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IO Express HDMI out not working properly

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Jorge TorrensIO Express HDMI out not working properly
by on Oct 23, 2009 at 9:25:35 am

Hi, I have just recived an Io Express, I'm monitoring through a calibrated HP Dreamcolor, both using directly hdmi out of the IO and sdi to a blackmagic hdlink pro and dvi to the Dreamcolor. And I'm having problems with the HDMI output.

1. HDMI OUT IOExpress / RGB mode -> HDMI IN Dreamcolor / Rec 709 colorsapce , the blacks look washout and noisy. I have tried several HDMI cables with the same result.

2. SDI OUT IOExpress / RGB mode -> DVI out HDLINK -> DVI IN Dreamcolor / Rec 709 colorsapce blacks look right.

3. HDMI OUT IOExpress / YUV mode -> HDMI IN Dreamcolor / colorspace managing disabled blacks look right although the colorspace is wrong so is no useful

4. HDMI OUTIOExpress with HDMI to DVI conversor / RGB mode -> DVI IN Dreamcolor / Rec 709 colorsapce blacks washout.

Does anybody have a similar setup, and how is it working for you?

Best regards
Jorge Torrens








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Jeremy GarchowRe: IO Express HDMI out not working properly
by on Oct 24, 2009 at 2:03:13 am

You need to send p, true p (not psf) to the Dreamcolor, other wise you will not get the Dreamcolor engine to work properly. What format are you working in?

Also, to adjust the proper pluge level, you need to send bars to the monitor and adjust the black level.

Jeremy


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Jeremy GarchowRe: IO Express HDMI out not working properly
by on Oct 24, 2009 at 3:59:40 am

Oh, and use the Rgb setting.


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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 24, 2009 at 8:06:32 am

Thanks Jeremy, but I was sending a true progresive signal in RGB, I'm not having a problem being able to access the colorspaces in the dreamcolor, is with the hdmi output in the aja IoExpress that doesn't seem to send a proper signal using hdmi, the monitor is already calibrated and works right if I go via sdi from the aja and use hdlink to convert to dvi.

Best regards

Jorge


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gary adcockRe: IO Express HDMI out not working properly
by on Oct 24, 2009 at 2:21:12 pm

[Jorge Torrens] "Thanks Jeremy, but I was sending a true progresive signal in RGB,"

jorge.

You set the HDMI preference to be RGB in the Kona Control Panel?

how are you sure the content RGB?
I do this regularly and I am not having any issue with the IoXpress.

[Jorge Torrens] "he monitor is already calibrated and works right if I go via sdi from the aja and use hdlink to convert to dvi. "

how is the HDlink configed internally? is it configed to handle some of the conversion?

- ( FYI - HP does not recommend that config for proper handling of the content only the Geffen and AJA boxes are supported for HDSDI -HDMI conversion)


gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows for the Digitally Inclined
Chicago, IL


http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 24, 2009 at 3:31:07 pm

Thanks for your reply Gary, yes I have set the HDMI preference to RGB and tried both, Full Range and SMPTE in the drop box next to it, sorry I don't recall how this preference is called.

I have tried this with red footage converted to prores, straight red footage in color and also a generated gradient in nuke which is allways RGB, and in all programs with the same result.

The HdLink always converts to rgb, and the only prefrence is for using true progressive intead of PFs, and I'm aware this is not the prefered way to do it, The HDLINK downsamples to 8bit, as dvi is only 8bit, that's why I bougth the IoExpress, to use HDMI 1.3 straight of the IOExpress, going trough SDI and the HDLink was only a way to test if the problem was with all of the Aja outputs ore only with HDMI.

Before, I was using sdi out of a multibrige pro with the hdlink going to the dreamcolor via dvi, and it was working just fine, besides being 8bits of course, and thats the reason that I went to the aja, to use the 10bits out of the HDMI 1.3 as i said above.

I doubt it has anything to do with the cables, I have tried a couple, so I'm quite lost as what is causing the problem.

Thanks a lot for your help

Jorge


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Jeremy GarchowRe: IO Express HDMI out not working properly
by on Oct 24, 2009 at 11:56:11 pm

Just to reiterate, you have the video output set to true p in FCP?

I'll have to try this on MOnday, but right now I have the HDP2 with a DVI to HDMI cable. True p, 10bit and the scaling and de-interlacing is awesome with the HDP2 (for non p sources).

Jeremy


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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 25, 2009 at 4:04:00 am

Hi Jeremy, yes I have true p originated material, I work mostly with Red originated files or panasonic 3000 and both in 24p or 25p. My problem is not with the quality of the image, it looks fine, but with the black levels, that are too high and noisy even in a graphic image, such as a gradient and viewing it in a native rgb program like after effects or nuke.
On monday I will try to create a new rec 709 calibrated profile with the hp probe and see how it looks. but I'm not confortable doing this, as the monitor is already calibrated and I think that is the Aja HDMI output the culprit here.

Thanks a lot for taking and interest trying to help me whit this issue.

Jorge


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Jeremy GarchowRe: IO Express HDMI out not working properly
by on Oct 25, 2009 at 4:33:28 pm

It does matter that your material is also progressive, but your video output of FCP must be set for p and not psf. It makes all the difference. The Dreamcolor will tell you if you're getting 24 or 25 Hz. Psf would be 48 or 50 Hz. This is a good way to check if you're getting true 1080p and not SMPTE psf.


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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 25, 2009 at 4:53:22 pm

Hi Jeremy, sorry but probably is my lack of command of the english language, spanish is my mother tonge, I'm using true progresive material originated at 4k in a RED camera at 24 fps and converted to prores 422 at 1080p also in 24 fps. and in a 1920x1080 24fps timeline, if I would be outputing 24PsF the dreamcolor would not allow me to select a colorspace other than full range and I can choose rec709 with no problems.

I've been using the dreamcolor with a multibridge and a hdlink for over a year now with no problems at all, but I wanted to use the 10bit monitoring capabilities of the aja over HDMI and there is where I see the problem, the dvi output off the aja works well.

Thanks Jeremy for your help, and patience.

Jorge


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Tim KolbRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 12:41:00 am

Can you supply a bit more information?

for instance, are you on a Mac or a PC? i don't find any indication in your posts...the IO Express works on the dark side too.

second...can you tell us what the settings are for out put in the IO Express control panel...and what happens if you play a clip out of Machina? (this would be for a PC...I don't know is Machina is on the Mac side)

What are you edit project settings?




TimK,
Director, Consultant
Kolb Productions,


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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 3:15:33 am

Hi Tim, I though it was clear from the conversaion that I was using a mac and FCP as well as nuke and after effects, as for the settings I have tried every combination in the hdmi tab, but for the dreamcolor the only one that has sense is RGB, as it needs to be driven by a true progresive RGB signal to activate the colorspace settings otherwise the monitor works in full range. For the program settings in fcp I use 1080p 24 and 25 fps settings in prores 422, and in nuke and fcp there are no timeline settings as suchs as the image is allways progresive RGB uncompress.

I have not tried the own aja application, I don't recall the name either, I will give it a try on monday but I don't belive it would make a difference as every other application gives me the same result on the blacks, as if they where lift and to noisy, even in a computer generated graphic where there is no noise.

Jorge


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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 10:00:08 am

Ok, I've tried a couple of things, just in case, but clearly the problem is with the aja output.

1. I connected the Dreamcolor straight to the computer via a dvi->hdmi to check if it was the Dreamcolor HDMI input the culprit, and the levels look fine, just in case I created another REC 709 profile with the HP probe using the HDMI input and it look fine too, the image looked the same if I switched from the dvi to the hdmi input in the monitor.

2. I installed the pro-aplications upgrade that came out last week, no changes.

3. As per Tim's suggestion I've tried aja own application TVout and the same results, black levels to high.

Sorry to keep coming back with this problem but It would really like to make it work, it would be a very good solution if it worked properly, the sdi output works perfectly.

Jorge Torrens



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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 10:22:31 am

One more thing, I thought that I've checked the IOExpress with After Effects, but I was mistaken I have only checked with FCP, Nuke and Aja own's TVOut, at the moment IOExpress does not work with AE or Motion, sorry for the confusion.

Jorge



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gary adcockRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 1:02:38 pm

[Jorge Torrens] " I thought that I've checked the IOExpress with After Effects, but I was mistaken I have only checked with FCP, Nuke and Aja own's TVOut, at the moment IOExpress does not work with AE or Motion, sorry for the confusion. "

Thats not right.
all three of those Apps (AE, Motion and Nuke) all work on my Io Express.



gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows for the Digitally Inclined
Chicago, IL


http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 1:13:56 pm

Hi Gary, In my case neither AE4 or Motion allow me to select Aja as a video output device, maybe there is something wrong with my installation?

Jorge


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gary adcockRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 1:00:41 pm

[Jorge Torrens] "Hi Jeremy, yes I have true p originated material, I work mostly with Red originated files or panasonic 3000 and both in 24p or 25p."

First jorge.
understand there is a big difference between RED files which are 1080 true P and the Panasonic cameras which shoot P over interlace- these are NOT the same formats in the timeline.

[Jorge Torrens] " but for the dreamcolor the only one that has sense is RGB, as it needs to be driven by a true progresive RGB signal to activate the colorspace settings otherwise the monitor works in full range. "

your HDMI connection is always delivering a "P" signal regardless of the signal sent to it, you are correct that the output is progressive, but not always RGB, HDMI can be YUV or RGB as you not.


[Jorge Torrens] "or the program settings in fcp I use 1080p 24 and 25 fps settings in prores 422, and in nuke and fcp there are no timeline settings as suchs as the image is allways progresive RGB uncompress. "

NO it is not. FCP will always default to YUV color when outputting captured video. Your RED files would be converted to YUV in RED apps when you convert to 1080.

WHAT does the IoExpress/ Kona control panel say the video space is? not what you think it is- what does it SAY it is?

[Jorge Torrens] "I connected the Dreamcolor straight to the computer via a dvi->hdmi to check if it was the Dreamcolor HDMI input the culprit, and the levels look fine"
So you do not seem to think that the DVI connection could be doing anything to the signal?

There is a defined color space for the DVI output from the HDLINK that you seem to be forgetting about.
Since the HDLink device does allow for setting color space and lut info - how do you know that that process is not being used here.? Those settings are meant to compensate for the 8bit processing in the device.

a 10 bit signal should show more detail and by-passing any LUT's that are being used in the default mode on the HDLink.

maybe posting images would help us understand.




gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows for the Digitally Inclined
Chicago, IL


http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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Jorge TorrensRe: IO Express HDMI out not working properly
by on Oct 26, 2009 at 3:01:14 pm

Hi Gary thanks for your time I really appreciate it.

I believe you are misinterpreting me, most likely due to my english, I understand perfectly how the dreamcolor works, I've been using it without problems for over a year, so I'm not worried about how to get it to work with a predefined colorspace. I'm not asking how to send a true progressive RGB signal to the dreamcolor.

My problem is exclusively with the black levels out of the HDMI output of the Aja IoExpress, and I'm seeing the problem irregardless of where the material originated or the application I'm using.

I see the wrong levels in:
  • YUV originated material, AVCIntra panasonic in FCP and color
  • RGB converted to YUV, RED to prores in FCP and color
  • RGB native, computer generated gradient in nuke
  • RGB native, Red r3D in nuke and color


  • [gary adcock]WHAT does the IoExpress/ Kona control panel say the video space is? not what you think it is- what does it SAY it is?

    I'm positive that the settings in the IoExpress control panel are:

  • Protocol: HDMI
  • Color Space: RGB 10 bit
  • Output Video Range: I have tried both SMPTE Range and Full Range.


  • The way I see it is either the HDMI output from the Aja is sending the wrong information or the HDMI input in the dreamcolor does not work. And if the problem was located in the dreamcolor it would display the same wrong image when in rec709 colorspace, both with the aja, or when conected straight to the display card of the computer or with the multibridge, and it doesn't. The levels displayed with the blackmagic and the ones from the computer card are correct.

    The reason why I've tried going through straight from the computer or via the hdlink is to make sure that is not the hdmi port in the monitor the one to blame.

    [gary adcock]a 10 bit signal should show more detail and by-passing any LUT's that are being used in the default mode on the HDLink.

    That is exactly the reason I would like to use the Aja for, a cleanest signal, one less conversion, and more detail in 10 bit.

    Thanks again for your time and sorry for the lenghty posts as it's hard for me to convey clearly my problem in english.

    Jorge




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    gary adcockRe: IO Express HDMI out not working properly
    by on Oct 26, 2009 at 4:33:36 pm

    [Jorge Torrens] "My problem is exclusively with the black levels out of the HDMI output of the Aja IoExpress, and I'm seeing the problem irregardless of where the material originated or the application I'm using.

    I see the wrong levels in:
    YUV originated material, AVCIntra panasonic in FCP and color
    RGB converted to YUV, RED to prores in FCP and color
    RGB native, computer generated gradient in nuke
    RGB native, Red r3D in nuke and color
    "


    Jorge,
    your english is excellent.

    I understand that you are not seeing Black Levels that you expect- have you looked at a waveform or vectorscope to check the signal from the source?

    You are trying to match to something that may or may not be changing your video-out signal via the HDLink and any of those things can affect the output. There are LUT's for the HDLINK converter. ( look up tables- files that change the nature of a signal being played)

    1) The DreamColor is NOT a video display, it is a computer display that can handle a video signal.

    2) Do NOT use the FULL RANGE for HDMI- the default is SMPTE for a reason.

    You cannot call something RGB because you think it is- the HDLINK is converting YUV video to RGB via some unknown factor- it is conforming your video to the 709 color space and then to RGB for the HDMI to the DreamColor settings as REC 709- you have no choice in this if you are trying to use this computer monitor as a video monitor.


    3) RGB signals are traditionally DUAL LINK HDSDI- if you are trying to send RGB over a SINGLE cable of HDSDI this is the first place to start.

    4) Video is by it's nature a YUV (Y'Cr'Cb' in HD) signal.

    5) Depending on how the RED footage was converted it is YUV within the REC 709 Color space. Your Panasonic 3000 footage is always YUV and 1080 Psf.

    OK I took My Io Express and sent a 1920x 1080 ProResHQ file of the ASC's StEM demo footage and set it up so that I could simultaneously view 3 different sources via Component to a Panasonic 17' display, via HDMI to a HP Dreamcolor and using the HA5-3G converter (HDSDI- HDMI) from the HDSDIO output to my Sony Bravia XBR client monitor direct out of the IoExpress.

    I do not see any difference between the signals, and my Tektronics scope confirms my visual inspection, but I do not have a HDLINK to test this on, but I am not seeing the differences you describe in the signal output with my tests.




    gary adcock
    Studio37
    HD & Film Consultation
    Post and Production Workflows for the Digitally Inclined
    Chicago, IL


    http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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    Jeremy GarchowRe: IO Express HDMI out not working properly
    by on Oct 26, 2009 at 4:47:39 pm

    I agree, your English is way better than my spanish.

    Your FCP video out shoudl look like this (you can choose the proper frame ratefor your footage):






    And the ioExpress Control Panel should look like this:






    Jeremy


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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 26, 2009 at 5:12:55 pm

    Thanks Jeremy my Aja settings are exactly as you show them and so are the FCP with the exception of the frame rate which is 24 fps instead of 23.98, my material originated as 24 and is an offline for a film out at 24 fps. But my problem occours also in nuke where the settings are completely different.

    I'm really sorry to be such a drag but I would very much like to make it work as I find it to be a very nice solution for monitoring 10bits out to the HP

    By the way I am receiving very soon a Kona LHi and I have another dreamcolor where I can try both side by side.

    Jorge


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    Jeremy GarchowRe: IO Express HDMI out not working properly
    by on Oct 26, 2009 at 5:31:40 pm

    If it is at all possible, it'd be nice if you could upload one second of an example image at full reoslution as a zip file. If a color chart/chroma du monde was shot, that'd be a nice example. I understand if you can't.

    I am finding the same results as Gary. Everything is looking ok here. I did have to setup the black level to get it the contrast/brightness correct. It is located in the image control menu. Using bars from FCP, I have a value of 125.

    Jeremy


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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 26, 2009 at 6:03:05 pm

    Hi Jeremy I tried changing the black levels with a set of bars and with a value of 125, the same as yours and looks much better, the original one was 128, but I find odd that the monitor was calibrated using a probe and it worked fine before with a blackmagic card.

    Anyway until I can test the signal with a waveform monitor, I believe it is close enough now to be usable.
    I have created a new profile specific to the HDMI input that uses the colometry of the calibrated REC 709 colorspace with your suggested black levels.

    Thanks a lot and best regards

    Jorge


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    Jeremy GarchowRe: IO Express HDMI out not working properly
    by on Oct 26, 2009 at 6:11:31 pm

    No worries and good luck with your project.

    Jeremy



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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 26, 2009 at 5:21:13 pm

    Hi again Gary

    [gary adcock]OK I took My Io Express and sent a 1920x 1080 ProResHQ file of the ASC's StEM demo footage and set it up so that I could simultaneously view 3 different sources via Component to a Panasonic 17' display, via HDMI to a HP Dreamcolor and using the HA5-3G converter (HDSDI- HDMI) from the HDSDIO output to my Sony Bravia XBR client monitor direct out of the IoExpress.

    I do not see any difference between the signals, and my Tektronics scope confirms my visual inspection, but I do not have a HDLINK to test this on, but I am not seeing the differences you describe in the signal output with my tests.


    Ok, here is where we are seeing something different, I'm sure you have the right setup to test it so I guess there is something wrong with mine. I only have access to a blackmagic ultrascope so no hdmi input to test it on.
    You mention in your last post that you could access the video out for the aja in motion and after effects. Could it be that you are using a newer version of the drivers than the ones posted in aja's website?

    I understand the points you make about YUV and pfs but If I take YUV and pfs out of the ecuation by generating a gradient in nuke and monitoring from there, the wrong black levels persist.
    Remember that I always have been able to access the different colorspaces in the Dreamcolor and this is only posible if you send a signal that is both RGB and true progressive.

    Would you be so kind to check if your Dreamcolor firmware version is the same as mine TR:133 SL:063BL:167, and your IoExpress drivers are 1.0?

    I am receiving very soon a Kona LHi and I have another dreamcolor where I can try both side by side.

    Thanks again for your time and your answers, they are very thorough, both you and Jeremy are more than helpful.

    I'm hopeful that with both your help I will be able to get to the bottom of my problem.

    Jorge





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    gary adcockRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 12:30:28 pm

    [Jorge Torrens] "I understand the points you make about YUV and pfs but If I take YUV and pfs out of the ecuation by generating a gradient in nuke and monitoring from there, the wrong black levels persist. "

    First - The 1.0 Release version of the Io Express software does not support RGB V-out from any the animation sources you list. So there is some color conversion going on in your workflow that is not being accounted for.

    Second- YUV and PsF are different things- one (YUV or Y'CrCb) is a Color Space- the other is a signal transport for progressive imagery as interlaced fields.


    So lets start back at the beginning.
    What do the Color Bars generated by Kona Control Panel via the device look like on your Display, not some questionable video but just something like 75% Bars?



    gary adcock
    Studio37
    HD & Film Consultation
    Post and Production Workflows for the Digitally Inclined
    Chicago, IL


    http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 1:37:18 pm

    Hi Gary,

    [gary adcock]First - The 1.0 Release version of the Io Express software does not support RGB V-out from any the animation sources you list. So there is some color conversion going on in your workflow that is not being accounted for.

    I'm just using the HDMI output from to Aja to the HDMI input in the dreamcolor, so no extra conversions, and I can monitor in Nuke with no problems, but no in AE or Motion.

    [gary adcock]Second- YUV and PsF are different things- one (YUV or Y'CrCb) is a Color Space- the other is a signal transport for progressive imagery as interlaced fields.

    I clearly understand that, What I was meaning is that using nuke and a gradient generated in nuke it would be by definition a progressive rgb image, so it would not be any extra conversion from yub to rgb or psf to true progressive, and would be one less thing to consider.

    [gary adcock]So lets start back at the beginning.
    What do the Color Bars generated by Kona Control Panel via the device look like on your Display, not some questionable video but just something like 75% Bars?


    Exactly the same problem, the black level is to high. If I adjust the black level in the monitor as per Jeremy's suggestion I can get an image that looks fine, but it kind of defeats the porpouse of having a calibrated monitor, doesn't it?

    For the time being, I hope to have access this week to a hdmi to sdi converter to check the signal in a waveform monitor, this solution is ok, but I'm not very comfortable with it

    Thanks again for your help

    Jorge








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    gary adcockRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 2:16:53 pm

    [Jorge Torrens] "[gary adcock]First - The 1.0 Release version of the Io Express software does not support RGB V-out from any the animation sources you list. So there is some color conversion going on in your workflow that is not being accounted for....

    I clearly understand that, What I was meaning is that using nuke and a gradient generated in nuke it would be by definition a progressive rgb image, so it would not be any extra conversion from yub to rgb or psf to true progressive, and would be one less thing to consider."

    OK - the IoX does not support RGB video out- so something is doing the conversion from your Nuke file to YUV- it is NOT the hardware.

    [Jorge Torrens] "Exactly the same problem, the black level is to high. If I adjust the black level in the monitor as per Jeremy's suggestion I can get an image that looks fine, but it kind of defeats the porpouse of having a calibrated monitor, doesn't it? "

    Isn't that what calibrating a monitor is??- adjusting it so that the viewing space is a close to correct as possible? Correct calibration of BroadcastVideo monitors is done using the "blue only settings" while viewing 75% SMPTE Color bars.



    gary adcock
    Studio37
    HD & Film Consultation
    Post and Production Workflows for the Digitally Inclined
    Chicago, IL


    http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 3:21:51 pm

    Hi Gary

    [gary adcock]OK - the IoX does not support RGB video out- so something is doing the conversion from your Nuke file to YUV- it is NOT the hardware.

    Good to know, then it must be nuke the one doing the conversion to YUV, but then how it is posible that the Dreamcolor sees the image as RGB, otherwise it would not allow to select a colorspace?

    [gary adcock]Isn't that what calibrating a monitor is??- adjusting it so that the viewing space is a close to correct as possible? Correct calibration of BroadcastVideo monitors is done using the "blue only settings" while viewing 75% SMPTE Color bars.

    I meant having the monitor calibrated by the probe as opose to manually calibrating using bars and blue only settings. But as Jeremy points out in his last post, it is posible to have the colorimetry of the monitor calibrated by the probe and then modify the black levels in the dreamcolor without modifing the relationship between the colors or the contrast.

    I guess what made me uncomfortable was the fact that if I had the monitor calibrated before and the different outputs from the IoExpress as well as the ones from the blackmagic should be outputting the same levels, then why should I have to adjust the black level of the monitor when changing from one output to another.

    Sorry again Gary for the trouble, this threat is getting very long and I'm feeling guilty of wasting your time and Jeremy's in a problem that is quite particular to my workflow.

    Jorge







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    Jeremy GarchowRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 3:31:00 pm

    [Jorge Torrens] "this threat is getting very long and I'm feeling guilty of wasting your time and Jeremy's in a problem that is quite particular to my workflow. "

    Not at all, Jorge. The Dreamcolor represents a different workflow and thinking behind a traditional CRT calibration. It is something that should be discussed, do not feel guilty and if you are enabling this kind of workflow, there are many many more people out there who are doing this workflow or at least thinking about doing this type of workflow and they will benefit from this thread.

    [Jorge Torrens] "but then how it is posible that the Dreamcolor sees the image as RGB, otherwise it would not allow to select a colorspace?"

    The ioExpress is outputting RGB.

    [Jorge Torrens] "I guess what made me uncomfortable was the fact that if I had the monitor calibrated before and the different outputs from the IoExpress as well as the ones from the blackmagic should be outputting the same levels, "

    That's a rather broad assumption. The purpose of the calibration is to calibrate the material to your output. Also, DVI is 8 bit, and HDMI 1.3 is 10bit. The HDP2 and ioExpress can both output true 10bit HDMI 1.3a signals, not sure about the Blackmagic. I don't think it offers this capability. The HDP2 does this over a physical DVI port connection, but all you need is a DVI to HDMI cable and you are sending an HDMI 1.3a signal. It's pretty cool.

    Jeremy


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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 3:57:53 pm

    [Jeremy Garchow]That's a rather broad assumption. The purpose of the calibration is to calibrate the material to your output. Also, DVI is 8 bit, and HDMI 1.3 is 10bit. The HDP2 and ioExpress can both output true 10bit HDMI 1.3a signals

    Yes, but shouldn't the levels of all the outputs been the same, leaving aside the difference between 8bits and 10bits, or in other words if I were to monitor the diferent outputs in a waveform monitor I should not see any difference, shouldn't I?, If it were the case then I should not have to recalibrate my monitor when changing the outputs in the card.

    The blackmagic outputs 8bits, but it also works with both HDMI and DVI, is equivalent to the HDP2 with the very important difference of not supporting HDMI 1.3, the reason why I changed to Aja after years of using blackmagic products.

    [Jeremy Garchow]
    [Jorge Torrens] "but then how it is posible that the Dreamcolor sees the image as RGB, otherwise it would not allow to select a colorspace?"

    The ioExpress is outputting RGB.

    I was refering to what Gary said about the IoExpress not being able to output RGB at the moment from animation packages as Nuke, or at least this is what I understood.

    Thanks again

    Jorge



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    Jeremy GarchowRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 4:09:38 pm

    [Jorge Torrens] "Yes, but shouldn't the levels of all the outputs been the same, leaving aside the difference between 8bits and 10bits, or in other words if I were to monitor the diferent outputs in a waveform monitor I should not see any difference, shouldn't I?"

    Yes, this is the point of calibration. Nothing is the same. NTSC, Never The Same Color. Different devices handle the signal path differently.





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    gary adcockRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 4:06:49 pm

    "[Jorge Torrens] "but then how it is posible that the Dreamcolor sees the image as RGB, otherwise it would not allow to select a colorspace?"

    [Jeremy Garchow] The ioExpress is outputting RGB. "



    This is one of those tricky areas in communication.

    Technically the HDMI output is RGB - Since the Io Express v1.0 was not designed to handle the RGB Video Out signal from animation or graphics applications.

    The default setting for ALL HDMI devices is to output RGB.

    All RGB is not created equally. Also remember that HDMI is not and has not been considered anything more than a Consumer grade connection.


    It was designed initially as a low cost AV connector for computer monitors and displays- that has been accepted as the default for Home Video and Television connectivity , it does not carry any ancillary data other than the HDCP digital rights protection.



    gary adcock
    Studio37
    HD & Film Consultation
    Post and Production Workflows for the Digitally Inclined
    Chicago, IL


    http://library.creativecow.net/articles/adcock_gary/AJAIOHD.php




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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 4:14:37 pm

    Ok, so what you mean is that although the IoExpress does not see a RGB image from Nuke the Dreamcolor assumes that because the signal is coming from HDMI it should be RGB?

    Jorge


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    Jeremy GarchowRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 2:53:47 pm

    No, it doesn't defeat the purpose in my opinion. Basically, the Dreamcolor works on full RGB. You do the calibration and the colors are matched and then the colors get mapped to the different specifications, REC709 being one of them. This is similar to a LUT. Now, as far as what is traditionally known as brightness on a CRT, you have to calibrate the monitor to that relative to your room. The 'black level' as it's known in the monitor is akin to brightness on a CRT. Part of calibrating the monitor is to have you adjust the black level. That doesn't have anything to do with the probe. The probe gets you the accurate RGB colors and then maps that to the appropriate color space. You can then use the pluge on SMPTE bars to change the black level of the monitor, and then you can turn up or down the overall brightness of the monitor without effecting color or contast, it just changes intensity. It is ultra cool if you ask me. Sure, it might have be a monitor from a computer company, but it is unlike any flat panel monitor I have seen. The LED backlighting and 10 bit panel are very nice looking, especially when you factor in the price.

    Jeremy


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    Jorge TorrensRe: IO Express HDMI out not working properly
    by on Oct 27, 2009 at 9:03:21 pm

    News from Aja, I have just received a mail from Rudy in Aja technical support telling me that engineering in Aja has replicated my problem and there will be a driver fix in the next couple of weeks.

    So I will use the adjusted black level in the mean time and see what happens with the new drivers.

    Thank you very much Gary and Jeremy for the time that you have spent looking into it, and for me it has been a very informative conversation, and also thank you Aja for a very good and prompt technical support.



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