SubType Property

Summary

Gets or sets the subtype of the media sample.

Syntax
C#
VB
C++
public string SubType { get; set; } 
Public Property SubType As String 
public: 
property String^ SubType { 
   String^ get(); 
   void set (    String^ ); 
}

Property Value

A GUID representing the subtype of the media sample.

Remarks

The returned string contains a formatted Globally Unique Identifier (GUID) of the form {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}. For more information on the available GUIDs, refer to the DirectShow documentation. Assignment can raise an error exception. For more information, refer to the Error Codes.

Example
C#
VB
using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
public bool _result = false; 
public ConvertCtrlForm _form = new ConvertCtrlForm(); 
 
public void GetFormatDataExample() 
{ 
   // reference the convert control 
   ConvertCtrl convertctrl = _form.ConvertCtrl; 
 
   // input file and output files 
   string inFile = Path.Combine(LEAD_VARS.MediaDir, "MediaType_ShortSource.avi"); 
   string outFilePfx = Path.Combine(LEAD_VARS.MediaDir, "MediaType_GetFormatDataExample"); 
   string sampleFileName; 
 
   // This example demonstrates how to use SampleTarget and MediaSample 
   // objects to directly access sample frames from a conversion graph. 
 
   try 
   { 
      // set the source and target files 
      convertctrl.SourceFile = inFile; 
 
      // set the preview 
      convertctrl.Preview = true; 
 
      // create a new sample target 
      SampleTarget st = new SampleTarget(); 
 
      // set the target media type for the video stream 
      MediaType mtTarget = new MediaType(); 
      mtTarget.Type = Constants.MEDIATYPE_Video; 
      mtTarget.SubType = Constants.MEDIASUBTYPE_RGB24; 
 
      // set the sample target's accepted media type 
      st.SetAcceptedMediaType(mtTarget); 
 
      // assign the sample target to the capture control 
      convertctrl.TargetObject = st; 
      convertctrl.TargetFormat = TargetFormatType.StillImage; 
 
      // run the convert 
      convertctrl.StartConvert(); 
 
      MediaSample msFrame = st.GetSample(1000); 
      long sampleStart, sampleStop; 
 
      while (msFrame != null) 
      { 
         // get the sample target's connected media type 
         MediaType mtSample = st.GetConnectedMediaType(); 
 
         // demonstrate media type properties copy 
         MediaType mtCopy = new MediaType(); 
         CopyMediaTypeAttributes(mtSample, mtCopy); 
 
         // get the sample times 
         msFrame.GetTime(out sampleStart, out sampleStop); 
 
         // create the file name for this frame bitmap 
         sampleFileName = string.Format("{0}_{1}-{2}.bmp", outFilePfx, sampleStart, sampleStop); 
 
         // create the bitmap for this frame 
         WriteSampleBitmap(sampleFileName, msFrame, mtSample); // mtCopy); 
 
         try 
         { 
            // create a media sample using the captured sample from above  
            msFrame = st.GetSample(1000); 
         } 
         catch (COMException cex) 
         { 
            // if we have reached the end of stream we are finished 
            if (cex.ErrorCode == (int)ErrorCode.VFW_E_SAMPLE_REJECTED_EOS 
               || cex.ErrorCode == (int)ErrorCode.VFW_E_WRONG_STATE) 
               break; 
            else if (cex.ErrorCode == (int)ErrorCode.VFW_E_TIMEOUT) 
               continue; 
            else 
               throw cex; 
         } 
 
         // set the result 
         _result = true; 
 
         // 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. 
         if (convertctrl.State == ConvertState.Running) 
            Application.DoEvents(); 
      } 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
} 
 
private bool CopyMediaTypeAttributes(MediaType pSource, MediaType pDest) 
{ 
   int fmtDataSize; 
 
   // return error if either source or dest is null 
   if (pSource == null || pDest == null) 
      return false; 
 
   // get the format data size 
   fmtDataSize = pSource.FormatSize; 
 
   // any format data 
   if (fmtDataSize > 0) 
      pDest.SetFormatData(fmtDataSize, 
         pSource.GetFormatData(fmtDataSize));    // yes, then copy it 
   else 
      pDest.FormatSize = 0;                 // no, just set the dest size to zero 
 
   // copy type, subtype, formattype 
   pDest.Type = pSource.Type; 
   pDest.SubType = pSource.SubType; 
   pDest.FormatType = pSource.FormatType; 
 
   // set dest fixed size samples and temporal compression 
   pDest.FixedSizeSamples = pSource.FixedSizeSamples; 
   pDest.TemporalCompression = pSource.TemporalCompression; 
 
   // copy samplesize 
   pDest.SampleSize = pSource.SampleSize; 
 
   return true; 
} 
 
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); 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media"; 
} 
Imports Leadtools 
Imports Leadtools.Multimedia 
Imports LeadtoolsMultimediaExamples.Fixtures 
 
Public _result As Boolean = False 
Public _form As ConvertCtrlForm = New ConvertCtrlForm() 
 
Public Sub GetFormatDataExample() 
   ' reference the convert control 
   Dim convertctrl As ConvertCtrl = _form.ConvertCtrl 
 
   ' input file and output files 
   Dim inFile As String = Path.Combine(LEAD_VARS.MediaDir, "MediaType_ShortSource.avi") 
   Dim outFilePfx As String = Path.Combine(LEAD_VARS.MediaDir, "MediaType_GetFormatDataExample") 
   Dim sampleFileName As String 
 
   ' This example demonstrates how to use SampleTarget and MediaSample 
   ' objects to directly access sample frames from a conversion graph. 
 
   Try 
      ' set the source and target files 
      convertctrl.SourceFile = inFile 
 
      ' set the preview 
      convertctrl.Preview = True 
 
      ' create a new sample target 
      Dim st As SampleTarget = New SampleTarget() 
 
      ' set the target media type for the video stream 
      Dim mtTarget As MediaType = New MediaType() 
      mtTarget.Type = Leadtools.Multimedia.Constants.MEDIATYPE_Video 
      mtTarget.SubType = Leadtools.Multimedia.Constants.MEDIASUBTYPE_RGB24 
 
      ' set the sample target's accepted media type 
      st.SetAcceptedMediaType(mtTarget) 
 
      ' assign the sample target to the capture control 
      convertctrl.TargetObject = st 
      convertctrl.TargetFormat = TargetFormatType.StillImage 
 
      ' run the convert 
      convertctrl.StartConvert() 
 
      Dim msFrame As MediaSample = st.GetSample(1000) 
      Dim sampleStart, sampleStop As Long 
 
      Do While Not msFrame Is Nothing 
         ' get the sample target's connected media type 
         Dim mtSample As MediaType = st.GetConnectedMediaType() 
 
         ' demonstrate media type properties copy 
         Dim mtCopy As MediaType = New MediaType() 
         CopyMediaTypeAttributes(mtSample, mtCopy) 
 
         ' get the sample times 
         msFrame.GetTime(sampleStart, sampleStop) 
 
         ' create the file name for this frame bitmap 
         sampleFileName = String.Format("{0}_{1}-{2}.bmp", outFilePfx, sampleStart, sampleStop) 
 
         ' create the bitmap for this frame 
         WriteSampleBitmap(sampleFileName, msFrame, mtSample) ' mtCopy); 
 
         Try 
            ' create a media sample using the captured sample from above  
            msFrame = st.GetSample(1000) 
         Catch cex As COMException 
            ' if we have reached the end of stream we are finished 
            If cex.ErrorCode = CInt(ErrorCode.VFW_E_SAMPLE_REJECTED_EOS) _ 
               OrElse cex.ErrorCode = CInt(ErrorCode.VFW_E_WRONG_STATE) Then 
               Exit Do 
            ElseIf cex.ErrorCode = CInt(ErrorCode.VFW_E_TIMEOUT) Then 
               Continue Do 
            Else 
               Throw cex 
            End If 
         End Try 
 
         ' set the result 
         _result = True 
 
         ' 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. 
         If convertctrl.State = ConvertState.Running Then 
            Application.DoEvents() 
         End If 
      Loop 
   Catch e1 As Exception 
      _result = False 
   End Try 
End Sub 
 
Private Function CopyMediaTypeAttributes(ByVal pSource As MediaType, ByVal pDest As MediaType) As Boolean 
   Dim fmtDataSize As Integer 
 
   ' return error if either source or dest is null 
   If pSource Is Nothing OrElse pDest Is Nothing Then 
      Return False 
   End If 
 
   ' get the format data size 
   fmtDataSize = pSource.FormatSize 
 
   ' any format data 
   If fmtDataSize > 0 Then 
      pDest.SetFormatData(fmtDataSize, pSource.GetFormatData(fmtDataSize)) ' yes, then copy it 
   Else 
      pDest.FormatSize = 0 ' no, just set the dest size to zero 
   End If 
 
   ' copy type, subtype, formattype 
   pDest.Type = pSource.Type 
   pDest.SubType = pSource.SubType 
   pDest.FormatType = pSource.FormatType 
 
   ' set dest fixed size samples and temporal compression 
   pDest.FixedSizeSamples = pSource.FixedSizeSamples 
   pDest.TemporalCompression = pSource.TemporalCompression 
 
   ' copy samplesize 
   pDest.SampleSize = pSource.SampleSize 
 
   Return True 
End Function 
 
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 NotInheritable Class LEAD_VARS 
   Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media" 
End Class

Requirements

Target Platforms

See Also

Reference

MediaType Class

MediaType Members

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Leadtools.Multimedia Assembly
Introduction
Getting Started
Namespaces
Leadtools.Multimedia Namespace
Leadtools.Multimedia.Common Namespace
Assemblies