使用 IMediaSample DirectShow.Net 寻找关键帧

发布于 2024-10-14 09:53:02 字数 489 浏览 1 评论 0原文

据我所知，为了检查某个帧是否是关键帧，我必须检查 IMediaSample::IsSyncPoint() 方法，如果该帧是关键帧，则返回 0 (S_OK)，否则返回 false其他情况。

但 IsSyncPoint() 方法只是在抓取并传递给 ISampleGrabberCB::SampleCB() 回调方法的每个帧中返回 0。

我的回调包含的代码很简单：

  public int SampleCB ( double sampleTime, IMediaSample mediaSample )
  {
   Console.WriteLine ( "SampleCB Callback" );
   Console.WriteLine ( mediaSample.IsSyncPoint ( ) + " " );

   Marshal.ReleaseComObject ( mediaSample );
   return 0;
  }

我在这里缺少什么？

原文

As far as I know, inorder to check if a frame is a key frame or not, I have to check the IMediaSample::IsSyncPoint() method, which returns 0 (S_OK) if the frame is a key frame, or false in the other case.

But the IsSyncPoint() method is simply returning 0 in every frame that is grabbed and passed to the ISampleGrabberCB::SampleCB() callback method.

The code that my callback include is simple :

  public int SampleCB ( double sampleTime, IMediaSample mediaSample )
  {
   Console.WriteLine ( "SampleCB Callback" );
   Console.WriteLine ( mediaSample.IsSyncPoint ( ) + " " );

   Marshal.ReleaseComObject ( mediaSample );
   return 0;
  }

What am I missing here?

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