View Full Version : MemoryGetDib - Doesn't release memory, plus 2 cameras

March 15, 2002, 19:29:17
When I repeatedly call MemoryGetDib, the memory used keeps increasing (as shown in Win2000 Task Manager) until the computer dies.
I need to do this because I need to keep a circulating buffer of images, so that when a certain event occurs I can save a recording of what happened a minute or 2 BEFORE it occurred.
I see a MemoryReleaseImageData, but nothing to release a DIB.

While I'm here:
I need to be recording with 2 cameras on "01 Composite Video" and "02 Comp...".
If I create 2 controls, it says "...bandwidth is too low". A previous message in this forum says that it may be a driver problem.
I have a card with a BT878A on it, using a driver from Conexant and can't seem to find any other driver. Driver Details says BT848.sys vers copyright 1996-1999. Any suggestions?

This message was originally posted by Paul Jackson in the old IC Imaging Control Support Forum.

March 19, 2002, 21:25:54
Hello Paul,

1) MemoryGetDib returns a memory handle to a dib. The caller owns the memory. Therefore, if you are done with the dib, you have to call the API function GlobalFree in order to free the memory.

2)Using the Connexant driver with a BT878 based card is ok. We tested the driver and it works ok. The BT878 has only ONE video converter. Because of this tonly one in put may be active a the same time. If you are using 2 cards in one system, you will recognize damaged images because the output FIFO of the BT878 is very small. If two BT878 are trasnferring image data at full resolution over the PCI bus, FIFO overruns occur because one chip has to wait to long for the PCI bus while the other one does bus master DMA (trasferring image data). There are two solutions for this problem: One the one hand you should reduce the width of the images on the other hand you should reduce the pixel depth (change the video format from RGB24 to RGB16 or RGB8).

Best regards
IC Support

This message was originally posted by IC Support in the old IC Imaging Control Support Forum.