ILMVUserCallback Interface

The ILMVUserCallback interface is a user-defined interface. It must be registered by calling the put_ReceiveProcObj method of the ILMVCallback interface. This interface has one method.

Methods

HRESULT ReceiveProc (long pData, long lWidth, long lHeight, long lBitCount, long lSize, long bTopDown)

Description

This method is called for each frame received by the Video Callback Filter.

Parameters

pData

A valid pointer to the frame data, passed in a long variable.

lWidth

Width of the frame.

lHeight

Height of the frame.

lBitCount

Bits per pixel of the frame.

lSize

Size of the frame buffer, in bytes.

bTopDown

Value that indicates whether the image in the passed buffer (pData) is top-down (1) or bottom-up (0).

Comments

The user can modify each frame by making changes to the frame's data. Please note that the memory for each frame is owned by the callback filter. If you wish to keep the frame data, you must make a copy of it. The user callback can dictate if this frame should continue to be used after the callback via the user callback function return code.

Notes

Returns

After working on the frame data, this method can return one of the following values:

Return Description
VDCALBK_ERR_OK Success. The filter continues normally, delivering the processed frame.
VDCALBK_ERR_DROP Do not deliver the frame. The filter drops the frame and continues normally with the next frame in the stream.
VDCALBK_ERR_DELIVERLASTFRAME Deliver the previous frame (the last one delivered). The filter saves the last frame it delivers downstream, in case the same frame is needed more than once.
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© 1991-2022 LEAD Technologies, Inc. All Rights Reserved.