Mpeg2 is the format of DVD data. The problem is, that in rendering a DVD from an Mpeg2 file, this is a complicated process of putting the data into a format that DVD players can accept and use. This involves not only writing the video data, but also ?multiplexing? the audio data so that is properly synchronized with the video data, making an info data file with information about the formatting including chapters, subtitles, languages etc. This is what takes the time and processing power to complete. This process is hardware limited by the cpu speed primarily (as long as RAM, HD speed is adequate). If you acquire the file in AVI from your source, the data is probably not compressed. But when you go to translate the data into a DVD, it must first be compressed to an Mpeg2 file, your computer will have to spend considerable time compressing your file into the Mpeg2 format before you start the rendering process to write a DVD. You are best off capturing your video in Mpeg2 format to avoid that extra processing time. That is why a hardware based Mpeg2 encoder saves time. The file size is considerably different. One hour of video can be captured in a 2g Mpeg2 file. One hour of video will generate an 11g uncompressed AVI file.
I use Arcsoft Showbiz DVD 2 as my capture/editing/writing software. It has the ability to handle dvr-ms (digital video recording from cable to hard disc) files, import uncompressed AVI files, Mpeg2 files, edit them, and then ?author? a DVD. When writing the DVD, I have two options. The ?smart rendering? option takes advantage of the fact that the material is already in the Mpeg2 format and is more efficient. A 1? hour video will take about 1? hours to render a completed DVD disc with near commercial DVD quality when played in a standard DVD player. The limitation is that only 1 ? hrs of video will fit on a standard DVD blank. As a comparison, standard rendering will take 2 + hours to render the same 1? hr video at 3mbits/s and this is at a modest reduction in resolution. But 2hrs of material will fit on a standard DVD when rendering in the standard mode at 3mbits/s (necessary for longer movies). If your video is less than 90 min, smart rendering can produce a very high resolution DVD in less time. You can find the software online for download on a limited time trial, or order it retail at for less than $70 at Amazon. By the way, a Sony HC 32 miniDV camcorder has an Mpeg2 hardware encoder, and you can capture your video digitally in the Mpeg2 format on the fly with the firewire connection.