In This Topic ▼

SubType Property

Summary

Gets or sets the subtype of the media sample.

Syntax

C++/CLI

public string SubType { get; set; }

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

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, "ConvertCtrl_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:\LEADTOOLS23\Media"; 
}

Requirements

Target Platforms

Reference

MediaType Class

MediaType Members

Download our FREE evaluation

Help Version 23.0.2024.2.29

Leadtools.Multimedia Assembly

Introduction

Getting Started

Namespaces

Leadtools.Multimedia Namespace

Leadtools.Multimedia.Common Namespace

Assemblies