I'm using Nero Vision (in Nero 7) to burn an AVI movie onto DVD. I added the movie, and then I clicked "Video Options" to customize the transcoding quality (resolution, bit rate, etc.), and in the part that lists the video resolutions for me to choose, I see one called: 720 x 480 (CCIR-601 D1). My question is what does "CCIR-601 D1" mean? I can use that one, as opposed to regular "720 x 480 D1." I just need to know the difference between the two (in a nutshell). Thanks.