Dropped frames

[brilliant ken]

Hi! I have read all about dv capturing in this forum, particularly about the issue of dropped frames. I checked my videos that were captured using a PAL miniDV, with virtualdub, and it was reported that my videos were indeed 25.000 fps. However, I am still quite uncomfortable with the smoothness of the videos, especially during high-motion scenes when I view them on my LCD monitor. The videos were particularly unsmooth at the end,which, I presume, RAM inadequancy was to account for. (The video was slightly more than an hour long) Could this possibly have been the case for a full-resolution dv capture?
Another thing, I noticed that the data rate of the video, as reported by VirtualDub, recorded on one particular type(brand) of miniDV tape was slightly different from that of another type, though both were in SP mode. As such, could this possibly by any means affect the quality of the videos? Thank you.

[thecoalman]

Video won't look as good on a monitor as it will on a TV. Made for TV video is intelaced...... Try loading it in a good program for playing TV video like PowerDVD and you'll see a difference or try doing a short test clip and author it and play on a TV before you make any judgements.

As for your second question I have no idea but that seems odd as I thought DV was a fixed data rate.

[ZippyP.]

I am still quite uncomfortable with the smoothness of the videos, especially during high-motion scenes when I view them on my LCD monitor.

Probably your monitor refresh rate is not fast enough to keep up.

[brilliant ken]

Well, my computer's monitor is 60hz and that should be fast enough for 25fps vidoes right?

[thecoalman]

Even if it was capable od 120hz it still would not look as good. I've noticed a ghosting affect on LCD monitors now that Zippt brought it up.

Regardless, make a test burn and view on a TV before making any judgements. You have to eliminate whether you actually have a problem with the video or not.

[guns1inger]

What is the monitor speed in milliseconds ? 8ms or faster is really required for video playback (although this still isn't really fast enough for high motion). Anything slower will ghost to some degree. I have seen LCD TVs that are as slow as 20 ms, and virtually unwatchable for anything but the news.

[ZippyP.]

Well, my computer's monitor is 60hz...

LCD refresh rate is given in milliseconds (mS.), 12 or lower would be good.

[junkmalle]

Open your video in VirtualDub and step frame-by-frame through the parts you think might have dropped frames. If frames are dropped it's usually pretty obvious. In all likelyhood you just have a playback issue.

[brilliant ken]

Thanks to everyone for all your response! After checking, I'd realized that my LCD monitor is 16 ms.
If virtual dub reports that my videos are 25.000 fps, there should theoritically, really be no dropped frames right? I'm still puzzled over this matter as my video file, 62 minutes in total, is only 12.3GB. Shouldn't DV be 13 GB in size?
Hence arise my suspicion to the issue of dropped frames.
Thanks again.

[junkmalle]

If virtual dub reports that my videos are 25.000 fps, there should theoritically, really be no dropped frames right?

No. VirtaulDub is simply reading the frame rate from the AVI header.

I'm still puzzled over this matter as my video file, 62 minutes in total, is only 12.3GB. Shouldn't DV be 13 GB in size?
Hence arise my suspicion to the issue of dropped frames.

12.3 GB does sound a little small. But I haven't worked with PAL DV so I'm not sure.

[skeg64]

All you have to do is open it in virtual dub and press } to go the the next dropped frame.
i.e. hold the SHIFT key and press ].

If there are none it will say so down the bottom.

[thecoalman]

12.3 GB does sound a little small. But I haven't worked with PAL DV so I'm not sure.

I'm not familiar with it either and evertime I stick my nose in it I get it chopped off....

Just like to mention that Type1 and Type2 files will differ in file size. Type 2 will be slightly larger. Maybe that's where your seeing the difference in file size and data rate. I was under the assumption that Vdub only accepts type2 but I have seen a few posts reporting the new version accepts type 1, you'd have to confirm that for yourself.

[junkmalle]

Examine the total number of frames in VirtualDub. Multiply the running time of the original video (in seconds) by the frame rate. Do the numbers match? 62 minutes at 25 fps should give 93,000 frames (62 * 60 * 25).

[brilliant ken]

Assuming that the running time of the original video as reported by Virtual Dub was for real and not calculated based on the number of frames, the numbers do match.

[thecoalman]

Something else comes to mind, there's two file sizes. Right click on the file in windows explorer, select properties, and you'll see what I mean. The real size and how much disk space it's taking up.