[MacDV] Re: Burning DVD's - 3 Macs at once

[Mark M. Florida]

On 12/25/03 10:46 AM, "Erica Sadun" <erica at mindspring.com> wrote:

> At 6:08 AM -0600 12/25/03, R B Williams wrote:
>> Merry Christmas to All !
>> 
>> There are some details I'd love to get a handle on as I
>> approach the end of a long editing project. It is living in
>> iMovie 3 and will be right at an hour in length.
>> 
>> 1) I've seen postings about the point where the iMovie
>> program downgrades quality in order to fit on a DVD (an
>> hour?)  I don't want to hit that wall. How do I know where
>> that moment is? Length, size, what???
> 
> DVDs *always* downgrade quality. It's the standard
> MPEG-2 compression.
> 
> Digital video (DV) occupies (approx) 13 gig an hour.
> 
> You can stick about an hour at most at best quality on
> a DVD without exceeding the maximum instanteous bitrate.
> So at best quality, a DVD stores about 1 hour in 4.7 gig.
> 
> Further, DV itself is already compressed at 5:1.
> 
> Compression is just a thing you have to deal with when
> you work with digital video.
> 
> Alternately, there's film.

Wha???  You're talking about using film if you're a "quality purist"?

I think the main issue was the point at which iDVD goes into "90 minute
mode" and lowers the bit rate to squeeze in the extra 30 minutes.  From my
experience, and from what I've read and heard elsewhere, even iDVD's 90
minute mode is pretty good quality -- unless the source footage is super
grainy with lots of crazy camera movements, in which case you may get some
excessive MPEG artifacting...

>> 3) My habit has been to burn a rewritable disc to view and
>> check for any issues. After all is right, I make a DVD-r
>> version. That means encoding the project twice. Has anyone
>> tried making a disc image from an rw that will then burn
>> DVD-r's ?

> Just make an image and burn from there.

Yup -- or as one other person noted, copy the AUDIO_TS and VIDEO_TS folders
from the DVD-RW that you made and then burn your copies in DVD mode in Toast
(it needs to be UDF to be read as a video disc by DVD players).

Or, if you just burn the additional copies immediately with iDVD, it won't
re-encode it for those copies.

2 more cents.

- Mark