Blackmagic Forum

Does Resolve have any transform for this, I could not find any?

Alternatively is there anyone who wrote a DCTL for this one?

This is for the case when a Rec.601 video needs to be transformed to a Rec.709 color space.

I don't think the differences are enough to worry about.

http://www.glennchan.info/articles/tech ... -space.htm

Rohit Gupta said sometime back that when you do the conversion within Resolve, it's supposed to automatically applies a color matrix to compensate:

https://forums.creativecow.net/thread/277/4025

My memory is the main difference is a couple of points of Green, not a huge deal.

Cary Knoop wrote:Does Resolve have any transform for this, I could not find any?

Alternatively is there anyone who wrote a DCTL for this one?

This is for the case when a Rec.601 video needs to be transformed to a Rec.709 color space.

Rec. 601 is standard for SD while 709 is standard for HD. So why convert from 601 to 709? The differences are very minor (max. 3% in color values), and depend on NTSC vs. PAL. Gammy curve is the same for both standards.

Here the details of chromaticity values:

Parameter REC. 709/ Rec.601(NTSC)/ Rec.601(PAL)

Reference White x=0.3127/ x= 0.3127/ x=0.3127
(D65) y=0.3290/ y=0.3290/ y=0.3290

Color primaries
Red x=0.640/ x=0.630/ x=0.640
y=0.330/ y=0.340/ y=0.330

Green x= 0.300/ x=0.310/ x=0.290
y=0.600/ y=0.595/ y=0.600

Blue x=0.150/ x=0.155/ x=0.150
y=0.060/ y=0.070/ y=0.060

From this table you can see the minor differences.

My proposal is leave colors of SD material unchanged when importing into a HD-project and vice versa.
Joachim

Quite bad approach and also- Resolve should convert YUV based HD/SD sources properly anyway. If it doesn't then it needs to be fixed.
When you import material it's not the biggest issue as you most likely going to mess with colors anyway. When you export this has to be correct and use correct math depending on output format. These are basics!

Found this Color space conversion LUTs at vegascreativesoftware forum https://www.vegascreativesoftware.info/ ... n--104869/
http://www.pantarheon.org/601vs709luts.zip

P.S. it s real shame that there is no any native Rec.601 <-> Rec.709 transform in Resolve.
In some situations difference between Rec.601 and Rec.709 may be dramatic:

I've dealt with documentaries that indiscriminately mix SD and HD material within the same HD show, typically a historical retrospective or a news documentary. I just color correct everything to that it looks reasonably good in Rec709 HD. This is not difficult work. It's insignificant compared to the video changes I personally impose on the material, because I usually wind up having to do a lot of squashing & stretching with levels, plus NR and enhancement here and there.

If it's a really good SD capture, like from DigiBeta or something, then there's bars on the head and I can generally see exactly where they were and what it started out as. Often, it winds up needing very, very little change if it starts off at high quality. I do generally have to compensate for the 7.5ire blacks and stuff like that, but it's not a lot of work. I've done far more difficult things in my time.

Even Apple Motion with its very limited color management have option for Rec.601 input.

It's a different primaries matrix for doing the conversion from YUV to (Y)RGB. You can do as much manual correction after the fact as you want, but some colours are going to be clipped and we all know you can't restore something that has been clipped into oblivion. Stop making excuses and workarounds for missing basic functionality.

Also when you deliver to broadcast then you 100% can't treat Rec.601 and Rec.709 as similar enough and misinterpret footage.
There definitely should be functionality to address those issues if Resolve wants to be a "generic" NLE (specially when Resolve is all about color spaces and conversions between them).
And this is what BM is trying to sell me every day- how great NLE Resolve is and that I can forget about Premiere, AVID and other solutions. Problem is that for exactly reasons like above I can't.

I'm with Marc, done many different documentaries, where more important than going from rec601 to Rec 709 is matching as much as you can the SD footage to the HD footage. I had never worried not even once about converting 601 to709, as soon as it is in Resolve and you start grading it to make it look right, you are already in 32 bit YRGB previewing it in Rec709, so it really does not matter.

More important than worrying about rec601, is the conversion from Rec709 to Rec2020

This what you said is fine when we look at Resolve a grading tool.

Here is simple task as NLE.
I will give you Rec.709 HD master and ask you just to make me accurate SD Rec.601 version which will go to broadcast. Good luck doing it manually

I just ran a series of tests on Mac OSX, Resolve 14b8.

I used a clip of accurate rec709 EBU colour bars in 1080P as a source file.
Resolve project set at 1080P.
Rendered out as HD 1080P Prores, and also SD 720x576 Prores & SD 720x576 AVID codec in MXF file.

Using Resolve only, I did an import of the rendered clips and checked scopes on both HD & SD timelines.
All clips showed correct bars with no issues.
My conclusion: Resolve accurately determines colour space transforms from the source file format.
Output rendering transforms are also based on output format selected.

Imported into FCPX and used both internal and external scopes with BMD mini-monitor output.

Using the Prores files:
FCPX projects (timelines) set at HD 1080P and SD 720x576.
FCPX set at SD 720x576 resulted in inaccurate bars for the SD clip.
FCPX set at HD 1080P resulted in inaccurate bars for the SD clip.
Inspector showed SD clip as rec709, which is incorrect.

Did the same test with SD AVID MXF bars.
FCPX set to HD or SD resulted in perfect bars with no issues.
Inspector showed SD clip as rec601, which is correct.

Final conclusion:

Some applications and playback software interpret Prores files as rec709 by default even if they are encoded as rec601. This can be misleading as the file data itself is correct.

Resolve correctly applies the appropriate colour space conversion based on the file format and encoding.
It is possible that some other formats are not interpreted correctly, as I did not test every available format.
What IS important is that you test your workflow, formats etc. and do not assume anything. Just because there is no visible transform setting or plugin does not mean there is an issue.

Andrew Kolakowski wrote:Here is simple task as NLE.
I will give you Rec.709 HD master and ask you just to make me accurate SD Rec.601 version which will go to broadcast. Good luck doing it manually

Resolve will do this as a standard part of the output to a different format. No need to manually do anything!

Really?

Who wants a Rec.601 for broadcast?

Every SD has to be Rec.601 for broadcast.
It's not a matter of choice but hard requirement.

Where in the world? And if they are still broadcasting SD 601, can they afford equipment that will show them errors?


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.....I would deliver 1080 and let them do the rest themselves....


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Roen Davis wrote:Where in the world? And if they are still broadcasting SD 601, can they afford equipment that will show them errors?

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They have plenty of old equipment for this

Roen Davis wrote:.....I would deliver 1080 and let them do the rest themselves....


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Well- this is fine if they are happy to do, but in many cases they will say you/client have to pay for conversion.
There are plenty places which are strict about it- they give you spec and it's your problem. They are not charity.
Files have to be perfect- they have to be in gamut, audio has be normalised, file format as requested including things like 16bit v 24bit ( or even Little Endian v Big Endian) for audio in MOV which sounds bit odd, but they will reject it.

Peter Cave wrote:

Andrew Kolakowski wrote:Here is simple task as NLE.
I will give you Rec.709 HD master and ask you just to make me accurate SD Rec.601 version which will go to broadcast. Good luck doing it manually

Resolve will do this as a standard part of the output to a different format. No need to manually do anything!

This is the way how some NLEs do and it's fine.

Peter Cave wrote:Final conclusion:

Some applications and playback software interpret Prores files as rec709 by default even if they are encoded as rec601. This can be misleading as the file data itself is correct.

Resolve correctly applies the appropriate colour space conversion based on the file format and encoding.
It is possible that some other formats are not interpreted correctly, as I did not test every available format.
What IS important is that you test your workflow, formats etc. and do not assume anything. Just because there is no visible transform setting or plugin does not mean there is an issue.

I don't trust any software

Problems with Resolve v14b8 SD ProRes files is that MOV (and private ProRes frame) headers are set to Rec.709 and this is not good. What goes to headers in v14b8 is read from projects settings (viewtopic.php?f=31&t=63489) and you can't set Rec.601 there as you have no such an option. This is where mess starts- some apps do rely on headers info, other uses resolution logic etc. This is why BBC has created this:
https://github.com/bbc/qtff-parameter-editor

in case of SD (specially intended PAL/NTSC) files headers should be strict and fixed to correct values, specially when Resolve (behind the scenes) converts data to Rec.601. It's still not good overall. It's "sad" that so many open source tools have all of this implemented correctly, but pro apps are so often far from being correct (applies to many apps not only Resolve).

Roen Davis wrote:Where in the world? And if they are still broadcasting SD 601, can they afford equipment that will show them errors?

I'm baffled by that as well. All the standard-def transmitters (for the most part) are shut down. You can still get down-converted HD as SD via cable TV and satellite, but as far as I know, it's just a straight-across conversion from HD 1080i to 525i. I don't think there's enough of a difference to worry about it, provided there's no gamut errors or other excessive level problems. I would also worry about Safe Action a lot more if I suspect the show was going to air somewhere in full-frame 4x3.

BBC accepted only SD masters for commercials just a year or so ago Not sure if it has changed. At the time actually only ITV (if I'm correct) was accepting HD masters for commercials, so we are talking all major UK broadcasters asking just for SD masters.
All high end HD work in Flame was moment later converted to SD and shown as SD and upscaled on HD channel. Crazy but this is broadcast being so outdated reality.
Look at EE (http://ee.co.uk) beloved green color. Try misinterpreting Rec.601 v Rec.709 for this one= client not happy saying that it's wrong color
For every your argument saying that it's so close I can show you argument that it still can be a problem.
You are still showing arguments from colourist point (or Resolve as grading tool), not delivery point and these are bit different.

Andrew Kolakowski wrote:BBC accepted only SD masters for commercials just a year or so ago...
You are still showing arguments from colourist point (or Resolve as grading tool), not delivery point and these are bit different.

I only know my world, which is delivering feature films and TV series. And that's all HD 23.98 and sometimes 4K 23.98. 4x3 is not part of that world, and SD is not part of what I do. I think in 2017, we have moved far past standard definition. As Stephen King says, "the world has moved on."

I did just do two commercials on Thursday, but those were for America and were all 29.97 HD 1080i for broadcast, cable, and online.

BM can't think like this, they need to address all global needs.

Andrew Kolakowski wrote:BM can't think like this, they need to address all global needs.

Well, they're based out of Sydney and have offices in Malaysia and California and Beijing and England and Tokyo, and other cities. I think they do very much consider the global market for everything they make.

Well....I am in Sydney. I think BM have HQ in Melbourne. I believe Resolve is engineered in Singapore. I guess if SD601 delivery was on the radar somewhere, they would have it covered.


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Roen Davis wrote:Well....I am in Sydney. I think BM have HQ in Melbourne. I believe Resolve is engineered in Singapore. I guess if SD601 delivery was on the radar somewhere, they would have it covered.


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I'm based in Melbourne and must deliver both HD and SD to broadcasters and web advertisers every week. It works fine delivering from Resolve as the SD export has the rec601 conversion as an automatic process with no user input required. The issues are mostly related to Prores as the Prores format was intended for HD and usually is flagged in the file as rec709 even when the data is correctly converted to rec601. This is an Apple Prores issue, not a Resolve issue. I never deliver SD Prores unless I can confirm the files decode correctly.

Yes, engineering is done in Singapore. I used to work there and knew the people responsible for taking Resolve from a $800,000 turnkey grading suite to the software we use today.

If this is correct you have plenty just SD channels in Australia:

https://en.wikipedia.org/wiki/List_of_d ... _Australia

Andrew Kolakowski wrote:If this is correct you have plenty just SD channels in Australia:

https://en.wikipedia.org/wiki/List_of_d ... _Australia

Yes that is correct.

Peter Cave wrote:

Roen Davis wrote:Well....I am in Sydney. I think BM have HQ in Melbourne. I believe Resolve is engineered in Singapore. I guess if SD601 delivery was on the radar somewhere, they would have it covered.


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I'm based in Melbourne and must deliver both HD and SD to broadcasters and web advertisers every week. It works fine delivering from Resolve as the SD export has the rec601 conversion as an automatic process with no user input required. The issues are mostly related to Prores as the Prores format was intended for HD and usually is flagged in the file as rec709 even when the data is correctly converted to rec601. This is an Apple Prores issue, not a Resolve issue. I never deliver SD Prores unless I can confirm the files decode correctly.

This is purely Resolve issue and has nothing to do with ProRes itself.
ProRes is not bound to any resolution or spec. What's more proper Rec.601 flagging is part of its spec and it's well covered. You have to remember that this is just metadata and some tools rely on it others don't. If you know your actual video data is Rec.601 then flagging is another issue, although it should be aligned with video data to avoid issues.

Well, there you go! I haven't had to deliver any SD for about 8 years. I am mostly doing documentaries for big and small screen and museum installations.


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Well, this AGAIN shows you how broadcast is outdated We now watch UHD on our phones over 4G, but so may channels are still just SD (this is regarded of argument if we really need UHD at home).

Roen Davis wrote:Well....I am in Sydney. I think BM have HQ in Melbourne. I believe Resolve is engineered in Singapore. I guess if SD601 delivery was on the radar somewhere, they would have it covered.

You are absolutely right -- Sydney and Melbourne, my apologies.

An extra complication is that rec601 was developed when the only displays were CRT monitors, which have different primaries and transfer characteristics to LCD or LED monitors. Most professional flat panel monitors are rec709 or sRGB and can't natively display a rec601 signal accurately unless the input has been corrected to allow for the slight difference between the two standards.

In Resolve there is a checkbox to use a rec601 matrix for the SDI out, when using BMD hardware for SDI output to a rec601 display. I don't think many people are still using rec601 displays but the option is there for legacy compatibility.

It's a messy business with all these formats coexisting, but that's the job we do as editors & colourists!

For anyone who wants the full tech article:http://www.ece.rochester.edu/~gsharma/papers/lcdvscrtprocieee.pdf

But wasn't Rec709 also defined before flat screens had decent colors? AFAIK they took Sony's Trinitron for one reference.

Uli Plank wrote:But wasn't Rec709 also defined before flat screens had decent colors? AFAIK they took Sony's Trinitron for one reference.

That's correct but very few flat panel monitors have rec601 support.

Sony BVM 4K doesn't support it either, at least v1 didn't.

Uli Plank wrote:But wasn't Rec709 also defined before flat screens had decent colors? AFAIK they took Sony's Trinitron for one reference.

Many people keep doing that even now.

Done a little test:
SD test pattern generated by Kramer fc-400 and captured by Intensity Pro to ProRes422 HQ
Input and Timeline set to Rec709 in Davinci Resolve.
Another test pattern generated directly in Davinci Resolve.

Color primaries seems correct in both patterns. This proves that Davinci Resolve can read hidden information in .mov files and converts Rec.601 to Rec.709 under the hood. But probably this may not work correctly with different containers and codecs, or even with .mov files converted from difefrent containers and codecs.

Andrew I don't understand in what world you live in?

When you write about all those SD channels, I'm like - is he writing from the past?

It has been at least 9 or 10 years since I had to create an SD master, and I have worked in hundreds of Commercials, TV Series and Feature films.

if anyone like 8 years ago was still broadcasting in SD, they as well were using tapes like HDCAM and Digibeta, and the SD master would come out just doing a Deck to Deck from HD to SD copy.

I really find hard to believe all those stories about BBC only receiving Spots in SD one year ago, I feel like you are just trolling us

Caryl Deyn wrote:Andrew I don't understand in what world you live in?

When you write about all those SD channels, I'm like - is he writing from the past?

It has been at least 9 or 10 years since I had to create an SD master, and I have worked in hundreds of Commercials, TV Series and Feature films.

if anyone like 8 years ago was still broadcasting in SD, they as well were using tapes like HDCAM and Digibeta, and the SD master would come out just doing a Deck to Deck from HD to SD copy.

I really find hard to believe all those stories about BBC only receiving Spots in SD one year ago, I feel like you are just trolling us

This world
Look how many channels worldwide are still SD only. Maybe in USA jump to HD has already "really" happened.

I worked for company which creates probably 30% all UK ads (including most expensive ones), so I'm not trolling. Don't worry- when I've heard this first time I was in the same shock
Keep in mind this is related strictly to adverts, not long form etc. programmes.

It's just now (April) when BBC started accepting only files (with some possible exceptions) as deliver format:
http://www.bbc.co.uk/commissioning/tv/p ... ments#file

Wow Andrew it is an eye opener I have worked not only for US channels but for some in Latin America, and I felt the SD was already completely dead, I'm actually now in the transition to HDR since Studios like Netflix prefer their content in 4K and in HDR. Guess a lot of channels have a long way to go

Well SD is about dead, it's just broadcast which feels still so outdated. No one wants to invest money there- they are so slow and have a lot of hardware which needs to be replaced. Any change quite often involves huge investment which these days is not easy to push through. Netflix and TV manufactures became industry "pushers".

Sorry to drag up this thread from three years ago.

I use DaVinci Resolve mostly as a video editor. I've been a Video Editor in the broadcast industry since the 1980s. I have a lot of archive media in BT 601. I want to mix that in BT 709 timelines.

I am not a colourist, but I am completely anal about preserving colour accuracy. As are our R&D department.

It seems such a shame that in a "Davinci YRGB color managed" timeline I cannot set the "Input color space" of an SD clip to "Rec 601". Instead I have to remember to add a 601->709 LUT on each shot.

I also have to add a 2.5% horizontal stretch to each SD shot because DaVinci Resolve does not correctly scale the 702 / 710.85 ACTIVE pixels of SD "PAL" / "NTSC" (not the full 720 pixels) to the ACTIVE area of HD (i.e. all of it!). But that's a separate issue.

Is there a way to get feature requests into DR?

As it was answered here before - Resolve, is automatically applies color matrix depending of source resolution.
No need to add additional manual color transforms for SD videos.

You can easy proof it for yourself:
Take your SD video source.
Transcode it with something like Hybrid app. to HD with applied Rec601-to Rec709 matrix.
Open both source and transcoded files in Resolve.
Stretch to frame size and compare side by side.
They will look 100% exact the same.

Same time if you open both same SD and HD files in some non color managed app like VLC player - files will look slightly different. SD will have slightly yellow tint in reds.

So let me get this straight - if I'm converting VHS to digital via e.g. BrightEye75 - SDI Blackmagic SD Thunderbolt Recorder, resolve simply knowing the resolution of the footage will apply rec .601? That's how I read your comment. It surprises me - why they don't just set it as an option so we can be sure instead of having to read random threads with opinions about undocumented features that may or may not exist right? Maybe I should go read the manual again.

Yes, Resolve simply knowing the resolution of the footage will apply rec .601