I’m looking at purchasing a USB video capture device so I can convert some home movies to DVD. I was wondering how many minutes of video I can get onto each DVD-R? Thanks!
On my Apple Powerbook, iDVD will handle up to 2 hours of video content on a 4.7gb DVD-R. That’s at normal DVD compression, though. Standard DV (from a digital capture card, say, or a digital video recorder) takes up a whopping 12gb per hour, so it gets considerably compressed for a DVD-R. On the other hand, if you’re capturing on a USB capture device, you may be capturing MPEG-3 (or 4? I forget), in which case you can probably fit considerably more on a DVD.
The other question, however, is whether you want to be able to play it in a standard set-top DVD player hooked to your TV. Then you’ll probably only get 2 hours max on the DVD, because that’s the format the DVD player reads.
It depends… on how much detail and motion is in the video you start with, and how much you compress it.
This is referred to on many discs’ packaging where a little chart says something like, “60 minutes at high quality, 120 minutes at standard play, 180 minutes at extended play, 240 minutes at extra long play”.
This is an oblique way of referring to the rate at which the video data comes off the disc: the more data per second, the more detail possible in the resulting video, but the shorter in duration the video will be. Conversely, the less data per second, the less detail, but the longer the resulting video.
Consider that a commercial-movie DVD contains two hours of high-quality video recorded at much better quality than VHS or mini-DV or any other consumer tape format. Commercial-movie DVDs use all the capability of the DVD standard: they max out the data-transfer speed (to around 8 or 9 megabits per second) to provide all the data required for all that detail.
True, they often use a two-layer disc to do this. But even with one layer, you could get an hour of this high-quality video.
At half the bit rate (4 megabits per second), I managed to get four hours of video from my mini-DV camera onto one single-layer disc and it still looked pretty good (though occaisionally blocky in areas of fast complex motion). Mini-DV video has less detail than commercially-recorded movies.
Video from VHS tape has much less detail than that from mini-DV tape. I would bet that you could get four hours of VHS video on one single-layer disc with no problems. I would not be surprised to get six hours, actually, without losing any detail compared to the original tape.
If you reduce any video noise in the signal coming from your VHS tapes, you should be able to get even more video on the disc. Video noise adds random detail that takes up space.
(All this is with the standard encoding scheme (MPEG-2) used by commercial DVDs. If you use one of the newer codecs such as DivX or MPEG-4, as tofergregg mentioned, you can get the same data into even less space. But not all players will play the newer codecs.)
Thanks for the info.