AJA RGB Levels issue between Color and FCP

[Chris Seguine]

Aja 10bit rgb is still broken in color with the 5.0 codec.

Silicon Color supported AJA10bit RGB before it had a range dialog option. When apple adopted it they did not add a quicktime options dialog or choose the correct range setting.

Color imports AJARGB codec correctly
Color processes at FULL range
On render to AJARGB it uses the codec default, SMPTE.
So the range gets stretched out and black 0-64 get crushed to 0 and whites 940-1024 get clipped to 1024. You can verify this by just creating a ramp in After Effects and importing it into color and rendering it with no grade.

It always looks correct in Color, because color never shows you the rendered file – it always shows you the grade applied live on the source media, even after you have rendered. Bad design.

The workaround – Import AJARGB, but Render to DPX (or cineon). Use AJA tool to wrap DPX as AJA quicktime if you are going to SR and not working as data.

You can also add a primary out grade that kind of corrects the problem, but you would be loosing some quality as your pulling and pushing ranges needlessly.

If AJA just made FULL the default range setting it would be a simple fix to the problem.

Send a email to AJA, they are aware of the problem, but a nudge might help move it up the todo list.

—
Christopher Seguine
Sublime Films, San Francisco

[Ruslan Akmanov]

Hi to all,
SublimeFilms, the problem which creative_tech described is problem with AJA drivers only. This is old issue haved plase in 3.0 and 4.0 drivers. Only one driver release was this problem fixed – 3.4. The problem is that if You have 10bit RGB timeline in payse Kona switches to YUV mode and in palyback to RGB mode. You can check it in AJA ControlPanel during work. I wrote several times to AJA and wait fixes for now . .

[Gary Adcock]

[creative_tech] “Got a HDCAM SR RGB 4:4:4 1080 23.98 project that has been edited in FCP…. was sent to Color and graded… rendered out using the AJA KONA 10bit CODEC… back to FCP, the files appear in a new timeline as usual, no problems what so ever.
Then, you glance over at the hardware scopes…the blacks are crushed. “

First off – should have used the AJA LOG codec, the “plain” 10bit codec works in a linear color space, and that can can crush depending on the settings in Color – stuff like force RGB, Broadcast safe setting, etc. if you are not looking carefully at the content.

It sounds like a Color Issue to me.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD

[Chris Seguine]

R3d, yes there are additional problems monitoring AJARGB as you described.

This has been addressed in FCP in the 5.0 aja driver, if you select 1080 10bit RGB as our vout you will no longer get gamma shifts between play/pause, and the Kona output will be a RGB frame buffer.

This is not the case in Color, RGB output is not a selectable option – so yes in Color you are always monitoring in YUV converted space, not a good way to work. Specially since the Color scopes are YUV and not switchable to RGB.

Gary,

Using the AJARGBLog codec will not address the problem, and is not even really possible in Color. The Log/Lin conversion option for DPX and Cineon that is detailed in the manual, does not exist in the software – and it was never for AJARGBLog anyway.

ForeceRGB setting is for YUV source media only, not applicable to AJARGB or AJARGBLog.

BroadcastSafe Settings will clip values no matter what codec you use, Log or Linear.

There are situations to use a LOG codec and situations to use the Lin codec, both need to function correctly.

The codec chosen is dictated by the source material. LOG/Linear based on your telecine/camera choice, and Full/SMPTE based on your SR recorder settings/data settings.

There are plenty of problems with Color, this particular problem is a codec issue.

—
Christopher Seguine
Sublime Films, San Francisco

[Gary Adcock]

[Chris Seguine] “Using the AJARGBLog codec will not address the problem, and is not even really possible in Color. The Log/Lin conversion option for DPX and Cineon that is detailed in the manual, does not exist in the software – and it was never for AJARGBLog anyway. “

The AJA 10 bit Log codec is the only one supported – and when working with DPX / Cine files it is the only codec for proper control of the REF movies.

Final Touch < now Color> was designed with the a log RGB file structure in mind.

“ForeceRGB setting is for YUV source media only, not applicable to AJARGB or AJARGBLog. “

Actually not, it is so that files the are used in the”Send to Color” command from FCP are not improperly rendered as FCP;s default color space

“BroadcastSafe Settings will clip values no matter what codec you use, Log or Linear. “
I did not say use it, I asked if it was on, I would tell you to turn it off.

“The codec chosen is dictated by the source material. LOG/Linear based on your telecine/camera choice, and Full/SMPTE based on your SR recorder settings/data settings.”

I choose the codec based on what needs to be done in Post- not solely based on what it was shot on.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD

[Chris Seguine]

(gary adcock) “The AJA 10 bit Log codec is the only one supported “

No:

“Color also supports the following third-party codecs for import.
AJA Kona 10-bit Log RGB
AJA Kona 10-bit RGB”

Both are supported, neither properly, and the Log codec is not even available as a choice on the quicktime export list.

“Actually not, it is so that files the are used in the”Send to Color” command from FCP are not improperly rendered as FCP;s default color space”

Actually, yes.

“Force RGB: This setting is meant to be used when you

[Ruslan Akmanov]

Hi Chris,
In old 3.4 drivers from AJA I always selected 1080i26 10 bit output mode and AJA didn’t switch to YUV mode. By the way 5.0 drivers don’t have 1080i25 10bit RGB output mode. Only 1080i25 10bit RGBA mode. I tryed to switch to this mode – its OK picture in Pause/Play fine> But in normal situation used mode must be 1080i25 10bit RGB mode.
And in critical correction I always use MOV>DPX (Color)>MOV (FCP) pipeline.

[James Willett]

Hi all,

Thanks for all you’re posts. I apologise for not replying sooner – My account stopped functioning and then I was in a super busy period – crazy!

The quicktime in >> DPX/CINEON out route makes sense, except you can’t specify anything other than quicktime in a round trip to final cut can you, so I guess I’d have to export a self contained movie from final cut & an EDL, then import into Color using these. In turn, I can then render out an image sequence? Does that make sense or is there a better way?

Notice AJA have released 5.1 now – anyone know if it addresses some of the problems we have all been having with this, or is it fundamentally the fact the Color is somewhat still ‘broken’ with the lack of range options on the RGB codecs? have’nt installed it yet!

Thanks in advance.

[Gary Adcock]

[James Willett] “Notice AJA have released 5.1 now – anyone know if it addresses some of the problems we have all been having with this, or is it fundamentally the fact the Color is somewhat still ‘broken’ with the lack of range options on the RGB codecs?”

It is an FCP / Quicktime issue —not an aja problem

Quicktime is handling the RGB x YUV conversion in 8bit and crushing the color space of the output.

gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Inside look at the IoHD