4:4:4 12-bit Uncompressed DVX100

[Luis Caffesse]

That's good to hear. For a minute I thought you were back to
square one.

I didn't notice them right away either, probably because they
were up against the white wall. I've scrutinized the frame, and
haven't found any other speckles in there.


One other small request. When you have a moment (which I'm
sure you don't have many) could you give us a quick summary of
the different capture options that will be available. So many have
been batted around, I just want to make sure I know which are
staying in the design and which are going.

(i.e. will SDI still be implemented? etc.)

I think a quick list would help a lot of people.
In fact, we may want to start it out in a new thread, seeing as
the camera prototype is now completed. Perhaps the new
thread could cover the contruction of the box, and capture of the
footage.

This thread seems to be getting kind of hard to search, and it
seems people (myself included) keep asking questions that have
already been covered.


-Luis

[Justin Burris]

Juan,

About 3 weeks ago, you said that you were going to redo the 35mm to DV to RAW comparison. Any progress on that?

[Brett Erskine]

Speaking of questions that may or may not have already been asked heres one I think is VERY important for this project.

Can we see screen grabs both from a normal DVX100 and a uncompressed DVX100 AFTER its been thru DVD's standard MPEG2 compression?

Dont get me wrong, Im a perfectionist so uncompressed screen grabs are great to look at but what I would really be interested in is see what the difference is THE REAL world application that most of use will use it for - DVD.

Film outs are totally different story and no doubt uncompressed footage would look much better...but Im also a realist and know most people arent doing film outs all the time. All numbers and specs aside Im very interested in seeing what is can do for 99.9% of our projects that are going to DVD.

[Luis Caffesse]

Brett,

I don't know that that test is really necessary.
Most people would already agree that uncompressed 10 bit
footage looks better going to MPG2 than DV footage does. I've
done both and I can tell you that DV looks worse everytime. Of
course it all depends on the compression program you are using,
and the skill of the person doing the encoding, but you'd be hard
pressed to get a cleaner encoding from DV.

You can try it yourself with the stills that have already been
posted from Juan.

There is a reason most people master onto D1, or Digibeta at the
lowest end, when encoding movies shot on 35mm for DVD.

Either way, if Juan posts a 5-10 second clip in the near future, as
he said he would, perhaps he can also roll a tape in the camera
so we can compare the DV and uncompressed footage. That
would be good to test how the footage stands up to the entire
post process. I guess it can't hurt.

-Luis

[Kin Kwan]

Brett Erskine said:

"Can we see screen grabs both from a normal DVX100 and a uncompressed DVX100 AFTER its been thru DVD's standard MPEG2 compression?"

If you only apply MPEG2 compression onto the uncompressed DVX100 frame and not the compressed frame, then it wouldn't be a fair comparison.

But it doesn't matter anyways, because the uncompressed version will look better no matter what, since it has only been through one compression (MPEG2) rather than two compressions (DV and MPEG2)

This is why it's better if we see the actual uncompressed frames.

[Michael F. Grgurev]

Okay, some quick questions and then some hypotheticals.

I looked over the boards quickly and couldn't find this asked before, but am I correct in assuming, since your only taping video straight from the chip, there is no audio included in the mod, thenceforth you will always have to record to MiniDV/Firwire and resynce the PCM audio from that, into your Mod-Captured footage?

Also, I was reading some recent posts concerning loosing the in-camera effects, which is part of what concerned me previously, though it's great to hear the white balancing is still intact. I've been recently pondering over this in regards to the XL2, seeing all those neato in camera features in posses. One thing I've considered is you could always keep a record of all your settings and/or record to MiniDV for comparison.. to help your match any in-camera settings you want to replicate in post. It's not the most convenient thing in the world... although not too high a price to pay for uncompressed 4:4:4. Oh and that also brings up my question.. what activates the recording process on the mod, assuming it's separate from the cameras record activation? And if separate, can the two be synced?

And lastly, to appease my hypothetical brain... if you –could- tap into the pre-DV YUV signal and say.. put it on a wire or whatnot.. then you had a method to convert it to RGB.. say like a standard DVI output... your mod then could be applied from there, correct?

[John Alton Disciple]

Hey Juan, I haven't posted in a while, but I'm still keenly interested in your mod. Looking forward to your clips =)

[Juan P. Pertierra]

To answer Michael's questions:

1.Correct, there is no audio handled in the mod.(I gotta stop calling this a mod!) But it is trivial to simply make sure the DV tape is going, and then match the DV audio to the RAW frames. Remember, they are the exact same frames, so you don't even need a snap board(or whatever it's called), just any kind of quick motion will allow you to find two matching frames and synch them. Then delete the DV video and you are left with the audio.

2.Loosing the in-camera processing is the (LOW) price to pay for pristine data straight from the A/D's. Same thing with the Viper.

3.Not sure what you mean, but we wouldn't want to tap into the YUV data on the DVX, because it is lower-precision and a stage after the clean RGB data. My device does have a DVI output for monitoring purposes.

As far as the MPEG-2 compression comparison, if you are interested you can just grab any of the DV-RAW comparisons I've posted on this thread and compress BOTH with your favorite MPEG-2 compressor.

Like it has been said by Kin, the correct comparison is to compress both frames.

I'll try and take that clip tonight! :)

[Mark Grgurev]

I dont want to buy a camera and then loose all the features that I paid for, 4:2:2 uncompressed is still better than DV and its better than just dropping samples. 4:4:4 uncompressed may give film-like latitude but it also means that postproduction will take longer and it will take up more disk space.

[Kin Kwan]

Filming 4:4:4 uncompressed is only an option.

Yea, it's true that you're going to lose some features and in-camera effects, but you can always shoot in regular DV if you want.

If I had a camera with potentials like that, I'd kick myself for not using it to the max. (even if it means I lose a few lousy in-cam effects)

[Nicholi Brossia]

As far as editing cpu speed and hard disk space, you could always use the DV tape as an offline edit source that will later be replaced by the uncompressed footage. Of course this would have to be rough edits with no color correction, but would save time and space none the less.

Also, a majority of the camera effects and features could be duplicated in post. Sure that will result in more render time in the edit bay, but sometimes you have to give a little to get a little. Personally, I feel the gain of uncompressed video captured straight to hard disk is far more significant than loosing the in camera features. So you're giving a little to get a whole lot.

Juan has done an excellent job of "unlocking" these amazing abilities of the DVX while at the same time preserving those included stock. Like Kin said, with a camera capable of this much, it would be disappointing to use it for anything less than its highest potential.

[Michael Struthers]

This is really amazing stuff, Juan. Would somebody pay this guy? He needs some assistance!!

I wonder whether Panny should put him on the payroll. If this guy had a budget he might be further along.

Rock on bro!

[Luis Caffesse]

"As far as editing cpu speed and hard disk space, you could always use the DV tape as an offline edit source that will later be replaced by the uncompressed footage. Of course this would have to be rough edits with no color correction, but would save time and space none the less."

Nicholi,
That sounds like a great idea, but what are you keeping the uncompressed footage on? D1 tape?

Usually offline edits are done to save hard drive space in post.
There is no point in doing offline editing if all your source material is captured to hard drive to begin with.

This is why I think the SDI out solution is ideal. Granted, I still want the 4:4:4 uncompressed option, as it would be great for some special effects shots, when compositing or greenscreen is planned. But otherwise, going SDI out into a computer would be much more feasible with long form projects.

-Luis

[Nicholi Brossia]

Yes, you're right that initial hard drive space wouldn't be saved since the information is being recorded directly to hard drive to begin with. However, please correct me if i'm misunderstanding, after the individual .TIF frames are recorded to the camcorder's hard drive, you still have to process those frames into video, thus taking up space on the computer's hard drive. By rough editing with DV first, you will get an idea of what RAW footage isn't necessary and won't have to process or store that "extra" uncompressed video, thus saving both time and drive space.

No matter what process you take, you will always need to capture the DV tape in order to get your audio. I figure its a good idea to take advantage of this less-drive-intensive format since you have to capture it anyway.

Of course, a lot of what I'm saying is entirely dependant on Juan's program and how it functions. If there is a way to pick and choose which .TIF image "clips" to process, then this offline system could work well.

I agree, SDI would be great with long form projects, especially studio shots and chroma keying. You would only keep the acceptable clips and wouldn't have to deal with processing or capturing later. The only downside I see here is having to carry a computer along with the camcorder. Again, this is all about what setup best suits your production.

[Luis Caffesse]

"I agree, SDI would be great with long form projects, especially studio shots and chroma keying. You would only keep the acceptable clips and wouldn't have to deal with processing or capturing later. The only downside I see here is having to carry a computer along with the camcorder."


Actually, what I was saying was that 4:4:4 12 bit uncompressed would be best for chroma keying. You could record the rest of your footage through SDI if you didn't mind the loss of color information. But, for select shots you would still have the option of capturing 4:4:4.

And, SDI would not necessitate a computer (although I wouldn't mind carrying one around). If you didn't mind the 2:1 compression you could always go out to digibeta.

I realize this still isn't as ideal as uncompressed, but let's remember we're still talking about digibeta quality out of DVX. That is still amazing to me.

This is what I like the best about the modification. It will allow for various options which can fit numerous different production environments and situations. One capture solution obviously won't work for every scenario. Hell, who knows, there may still be times I'd want to use my DVX as simply a DV camera.

It's great to be able to get anything from DV to 4:4:4 uncompressed out of the same camera, and chances are I would use every single option at one point or another.

-luis