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View Full Version : Skipped frames during Capture but not Preview


j7n
11th July 2007, 13:39
I've been trying to digitize an old VHS tape, but are unable to get all frames. Let alone jerky sections, this causes the audio to get out of sync.

I have an old chinese Brooktree 878 based board and have installed this driver (http://btwincap.sourceforge.net/supportedcards.html). My system is Windows XP SP1, the target harddisk partition is empty. I don't know if the board could capture under Win98/VFW because on the old computer I didn't have harddisks big enough to even think about capturing video (and it is not possible to install a big harddisk there at all).

I tried capturing using the included AmCap application. I set the same resolution (720*576) on both Capture and Preview pins. The display shows all motion fluent, but it won't capture the same section of the video to file without dropped frames. On the statusbar it says 0 dropped frames, but the indicated rate reads somewhere at 15 fps, where it should be 24.9~25.0 fps.

Is there anything to be done to narrow down the problem?

communist
11th July 2007, 15:44
Did you try VirtualDub or VirtualVCR?

j7n
11th July 2007, 15:59
I tried VirtualDub and the skipped frames were present in VDub's Preview window too (w/o capturing to disk). Overlay mode didn't work, maybe because I'm using i965 integrated video. Would it be worth to try VirtualVCR?

communist
11th July 2007, 16:15
Well its free so no problem trying it out. Also VDub allows to turn off preview completely - does this help or make no difference? Oh and the Analog Capture Guide contains some good info on how to setup VDub.
http://www.doom9.org/index.html?/capture/start.html