DV issues in a 720 x 486 world

[Gary Adcock]

[Manny Kivowitz] “Is anyone aware if it’s possible to digitize dv footage via SDI (or even firewire) in such a way that the footage is scaled/cropped to full frame 720 x 486 without the 3 black horizontal lines at the top and bottom of the image?”

Nope

the DV spec is 720×480 you need to use some other type of compression –
photojpeg comes to mind

Gary Adcock
Studio37
HD and Film Consultation
Chicago, IL USA

[Manny Kivowitz]

Shooting DV, we’re stuck with 720×480 as our originating source. The problem is workflow and issues that arise from having 3 odd lines of black at the top and bottom of the frame (or white depeding on how you handle the move from dv to 720×486).

The workflow issues stem from the fact that all of our footage is created in 720×480 but our graphics are created uncompressed 720×486 and make up as much as 15% of the content of any one program. Our final sequences for color correct & mastering are 720×486 10 bit uncompressed. If you dumb the graphics down to 720×480 dv codec they of course look “soft” which is unacceptable for delivery but fine for offline. It is however an extra step and often the resizing of the gfx can cause issues later, especially if the editor has moved.

So we have the option of either working in a dv sequence till picture lock (with downcoded gfx), then upres the footage either through a software export, recapture from the sources or output back to dv/dvcam and re-import via sdi.

Or we can bring the footage in via sdi from the get go using motion jpeg for offline (we have enough storage to work either in full res dv through the rough cuts but not enough for uncompressed) and redigitize from the masters. The problem here is that all of our renders, working in a 10bit uncompressed sequence, will a)take a long time compared to dv renders b) take up a ton of space c) be required quite frequently

It’s hard to believe that with the proliferation of dv as an acquisition medium and the ever expandig prescense of graphical elements across all programming that we’re alone in struggling with these issues.. any insight would be appreciated.

[Gary Adcock]

[Manny Kivowitz] “Shooting DV, we’re stuck with 720×480 as our originating source. The problem is workflow and issues that arise from having 3 odd lines of black at the top and bottom of the frame (or white depeding on how you handle the move from dv to 720×486).”

Why? only the signal over FW is 720×480 the BNC video stream out of a deck will be D1 (720×486).

You are not alone, you have hit one of the big limitations of a dv25 workflow, now it is time to start thinking about
working in an uncompressed format so that all of your files are treated with the same respect as your graphics.
Whether you realize it or not your camera files are getting beat up the same as your graphic files are, you just don’t see it.

Gary Adcock
Studio37
HD and Film Consultation
Chicago, IL USA

[Manny Kivowitz]

Thanks Gary, it’s good to know we’re not alone.. but it’s a shame that a vendor hasn’t stepped up to the plate to effectively deal with the issue. Pinnacle’s cinewave was a step in the right direction that sadly led to a dead end. Relying on the system processors to handle mixed codecs seems to remain a distant pipe dream.

[Jeff Bernstein]

Manny, you have touched upon a topic near and dear to my heart. The issue is that DV25 and DV50 are both locked to 720×480. Moreover, for whatever reason, FCP finds it difficult to handle the 6 line differential. As such, we can’t mix and match in the timeline. This results in a real issue. If a JPEG format in FCP took advantage of RT Extreme, this would not be as big an issue. Plus, with these JPEG formats, we would also have 4:2:2 color space and lower data rates, yet great quality.

So, my hope is that Apple will unleash the still untapped power of the GPU. Keep in mind, Avid Adrenaline can mix and match on the timeline on OS X with AGP. It should not require PCIe to accomplish, but it wouldn’t hurt by having the added bandwidth.

Jeff Bernstein

Digital Desktop Consulting
Apple Pro Video VAR
XSAN Certified

323-653-7611

[Walter Biscardi]

[Jeff Bernstein] “Moreover, for whatever reason, FCP finds it difficult to handle the 6 line differential.”

it handles it just fine. you just need to move your DV footage one vertical scan line in a 720×486 uncompressed timeline. Your Center Settings should be 0,1 in the Motion tab.

[Jeff Bernstein] “Keep in mind, Avid Adrenaline can mix and match on the timeline on OS X with AGP.”

CineWave was mixing and matching on the same timeline almost two years ago with FCP. It was / is still the only card that had on-board processing to allow the mix and match. Hopefully Apple will add it with the next release.

Walter Biscardi, Jr.
https://www.biscardicreative.com

Now editing “Good Eats” in HD for the Food Network

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

[Steve Covello]

If you create a new D-1 720 x 486 timeline and then copy/paste your DV contents from the DV timeline into it, FCP will autmatically make the scan line adjustment and ‘canvas’ the DV image onto 720 x 486. However, it seems to make a slight downscale adjustment too [?] which is a pain to take out in every shot.

As mentioned before, if you re-cap UC 10-bit from DVCam deck via SDI, your frame size should be 720 x 486. I don’t know definitively how the scan line issue reconciles — whether the DV output is ‘canvased’ onto a D-1 frame size inside the DVCam deck prior to SDI output, or whether it is scaled vetically. I have not seen scan line artifacts as a result of having captured DVCam/SDI, so I am venturing to say it is the latter.

steve covello
double wide post

[Gary Adcock]

[Manny Kivowitz] “Thanks Gary, it’s good to know we’re not alone.. but it’s a shame that a vendor hasn’t stepped up to the plate to effectively deal with the issue. “

Manny
DV is not an end all be all, I only work in DV for demo’s — I no longer ever work with DV 25 materials if i can help it. ( I have actually only done 2 -SD jobs in the last 3 years- my work is all HD)

but If your going to be a broadcaster you need to start handling your content like the pros do, it sloves a large number of the small issues that nag at people. There is a reason that Uncompressed workflows exist.

Gary Adcock
Studio37
HD and Film Consultation
Chicago, IL USA

[Richard Dee]

ADC makes a DV- SDI converter (API- 560 I think) that would probably work.

Not sure about what the qauily looks like vs. and SDI Dvcam deck.

It’s about $900

[Gary Adcock]

[Deadhead] “ADC makes a DV- SDI converter (API- 560 I think) that would probably work. Not sure about what the qauily looks like vs. and SDI Dvcam deck. It’s about $900”

Not really a good idea, remember that tapes decks are built to properly handle the decompression issue of DV encoded material from tape because thats what they are made to do.
A Deck with BNC connectors is going to be able to handle the full bandwidth of the video signal at the correct D1 frame size, not to mention that an SDI or Component signal out is VASTLY superior to what a DV signal looks like.
(and to be clear– RCA video out does not qualify {DSR11}

Gary Adcock
Studio37
HD and Film Consultation
Chicago, IL USA