Read an avi file using "Read from binary file" vi

Question

My question is how to read an avi file using "Read from binary file" vi .
My objective is to create a series of small avi files by using IMAQ AVI write frame with mpeg-4 codec of 2 second long (so 40 frames in each file with 20 fps ) and then send them one by one so as to create a stream of video. The image are grabbed from USB camera. If I read those frames using IMAQ AVI read frame then compression advantage would be lost so I want to read the whole file itself.
I read the avi file using "Read from binary file" with unsigned 8 bit data format and then sent to remote end and save it and then display it, however it didnt work. I later found that if I read an image file using "Read from binary file" with unsigned 8 bit data format and save it in local computer itself , the format would be changed and it would be unrecognizable. Am I doing wrong by reading the file in unsined 8 bit integer format or should I have used any other data types.
I am using Labview 8.5 and Labview vision development module and vision acquisition module 8.5
Your help would be highly appreciated.
Thank you.
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read avi file in other data format.JPG ‏26 KB

Answer 1

Hello,
Check out the (full) help message for "write to binary file"
The "prepend array or string size" input defaults to true, so in your example the data written to the file will have array size information added at the beginning and your output file will be (four bytes) longer than your input file. Wire a False constant to "prepend array or string size" to prevent this happening.
Rod.
Message Edited by Rod on 10-14-2008 02:43 PM