Silly DeComb Question

[dinesh]

I have been reading a lot about DeComb and its benefits.
My situation is as below.
I capture 640x480 at 20fps since at other higher frame rates I get dropped frames. The original source is NTSC(29.97 fps) and hence my output has interlacing artifacts.
Can DeComb 3.1 help me ...
1) Remove the interlacing
2) Convert my frame rate to 30fps without change in duration using Decimate option.
I am asking this only because I have a non-standard frame rate as 20 fps. I have not tried anything as yet.

[Guest]

Telecide may recover your progressive frames for you but there is no way Decimate can get you back to 30fps. You are much better advised to get your capture situation under control so you can capture at the full frame rate without dropping frames. What you are doing is just playing around; it is not serious. :)

[TactX]

I would try capturing at a lower resolution (480x480, 352x480 or sth. in between), because it's more important to have smooth motion than a sharp picture.

[dinesh]

Thanks for the replies.

[Blight]

There are all sort of steps you need to check to make sure your capture system is configured for minimum frame loss.

Most of these are discussed here (http://www.inmatrix.com/articles/videocapture.shtml).

[McQuaid]

Yeah definitely lower the resolution if your going to stay on your existing hardware.

Use picvideo instead of huffy. I wouldn't go lower than 17 with picvideo try 18 or 19, don't bother with 20, if your going to use 20 you might as well use huffy. On my lowly PII400, I can capture 352x480 with a picvideo setting of 18 without ever dropping frames. This is of course using avi_io. If your not using this to capture, switch now. Its the best at capturing and you'll never have sync problems with this. Or not at the fault of the program anyway. The other main bottleneck is the harddrive. Try and cap to your fastest drive. Make sure its always defragged, maybe set up another partition. I know, defragging takes forever with microsoft's internal defragger. Use voptme. Its the best defragger and its really fast. Also use a fixed swapfile. This eliminates the possibility of swap file thrashing during a capture. Make sure its large enough that you don't run out of memory. The more ram you have the less size your swapfile needs to be. But its better to error on the large side. My swap file is 350megs and I have 64 megs of ram. Also voptme has the option of making your swapfile all together and at the start of your harddrive for fastest access.

The key thing is not drop frames and be capturing at 480 lines of resolution. I cap at 352x480 cause I going to vcd and my system drops at 640x480 and I find 352 to be sufficient. If your encoding to divx you might even try capturing at 320x480 which will slightly alleviate your harddrives burden. I personally think this is better because when you encode to 320x240 for divx, you don't have to worry about aspect ratio problems and manually configuring a player to stretch it properly.

Btw, does anyone know if the aspect ratio flags (which mpeg1 & 2 have) are part of mpeg4 iso standard?

If you do all this and still drop frames, your going to have to upgrade your system if you want to be serious about capturing.

[dinesh]

Thanks for your replies and suggestions Guys.
FYI,I had described my capturing problem earlier on this forum and concluded this to be a driver problem.
http://forum.doom9.org/showthread.php?s=&threadid=9341