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LEADTOOLS Multimedia (Leadtools.Multimedia assembly)
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Buffer Property






Leadtools.Multimedia Namespace > MediaSample Class : Buffer Property
Gets a reference for direct access to the media sample buffer.
Syntax
public byte[] Buffer {get;}
'Declaration
 

Public ReadOnly Property Buffer As Byte()
'Usage
 

Dim instance As MediaSample
Dim value() As Byte
 
value = instance.Buffer
public:
property array<byte>^ Buffer {
   array<byte>^ get();
}

Property Value

A byte array containing the media sample data.
Remarks
The returned array allows direct read and write access to the sample buffer for in-process clients only (which is the typical case). Out-of-process clients should treat the returned array as read-only and should call the SetData method to write to the buffer.
Example
Copy Code   
Imports Leadtools
Imports Leadtools.Multimedia
Imports LeadtoolsMultimediaExamples.Fixtures

Public _result As Boolean = False
Public _form As CaptureCtrlForm = New CaptureCtrlForm()
Public Sub CaptureFrameExample()
   ' reference the capture control
   Dim capturectrl As CaptureCtrl = _form.CaptureCtrl

   ' output file
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "CaptureCtrl_CaptureFrameExample.bmp")

   Try
      ' set the video capture device, use your capture device name here
      If capturectrl.VideoDevices("Logitech") Is Nothing Then
         Throw New Exception("No Logitech video device available")
      End If

      capturectrl.VideoDevices("Logitech").Selected = True

      ' create a new sample target
      Dim st As SampleTarget = New SampleTarget()

      ' set the target media type for the video stream
      Dim amt As MediaType = New MediaType()
      amt.Type = Leadtools.Multimedia.Constants.MEDIATYPE_Video
      amt.SubType = Leadtools.Multimedia.Constants.MEDIASUBTYPE_RGB24
      st.SetAcceptedMediaType(amt)

      ' assign the sample target to the capture control
      capturectrl.TargetObject = st
      capturectrl.TargetFormat = TargetFormatType.AVI

      ' prepare the manual frames capture
      capturectrl.ReadyCapture(CaptureMode.ManualFrames)

      ' do something before the capture starts
      If capturectrl.IsModeAvailable(CaptureMode.ManualFrames) Then
      End If

      ' set the capture mode to manual frames
      capturectrl.StartCapture(CaptureMode.ManualFrames)

      ' capture a frame
      capturectrl.CaptureFrame()

      ' create a media sample using the captured sample from above 
      Dim ms As MediaSample = st.GetSample(-1)

      ' get the sample target's connected media type
      Dim mt As MediaType = st.GetConnectedMediaType()

      Dim bmp As Bitmap = WriteSampleBitmap(outFile, ms, mt)

      ' stop the capture
      capturectrl.StopCapture()

      ' check for the capture file and set the result
      If File.Exists(outFile) Then
         Dim test As Image = Bitmap.FromFile(outFile)
         _result = (test.Width = bmp.Width AndAlso test.Height = bmp.Height AndAlso test.PixelFormat = bmp.PixelFormat)
      End If
   Catch e1 As COMException
      _result = False
   Catch e2 As Exception
      _result = False
   End Try

   ' we'll loop on the state and pump messages for this example.
   ' but you should not need to if running from a Windows Forms application.
   Do While capturectrl.State = CaptureState.Running
      Application.DoEvents()
   Loop
End Sub

Private Function WriteSampleBitmap(ByVal outFile As String, ByVal ms As MediaSample, ByVal mt As MediaType) As Bitmap
   ' get the video information 
   Dim vih As VideoInfoHeader = mt.GetVideoFormatData()

   ' create a bitmap to hold the sample and copy it
   Dim bmp As Bitmap = New Bitmap(vih.bmiHeader.biWidth, vih.bmiHeader.biHeight, FormatFromBitCount(vih.bmiHeader.biBitCount))
   Dim bmpData As BitmapData = bmp.LockBits(New Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadWrite, bmp.PixelFormat)
   Marshal.Copy(ms.Buffer, 0, bmpData.Scan0, GetBitmapSize(bmp, vih.bmiHeader.biBitCount))
   bmp.UnlockBits(bmpData)

   ' flip the upside down buffer
   bmp.RotateFlip(RotateFlipType.Rotate180FlipX)

   ' save the image
   bmp.Save(outFile, ImageFormat.Bmp)
   Return bmp
End Function

Private Function FormatFromBitCount(ByVal bitCount As Integer) As PixelFormat
   Select Case bitCount
      Case 8
         Return PixelFormat.Format8bppIndexed
      Case 16
         Return PixelFormat.Format16bppRgb555
      Case 32
         Return PixelFormat.Format32bppRgb
      Case 48
         Return PixelFormat.Format48bppRgb
      Case 24
         Return PixelFormat.Format24bppRgb
   End Select
   Throw New Exception("Unrecognized bit count")
End Function

Private Function GetBitmapSize(ByVal bmp As Bitmap, ByVal bitCount As Integer) As Integer
   Dim pixelSize As Integer = CInt(Math.Log(CDbl(bitCount)))
   Return (bmp.Width * pixelSize + pixelSize And (Not 3)) * bmp.Height
End Function

Private Function GetBitmapScanRowSize(ByVal bmpSize As Integer, ByVal stride As Integer, ByVal width As Integer) As Integer
   Return CInt(bmpSize / (stride / width))
End Function

Public Sub CaptureFrame_Helper(ByVal sender As Object, ByVal e As EventArgs)
   ' set result
   _result = True
End Sub

Public NotInheritable Class LEAD_VARS
Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 19\Media"
End Class
using Leadtools;
using Leadtools.Multimedia;
using LeadtoolsMultimediaExamples.Fixtures;

public bool _result = false;
public CaptureCtrlForm _form = new CaptureCtrlForm();
public void CaptureFrameExample()
{
   // reference the capture control
   CaptureCtrl capturectrl = _form.CaptureCtrl;

   // output file
   string outFile = Path.Combine(LEAD_VARS.MediaDir,"CaptureCtrl_CaptureFrameExample.bmp");

   try
   {
      // set the video capture device, use your capture device name here
      if (capturectrl.VideoDevices["Logitech"] == null)
         throw new Exception("No Logitech video device available");

      capturectrl.VideoDevices["Logitech"].Selected = true;

      // create a new sample target
      SampleTarget st = new SampleTarget();

      // set the target media type for the video stream
      MediaType amt = new MediaType();
      amt.Type = Constants.MEDIATYPE_Video;
      amt.SubType = Constants.MEDIASUBTYPE_RGB24;
      st.SetAcceptedMediaType(amt);

      // assign the sample target to the capture control
      capturectrl.TargetObject = st;
      capturectrl.TargetFormat = TargetFormatType.AVI;

      // prepare the manual frames capture
      capturectrl.ReadyCapture(CaptureMode.ManualFrames);

      // do something before the capture starts
      if (capturectrl.IsModeAvailable(CaptureMode.ManualFrames))
      {
      }

      // set the capture mode to manual frames
      capturectrl.StartCapture(CaptureMode.ManualFrames);

      // capture a frame
      capturectrl.CaptureFrame();

      // create a media sample using the captured sample from above 
      MediaSample ms = st.GetSample(-1);

      // get the sample target's connected media type
      MediaType mt = st.GetConnectedMediaType();

      Bitmap bmp = WriteSampleBitmap(outFile, ms, mt);

      // stop the capture
      capturectrl.StopCapture();

      // check for the capture file and set the result
      if (File.Exists(outFile))
      {
         Image test = Bitmap.FromFile(outFile);
         _result = (test.Width == bmp.Width && test.Height == bmp.Height && test.PixelFormat == bmp.PixelFormat);
      }
   }
   catch (COMException)
   {
      _result = false;
   }
   catch (Exception)
   {
      _result = false;
   }

   // we'll loop on the state and pump messages for this example.
   // but you should not need to if running from a Windows Forms application.
   while (capturectrl.State == CaptureState.Running)
      Application.DoEvents();
}

private Bitmap WriteSampleBitmap(string outFile, MediaSample ms, MediaType mt)
{
   // get the video information 
   VideoInfoHeader vih = mt.GetVideoFormatData();

   // create a bitmap to hold the sample and copy it
   Bitmap bmp = new Bitmap(vih.bmiHeader.biWidth, vih.bmiHeader.biHeight, FormatFromBitCount(vih.bmiHeader.biBitCount));
   BitmapData bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadWrite, bmp.PixelFormat);
   Marshal.Copy(ms.Buffer, 0, bmpData.Scan0, GetBitmapSize(bmp, vih.bmiHeader.biBitCount));
   bmp.UnlockBits(bmpData);

   // flip the upside down buffer
   bmp.RotateFlip(RotateFlipType.Rotate180FlipX);

   // save the image
   bmp.Save(outFile, ImageFormat.Bmp);
   return bmp;
}

private PixelFormat FormatFromBitCount(int bitCount)
{
   switch (bitCount)
   {
      case 8:
         return PixelFormat.Format8bppIndexed;
      case 16:
         return PixelFormat.Format16bppRgb555;
      case 32:
         return PixelFormat.Format32bppRgb;
      case 48:
         return PixelFormat.Format48bppRgb;
      case 24:
         return PixelFormat.Format24bppRgb;
   }
   throw new Exception("Unrecognized bit count");
}

private int GetBitmapSize(Bitmap bmp, int bitCount)
{
   int pixelSize = (int)Math.Log((double)bitCount);
   return (bmp.Width * pixelSize + pixelSize & ~3) * bmp.Height;
}

private int GetBitmapScanRowSize(int bmpSize, int stride, int width)
{
   return bmpSize / (stride / width);
}

public void CaptureFrame_Helper(object sender, EventArgs e)
{
   // set result
   _result = true;
}

static class LEAD_VARS
{
public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 19\Media";
}
Requirements

Target Platforms

See Also

Reference

MediaSample Class
MediaSample Members

Error processing SSI file
Leadtools.Multimedia requires a Multimedia or Multimedia Suite license and unlock key. For more information, refer to: LEADTOOLS Toolkit Features