Since firewire capture is already compressed perhaps Video capture thru
S-video cable is better or a capture card..

Video can be captured at 8megs per second with lower compression ratio.
Other boards I believe capture at even lower rates of compression ...
since uncompressed video is 28 megs per second

Any help here? I am looking for the best quality of image

thanks
Fraser in Toronto

Firewire is the way to go. If you go out and shoot on digital tape, the
video is already compressed on the tape. When you transfer firewire,
you're basically just transferring the compressed data as is. When you
use a capture card, you're going to have to compress the video a second
time, plus you'll have the jump from digital to analog to digital.

frasser@gmail.com wrote:

If you are capturing DV firewire is your best solution. It is a digital
transfer. Capturing from S-Video would still be capturing the same data, not
an uncompressed version .
<frasser@gmail.com> wrote in message news:41F7ECF8.1010405@gmail.com...

On Wed, 26 Jan 2005 14:18:16 -0500, frasser@gmail.com wrote:

Firewire.

... has anyone heard of this??

DVX100 (bypasses the DV compression) and records 720 HD in raw format
from the block has 4:4:4 video!!! Needs lots of hd space to capture in
the field. Gives great colour depth..

This stuff from our mini DV cams is a poor mans 16mm attempt using DV
to 35.

Laurence Payne wrote:

There are any number of devices that capture uncompressed. What is the
issue? See Canopus, etc.

Your statement about a poor man's 16mm attempt (or another author) is just
dumb. Please read up on what is going on here.


<frasser@gmail.com> wrote in message
news:smWJd.4350$Yg6.981793@news20.bellglobal.com.. .

frasser wrote ...
Thats great if you are feeding RGB directly from an HD camera.

You can't shoot something on DV and "bypass the DV compression"
DV is compressed 5:1 between the lens and the tape, and nothing
you can do subsequently will recover that lossy compression.

If you are shooting on DV (or miniDV or DVCAM or DVCpro25)
then the optimal method of capturing the video is via Firewire.

Capturing via composite or Y/C ("S-video") is significantly
lower quality as you are taking the 5:1 DV video, expanding
it and converting to analog, then converting back to digital.
This method has only disadvantages and NO advantages.

5:1 compressed DV video takes ~ 13.5GB/Hour to store and
there is no significant advantage to expanding and storing at a
lower compression (even zero).

On Wed, 26 Jan 2005 19:17:13 -0500, frasser@gmail.com wrote:

Are you aiming to capture directly from camera, or to playback a
recording made in the camera?

If the former, raw format is a possibility.

If the latter, the compression has already taken place when the camera
recorded to its internal tape. Firewire will transfer everything
there IS to transfer.

On Wed, 26 Jan 2005 14:18:16 -0500, frasser@gmail.com wrote:

Firewire is used to transfer material that is already DV. What you get
is an exact copy, with NO degradation at all. So, if you have DV, just
pass it through Firewire.

On Wed, 26 Jan 2005 18:42:46 -0800, "Richard Crowley" <rcrowley7@xprt.net>
wrote:

I think this needs clarification. If the capture card in the PC has a firewire
input and an analog input (composite video or SVHS), the analog input on the
capture card would yield uncompressed (meaning better quality) video after the
PC capture device has digitized it internally.

You might have a camcorder that has an analog output that has been derived from
compressed DV inside the camera. But that is not what the OP wants to know I
think. IF you connect one expensive high-quality MINI-DV camcorder to the
firewire input then connect a brand new analog only camera to the analog input
of the capture card, you are not decompressing DV to get analog when using the
analog input on the capture card.

I can prove that my capture device (Matrox RTX100) can capture uncompressed RGB
or YUV video, not compressed-decomprressed DV video. You can see what format the
incoming digital video is by using a tool that comes with the DirectX SDK
(called Graphedit.exe). Using this, you can access the internal digital video
formats and see what type of digital format it is. If there's a compressor in
the chain, you will see it using this tool.

If you'd like to see some screen shots of my internal "filter graphs" using the
different ways of connecting to the capture card, I'll post them. Let me know.

Dave

On Thu, 10 Feb 2005 00:15:00 -0800, Dave <dju@nospam.net.com> wrote:

Sorry, it's spelled graphedt.exe.

"Dave" <dju@nospam.net.com> wrote in message
news:8j3m015g80odfe2op9nq2i2ai4aqdu53sc@4ax.com...
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.

"Dave" wrote ...
Do you think he has a camera with true analog output AND
DV/Firewire output? Does such a thing even exist?
If he has the option of Firewire, chances are 99 of 100 that
he has a DV camcorder.

On Thu, 10 Feb 2005 05:09:22 -0800, "Richard Crowley" <rcrowley7@xprt.net>
wrote:

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

On Thu, 10 Feb 2005 05:14:54 -0800, "Richard Crowley" <rcrowley7@xprt.net>
wrote:

The Sony VX1000 has that, FWIW. That's what I have.

Dave