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-   -   Does HDV loses its quality when Color Correcting? (https://www.dvinfo.net/forum/high-definition-video-editing-solutions/468164-does-hdv-loses-its-quality-when-color-correcting.html)

Rich Mayer November 21st, 2009 07:57 PM

Does HDV loses its quality when Color Correcting?
 
I am recording HDV with a Sony V1U, when I upload the footage and I see the plain video in the monitor it looks like HD, you can see the pixels and the quality of the video, however when I add color correction I notice that pristine quality of HD where you can see every detail is lost, the video starts to look like plain DV shot on widescreen... is this common for others? or is it my imagination?

By the way Im using Premiere with a Matrox card, the color correction is a Matrox feature, not Premiere feature.

Thanks

Battle Vaughan November 21st, 2009 09:06 PM

Premiere has a "feature" that adapts the preview image to the load on your cpu to try to keep a real-time playback. (You can turn this off). It is likely that the additional calculations for the color correction are causing Premiere to drop back to a lower res preview. Try rendering the clip first and playing back in high-quality mode and see if that's the problem.../ Battle Vaughan

Rich Mayer November 22nd, 2009 12:19 AM

even after rendering the quality of the video with the color correction doesnt look as pristine as the original HD file without color correction

Mike Calla November 22nd, 2009 01:58 AM

"Does HDV loses its quality when Color Correcting?"

YES YES YES YES and also YES!!!!

You should transcode to another, higher quality codec. HDV does not store a lot of colour information in its codec, and to start, it is a highly compressed codec. It was designed for capture, not editing.

If all you do is straight cuts and nothing else, then you are ok and you can happily use HDV in its native format - most every app will not need to rerender on "cuts only". But as soon as you do ANYTHING else: fade, fx, or colour correct, the program will need to render and you will lose information(quality).

Take a look at the Cineform NeoScene codec(or similar product). For 99$ you can colour correct, apply fx, render and rereender to your hearts content and you won't notice a difference ...for a few generations as least. With HDV you WILL notice after one gen!!

Marcus Martell November 23rd, 2009 02:17 AM

HI MIKE, so u r telling that the best workfolw to get max quality colors is to trascode in intermediate right? For 3 years i have been editing and color correcting m2t files with Vegas without having this in mind:To trascode with CINEFORM!WHY?
because my hardware can handle hd very quickly and easy and never had particular problems(even with the bullet).
So if now i decide to start using cineform i'll notice better colors?

thx a lot and i appreciate your help

Peter Moretti November 23rd, 2009 05:56 AM

Quote:

Originally Posted by Rich Mayer (Post 1450681)
I am recording HDV with a Sony V1U, when I upload the footage and I see the plain video in the monitor it looks like HD, you can see the pixels and the quality of the video, however when I add color correction I notice that pristine quality of HD where you can see every detail is lost, the video starts to look like plain DV shot on widescreen... is this common for others? or is it my imagination?

By the way Im using Premiere with a Matrox card, the color correction is a Matrox feature, not Premiere feature.

Thanks

Rich, Try color correcting in Premiere and see if the same thing happens. To be honest, it sounds like a Matrox issue more than an inherent problem w/ CCing HDV.

Tripp Woelfel November 23rd, 2009 08:43 AM

I've been wondering about how cc actually gets applied to footage in this scenario and if the format of the source footage matters at all. It appears that cc in PP is non destructive. CC filters are applied to a clip as instructions to the program on how to manipulate the clip "data" when rendered for output. The changes then are manifest only in the output file and are subject to the limitations of the output codec. So, if one color corrects an HDV clip then renders it out to h.264 for BluRay shouldn't the limitations be only in the output format?

Now, if an editor's cc tools operate only within the color space of the source format, my argument is invalid, but wouldn't it make sense for a cc tool to operate in a 4:4:4 space or would that involve too much overhead for the conversions.

I raise this because I believe the answer to the OP's question hinges upon how cc really works inside of an editor.

Chris Barcellos November 23rd, 2009 12:26 PM

Quote:

Originally Posted by Marcus Martell (Post 1451110)
HI MIKE, so u r telling that the best workfolw to get max quality colors is to trascode in intermediate right? For 3 years i have been editing and color correcting m2t files with Vegas without having this in mind:To trascode with CINEFORM!WHY?
because my hardware can handle hd very quickly and easy and never had particular problems(even with the bullet).
So if now i decide to start using cineform i'll notice better colors?

thx a lot and i appreciate your help

This from Cineform Site: You can download a trial version and test yourself to see what you get for your $ 129. I have used it for 2 years now, I think.


"Chroma Interpolation: 4:2:0 → 4:2:2. Background: Most HDV and AVCHD camcorders record chroma (color) in a format known as 4:2:0. Without boring you with details, 4:2:0 chroma is half the color resolution of more professional 4:2:2 formats. When Neo Scene detects 4:2:0 chroma it properly interpolates the source chroma to 4:2:2 for more accurate color processing during editing and effects work. And if you ever "key" your material, CineFormís chroma interpolation will substantially improve your resulting visual fidelity."


Here is site:

Cineform NeoScene : Features

Rich Mayer November 23rd, 2009 05:28 PM

Chris, I went to the cineform website and read the information and it actually looks interesting, if it does everything it says it does I think its a good investment, but how does it work specifically?? not even the website explains that.

Is it an individual program? you have to open it and load the footage and then save it in a different format? does it work INSIDE Premiere? do you have to call it once on premiere like an effect, how does it affect the performance on Premiere? I mean the website doesnt give you any information as to how exactly would be the functioning of the program, how is it?

Jim Snow November 23rd, 2009 06:51 PM

Rich, the Cineform website actually explains how their products work in considerable detail. I suggest you look over the information in their Tech blog. Cineform Tech Blog CineForm Technotes

Chris Barcellos November 23rd, 2009 07:06 PM

Quote:

Originally Posted by Rich Mayer (Post 1451454)
Chris, I went to the cineform website and read the information and it actually looks interesting, if it does everything it says it does I think its a good investment, but how does it work specifically?? not even the website explains that.

Is it an individual program? you have to open it and load the footage and then save it in a different format? does it work INSIDE Premiere? do you have to call it once on premiere like an effect, how does it affect the performance on Premiere? I mean the website doesnt give you any information as to how exactly would be the functioning of the program, how is it?

Essentially, your video is being transcoded to a new editable codec-- whether it comes from HDV or ACHVD, or other recording formats. For HDV, you capture via firewire, pretty much real time. For file based video, its a matter of locating the files, and telling the program to create a Cineform file.

By the way, my understanding is that Cineform was used with Slum Dog Millionaire, the big 2009 Oscar winner.

Rich Mayer November 23rd, 2009 08:01 PM

Chris, so basically it becomes a function inside Premiere? just like Matrox works "inside" Premiere, all the Cineform functions would be performed within the Premiere timeline like one more video effect??

Peter Manojlovic November 23rd, 2009 11:33 PM

Hey Rich.
The way you worded your question, is sort of open ended.

Basically, the Matrox card uses a proprietary I-Frame MPEG codec, that allows the board to do realtime CC..
As far as CC is concerned, 8 bid HDV is already a compromised structure (since it was designed as a delivery format). Any CC at this level, is rudimentary, and is sort of "mid level".

The advantage of Cineform, is it allows and does calculations with files that have way more colour information than HDV. You can tweak RGB parades to much finer levels than an 8 bit HDV file could ever get to. But unless you're working with some higher end monitoring, and delivering back to a 10bit signal, you probably won't gain much using Cineform vs Matrox.

But as far as your particular problem is concerned, there is something else wrong.
Since all my delivery is SD, I personally use a broadcast monitor, and have my Matrox card do a realtime down-convert for monitoring, via the RGB analogue cabling.

You haven't mentioned how you monitor, and to what format your renders are made..Perhaps a few more specifics, and we can solve your issues...

Chris Barcellos November 23rd, 2009 11:47 PM

Quote:

Originally Posted by Rich Mayer (Post 1451518)
Chris, so basically it becomes a function inside Premiere? just like Matrox works "inside" Premiere, all the Cineform functions would be performed within the Premiere timeline like one more video effect??

Rich:

Mostly, you use a utility to capture HDV or transcode files. It is called HDLink, a simple file for selecting the files or communicating with the HDV unit to capture and convert. From there, you open your project and import transcoded files for edit.

You will be able to render out to that codec, too, from within your NLE maintain files for further compiling of a final product. The point of using that codec in that way is that it is nearly lossless tool for success renders.

Rich Mayer November 24th, 2009 12:15 AM

Chris,

Thank you, I think I understand how it works, let me ask you a question. I presently capture video through a firewire cable that comes out of the Matrox box. The way my system is set up, the only way to capture video thru this firewire is by using Premiere with Matrox.

If I install Cineform, would the program be able to use this same firewire connection to capture? do I have to program it to work that way? is it complicated?

Sorry I ask so many question, the thing is I have absolutely no knowledge of how to install, uninstall or set up programs, I can edit very well but I pay somebody to put the system together and do the entire programming and connections. I dont touch the programming as I can not afford to mess up with it and not being able to work so I am "extremely" careful what I install or how it works or what I could mess up with. If my system stops working I would never start installing or unistalling programs, I would take it to somebody who I'd pay to fix the problem, I would rather not do that.

Thanks


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