A direct method to export mattes to external applications, such as Fusion??? Possible???

[Michael Mccune]

Dmitry; also, as you know, on a PC only the two Quicktime uncompressed alpha codecs are available.

And on a PC, two other alpha-labeled codecs, DPX Alpha 8 bits and DPX RGBA 8 bits are not in your list.

Did your tests show that those two DPX alpha codecs also work? On a PC???

Thanks again, Dmitry

[Glenn Sakatch]

Yes im on windows as well.

Glenn

[Glenn Sakatch]

“A thorough testing of any intended workflow is recommended.”

That is kind of what we are doing, and we can’t get it to work.

Perhaps Dmitry could outline with a bit more detail his workflow to get these into Fusion (or AE)
As stated earlier, I tried some of the codecs that are supposed to work, and they didn’t.

AFAIK, there is nothing in Fusion that is needed on the loader to say “this has alpha”, it should just see it.
There is a setting to tell whether you want it premultiplied or not, but that doesn’t affect the alpha channel in the viewer.

Is there something else that needs to be setup in Resolve to turn on Alpha output…more than just having an Alpha output node activated?

Glenn

[Dmitry Kitsov]

You should have the option to turn on the Export Alpha checkbox in the Video panel of the render settings whenever you render individual source clips starting with version 12.5. When you do so, DaVinci Resolve renders clips with alpha channels in either of two cases:
• Whenever there is an alpha channel embedded in the source media for that clip, the embedded alpha channel will be copied to the rendered version of that clip.
• Whenever a clip’s grade has a key connected to an alpha output, the alpha output will be rendered as an alpha channel for that clip.

If a specific Codec/Format does not have this ability you will not see the Export Alpha check box under the Video tab of the delivery page settings.
DPX RGBA is another format that supports it.
DPX 8 bit alpha is intended to produce a DPX with only alpha present.

Dmitry Kitsov,
Blackmagic Design technical support agent

[Michael Mccune]

Dmitry; very welcome information. Thank you.

However, cannot see the check box option in the Deliver/Video page to Export Alpha.

Test setup, as simple as possible:
New project, add single short clip, picture of a face (or whatever);
Add simple window, say, around the face (perhaps adjust saturation and gain to make the effect obvious to ourselves that the window works;
Select the Node Key tab on the color page to view the key/power window, and, again, verify to oneself that the key exists at that point;
Select the Hightlight mode (shift-H), again, just to verify to oneself that the key exists there;
Add an alpha output to the node tree and connect the node key output.

Should be ready to go to the Deliver page and Export Alpha, right? OK.

In the Deliver page, choose one of the alpha codecs (for PC), such as DPX Alpha 8-bit (alpha only, no video), DPX RGBA, Quicktime Uncompressed BGRA or Uncompressed ARGB.

Look down the Deliver page Video column for the Export Alpha option you mentioned.: Don’t see it. Not for any of the above-mentioned four alpha output codecs for PC Resolve.

I do see the usual Video/Advanced option list that includes Aspect ratio, Data Levels, Data Burn-In, Use Optimized …, use Flat Pass and three check boxes for sizing and debayer. But no Export Alpha option.

Gotta be something simple, Dmitry. What am I missing??? This isn’t an Apple/PC issue is it???

Thanks again, Mike

[Glenn Sakatch]

the key is to select individual clips, not single file.

quick peak, there is an export alpha option under dnx444. Haven’t done an extensive test yet.

Glenn

[Michael Mccune]

Thanks, Glenn; Really appreciate your help on this. And, yes, “individual clips” is mentioned in the documentation (page 1108).

BUT–I have to say, as an old English major–the documentation actually is not clear that it is NECESSARY to select, “Individual clips,” even when there is only one clip on the timeline. (This was my situation.)

Why is the documentation here unclear as written??? Because the purpose of this selection is to select how file(s) are output, either as a single file or multiple files. And if there is only one clip in the timeline, then the “Individual clips” choice is immaterial as it will always be a single file.

And there is no clue here that the alpha output option is hidden there.

But the actual necessity of this selection with regard to alpha output could easily be indicated by, for example, simply adding the the words, “… but alpha will be output ONLY if ‘Individual clips’ is selected, even if there is only one clip on the timeline.”

Dmitry, if you are reading this, please respond if you agree and please ask your team to clarify this point in the documention.

Thanks again, Glenn and Dmitry.
Mike

[Michael Mccune]

Glenn and Dmitry; … Next steps on exporting alpha from Resolve, intended for Fusion:

At this point, we think there are four codecs in Resolve that output alpha, two DPX codecs (DPX RGBA and DPX Alpha 8-bits)and two Quicktime codecs (Uncompressed BGRA and Uncompressed ARGB).

If I understand the alpha export process correctly–after Glenn’s helpful tip clarifying Dmitry’s statement that there is an Export Alpha option on the Deliver page if one selects Individual Clips–then the Resolve alpha exports should import into Fusion.

And then Fusion should alternately display the RGB video channels or the alpha channel by selecting the Color/Alpha button under each display window. Right?

Let’s try it:
In Resolve, a single clip in a new project with a simple window, say a circle in the center of the image.
Add the alpha output to the node tree.
In the Deliver page, select a codec, say, QT Uncompressed BGRA, and select Independent Clips and Export Alpha. Export.
Open Fusion, drop the BGRA clip in the flow editor, view the display.

Seems to work! The RGB video option shows the image with the window. And the alpha option shows the B/W alpha window. OK!

We are done, right? Not yet.

Try this same node tree and the same Deliver page settings but this time with QT Uncompressed ARGB (not BGRA): Fusion now has a problem with this codec.

The Fusion display for ARGB shows an image that is cropped and stretched horizontally (my circle window is distorted horizontally) and shows a grey scale RGB image. And the Fusion alpha display shows an opaque (white) screen as the alpha.

And the two DPX alpha export files don’t import into Fusion at all.

Dmitry or Glenn: am I seeing this correctly???

Thanks again, Mike