Does capturing video at 720x480i use a ton of computing power ?

[JLegnon]

Does capturing video at 720x480i use a ton of computing power ? Whenever I capture at 720x480i the videos are all choppy and messed up . When I capture at 352x480i everything is fine .

Does the extra resolution eat up alot of CPU ?

My computer is a P4 1.8 GHz, 1 Gig Ram, Win XP.

[kpmedia]

A P4 1.8Ghz is adequate for MPEG-2 and lossless/uncompressed AVI captures. I used one for years.

Lossless and uncompressed video is mostly heavy on the hard drive (I/O resources), and light on RAM and CPU. It's mostly moving data off the video capture chips directly into data files with no further processing.

MPEG-2 capturing would depend on the card. Hardware compression cards would perform the same as the AVI, mostly being the movement of data. Because MPEG-2 is smaller, there's less I/O overhead. Software or hybrid hardware/software compression involves some CPU cycles, so you'll want to verify that Windows is running lean, with few open programs or running background services (and disconnected offline, in many cases).

RAM (memory) is not really used for video capture. The VPU/chipset on the video capture card handles that.

The difference in 352x and 720x is twice the bandwidth. You may have an issue with either I/O or CPU, depending on the capture format.

I/O issues on a computer from that era often means the drive has jumped out of DMA/UDMA mode, and is running as PIO. This is discussed in the dropped frames guide, because most "messed up" video is the result of dropped frames. See that here: How to Prevent Dropped Frames and Audio Sync Problems

If you figure out what's wrong, reply with the solution.

[JLegnon]

Thanks for all that info .

So whats weird is the video recorded at 720x480i that played blurry and choppy on my PC plays fine on my dads Apple Macbook . Theres a few dropped frames but other than that it seems fine . So playing the video back on my PC is the problem . Heres the test video , I uploaded it to youtube .

[lordsmurf]

Be very sure that you measure dropped frames ONLY by the meter in the capturing software. Never trust your eyes. As you've learned the hard way, software players are not reliable. Anything else happening on the computer can cause choppy performance. Even flaws in the software can cause it.

Note that even a Youtube version is unreliable. It's been altered, so only the original file is worth analyzing.

I do see what may be dropped frames. Regardless of what causes the jerky quality, I would not be happy with that. As a viewer, I'd stop watching after the second or third jerk. It gives me a headache.

I'd keep troubleshooting for what may cause dropped frames, if they exist. VirtualDub shows frame drops and dupes.