What is the best format for re-editting?

[RCG]

I need to make a few videos and then use those to make another and then use that to make yet another.

Is there a best (or better) format (avi, wmv, mpeg, flv, etc) for doing this to have the least loss due to the reuse or is there some trick to avoid loss (other than mastering everything in one project from the originals)?

[Ken Berry]

The least lossy -- indeed almost totally non-lossy -- format is DV/AVI. But it is large: 13 GB per hour of video. This used to be a problem, but these days external hard discs are huge and fairly cheap.

[RCG]

Thank you.

Is there a second-best?

[Ken Berry]

In a sense, the answer really depends on what format your original video is in and what format your new videos are going to have. My DV/AVI answer was really predicated on the assumption that you were dealing with standard definition video. If this is indeed the case, and if, for instance, you were going to produce DVDs with it, then the second best format would be DVD-compatible mpeg-2 using a high bitrate to maintain the quality.

If, on the other hand, your video is high definition and you wanted to produce more high def video with it, then there would be no point in downgrading it to standard def DV/AVI as all the quality that comes with high def would be gone. So in that case I would just leave it in whichever format it came in. The main formats are AVCHD (mpeg-4) or HDV (mpeg-2). HDV is a bit like DV and has essentially the same bitrate throughout (25 Mbps), though since it is filmed on mini DV tape, is also large in file size.

AVCHD users Variable Bitrate, so if you were preserving and reusing it, then you would need to maintaina high bitrate to preserve its quality as far as possible.

Being mpeg, though, it is all lossy. And this is the case, whether it is standard or high def mpeg. Maintaining a high bitrate will preserve quality only to an extent. Every re-render will still involve some loss of quality, though your eyes might not be able to detect it the first one or two times. But after that, it is likely that the quality loss would become more visible.

[RCG]

Thanks again!