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DVCPRO and DV - workflow

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mike simpson
DVCPRO and DV - workflow
on Jul 21, 2009 at 11:04:33 pm

So I've just been reading about sampling methods of both these formats as i work for a company that records in both formats on the same job.
I personally have not been impressed with how some of the footage looks but put it donw to the cameras.
Now that i understand that the sampling is different for both formats i'm wondering whether we should change the way we do things.
Basically we record composite feeds onto Panasonic AJD 455s and other footage in camera in DV format.
The AJD 455 footage is later captured in DV and edited with the other DV footage.
So...are we going about things the wrong way due to the fact that DVCPRO is 4:1:1 and DV is 4:2:0?
Would we be better off capturing all material using DVCPRO 50?

Any clues as to how to make everything look better would be most welcome.
If i need to answer any questions to gain further help then i'm more than willing to explain the entire workflow etc.
Thanks for any help in this.
(By the way we are in PAL land here and only working in SD)
Mike


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Chris Blair
Re: DVCPRO and DV - workflow
on Jul 22, 2009 at 1:46:40 am

We're primarily a DVCPro50 shop so I can help a little here.

You'd definitely be better off using DVCPro50. It records using 4:2:2 and is effectively double the data rate of DV. The other area you could drastically improve video quality is capturing into the AJD 455 deck using something other than composite signals. SDI would be best if it's an option, but at the very least you should be sending component video into it.

Another option would be to capture the feeds (using DVCPro50 compression if possible) into your NLE system at the same time you're recording to tape. This would save a generation and the time spent capturing from tape.

As far as the difference between DVCPro25 and DV. It's virtually non-existent when it comes to quality. Both are throwing out half the color information, both are encoding at 25Mbits/sec. So they're going to look very similar.

You should also shoot in DVCPro 50 if you have the capability, then capture via SDI using at least DVCPro50 codecs in your editing system.

The only drawback to using DVCPro50 vs. DV or DVCPro is that it uses more drive space.

Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com


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mike simpson
Re: DVCPRO and DV - workflow
on Jul 22, 2009 at 12:33:23 pm

Thanks for the input.

I was aware of most of your points and sadly we currently cannot do anything regarding recording via composite! This frustrates me a lot as i know going SDI would be far superior...and component would be at least a step up. Sadly the cameras we use do not currently have the option of component out but there is an SDI board available. We are hopefully about to test one out now that JVC have one for us to try.
Apparently when the decks were first bought they came with SDI boards but were not installed and cannot be found now!!! How annoying is that.

We are looking into tapeless workflows - would be lovely not to have to log and capture all our footage.

Anyway...are you saying that if we capture all our footage into FCP using the DVCPRO50 codec that we would see the benefits? I'll give it a quick go next time a suite is free if the answer is yes.

Thanks again so far.

Mike


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Chris Blair
Re: DVCPRO and DV - workflow
on Jul 22, 2009 at 11:43:38 pm

On the capture question, it depends. You're not going to see much of a quality increase capturing DV originated footage shot with a DV camera, but you would see a difference in capturing feeds directly into a NLE rather than recording them to tape then capturing. That stands whether you use DV or DVCPro50. You'd basically be saving the a generation and a transcoding pass since you'd elimiate recording to tape (1 generation), and the transcoding from analog to digital capturing it into your NLE.

Hope that helps...



Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com


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Daniel Low
Re: DVCPRO and DV - workflow
on Jul 23, 2009 at 11:00:11 am

[Chris Blair] "You'd basically be saving the a generation and a transcoding pass since you'd elimiate recording to tape (1 generation), and the transcoding from analog to digital capturing it into your NLE."

Are you sure?

The signal is actually digital data as soon as it leaves the cameras sensor, if CCD, and then to the ADC (Analog to Digital Converter), but is purely digital if it's CMOS based.

Whether it then goes on to digital tape as digital bits or leaves the camera via the digital output as digital bits, they're still the same digital bits, so there is no generation loss.

With digital material if you transfer from like to like, there is no generation loss or transcode (in theory). 1=1, 0=0, 1=1, 1001001=1001001 and so on.

http://en.wikipedia.org/wiki/Camcorder
http://electronics.howstuffworks.com/camcorder.htm





__________________________________________________________________
Two years from now, spam will be solved. - Bill Gates, World Economic Forum 2004


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Chris Blair
Re: DVCPRO and DV - workflow
on Jul 23, 2009 at 6:07:20 pm

I was talking about the feeds he mentioned in the original post. I'm assuming he's talking about recording feeds from satellite and he said they're currently recording to DV tape via composite. So by capturing those feeds directly into the NLE, he's saving the generation and the transcoding hit I was referred to.

Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com


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Daniel Low
Re: DVCPRO and DV - workflow
on Jul 23, 2009 at 6:43:25 pm

Apologies, my mistake. Indeed you are correct, pretty well anything would be better than a composite feed.

__________________________________________________________________
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Bill Gates. Focus Magazine No. 43 (23 October 1995)


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mike simpson
Re: DVCPRO and DV - workflow
on Jul 23, 2009 at 8:12:50 pm

Thanks for your input...and i agree that anything would be better than composite and hopefully we will be doing something about that shortly. We installed HD SDI cabling in readiness for upgrading but i can't see us being able to afford such a huge step any time soon...that would mean upgrading everything - monitoring, routing switchers, decks, mixers etc etc.

My initial enquiry was regarding mixing our SD DVCPRO recorded material with our SD DV recorded material and whether we should be capturing all the footage in any format other than DV due to the sampling of these formats, all PAL.

Any comments on this are more than welcome as i love learning and have found the cow a great place to do just that...and it's a great place to help others out with their problems.

Looking forward to hearing more,

Mike


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Chris Blair
Re: DVCPRO and DV - workflow
on Jul 25, 2009 at 12:54:35 am

My initial enquiry was regarding mixing our SD DVCPRO recorded material with our SD DV recorded material and whether we should be capturing all the footage in any format other than DV due to the sampling of these formats, all PAL.

To reiterate, there is virtually no difference between SD DV and SD DVCPro in terms of quality. For that matter, there is no difference using DVCam at 25Mb/sec either. DVCam has a wider track pitch for data so the data is spread out over the tape, which means less data fits on it. So while you can record 60 minutes on a standard DV or DVCPro tape, you can only record about 40 on a DVCam. Some people argue that the wider track pitch results in less dropout, and while it may have been valid 6 or 7 years ago, as tape has gotten better, most engineers say that's hogwash.

Here's a nice website (Adam Wilt) that helps explain it.

http://www.adamwilt.com/DV-FAQ-tech.html#DVformats

Hope that helps.


Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com


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