View Full Version : FPS-Problem with DMK31 Firewire
April 9, 2010, 12:10:27
i hope to find some support here. i´m facing following problem:
in EVERY capture program the real frame per second-rate is exactly HALF of the chosen one. if i want 30 fps, i only get real 15 fps. if i take 15 pfs, i get 7,5 fps. :question:
i installed all new drivers, the SP2 firewire-patch (test with a direct firewire-connection to my second computer shows during file transfer approx. 200 mbit/s transfer rate, so it should be okay) and the newest drivers for the DMK.
my laptop is an amilo m 1420 with 512 MB RAM, Win XP SP2.
Thanks in advance for your help!
April 10, 2010, 12:41:07
no support here? no idea?!
April 12, 2010, 11:33:49
please excuse me not working in the office on the weekend. How do you determine the frame rate you get? Which capture programs do you use?
200 mBit transferrate seems to be a little bit less, I would expect with a test program at leat 400 mBit.
Also the camera driver have no influence on the FireWire bus speed, this is influence by hardware only.
April 12, 2010, 13:42:09
to get the real frame-rate is really easy. just devide the frames captured by the required time for this capture and my effect is in every capture program the same.
i tested with ICcapture and firecapture. last one shows also the real-FPS-rate written on HDD (http://firecapture.wonderplanets.de/)
and as written i only get EXACTLY half of the desired FPS-rate. when i want 30, i get only 15.....when i want 15, i get 7,5 fps!
it is really weird.
regarding my firewire-speed. it was just a simple test by copying a large file from one computer to another via firewire. so it is no real rest, but it already showed, that my firewire should work fine as it is faster than S100-Firewire (SP2-Firewire-Problem reduces to S100-Speed only).
April 12, 2010, 14:56:28
This is realy strange. We checked writing of single files to the hard disc and got only 10 fps on our fastest computers. Regardless, which frame rate was set. Saving AVI files needs less overhead as directory updating like single JPEG files.
However, counting images on the harddisc is no good idea for measure frame rates, because there are too many factors, that will influence the frame rate. You may try a RAM disk?
I usually count the number of frames delivered by the device in memory. I do not save anything for doing this.
April 12, 2010, 16:46:35
i don´t think, that this is a performance problem of the computer when capturing and saving Y800-avi-files. as i get 15 fps when trying 30 fps, the computer must also be able to do 15 fps when i chose 15 fps-setting....but i get 7,5 fps......
so i think it is a software problem of the driver or whatever, as the fps is exactly half of the desired one....
April 12, 2010, 17:05:48
If I measure frame rates on my 1.4MHz computer, then I will receive 15 fps, if I have set 15fps. However, I do not use saved files for measurement. I count the number of frames, that are received by my program.
April 12, 2010, 18:58:21
There is some misunderstanding.
Of course i do not measure afterwards in the finished file, but directly DURING the capturing. when i record the timer is running as well as the captured frames-number.
and i get only half fps of the desired one.
in firecapture it is more clear. firecapture shows the real fps-value captured and here it is the same!
i will post a sceenshot tomorrow...
April 13, 2010, 09:20:59
Please let me know, which driver installed.
April 13, 2010, 15:04:49
i use the actual from this site:
so it is the 188.8.131.52 driver
i also installed the FPM (fire wire performance manager), but it did not help....
April 13, 2010, 15:56:12
The FireWire Performance Manager has only an effect on Laptops and will only avoid damaged images. It has no influence on the frame rate.
Please create a support case at http://www.imagingcontrol.com/en_US/support/case/ . I can send you a small program, that I use for frame rate measurement.
Just an addition: I assume, you use very short exposure times for your frame rate measurement.
April 13, 2010, 16:18:33
the exposure i use is nearly fixed. when i use 30 fps i have 1/30s or less, when i use 15 fps i change to 1/15s or less. the brightness is controlled via gain.
only on very bright objects i go further down with the exposure times. on the sun for example i was able to reduce to 2 ms.
but also here i have only half frame rate...
April 13, 2010, 16:35:36
Please keep in mind, if the expsure time is longer than the frame rate allows, then the frame rate is halfed by the camera.
April 13, 2010, 21:15:12
i know that.....and of course i allways have an eye on it.
but also with 2 ms exposure i get only 15 fps....
April 14, 2010, 09:20:28
I wait for your contact, so I can send you my measurement program.
April 14, 2010, 09:43:25
pls send it to [email overwritten by Stefan]
April 14, 2010, 11:33:14
I have sent an email to your account. I also removed your email address from the post above to avoid spamming on your account.
April 14, 2010, 12:00:57
great....i will test it when i return home this evening...
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