More HELP with dropped frames.....please?

Hello everyone,

I continue to experience dropped frames when capturing at anything above 320x240.

I never use a frame rate above 10 fps-1/25. I use ToUcam software to capture ("webcam" or "V record"). I would like to be capturing at 640x480. I use the following Laptop:

Compaq Armada
PI with 10 G HD

Any ideas?

Happy Holidays,
Tom T.

Also, what webcam are you using? what kind of connection does it have to the PC?


Ivan

Hello Tom,

I had the same problem when I was using Vrecord (which, by the way, sucks big time!). I then moved on to QCfocus, which is what I presently use and I never had the same problem until the last imaging night a few days ago: in some of my 10fps avis I was loosing more than 10% of the frames which was a totally new experience for me. Although my laptop is a little more powerful than yours (pentium 4 Centrino 1.5 Mhz with 512 Mb RAM), I took the precaution to avoid jamming the USB port and did not use the USB mouse (touchpad was good enough), but the problem persisted. The puzzling thing is that the dropped frame ratio changed dramatically from one avi to another: some of the 2 min. 10fps films had no dropped frames whatsoever and I could not point out what changed between one instance and the next.

So I can't give you much help, but two things you can try out and see what happens: (a) be sure that you have only the webcam plugged in your USB port (which is one of the tips provided directly by Philips to have the best working conditions for the Toucam pro) and (b) most importantly change acquisition software: K3ccdtools I heard is very good, but I don't know it at all. Qcfocus I know well and I strongly advice, being very easy to use and serving the purpose just right. You can then move to Registax for processing (K3ccdtools has its own processing area, so it is a complete package for acquisition and processing. Your choice). I believe it would help also to stop all the unnecessary programs that may be running on your pc to free the CPU from useless jobs.

Sorry about the long reply. Hope this helps a little. I'm sure someone with more experience than me will come up with a better answer soon. If not try this and let us know.

Ciao and merry Xmas to you.
Luca

Tom, looking into Compaq's website, I searched for your laptop model... even though I do not know EXACTLY which Armada you have, I can pretty much tell you that the processor on your laptop might not be able to keep up with all the traffic...

I personally use IRIS for video capture, and it is freeware, so might want to give it a shot, as the software that you are using now COULD be part of the issue.

Frames dropped is something that happens normally, and it is not that bad, unless it is a BIG percentage of your capture session. For example I normally capture videos of 1800 frames, and might drop 30-50 frames. But then again, your laptop's processor plays a BIG part on this...

Also, might want to check and make sure you are not running any EXTRA software at the time... (specially unnecessary startup/resident software)
Defragging your HDD could also help a bit...



Take care, and Happy Holidays!



Ivan

Hello Tom,
I had a similar frame drop rate with my Toucam Pro with a PI 200mhz computer. The internal bandwidth capacity is just too small to handle the high data rates a webcam requires. As the others have suggested there are a few things you can do to lessen your problem.

1. Don't use the supplied software. Personally, I like KCCD3.

2.Limit your capture file size to less than available ram size so that the whole avi file can be buffered. Most frames are dropped during disk writes and reads. I learned early on that having an AVI file larger than 650 meg.(cdrom capacity) really makes file portability difficult.

3.And finally, if the dropped frames are still really bugging you, update your hardware. I went to a 650 mhz PIII and almost totally eliminated frame drops. But as others have said, dropped frames aren't really a big problem unless the problem is so severe that it is causing your computer to hang.

Merry Christmas
Ron