How to uncompress DV

[Cystonic]

How does one transfer DV into SD? do you need a hardware card? I am new to this.

I am running a G5 dual 2ghz with 4gig ram 500gig internal HD striped. booting off a Tempo HD pci card hard drive. with 2 external lacie 500gig FW 800 Big Disks.

Thanks for any input

-Cystonic

[David]

DV is compressed when videotaping occurs in the camera.

The transfer to hard drive is lossless, so no compression or recompression occurs when getting to your computer via fw.

Rendering for anything does affect the quality of the part of the footage that is rendered.

You can't "upsample" DV to a high quality codec, although you can transcode to uncompressed by rendering.

Some people say that improves the quality; other's don't.

The point is that once you upsample to uncompressed, you need a card to play it out to your monitor/deck.

[David]

Also remember that transferring via Firewire is essentially as ACCURATE
as you can get, since (dropouts excepted) it is the exact data on the tape.

Transferring via SDI represents an upres of the color information which
involves both decoding the DV and interpolation to increase the number of color samples.

[Cystonic]

[ QUOTE ]
You can't "upsample" DV to a high quality codec, although you can transcode to uncompressed by rendering.

Some people say that improves the quality; other's don't.

[/ QUOTE ]

So if rendering the dv into sd by uncompressing the footage doesn't neccesarily improve quality then whats the hoopla over working in sd?

[ QUOTE ]
The point is that once you upsample to uncompressed, you need a card to play it out to your monitor/deck.

[/ QUOTE ]

are you talking about something like an aja sd card (maybe not the sd card but something along those lines?). Also what do you mean by deck. (aja I/0?) I said I was a virgin with this stuff /2pop/ubbthreads/images/graemlins/blush.gif

Thanks

-Cystonic

[David]

To get uncompressed standard definition footage into your computer, you need a capture card with SDI/component inputs. They cost money, and you need fast enough drives to deal with 20 mb/s.

That footage has a higher bandwith and may believe better quality than so called DV or DVCAM footage, which runs at 3.6 mb/s.

For the later, you only need a firewire port. Both are standard definition because they are 720x480 or 486 at 29.94 fps.

However, uncompressed footage from a beta or digibeta deck has a better quality to look, many claim, and will handle fx, and titling better.

[MitchJi]

[ QUOTE ]
So if rendering the dv into sd by uncompressing the footage doesn't neccesarily improve quality then whats the hoopla over working in sd?

[/ QUOTE ]

Hi,

Every time you render DV it is decompressed-rendered-recompressed. Each time you go through the decompress-recompress cycle you lose quality. So if you are rendering the same footage more than once the quality will be better working uncompressed.

The other issue is that the decompress-recompress on a high end deck with SDI is probably better quality than the Apple codec.

A third issue is rendering and RT performance will be better with uncompressed because the footage doesn't need to be decompressed...

You probably want to check this aricle:
http://www.lafcpug.org/feature_capture_card.html
Thinking of going uncompressed? Well this article focuses on the different uncompressed hardware solutions available for Final Cut Pro. It attempts to answers questions such as: "What Capture card should I buy and do I even NEED an uncompressed system?" Also included is a side by side evaluation of the quality and functionality of each uncompressed hardware solution on the market today.

Best Wishes,

Mitch

[arniepix]

[ QUOTE ]
Every time you render DV it is decompressed-rendered-recompressed.

[/ QUOTE ]
This isn't really correct.

When you render DV (or any other video in FCP) a render file is created. That file is separate from the original media file, and the original media file remains untouched. That's why it's called 'non destructive' editing. When you re-render anything a 2nd, 3rd or 10th time a new render file is created. The original DV is refered to each time you create a new render, & there's no more than 1 generation of render loss at any stage, no matter how many times you change & re-render.

[David]

True, Arnie.

But the portion that is rendered is a generation loss, or some loss.

The quality of DV codecs is directly related to how good that rendered footage reproduces.

Bob Hudson swears that AVID DV codec renders better than Apple's and has a web site to that effect.

[MitchJi]

[ QUOTE ]
This isn't really correct.

[/ QUOTE ]

Hi,

Yes and no. In the workflow you described (which is probably the most common situation) you are correct. But if for example you export a QT movie to work in another application...

Best Wishes,

Mitch