drop frame: what cause it?

[ody96]

As I follow discussions regarding the above topic, most of you blame the drop frames (while capturing) on hard drive access speed, computer speed or video capture card. I believe (but not sure) there are a small factor from the source as well i.e. noise/error on camcorder or dirty tape or camcorder/vcr head. Am I right? I would appreciate if you could give me link of reference on this since I could not find it on my manuals.

[Ookami]

:readfaq: Q21 and 22.

[^^-+I4004+-^^]

Originally posted by ody96
As I follow discussions regarding the above topic, most of you blame the drop frames (while capturing) on hard drive access speed, computer speed or video capture card. I believe (but not sure) there are a small factor from the source as well i.e. noise/error on camcorder or dirty tape or camcorder/vcr head. Am I right? I would appreciate if you could give me link of reference on this since I could not find it on my manuals.

_yes,you are right!noise WON'T help your capturing:noise messes up the sync signals too so it's harder for the capture card to "read" the video signal:i'm experiencing better results on my bt8x8 based card with higher res & win2k(sourceforge drivers) when the video is noisy (higher average framerate) than with win98 & vfw drivers (picture quality is probably a bit on the win98/vfw drivers side,but "iuVCR" & "virtualvcr" (both for win2k/xp & wdm drivers) surely give me higher framerate & less drops than virtualdub&win98/vfw combo!)

(it's harder to use vdub on win2k:needs wdm->vfw wrapper that slows down the system:my cel600@700 can barely cope when the signal is clear...(cel@600 & mjpeg drops frames,at 700mhz does not drop)
if it's too noisy vdub on win2k drops to about cca. 20fps...i mean REAL NOISY!!.....
"iuvcr" & "virtualvcr" don't need this wrapper:they are native to wdm capturing...."iuvcr" even has segmented capture:surely usefull for us FAT32 people..virtualvcr author is stubborn enough not to include this feature,although his program also doesn't stablise FPS rate as virtualdub or iuvcr do ..ie. "25.110" rates are usual for this program..-so i don't consider it a decent choice for capturing...)



cheers