVCVideoInput)

Parameters

Returns

Remarks

Exceptions

Input_AddAsync(LVCAudioInput)

Parameters

Returns

Remarks

Exceptions

Input_AddAsync(LVCVideoAudioInput, bool)

Parameters

Returns

Remarks

Input_Count()

Returns

Remarks

Input_Get(int)

Parameters

Returns

Remarks

Input_Get(Guid)

Parameters

Returns

Remarks

Input_GetID(string)

Parameters

Returns

Remarks

Input_GetName(Guid)

Parameters

Returns

Remarks

Input_RemoveAsync(Guid)

Parameters

Returns

Remarks

Input_VideoAudio_Get(int)