DirectShow interface actual articles (3)
Playing speed setting
A method of using iMediaPosition is required.
MediaPosition.put_rate (1); // Normal
MediaPosition.put_rate (0.25); // Slow
MediaPosition.put_rate (2); // Fast
Single frame playback control
Need to use iVideoFramestep
VideoFramestep.Step (1, nil);
volume control
Need to use ibasicaudio
Increase volume: Basicaudio.get_volume (& volume); // Get volume Volume: = Volume VolumeStep; Basicaudio.Put_Volume (Volume); // Add a decibel minus volume: Basicaudio.get_volume (& volume); // Get Volume: = Volume -VolumeStep; Basicaudio.putVolume (Volume); // Decrease a certain amount of decibels
Display zoomal reduction control
Simply change the size of Edit1, then use the iVideoWindow interface method
VideoDow.SetWindowPosition (0, 0, Edit1.Width, Edit1.Height);
Single frame capture, grasp
In fact, many interfaces provide this feature, but I prefer to use the isamplegrabber interface to implement, relatively, efficient.
This control is a little more, first, when opening the file
Var MediaType: TAM_MEDIA_TYPE;
ZeromeMory (@MediaType, sizeof (tam_media_type));
MediaType.majortype: = mediatype_video; // video stream
MediaType.subtype: = MediaSubType_RGB24; // 24 bit image
MediaType.formattype: = format_videoInfo;
Samplegrabber.setMediatype (MediaType); // Association interface
Samplegrabber.setBuffersamples (TRUE);
Then you operate in the graphic button event
VAR
MediaType: TAM_MEDIA_TYPE;
VideoInfoHeader: TVideoInfoHead;
BitmapInfo: TbitmapInfo;
Bitmap: hbitmap;
Buffer: Pointer;
Buffersize: integer;
Begin
Samplegrabber.getConnectedMediatype (MediaType);
ZeromeMory (@VideoInfoHeader);
CopyMemory (@VideoInfoHeader, MediaType.pbformat, sizeof (VideoInfoHeader);
ZeromeMory (@bitmapinfo, sizeof (tbitmapinfo);
CopyMemory (@BitmapInfo, @ VideoInfoHeader.bmiheader, sizeof (VideoInfoHeader.bmihead);
Bitmap: = Createdibsection (0, BitmapInfo, DIB_RGB_COLORS, BUFFER, 0, 0);
Samplegrabber.getcurrentBuffer (Buffersize, Buffer);
Image1.Picture.bitmap.handle: = Bitmapend;
I.e.
Here, first summarize so much, I hope to help everyone, these is only a fur of DirectX, it can be implemented very powerful, I just summed up the problems I encountered in actual, back There are still many work, I think I will gradually summarize this experience in this area, I have to share it with you, ok, DirectShow interface is here, if you have addition or ideas, please express it. Summarize the finishing, thank you.
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