Best way to stream NTSC images captured with NI 1411 to hard disk?

[bentnail]

I would like to both display and stream to hard disk NTSC images that I might capture with the NI 1411, ideally using the IMAQ VIs. I need to capture every second frame from standard NTSC video (so 15 frames per second). A quick calculation shows 640x480x3(for 8-bit color)x15(fps)= 13.8 MB/s. My application also involves acquiring and displaying 5 additional channels of thermocouple data and 2 channels of Analog Input signals (very slow acquisition, ~10 samples/s, but I am worried about adding any VIs that might slow me down).

The discussion forum Document ID 1NUFFSIN suggests that the max transfer rates I can hope would be around 15 MB/s, and that requires a SCSI drive (i.e. the Seagate Cheetah). Since th
is is at the very edge of what I require (and the document doesn't mention anything about displaying images or additional AI DAQ), I am a bit reluctant to count on it.

The discussion forum Doc ID 2NG9SOLS suggests using the Conduant StreamStor product to achieve very high transfer rates, but I believe that bypasses system memory and so am I correct in assuming I will not be able to view the images as I'm acquiring them?

Any suggestions regarding hardware or software would be greatly appreciated.

[BruceAmmons]

How long is the interval you will need to record? Is it short enough to store the entire thing in the computer's memory, then write it to disk afterward?

Graftek would be able to discuss a variety of storage methods that might work for you. I know they have one product that stores directly to a hard drive, but I don't know if it lets you view it at the same time.

The analog inputs will be a very minor issue, unless you are using a laptop. In this case, they could be significant depending on the hardware you are using.

Do you really need color? Grayscale would reduce your bandwidth to 1/3 of what is needed for color.

The key thing is to create a large buffer that can handle short lags in the writing to disk.

Bruce

[Michael Noll-Hussong]

In addition to what Bruce mentioned:

I worked with the Vision Stream Lib from Alliance Vision (http://www.alliancevision.com/net/visionstream_lv/fr_visionstream_lv.htm) and it is possible to view your image stream while recording. If you are able to reduce the amount of data (perhaps using graysale images as Bruce mentioned) you do not need to have a special SCSI HD ...

HTH,
Michael