HDCam 29.97 to DV 29.97 — visual artifacts, field order issue?

[Jerry Hofmann]

Can’t get either link to work… Did something similar though just the other day. down convertered HDCAM to 8 bit NTSC uncompressed… no problems at all.

Jerry

[Gary Adcock]

[Pierson Jacquelin] We’re digitizing HDCam 59.94 sources through the Kona2 card to DV @ 29.97 for our offline edit. I’m encountering some weird field order issues that I believe are the result of the upper field first nature of HD being converted to the Lower Field first nature of DV

On most windows versions of DV it renders upper field first, and even AE on the Mac renders DV files that way. and there is nothing that says you cannot make your offline files force to upper field first when doing the capture. However if the content was shot at 24p you do not have to do that this way as progressive content does not have a filed order.

gary adcock

Studio37
HD and Film Consultation

[Pierson Jacquelin]

…here’s a link to the digitzed media:

https://triggersqueeze.com/test/8bitUncompressed.mov

It’s a few short seconds, but as it’s Uncompressed SD, it’s 57 megs. If you put it on your timeline, you can see that it plays back fine, it’s only when I use the DV compressor to dij it in that it gets funky.

I was thinking that it could be the 6 fewer scan lines in the DV codec causing the problem…

-Pierson

[Pierson Jacquelin]

[gary adcock] “On most windows versions of DV it renders upper field first, and even AE on the Mac renders DV files that way. and there is nothing that says you cannot make your offline files force to upper field first when doing the capture”

In Final Cut Pro, which we are using to digitize and edit, I don’t have any control of the field order when I dij. I can change the field order on the timeline, but even when I do, it doesn’t seem to affect the video output, i.e., I still get the same visual artifacting.

[gary adcock] “However if the content was shot at 24p you do not have to do that this way as progressive content does not have a filed order. “

True, although in our case, 95% of our field tapes are being shot at 30i. So our editing timebase for the project is 29.97. We had three HDV source tapes that were shot in some flavor of 24 and then transferred to HDCam at 29.97 so they could be incorporated into the show. When I look at the resulting HDCam dubs, I can see the 3:2 pulldown insertion pattern–and these tapes are particularly poor looking when digitized to DV.

-Pierson

[Pierson Jacquelin]

https://triggersqueeze.com/test/ThruDC.mov

…as you can see, there is a different type of motion “jutter” happening here. As it only happens when I’m choosing DV as my compressor (picture is clean in HD or Uncompressed SD) I really feel it’s because I’m compressing it with DV.

Ideas?

-Pierson

[Pierson Jacquelin]

Ok, after talking to Rudy at AJA I found out that what I was doing was half-wrong, half-right. Here’s what I was doing:

Use Easy Setup to set up for digitizing 10-Bit HD. Go to Capture Preset and change the compressor from Uncompressed 10 bit to DV-NTSC. Digitize… The result is what you see in my examples. Yes, it is DV from HD, but as I found out, the fields got a little messed up. Yuck. The thing that was really blowing my mind was that monitoring the realtime down-convert showed me a “correctly” interpolated picture. Hmmm…that should have been my cue!

Here’s how to do it correctly:

Use Easy Setup to set up for “525 8-Bit to DV”. Voila! What now happens is that upon detection of the 1080i SDI signal, the card Downconverts before it goes into the frame buffer/FCP. You can see the resulting AJA control panel setting here:

https://triggersqueeze.com/test/HD_to_DV_Input.tiff

Rudy had me set the Primary Format to 525i29.97 and the secondary format to 1080i29.97. Got it? Once again, “thank you” to the patient and friendly folks at AJA.

Final thoughts: you’ve got to upgrade the drivers to the latest version (1.1) and make sure you pay attention to the Conversion Mode (letterbox, anamorphic) so you get what you’re expecting.

Case closed!

-Pierson

[Gary Adcock]

[Pierson Jacquelin] In Final Cut Pro, which we are using to digitize and edit, I don’t have any control of the field order when I dij. I can change the field order on the timeline, but even when I do, it doesn’t seem to affect the video output, i.e., I still get the same visual artifacting.

FCP allows for you to create capture and Seq settings that allows for any number of possibilities when capturing data as long as you stay within the
FCP timebase for editing content ( sorry no 15 or 12 FPS anymore.)

[Pierson Jacquelin] We had three HDV source tapes that were shot in some flavor of 24 and then transferred to HDCam at 29.97 so they could be incorporated into the show. When I look at the resulting HDCam dubs, I can see the 3:2 pulldown insertion pattern–and these tapes are particularly poor looking when digitized to DV.

Of course you see the pulldowns from the HDV!. Assuming that SONY HDV was used for the shoot – your out of luck as the SONY HDV format is awful in terms of the cineframe settings ability to actually be 24p ( https://adamwilt.com/HDV/cineframe.html ) and you possibly did yourself a disservice by dubbing the HDV tape to HDCAM if you tried to stay at 24p on the HDCAm Master as the HDV camera tries to be at standard 3:2 but the HDCAM tape records at 2:2:2:4 when you do not have the optional 3:2 rev telecine boards installed

But I am glad that rudy got you straightened out on the HDCAM to DV down-conversion this is one of the great features of using the K2 boards.

gary adcock

Studio37
HD and Film Consultation

[Pierson Jacquelin]

[gary adcock] “FCP allows for you to create capture and Seq settings that allows for any number of possibilities when capturing data as long as you stay within the
FCP timebase for editing content ( sorry no 15 or 12 FPS anymore.)”

Yes, but not changing the field order in which it captures in the DV codec.

[gary adcock] “and you possibly did yourself a disservice by dubbing the HDV tape to HDCAM if you tried to stay at 24p on the HDCAm Master”

In our case, the dub to 29.97 was made to match the other 95% of the footage that is 1080i. The projects timebase is 29.97.

Thanks for all the help,

Pierson

[Oliver Peters]

No offense, but did you actually bother to read the Kona2 control panel manual (PDF) before doing this? Kona2 adds a whole lot of complexity to FCP in general. You really need to review and understand this before embarking on what is a very complex process.

Sincerely,
Oliver

Oliver Peters
Post-Production & Interactive Media
Orlando, FL
http://www.oliverpeters.com

[Pierson Jacquelin]

I did, but there’s not a section that really spells it out. For instance, there’s no flowchart or write-up about how to convert HD video to DV for your offline. The manual mentions it can be done and ultimately gives you info on how each aspect of the panel works, but no: “If you want to do this, then do this…”

You are right, this is a very complex process, and while my method (arrived at logically by reading the manual) will get the job done, it isn’t exactly the way the AJA engineers had in mind…which isn’t really in the manual. So, hint hint, why doesn’t someone write the “Idiot’s Guide to Working w/Hi-Def in FCP”? I could use another yellow refrence book on my shelf.

-Pierson