Does HDV loses its quality when Color Correcting?

[Rich Mayer]

Adam, in this case what you are saying is, no matter how I capture the video from the tape (firewire, SDI, Component) the codec will remain the same on the video, thus it doesnt matter how I capture it, the results when wanting to apply color correction will be the same, correct?

[Adam Gold]

In terms of capture, yes. But you can always then transcode to a better codec which gives you more latitude... but it won't do anything to improve the original video.

[Chris Barcellos]

Adam:

I think rich is talking about capture live using the component out like are available on the FX1. It was my understanding that that was a viable alternative to obtain the level of recording capability he was looking for. The idea was that feed is before any compression occurs. Anybody had experience that way ?

[Rich Mayer]

Adam,
so the only way (at least the only way mentioned on this thread) to transcode the video to a better codec, thus giving me more freedom when applying color correction or other effects without damaging the quality of the video, is by using a program like Cineform, correct?

[Rich Mayer]

Originally Posted by Chris Barcellos

Adam:

I think rich is talking about capture live using the component out like are available on the FX1. It was my understanding that that was a viable alternative to obtain the level of recording capability he was looking for. The idea was that feed is before any compression occurs. Anybody had experience that way ?

Chris,

no I was never planning to capture live, my editing system is extremely heavy and in a very small room, I wouldnt be able to get much by doing that, I was always refering to the case of having the footage on tape

[Adam Gold]

Chris--

Rick talked about recording HDV and uploading in his first post so I was pretty sure he meant recording to tape and then capturing.

Rich--

There are a variety of intermediate codecs, but Cineform seems to be among the best and most used for advanced post work.

If you can shoot to a better codec (using a better cam, like XDCAM EX, for example) or capture live uncompressed without ever recording to tape, you can get much better initial quality to start with.

[Brian Luce]

Originally Posted by Rich Mayer

Chris,

no I was never planning to capture live, my editing system is extremely heavy and in a very small room, I wouldnt be able to get much by doing that, I was always refering to the case of having the footage on tape

Capturing LIVE via component or SDI basically grabs the picture information BEFORE the camera has a chance to process and convert the information to MPEG2 and record it to tape. However this requires speedy RAID as has been discussed. Once the picture info is recorded to tape, you can't do anything magical to convert it to 422 color -- that information has to be there to begin with. However, cineform, prores422 and others can store your image information in a 422 CONTAINER, which is comparable to carrying one gallon of paint in a 5 gallon container. You still only have a gallon of paint, but in that big 5 gallon container, you'll be less likely to spill it or for it to slop out the way it might in a 1 gallon container filled to the brim.

[Chris Barcellos]

Ahh... my bad for not following thread closely. Well capturing from tape and into an intermediate codec is best you are going to get in that process, in my mind.

Capturing direct HDV mpeg files is really a matter of transferring 1 and 0s from the tape. There is no loss there. Converting at capture with an intermediate format like Cineform does involve a transcode, but its generally acceptable because controlled process provides a pristine and editable file. That has 4:2:2 interpolation allowing better access to color correction processes.

[Mike Calla]

Rich, I think the point everyone here is trying to make is:

ONCE YOU RECORD ON CAMERA - THAT IS THE BEST QUALITY YOU’LL GET

And if you use HDV (or certain other codecs), it doesn’t really hold up well when adding FX, colour correction, etc during editing.

So what we do is, we copy HDV to a better quality codec that can withstand the adding of FX, colour correction, etc. and preserve the original HDV quality.

Let me remind you;

- copying HDV to a better quality codec (Cineform) will not increase the original HDV quality

- It will only preserve the original HDV quality.

[Mike Calla]

ok Rich,
did a simple comparison for ya.

here is a HDV original screen shot,
and a cineform copy screen shot

i rendered both of them to an uncompressed format, and took a close up screen shot - ALREADY, even after ONE generation, the HDV copy has more artifacts! (look at blockiness to the left of the seagulls head in the HDV jpeg)

the first is HDV, the second Cineform (the crop between the two is not perfect, but negligible)


PS tech heads: I'm on my internet computer, not my workstation so I'm using Sony Vegas's pre-installed cineform V2.5 codec. Cineform's current NeoScene Codec is a MUCH MUCH improved codec over the Sony Vegas pre-installed cineform V2.5 codec. I added an simple S-curve and a simple Primary Color Corrector change to both clips.

the HDV JPEG is;
HDV > S-curve and a Primary Color Corrector > uncompressed render > jpeg capture > jpeg crop

the Cineform JPEG is;
HDV > Cineform V2.5 > S-curve and a Primary Color Corrector > uncompressed render > jpeg capture > jpeg crop