Re: [Hampshire] Editing DVD content?

>> You're seeing the
>> difference between a 25Mb/s DV stream with a DVD stream that is
>> generally
>> <10Mb/s (often much less). VBR is a Good Thing(tm), but DVD I-frames are
>> inevitably bandwidth-limited in the general case...
>
> I think you missed my point here.

No, I didn't. I just don't agree with it.

> Editing MPEG2 requires re-encoding so quality at the cut/fade/wipe
> point results in a degradation of image quality for the GOP containing
> the cut/fade/wipe point.

Re-encoding does *not* mean a visible degradation in quality as you imply.
Re-encoding only causes a reduction in quality dues to additional
quantisation noise (largely irrelevant in this scenario), and HF noise due
to motion estimation over previous compression artefacts (not a real
problem unless you're looking at very limited bandwidth).

Re-encoding a carved-up GOP will eat into your processor time, not your
output quality.

> Editing DV does not require re-encoding at all so never looses quality.

But DV doesn't get the compression levels of MPEG2, so you may start with
less quality - certainly for a given bandwidth, you would. Intra-frame
compression is only possible by way of quantisation of the DCT
coefficients - which generally means that fine objects (hair, leaves on
trees, etc.) lose definition in I-frames. MPEG2 fills in detail where
possible by way of P and B frames; DV cannot do this.

Vic.