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FrameGrabber

property

Delphi
property FrameGrabber: TFrameGrabber read GetFrameGrabber write SetFrameGrabber  default DEF_FrameGrabber;
C++Builder
__property TFrameGrabber FrameGrabber = {read=GetFrameGrabber, write=SetFrameGrabber, default=0};
C#
public TFrameGrabber FrameGrabber { get; set; }
VB.NET
Public Property FrameGrabber As TFrameGrabber
C++/Qt
TFrameGrabber GetFrameGrabber ();
void SetFrameGrabber (TFrameGrabber Value);

Enables and configures, or disables, the frame grabber, which makes it possible to capture frames and draw over them.

Values:

fg_BothStreams: the frame grabber is applied to both the preview stream and the capture stream,

fg_PreviewStream: the frame grabber is applied only to the preview stream,

fg_CaptureStream: the frame grabber is applied only to the capture stream,

fg_Disabled: the frame grabber is disabled.

Overview

The frame grabber is an RGB filter that makes it possible to capture frames and/or perform graphic and text overlays.

The frame grabber makes it possible to:

  • capture video frames: see Frame capture,

  • draw (or write text) over video frames: see Drawing over video frames.

  • if FrameGrabber = fg_BothStreams, the overlays are applied to the video window (preview) as well as to the captured frames and the video clip being recorded.

  • if FrameGrabber = fg_PreviewStream, the overlays are applied only to the video window (but not on the captured frames or the video clip being recorded).

  • if FrameGrabber = fg_CaptureStream, the overlays are applied to the captured frames and the video clip being recorded, but are not visible on the video window.

To capture frames without applying the overlays (while the overlays are still needed in the preview and/or the recorded video clip), enable the FrameCaptureWithoutOverlay property.

Recording

When the frame grabber is used on a stream (preview, capture or both), this stream is converted into RGB format.

The recording is made in the native format of the video source when RecordingInNativeFormat is enabled (default).

To apply the overlays to the recorded clip, disable RecordingInNativeFormat. The recording is then performed in uncompressed RGB with the overlays applied.

It is possible to compress the video stream with the overlays applied by selecting an audio or video compressor, according to the CompressionMode and CompressionType settings.

During recording, the frame grabber can be applied to the recording stream, the preview stream, or both.

To preserve the recording format while still capturing frames, either:

  • apply the frame grabber only to the preview stream (FrameGrabber = fg_PreviewStream),

  • or enable RecordingInNativeFormat, which saves the clip in the native (unmodified) format coming out of the video source.

Note: using the frame grabber requires more CPU, so it should be disabled if it is not required to capture video frames or draw over them during recording.