Screen Capture in VB.NET: Complete Guide to Record Desktop Video¶

Recording your desktop screen in VB.NET (Visual Basic .NET) applications is essential for building screen recorders, tutorial tools, and surveillance software. Whether you need full screen capture, region recording, or system audio capture, this guide provides step-by-step Visual Basic code examples using Video Capture SDK .Net.

Why Use Video Capture SDK .Net for VB.NET Screen Recording¶

Video Capture SDK .Net provides a complete screen recording solution for VB.NET developers:

Full desktop capture and custom region screen recording
Multi-monitor support with display enumeration
Mouse cursor capture with optional click highlighting
System audio recording (microphone and loopback/system sound)
MP4 output with H.264/H.265 encoding and GPU acceleration
Real-time screen preview during recording
Async/await pattern for non-blocking capture
WinForms and WPF support

Required NuGet Packages¶

Add the following packages to your VB.NET project:

<PackageReference Include="VisioForge.DotNet.VideoCapture" Version="2026.2.19" />
<PackageReference Include="VisioForge.CrossPlatform.Core.Windows.x64" Version="2025.11.0" />
<PackageReference Include="VisioForge.CrossPlatform.Libav.Windows.x64" Version="2025.11.0" />

Complete VB.NET Screen Recording Example¶

The following screen capture example demonstrates a WinForms application that records the desktop with audio and saves it to an MP4 file.

SDK Initialization and Display Enumeration¶

Initialize the SDK and enumerate available displays and audio devices when the form loads:

Imports System.IO
Imports VisioForge.Core
Imports VisioForge.Core.VideoCaptureX
Imports VisioForge.Core.Types.X.Sources
Imports VisioForge.Core.Types.X.Output
Imports VisioForge.Core.Types.X.AudioRenderers

Public Class Form1
    Private VideoCapture1 As VideoCaptureCoreX

    Private Async Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Initialize the SDK
        Await VisioForgeX.InitSDKAsync()

        ' Create the video capture engine with VideoView for preview
        VideoCapture1 = New VideoCaptureCoreX(VideoView1)
        AddHandler VideoCapture1.OnError, AddressOf VideoCapture1_OnError

        ' Enumerate available displays
        For i As Integer = 0 To Screen.AllScreens.Length - 1
            Dim scr = Screen.AllScreens(i)
            cbDisplayIndex.Items.Add(
                $"{i}: {scr.DeviceName} ({scr.Bounds.Width}x{scr.Bounds.Height})")
        Next
        If cbDisplayIndex.Items.Count > 0 Then cbDisplayIndex.SelectedIndex = 0

        ' Enumerate audio input devices (microphones)
        Dim audioSources = Await DeviceEnumerator.Shared.AudioSourcesAsync()
        For Each source In audioSources
            cbAudioInputDevice.Items.Add(source.DisplayName)
            If cbAudioInputDevice.Items.Count = 1 Then cbAudioInputDevice.SelectedIndex = 0
        Next

        ' Enumerate audio loopback devices (system sound)
        Dim audioOutputs = Await DeviceEnumerator.Shared.AudioOutputsAsync(
            AudioOutputDeviceAPI.WASAPI2)
        For Each audioOutput In audioOutputs
            cbAudioLoopbackDevice.Items.Add(audioOutput.Name)
            If cbAudioLoopbackDevice.Items.Count = 1 Then cbAudioLoopbackDevice.SelectedIndex = 0
        Next

        ' Set default output file path
        edOutput.Text = Path.Combine(
            Environment.GetFolderPath(Environment.SpecialFolder.MyVideos),
            "screen_capture.mp4")
    End Sub

Full Screen Capture to MP4¶

Use the ScreenCaptureD3D11SourceSettings class to capture the entire desktop at a specified frame rate and save to MP4:

    Private Async Sub btStartFullScreen_Click(
            sender As Object, e As EventArgs) Handles btStartFullScreen.Click
        Try
            ' Configure full screen capture source
            Dim screenSource As New ScreenCaptureD3D11SourceSettings() With {
                .MonitorIndex = cbDisplayIndex.SelectedIndex,
                .FrameRate = New VideoFrameRate(15, 1),
                .CaptureCursor = True
            }

            VideoCapture1.Video_Source = screenSource
            VideoCapture1.Video_Play = True

            ' Configure MP4 output
            VideoCapture1.Outputs_Clear()
            VideoCapture1.Outputs_Add(New MP4Output(edOutput.Text), True)

            ' Start capture
            Await VideoCapture1.StartAsync()
        Catch ex As Exception
            MessageBox.Show(Me, ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
    End Sub

Region Capture (Custom Area)¶

Capture a specific rectangular area of the screen instead of the full desktop:

    Private Async Sub btStartRegion_Click(
            sender As Object, e As EventArgs) Handles btStartRegion.Click
        Try
            ' Configure region capture with custom rectangle
            Dim screenSource As New ScreenCaptureD3D11SourceSettings() With {
                .Rectangle = New Rect(
                    CInt(edLeft.Text),
                    CInt(edTop.Text),
                    CInt(edRight.Text),
                    CInt(edBottom.Text)),
                .FrameRate = New VideoFrameRate(15, 1),
                .CaptureCursor = True
            }

            VideoCapture1.Video_Source = screenSource
            VideoCapture1.Video_Play = True

            ' Configure MP4 output
            VideoCapture1.Outputs_Clear()
            VideoCapture1.Outputs_Add(New MP4Output(edOutput.Text), True)

            ' Start capture
            Await VideoCapture1.StartAsync()
        Catch ex As Exception
            MessageBox.Show(Me, ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
    End Sub

Recording with System Audio (Microphone)¶

Add microphone audio recording to your screen capture:

    ' Configure microphone audio source
    Dim audioSources = Await DeviceEnumerator.Shared.AudioSourcesAsync()
    Dim audioDevice = audioSources.FirstOrDefault(
        Function(d) d.DisplayName = cbAudioInputDevice.Text)

    If audioDevice IsNot Nothing Then
        VideoCapture1.Audio_Source = audioDevice.CreateSourceSettingsVC(Nothing)
    End If

    VideoCapture1.Audio_Record = True

Recording with Loopback Audio (System Sound)¶

Capture system audio output (what you hear from speakers) instead of microphone input:

    ' Configure loopback audio source (system sound)
    Dim audioOutputs = Await DeviceEnumerator.Shared.AudioOutputsAsync(
        AudioOutputDeviceAPI.WASAPI2)
    Dim audioDevice = audioOutputs.FirstOrDefault(
        Function(d) d.Name = cbAudioLoopbackDevice.Text)

    If audioDevice IsNot Nothing Then
        VideoCapture1.Audio_Source = New LoopbackAudioCaptureDeviceSourceSettings(audioDevice)
    End If

    VideoCapture1.Audio_Record = True

Stopping Recording¶

Stop the screen recording and finalize the output file:

    Private Async Sub btStop_Click(sender As Object, e As EventArgs) Handles btStop.Click
        Try
            Await VideoCapture1.StopAsync()
        Catch ex As Exception
            MessageBox.Show(Me, ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try
    End Sub

Cleanup on Form Close¶

Properly dispose of resources when the application exits:

    Private Async Sub Form1_FormClosing(
            sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing

        If VideoCapture1 IsNot Nothing Then
            Await VideoCapture1.DisposeAsync()
            VideoCapture1 = Nothing
        End If

        VisioForgeX.DestroySDK()
    End Sub

    Private Sub VideoCapture1_OnError(sender As Object, e As ErrorsEventArgs)
        If Me.InvokeRequired Then
            Me.Invoke(Sub() mmLog.Text &= e.Message & Environment.NewLine)
        Else
            mmLog.Text &= e.Message & Environment.NewLine
        End If
    End Sub
End Class

Preview-Only Mode (No Recording)¶

To preview the desktop capture feed without saving to a file, skip adding the output:

' Configure screen source
Dim screenSource As New ScreenCaptureD3D11SourceSettings() With {
    .MonitorIndex = 0,
    .FrameRate = New VideoFrameRate(15, 1),
    .CaptureCursor = True
}

VideoCapture1.Video_Source = screenSource
VideoCapture1.Video_Play = True

' No output added - preview only
Await VideoCapture1.StartAsync()

Output Format Options¶

While this guide focuses on MP4 recording, you can save your screen capture in other formats:

WebM Output¶

WebM is ideal for web-based screen recordings, offering royalty-free VP8/VP9 encoding with smaller file sizes:

VideoCapture1.Outputs_Add(New WebMOutput(edOutput.Text), True)

AVI Output¶

AVI provides maximum compatibility with legacy video editors and Windows-based workflows:

VideoCapture1.Outputs_Add(New AVIOutput(edOutput.Text), True)

Sample Applications¶

Complete VB.NET sample applications are available:

Screen Capture X VB.NET (WinForms) — full-featured screen capture application with region and full screen modes

Frequently Asked Questions¶

How do I record both microphone and system audio simultaneously in VB.NET screen capture?¶

Create both sources and combine them. Set Audio_Source to the loopback device using LoopbackAudioCaptureDeviceSourceSettings, then add a microphone as a secondary audio source with Audio_AdditionalSource. Set Audio_Record = True to capture both tracks mixed into the output file. See the microphone and loopback audio sections above for the individual VB.NET code patterns.

What frame rate should I use for VB.NET screen recording?¶

Use 10–15 FPS for general desktop recording (documents, presentations, browsing) and 25–30 FPS for motion-intensive content like video playback or animations. Higher frame rates increase CPU usage and file size. The example code in this guide uses New VideoFrameRate(15, 1) — change the first parameter to your desired FPS. For GPU-accelerated encoding, pair higher frame rates with MP4Output which uses hardware H.264 encoding when available.

Can I record the screen without showing a preview in VB.NET?¶

Yes. Create VideoCaptureCoreX without a VideoView parameter: VideoCapture1 = New VideoCaptureCoreX(). Set Video_Play = False to skip rendering, configure the screen source and MP4 output as usual, then call Await VideoCapture1.StartAsync(). This reduces CPU usage because no frames are rendered to the UI. Console applications and Windows Services can use this approach for headless screen recording.

How do I handle high-DPI and scaled displays in VB.NET screen recording?¶

ScreenCaptureD3D11SourceSettings captures the native screen resolution regardless of Windows display scaling. A 4K monitor at 150% scaling is still recorded at 3840×2160 pixels. If your VB.NET WinForms application displays incorrect coordinates in region capture, add <dpiAware>true</dpiAware> to your app.manifest file or call SetProcessDPIAware() at startup so that Screen.AllScreens reports physical pixel dimensions instead of scaled values.