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Compression Property

Summary

This property is updated with the video compression of the video format.

Syntax

C++/CLI

public int Compression {get;}

public: 
property int Compression { 
   int get(); 
}

Property Value

A value that represents the video compression of the video format.

Remarks

This property is the video compression type of the video format. For compressed video and YUV formats, this member is a FOURCC code, specified as a DWORD value in little-endian order. For example, YUYV video has the FOURCC 'VYUY' or 0x56595559. For more information, see the Microsoft documentation on FOURCC Codes. For uncompressed RGB formats, the following values are possible: Value Meaning BI_RGB (0) Uncompressed RGB. BI_BITFIELDS (3) Uncompressed RGB with color masks. Valid for 16-bpp and 32-bpp bitmaps. For 16-bpp bitmaps, if biCompression equals BI_RGB, the format is always RGB 555. If biCompression equals BI_BITFIELDS, the format is either RGB 555 or RGB 565. Use the media subtype GUID to determine the specific RGB type. Use the CaptureCtrl.VideoCaptureFormats property to access the VideoFormats object that contains all of the formats available for the current capture device. The VideoFormats indexer obtains a VideoFormat object for each of the supported video formats. The properties of each object, obtained using the VideoFormats indexer, are updated with information about that specific video format. This information includes the following information:

SubTypeName
SubTypeFriendlyName
Height property
Width property
Compression
BitCount

Example

using Leadtools; 
using Leadtools.MediaFoundation; 
using LeadtoolsMediaFoundationExamples.Fixtures; 
 
 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
public bool _result = false; 
 
public void VideoFormatExample() 
{ 
   // reference the capture control 
   CaptureCtrl capturectrl = _form.CaptureCtrl; 
 
   int count, compression = 0, bits = 0, width = 0, height = 0; 
   int found, selected = -1; 
 
   // set a video device, use the name of your device here 
   if (capturectrl.VideoDevices["USB"] != null) 
      capturectrl.VideoDevices["USB"].Selected = true; 
 
   // reference the videoformats property 
   VideoFormats videoformats = capturectrl.VideoCaptureFormats; 
 
   try 
   { 
      // get count of available video formats 
      count = videoformats.Count; 
 
      // enumerate formats and select one 
      foreach (VideoFormat vf in videoformats) 
      { 
         // get the properties 
         bits = vf.BitCount; 
         compression = vf.Compression; 
         width = vf.Width; 
         height = vf.Height; 
 
         // select the format if it matches some criteria 
         if (bits == 16 && width == 640 && height == 480) 
         { 
            vf.Selected = true; 
            break; 
         } 
      } 
 
      // get the currently selected format 
      selected = videoformats.Selection; 
 
      // find a format based on subtype name, width and height (YUY2 320 x 240 video) 
      found = videoformats.IndexOf(Constants.MEDIASUBTYPE_YUY2, 320, 240); 
 
      // our found format is not selected, so select it 
      if (found != selected) 
         videoformats.Selection = found; 
 
      // get the new selected format 
      selected = videoformats.Selection; 
 
      // set our result based on what we expect 
      _result = (count > 0 && selected == found); 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
}

Requirements

Target Platforms

Reference

VideoFormat Class

VideoFormat Members

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Help Version 22.0.2022.12.7

Leadtools.MediaFoundation Assembly

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Leadtools.MediaFoundation Namespace

Leadtools.MediaFoundation.Common Namespace

Assemblies