Archived from groups: rec.video.desktop,rec.video,rec.video.production (
More info?)
On Thu, 10 Feb 2005 05:09:22 -0800, "Richard Crowley" <rcrowley7@xprt.net>
wrote:
>The video information was already compressed 5:1 between
>the lens and the tape. Capturing the analog output of a digital
>camcorder or VCR just runs the video information through an
>additional, superfluous, and destructive digital-to-analog-to-
>digital step. Storing the result of the superfluous uncompressed
>adds no value, takes more space to store, and puts more demands
>on the computer hardware.
>
>Direct digital transfer from DV tape to disk file remains the
>best way to preserve all the data remaining from the initial
>5:1 lossy compression inherent in DV.
After re-reading the entire thread before your statement, I realized that I
misunderstood that you were referring to capturing DV onto tape in the camcorder
first. I led myself to misunderstand your claim because I re-read the OP's
question and it didn't seem to say anything about recording to tape in the
camcorder...in the first place.
I think he was just asking about what method of video delivery into the PC would
yield the best quality result, analog input vs. firewire. There's no question
that raw video, derived from an analog input would yield better stored video
quality if it's not compressed anywhere first. And that is how it is using an
analog capture vs. firewire capture. If you don't believe that then I give up,
because I'm not trying to just argue for the sake of arguing.
Where I'm coming from is that I write video software under Windows using
Directshow and in fiddling with the filter graph and writing my own filters, I
have learned something about the way digital video is represented internally in
Windows and just wanted to clarify that using analog inputs can result in better
quality than DV inputs if the analog input is not compressed in the hardware
before capture. That is all.
So I don't disagree with your assertion since you were including 'recording to
DV tape' as part of the capture steps involved. I just disagreed with the simple
assertion that <using DV firewire to capture video will not result in as good a
quality digital video> as an uncompressed analog capture. Of course there are
huge drawbacks to raw capture, like too high a data rate causing frames to drop,
as I'm sure you already know.
Dave