You can typically record up to six hours on a dvd. Howerver some recorders have an eight hour mode. This applies only to single layer dvd. For dual layer you can record twice as much. The normal recording time (standard quality) is 2 hours single layer, four hours dual layer.
Actually, A Single layer 4.38G DVD can hold only the equivalent of 1 Hour of video without any compression. Anything over 1 hour requires the DVD recorder to use Compression software to squash the recording onto the disc. The extent of this compression can enable some recorders to make a disc last 8 hours. Obviuosly the quality degrades in line with compression but it very good quality up to 3 hours usually (better than VHS). A dual layer DVD can record twice this amount but unless the recorder has an internal Hard drive to provide a buffer, then only one layer at a time can be recorded which would make it effectively the same as using two single layer disks.
What are you talking about? Yes 1 hr mode gives the best potential quality, compression is applied to the video no matter what mode the video is recorded in. Yes some recorders require finalizing the first layer before the second can be used. The hard drive has nothing to do with recording directly to a disc.
I believe a Standard television transmission as you receive it will not be compressed any more than it has been to fit on a single layer DVD if the program is less than 1 hour in length. Similarly some DVD's you might choose to back-up will not necessarily need to be compressed to fit a blank DVD-5 but the length of the title is not a comparison you could use since a DVD format is not comparable to a TV broadcast. I believe some recorders with HDD's can use the HDD to facilitate continuous recording to a dual layer, (no stopping at 1st layer end to reset machine to record on second layer & hence missing some of the program) but I may be I'll advised on that point.
