Still having downconversion issues...are you out there RED?

[Joe Walker]

We shot some gorgeous 4K product shots of new GM cars. We transcoded them in REDCine to Apple Pro Res 422 1080 23.98. When played back through our Kona 3 card to a Blackmagic HD Link routed to a Apple 30" Cinema Display , the downconverted footage has massive jagged lines through it. I've got everything set up correctly:

1. Sequence is set to Apple Pro Res 422 1080 23.98, playback set to same.
2. Kona 3 is set to primary: 1080 23.98psf, secondary: 525i 23.98. (setting secondary to 23.98p has no effect)
3. HD Link set to play back both HD and SD to Cinema Display.

So far the only working solution has been to route the HD out of our Kona 3 to a Panasonic HD-150 DVCPRO HD deck, and then route that to our second Final Cut Suite and digitize it in at SD uncompressed. Any ideas would be welcome. Thanks.

[Clay Morrison]

Apparently you, me, and Leo are the only ones concerned...

[Finner]

I'm highly concerned but if no one from red wants to chime in then what do you do? With lack of red input on this it seems quite clear to me that they have no answer to this problem. So were pretty much all SOL for a while.

[Dj Joofa]

I'm highly concerned but if no one from red wants to chime in then what do you do? With lack of red input on this it seems quite clear to me that they have no answer to this problem. So were pretty much all SOL for a while.

Finner, the answer to this problem goes beyond simple low pass filtering as provided by the software/hardware solutions mentioned so far here on this forum. The good news is that some computer vision algorithms do exist that were developed to take care of similar problems and they might work here.

[Joe Walker]

I'm highly concerned but if no one from red wants to chime in then what do you do? With lack of red input on this it seems quite clear to me that they have no answer to this problem. So were pretty much all SOL for a while.

Finner this is the most re-assuring thing I've heard yet about this problem. I was beginning to think that I was losing my mind! I mean seriously, how are all these RED owners getting their footage compressed down to SD for DVD without either having major aliasing or just blurring out all the footage until there's nothing viewable?

[Andrew M.]

We shot some gorgeous 4K product shots of new GM cars. We transcoded them in REDCine to Apple Pro Res 422 1080 23.98. When played back through our Kona 3 card to a Blackmagic HD Link routed to a Apple 30" Cinema Display , the downconverted footage has massive jagged lines through it. I've got everything set up correctly:

1. Sequence is set to Apple Pro Res 422 1080 23.98, playback set to same.
2. Kona 3 is set to primary: 1080 23.98psf, secondary: 525i 23.98. (setting secondary to 23.98p has no effect)
3. HD Link set to play back both HD and SD to Cinema Display.

So far the only working solution has been to route the HD out of our Kona 3 to a Panasonic HD-150 DVCPRO HD deck, and then route that to our second Final Cut Suite and digitize it in at SD uncompressed. Any ideas would be welcome. Thanks.

Did you scale it down in REDCINE to 1920x1080 or you let it go out at 4K?
If you scale it down in REDCINE what scaling algorithm did you use?
I think I had similar problem some time ago, but resolved it.

[conrad gaunt]

If you can (ie, you have time), you need to use a good quality software resampler, speed is not everything. I`ve been downsampling 3k RAW files to SD for about seven years, no problem, ever. My background is in 3D programming, both realtime and non-realtime.
Real-time equipment is usually a compromise in quality. My downsampler, for example, will downsample 4k-> anything, no jaggies, ever, and will process 16bit TIFFs in floating point (or nearly any 8bit format, and AVI in the next few days). I`ve been throwing zone charts at it and all sorts.
It runs on Windows (3.1 and up!), Linux under WINE (I tested this) and almost certainly a MAC using similar compatibility software (rosetta?), or a dual boot system. I use Virtualdub to stitch 8bit output seq back together for encoding. I`ll add support for 16bit output soon (as a TIFF sequence) .
I wrote a version for my own use and have been trying to add an interface and encourage people to learn the difference between real-time orientated solutions, since Leo`s first post. I have no worries about downsampling, at all, but I`m also not time constrained when working which may be an issue for some. I`ll be mastering to 4k always, downsample will be at the end. I may call the tool Red Back Side? You don`t have to use my tool, but at least try it, it might ease your worries about an eventual solution coming along. I`ll be adding presets with cropping and black bars etc and eventually AVI output for people who might like using it, like me :)

Its good points:
- Freeware
- High quality downsampling in floating point, and ability to extract 16bit TIFF data
- Small. Just click and it runs, no installation
- It will not crash once you set it going (unless you run out of disk space overnight, but I`ll add a warning in a future update, or hit a corrupt image file, which is unlikely unless you download your footage!)


update: much better downsampler that supports a few formats:
www.northyorkshirecamerahire.com/tds48bit.zip

[Greg M]

Are you editing the proxies and then downconverting?

We are not having any issues downconverting our final edits to SD...they look gorgeous! We are exporting DPX sequences from Red Cine and then conform. We then downconvert inside our Smoke to SD. It looks great. Now, if we online from the QT proxies we see issues.

EDIT:
Just re-read your post...so you are playing your SD downconvert on a Apple display?
bad idea...try using an NTSC monitor.

[amrrahmy]

When played back through our Kona 3 card to a Blackmagic HD Link routed to a Apple 30" Cinema Display , the downconverted footage has massive jagged lines through it.

maybe I'm an idiot, but can't u connect two displays(or more)(like the 30" cinema monitors with a dual link video card or with two cards(they are less expensive then the kona 3 (i think?)))

u connect through kona only when ur outputting to an sd monitor, right?

and why are u using both kona 3 and a blackmagic hd link?

if ur using pixel to pixel with the 30" cinema, u need to change the resolution of the monitor to pixel to pixel, i think it's 1680x1050

if u try to input 1080 u get the aliasing, that's why it would work with 1080p and not 1050, go directly from the video card(s)

[amrrahmy]

that didn't come out right,

u only output through kona when ur not using a monitor.

okay, this sounds the same.

u output through kona when u cant use the video card.(that's it)