Jerky Motion

[dvnewbie]

I'm a real newbie who doesn't understand everything people are saying on this forum, so please bear with me.

I'm transfering video of a birthday party that was recorded on a Sony TRV-18 MiniDV camera, using a firwire connection and the Showbiz software that came with my computer. My system has the following specs: 512MB RAM, 120GB HD @7200rpm, Radeon 7000 64MB DDR Video Card (is that the same as the "capture card" I keep reading about?). I used the default settings to save the capture, which is 720X480, 24bit, 30.0 fps. I'm not sure I understand what all of that means.

My problem, in lay terms, is that the computer file is noticebly more jerky than the original tape file when I play them both back and compare.

I noticed many people in this forum seem to recommend another capture program (Huffy?), but I've also read that any program capturing dv to avi should be the same, since the avi file is essentially the same as the data on the tape.

I also noticed that many people on the forum complain about dropped frames. How does one know when there is a dropped frame problem? I looked at the properties of the file I had saved, and when I multiplied the number of seconds times 30.0 fps it looked like I was missing 66 frames over a 36 minute period. That, alone, couldn't account for the jerkiness throughout the playback. Also, if I understand correctly, NTSC actually plays at 29.97 fps. If I multiply the number of seconds times 29.97, I get exactly the number of frames I have according to the properties of the saved file.

Is there something obvious that I am doing wrong that is simple to correct? Do these settings sound right, assuming my goal is to edit the tape and burn it to a DVD (using MyDVD) to view on a normal television?

[bugster]

Capture cards, dropped frames etc are terms generally only used when referring to capture of analog material. Your camcorder is digital and so has stored the video as digital info. Whne you 'capture' it via your firewire connection all you are really doing is copying the data from the tape to a file on your HD, not capture in the normal sense. And yes, it is actually 29.97fps though many programs round this up to 30 for display purposes, I suppose they don't want to 'confuse' their users.

As to the jerky playback I am not sure. Make sure your HD is configured to use DMA and kill off any background apps that might be running to see if you can improve things. Make sure your desktop is configured to use 24bit colour or better too. It should play fine

Hope this helps

[jfebus]

Hi,

To avoid dropped frames when using firewire, try to check the DMA settings of the HD and leave the PC alone when capturing. What are you using to view the file? MS Media Player is not a good one ( it's kind of slow)!

Regards,

Jose

[dvnewbie]

Thanks for the response. I think the problem was just the viewer on the computer.

Can either of you clarify for me what happens when I use the camcorder to pass through the signal from my old, analog camcorder? In that case, is the new camcorder acting as the "capture device"? Would dropped frames be a problem there?

[bugster]

Can either of you clarify for me what happens when I use the camcorder to pass through the signal from my old, analog camcorder? In that case, is the new camcorder acting as the "capture device"? Would dropped frames be a problem there?

Yes, the camcorder is acting as the 'capture device' and dropped frames are unlikley to occur as the camcorder is designed specifically for video capture, be it via the lens and CCD or analog input.