Help: Picture check failed. Advise?

[Stephen Jay]

Its our first feature, edited and nearly entirely color-balanced in Edius 6. It just came back from the distributor's quality control with problems I'm not sure how to address. I'll start with the Technical Specifications they give of our film and then links to the images with the related problems. The "elevated black levels" and "inconsistent color correction" are fixed, of which were rarities. The majority is "posterization/blocking" and "incorrect line count."

I'm not privy to the lingo, but it seems that "posterisation" is a significant step from one color value to another: banding. It should be noted that the video was captured 8-bit (which displays inherent light banding), and shot in high contrast during some scenes crushing the blacks and whites, further developing banding in those areas after reversing the contrast to fit within cinema color scale. There's nothing I could do about those; the information wasn't there. If that is what they are seeing, I don't know how to correct it.

Technical Specifications & evaluation, should this mean anything to anyone:



Anybody know what these mean and how to fix them?

QC ERROR NOTE: Incorrect line count for aspect ratio (38/543) (should be 31/550 for 16x9 1.85 Letterbox). I have no idea what this means. I thought "lines" was specific to interlacing, i.e. 480i= 480 lines vertical.


QC ERROR NOTE: Solarized whites - window / door - man in store. If this is referring to the blown out whites that were dropped to make cinema safe, what does that mean I am supposed to do?


QC ERROR NOTE: Posterization error / blocking - man's shoulder


QC ERROR NOTE: Posterization error / building in background


QC ERROR NOTE: Posterization error - close up of black man


QC ERROR NOTE: Posterization error - close up of people's head (intermittent throughout scenes) (example) 1 I'm posting 4 examples from this scene because he said it occurred throughout. I don't know what I'm supposed to be seeing.


QC ERROR NOTE: Posterization error - close up of people's head (intermittent throughout scenes) (example) 2


QC ERROR NOTE: Posterization error - close up of people's head (intermittent throughout scenes) (example) 3


QC ERROR NOTE: Posterization error - close up of people's head (intermittent throughout scenes) (example) 4


Keep in mind, those who might berate my incompetence with your higher knowledge, I did not go to school for this and had to learn cinema color range by reverse-engineering other films. So a dozen problems out of 100 minute runtime, I consider a success.

BTW, I love edius for color balancing. Adobe's 3-way is inferior when it comes to speed and accessing stacked effects. The 3-way colorer is a dream. I can look at 2 images and immediately know what to change and how far. It's so fun.


Thanks,
Stephen Jay

[antonsvideo]

how compressed was the file you gave them? what file format etc?

[Stephen Jay]

Hi Anton.

I sent them uncompressed YUY2 on hard drive, 8 bit color, exported out of Edius. RAW was shot on DSLR 8 bit h.264, and during workflow used Canopus Lossless or uncompressed YUY2 for any transcodes thereafter. I have no doubt they are seeing the color correctly. Its Lionsgate.

[antonsvideo]

do you see these issues when playing your original clips on the timeline

what is the frame size you shot and delivered?

[Stephen Jay]

We shot in 16:9 1920x1080, (1.77). I matted the top and bottom within the 16:9 frame so only a 1.85 is visible. This was to fit the standard cinema screen to not have image falling off the projection screen, as that would appear unprofessional in the theater. The matted 1920x1080 image is what they got. The tech at Lionsgate is aware of this and has no problem with it. But I'm still in the dark about the "incorrect lines" lingo.

I saw the banding inherent to an 8 bit camera not shooting flat. When I brought these images out of their high contrast state the banding was apparent in the blacks and whites. If that is the "posterization" he's talking about, then yes, I see it.

I don't know if this "posterization" is simply banding, or an unrelated but similar-looking issue. So I don't know how to address it, or fix it, if it is something separate.

[PaulTV]

I wonder if they are suggesting that your crop isn't exactly correct in terms of line numbers, ie. the number of exposed lines in vision therefore not displaying the correct aspect ratio. how did you create the crop, is it accurate?

I've racked my early morning soggy brain over their numbers, bit odd, someone will decipher it....

Paul :-)

[antonsvideo]

if the project setting is 10bit and you export to 10bit, the banding issue should not be as bad

also, I assume you are using latest EDIUS 7 which has 10bit color correction filters when project setting is 10bit

I am not sure what they mean by incorrect line count 38/543

[PaulTV]

I'm maybe confused - is your delivery format NTSC SD for DVD?

Paul :-)

[Liverpool TV]

Stephen.

As long as you delivered full frame 16:9 1080, then your mask shouldn't really be an issue, it could be an artistic thing at the end of the day. Although, you may want to supply it in full frame and have the distributor apply the mask and any resize to fit a new ratio, such as academy etc. if you are talking cinema distribution. If it's DVD or BD distribution, then your crop is your crop, again this could be just an artistic impression and is not subject to technical scrutiny.

As for solarisation. This could be interpreted as the effect of 8 bit colour, or it could be a deliberate effect. In any event, it is not out of the ordinary for these things in a picture, as long as they don't break any "proper" tec specs. If it is deliberate solarisation, then it is what it is and not subject to anything but your artistic integrity. Banding is simply an unfortunate side effect of recording 8 bit, although it looks a bit like solarisation, any tec person should know the difference and should and not give a producer a hard over it. Check out the banding on every Pixar Disney release, right at the very beginning on the opening logo.

If the banding is something that is really getting in the way and you don't like it, there may be ways around it to mask it. You could try outputting the parts as 10bit, although you obviously don't gain any extra colour. Then use that 10bit in something that will dither back down to 8bit. This should then even out the banding by using a noise pattern to in the banding, with the result looking smoother. I have not tried this myself, as I don't like touching the picture in such ways, but I have read of a similar process that uses after effects. There may be a simpler 8bit to 8bit process that uses a 10bit buffer space, this would get around the intermediate and allow for a simpler workflow. Maybe do some googling and see what comes up as there may be other options for treating the banding.

It may be an idea if you post some footage so others can have a look. Although uncompressed is going to be huge, you could use HQ at an appropriate setting. There are many free file hosting options that give you a number of hundreds of meg for files, this would be enough for a good test chunk at HQ.

It may also be that the distributor is not decoding the codec properly? I know this can happen with most of the Edius outputs including uncompressed. Although you would think that uncompressed is universal, it too relies on a codec that has to be seen and implemented correctly on play back. Don't assume that a big distributor does not make technical mistakes, believe me, they do.

I have a feeling that someone is just being a stickler and giving you an unnecessary hard time. You don't buy a product for distribution knowing it is a budget shoot, then throw it back at the production company and complain about the issues inherent within the shooting format. If they were doing their job properly, someone there could just have easily given you an option at their end to do some corrections, as long as it was ok with you, the producer.

[Stephen Jay]

It may also be that the distributor is not decoding the codec properly? I know this can happen with most of the Edius outputs including uncompressed.

Most exports? So should I give them the Canopus codec pack? I know they use Mac because the review sheet it showed he transcoded it to ProRes 422. Thanks for the information. I'll try the 10 bit export and check google. I'll ask about posting a clip in HQ.

@paultv
The crop is actually a black still with a hole punched out using a mask. I calculated the 1.85 size by using [16/9=1.7778] formula as a model. I don't remember the math. Its NTSC Full HD delivery, 23.98p.

@anton
I don't have Edius 7. Not until we start another major project will I upgrade.


I'm glad I'm not the only one confused over this "line" business.

[Liverpool TV]

Stephen.

You really need to be doing some tests with whoever is doing the encodes at the distributor. Try doing some some short round robin clips back and forth to the distributor. From this you will see how the files are after they have done what they have done, and see any shifts etc. Or better still, go in with some short clips and sit with their editor and see what codecs work.

This is more the point seeing as it is a mac person doing the work. I don't want to sound disrespectful, but Mac people seem to struggle with anything that isn't already QT compatible.

Your fail safe option would be to go to HDCAM over SDI and then reingest on their system.

As for crop. The best way is to make a new blank sequence that matches your master sequence, then insert your master edit sequence into that. Now go to layouter and apply a mask over the whole master sequence sub clip. You can get accurate to the line using this method for 2.4 or 2.35 or whatever. Plus you will not have any issues with potential black level problems, as you can by using a still with a middle alpha knock through.


BTW. What aspect ratio are the distributors going to, and what resolution? It may be the case that you can totally go straight to the final encoder from an Edius produced file. Is this master for cinema, transmission, or sell through. I only ask as there are some difference between each, that one master may not do. Or at least one master from you may end up in the hands of someone who does not know what they are doing, and they may damage the resolution or ratio by incorrectly repurposing on master to another.

[Stephen Jay]

Haha. They originally requested only HDCAM SR, but our contract bypassed that. Guess why. I'm sure distribution is DVD & Bluray only.

It would make sense that other problems may occur if they don't normally do file-based. Either way I'll see about starting dialog with the guy.

[Liverpool TV]

Are you going to cinema, if so what aspect and resolution etc.?

For BD and or DVD, you do not have to supply anything like what you would for cinema. You can have full control of the master for these outputs and TV, as long as they can read them properly they can just do a straight encode.

If you are matting and re shaping for cinema, you don't have to do this for all the above. As long as you are happy to have full frame 16:9 you can do this, or if you are applying a mask, you still do this anyway for your 1080 master, effectively giving around 800 lines of picture info after a typical 2.3 to 2:4 mask.

Try finding what dedicated pro codecs they can use. There maybe a workflow to go to Sony SR file format, I don't think you can go straight from edius. But there may be a third party app on Windows that will see a GV codec and go form there. It is then a simple case of using the appropriate importer on the Mac for FCP etc. I think there is some thing on the Mac that just re wraps the MXF to mov.

Or find something as equally as good that does not rely on native mac codecs inside QT.