Reccomended video codecs for Cortex

[John Winter]

Hello chaps

Just wondering what codecs you guys are using for your video capture - I'm currently using the MJPEG video compressor @640x480, for on the fly capture. This pumps up my dual CPU usage to the max, and playback using WMP or Cortex's built in viewer is patchy at best - sometimes the video runs too fast, or freezes on the first frame.
Do any of you have any advice as to the best codec to use - to strike a good balance between performance, quality, and reliability?

Cheers

John

[Karam]

Does the CPU usage increase just on recording? What sort of camera input are you using and what frame rate?

I've got both USB and digitiser card cameras on an old Pentium XP and can't say I've noticed these types of symptoms. I know that using MPEG 4 V2 compression tends to create very large files for some reason, though quality is good. But I have found that using the ASF option gives adequate video quality for my own purposes with much smaller file sizes.

[John Winter]

Hi Karam

CPU usage runs at about 30-40% on idle (from the Cortex process), and when viewing fullscreen video, it jumps up to 90%. Interestingly, when viewing fullscreen and hitting the record button, cpu usage drops down to 20%, and the video display freezes. When the stop button is pressed, CPU jumps back up and the display updates again.

I'm beginning to wonder now whether the root cause is a video driver issue - either my display card or capture card, as even when I just obscure the fullscreen view with the task manager window for instrance, the CPU usage drops down....

I'm running windows server 2k3 on an Athlon dual core at 2.3ghz, 2gb ram, with an onboard Nvidia 6150SE configured with 256Mb shared memory.

[Karam]

Mine runs pretty much the same i.e 30-40% but doesn't get appreciably higher with larger display nor reduce on recording. Enabling motion detection does cause an increase of perhaps 5-10%. The display card is an NVIDIA GeForce FX 5200 128Mb. The PC is a Pentium 4 2.6Ghz running XP home.

Perhaps to discount the capture card you can try a USB web cam as an input and see if you get same issues.

[John Winter]

Thanks Karam - when I get a chance I'll have a go with the webcam. I did try ASF and whilst the CPU usage wasn't as high, the quality of recording wasn't high enough so I'll stick with MJPEG.
I suppose it's not the end of the world as everything works OK, but it would be nice to have an optimised system.