Frame droppings with fire wire camera

[Georg Rees]

Hi there,

I`ve some problems with capturing split screen-videos with 2 ccd firewire cameras by imaging source. We record the videos with the programm max
on a Mac Pro computer. We tried already a lot of things like changing almost all the different max parameters/attributes and also switched between the back & front firewire port (400) of the Mac Pro... but so far we couldn`t find a good solution. There are many frame droppings in all of the recorded videos - most of the time the beginning is ok and then after 2-3 minutes it`s startin with a lot of droppings, afterwards an acceptable period, and finally frame droppings again after 5-6 minutes till the end (our videos should be 8 minutes long).
Is there anybody who knows such problems and has some good tips?
Cheers,
Georg

[Stefan Geissler]

Georg,

Sorry for asking, but what operating system do you use?

May be the frame drops are caused by too much CPU load, so not all incoming data will be copied from the FireWire board into memory.
Also a high load on the PCI bus can cause frame dropps.

At least, the frame drops can also be caused by the file writer if the harddisc is too slow or there is too much data. What codec do you use (in case you use Windows as operating system)?

[Georg Rees]

Hi Stefan,

thanx for your answer and sorry for writing back only now... I wasn`t at my office in the last days. Anyway, we`re using Mac OS X (Version 10.5.8). You suggested there might be problems with the CPU load or too high load on the PCI-Bus or the file writer, but actually we checked all these things. We are convinced that the problem which causes the frame dropps is somewhere else.
We just don`t know where exactly....

Best regards,
Georg

[Stefan Geissler]

Georg,

We have no experiences with Mac OS X, so we can not say, where frame drops are cause. The camera will provide the images flawlessly, we checked this with an external FireWire sniffer. It must be something in your PC. Thus I suggest to ask the Apple support too.