Compress video and transfer it to another machine for display

[akang]

I am grabing images using 1394 b camera and want to compress the video by MPEG or other codec and transfer it to another remote machine by  wireless  LAN for display.
I need this happens in real time.
Is there any function in Labview or CVI that I can use?

Thanks




Message Edited by akang on 04-19-2008 01:15 PM

[Wes_P]

Hi akang,

Using NI-IMAQ, you can save video into the AVI format.  In LabVIEW, these VIs can be found by going to your functions palette, and selecting: Vision and Motion»Vision Utilities»Files»AVI.  On this palette, you can find all of the AVI VIs that are included with the NI-IMAQ driver.  These VIs allow you to select which codec you used to compress the images, but you can only create AVI files.  There is a really good example program which can be found by going to Help»Find Examples... and then selecting Hardware Input and Output»IMAQ»File Input and Output»Grab and Save to AVI.vi.

[PAR]

We have recently implemented what you are trying to do.  I our case the we are capturing a analogue image using a buffered image acquisition. When a  the next image is available on the buffer (IMAQ property: Frame count), the image reference is extracted from the buffer and using "IMAQ Flatten Image to Sting" the image information can now be captured as a string. (Be sure to use the JPEG compression even with 1000 quality factor).  I our case we transmit the flatten image using a network deployed shared variable but you could use any other IP transmission method.  At the receiving end, the image is unflattened using the common "Unflattened from String" primitive with Image reference as type.  The image reference is the displayed as normal.  We use the buffered image acquisition to decouple the acquisition from transmission process. 

Using a dedicated1Gb Ethernet line (through a hub), there has been no problem transmitting 640X480 8 bit images at 30fps without any difficulty.  Our  evaluation is that there is plenty of bandwidth left.

Paul A. Rochefort
AECL
Chalk River Laboratories