On Thu, 28 Dec 2000 13:02:36 GMT, JKE
>d_ruether@hotmail.com (Neuman - Ruether) wrote:
>>>5) Export the final video to some storage media, tape, disk, without any
>>>data loss.
>>Easy, in Mini-DV format...
>Please correct me if I'm wrong, but isn't Mini-DV format a lossy-format? So each
>time something is saved using a lossy codec the saved copy is not the same as
>original.
>
>So if you do the following:
>- load (using firewire) a DV-codec'd AVI from a DV camcorder. The video is
>recorded on PC's hard disk as an non-compressed AVI. Pretty much same as the
>original.
>- Open the AVI (don't make any changes) and save is using DV-codec. Althought no
>changes are made the now saved AVI is a "second generation" copy. So a lossy
>compression scheme is applied a second time.
>- Now you are ready to transfer the video to the DV cam. This PC "plays" to the
>video-file to camcorder which yet again applies the lossy codec before actually
>saving it to tape. Now we are looking at a third generation copy!
>
>At every turn the picture turns a little bit fuzzier. If you don't save it to DV
>tape you can save it on CD or DVD which employ lossy codecs as well. Why doesn't
>anyone invent a player that plays videos saved with a lossless codec.
They have: Mini-DV camcorders and decks...! ;-)
I think you have a misunderstanding of what Mini-DV is
about... The Mini-DV/DVCam/D8 camcorder (or VCR) itself
digitizes the picture and sound at a compression rate
of 5:1 frame-by-frame, and this is what is stored on
tape and/or sent unchanged to the computer HD. If no
filters/transitions/other-changes are applied during
editing, this exact same data is what is sent back out
to the recorder for mastering. Barring tape dropouts,
there are no losses... Even if you do alter the footage
in the editor, some codecs are so good that even with 10
generations of rerendering, there is very little loss
(see the samples at the end of my camcorder reviews, at:
www.David-Ruether-Photography.com/camcorder-comparison.htm ).
This ability to copy digital files without generation
losses is one of the main reasons for using Mini-DV
instead of Hi-8 and other otherwise decent formats.