imaq1394GetBuffer2

Format

rval = imaq1394GetBuffer2 (SESSION_ID sessionID, unsigned long bufferNumberDesired, unsigned long *bufferNumberActual, unsigned long onOverwrite, void **buffer);

Purpose

Copies the specified frame into a previously allocated buffer. Call this function only after calling imaq1394ConfigureAcquisition.

Parameters

Parameter	Type	Description
sessionId	SESSION_ID	A valid Session ID, which you can obtain using imaq1394CameraOpen2.
bufferNumberDesired	unsigned long	The cumulative buffer number for the image to retrieve. For continuous acquisitions, set this parameter to IMG1394_LASTBUFFER to get the next buffer, or set this parameter to IMG1394_IMMEDIATEBUFFER to get the current buffer.
bufferNumberActual *	unsigned long	The actual cumulative buffer number of the image retrieved.
onOverwrite	unsigned long	The overwrite policy to follow if a buffer is overwritten during acquisition. Specify IMG1394_ONOVERWRITE_GET_OLDEST to get the oldest valid buffer instead of the overwritten buffer. Specify IMG1394_ONOVERWRITE_FAIL to return an error if the requested buffer is overwritten. Specify IMG1394_ONOVERWRITE_GET_NEWEST to get the most recent valid buffer instead of the overwritten buffer. Note  IMG1394_ONOVERWRITE_GET_NEXT_ITERATION is not implemented by NI-IMAQ for IEEE 1394 Cameras and is only presented to keep the API consistent with NI-IMAQ 3.x.
buffer	void **	The buffer that contains the image when the function returns.

Return Value

On success, this function returns IMG1394_ERR_GOOD. On failure, this function returns an error code. You can obtain a more detailed error message with imaq1394ShowError.