ProRes 4444 with Alpha not working?

[CandyCoated]

I typically output png sequence to get an alpha, but I have reason to need ProRes 4444 file. First I've tried it with 13.5.2 and it will not render with the alpha. I switched to .png sequence and the alpha works fine. Am I missing something? For now I'm going to png and will convert to ProRes with Alpha in After Effects.

But would be nice to skip that step.

Thanks!

[slowtiger]

Works without flaw here (v11). Check if it works from other programs, like your video editor?

[Greenlaw]

If you're on Windows, I can confirm that movie files exported from Moho using ProRes with alpha does not work properly. However, movie files exported from Moho using ProRes with the PNG option does work fine. (If it hasn't been reported already, I'll let the devs know about this.)

FWIW, I don't normally render movie files from Moho when my intention is to composite in After Effects or another compositing program. For reasons explained elsewhere in these forums, It's always better to render to a PNG image sequence from Moho for compositing.

When I need to export to ProRes from a Windows computer, I like to use a convertor program called InterTake or the video editor Vegas Pro 19. Neither are cheap solutions but it was worth for me when I was freelancing because some clients required ProRes for final output. Hopefully ProRes 4444 for Windows will be working properly soon.

[synthsin75]

MOV (ProRez alpha-ALAC) exports with alpha here, on Windows 10.

[Greenlaw]

MOV (ProRez alpha-ALAC) exports with alpha here, on Windows 10.

That's weird...I could not get that to work at all this afternoon. For me, ProRes Alpha-ALAC always rendered with a solid background. Rendering ProRes with the PNG variant worked fine though. Tested both in After Effects.

I'll try again tonight and see how it goes.

[Greenlaw]

I just tried again with a simple circle drawn in Moho. Nope, no alpha when using ProRes Alpha-ALAC. When I render with this format, I can see Moho rendering with a solid white BG, and when I select Interpret Footage in Ae, the Alpha section is completely grayed out.

I wonder what we're doing differently.

[synthsin75]

I'm just importing the video back into Moho to check the alpha. But you're right. Importing the same video into HitFilm doesn't show the alpha.

That's not good, considering we're more likely to need to composite in other software.

[Greenlaw]

Interesting.

I tried importing the ProRes Alpha-ALAC movie into Moho and, on my system anyway, the alpha channel works in the Workspace preview but it doesn't work when rendering. So I think I the data exists, it's just not accessible for rendering in Moho, and not accessible at all to some other programs (HitFilm, After Effects...)

[synthsin75]

Interesting.

I tried importing the ProRes Alpha-ALAC movie into Moho and, on my system anyway, the alpha channel works in the Workspace preview but it doesn't work when rendering. So I think I the data exists, it's just not accessible for rendering in Moho, and not accessible at all to some other programs (HitFilm, After Effects...)

That's odd. ProRes Alpha-ALAC reimported back into Moho also renders with transparency here.

Do you have Quicktime Essentials (without the unsecure player) installed? That may be the difference? And I've read that HitFilm doesn't use Quicktime either. Don't know about AE off hand.

[Greenlaw]

Nah, I don't think I have QT installed at all anymore, original or essentials. That might be it.

Before I try that, I'll try importing to Vegas Pro 19 later this even. Vegas reads and writes ProRes but I think it's their own flavor of it since Apple doesn't officially license ProRes for Windows. (Same with InterTake, another program I use to convert and export to ProRes.)

[CandyCoated]

I'm aware of the benefits of rendering to image sequences. I've been doing 3D animation for more years than I care to mention. haha So rendering to an image sequence was the smartest way to avoid rerendering for hours when something crashed or there was a power outage, etc. Also, image sequences are more accessible to 3D apps when used as a texture because often the DCC loading them only has to load the current frame instead of an entire video file. This is very helpful especially with the use of GPU rendering these days. However, there are times that it is a convenience and / or other reason for wanting to go to prores with an alpha. 2D rendering takes nearly no time at all compared to 3D so I'm not worried about having to rerender something due to crash or power outage, and going straight to ProRes removes a step of processing when I need to pass files to others that are requesting prores with alpha.

This is a feature that appears to be somewhat broken, so I just wanted to confirm that it wasn't some setting I had missed.

My understanding is for any software to be able to use ProRes "officially", it is licensed by Apple, and Apple does indeed support ProRes officially on Windows but doesn't seem to be at the OS level (I could be wrong). So maybe you're onto something with the flavor of ProRes being used. In any case, it's a feature that's been added to Moho but is not working properly for me.

AHA! While typing up this response, I just read about Apple's iCloud Utility for Windows which adds ProRes support for viewing ProRes files from iCloud accounts. My hope is that it's adding those codecs at the system level. I'm going to try installing that and see if that kicks things in the right direction.

I'll report back here in a bit.

[CandyCoated]

NOPE. No joy.

Hoping Lost Marble can get this sorted.

[Greenlaw]

My understanding is for any software to be able to use ProRes "officially", it is licensed by Apple, and Apple does indeed support ProRes officially on Windows but doesn't seem to be at the OS level...

Ah, thanks for the info!

Yeah, I see now that they started licensing Pro Res for Windows in 2020. And until MS licenses it for the Windows OS itself, I'm sure official ProRes support will be program specific.

I found this list at Apple: https://support.apple.com/en-us/HT200321

Looks like quite a few companies license it now. I'm guessing the other companies that support ProRes (like the three programs I mentioned) are using a third-party 'non-Apple' variant, or they developed it in-house (I believe that was the case with Magix and Intertake.)

[arglborps]

I found even the ProRes 4444 that Moho creates on macOS has a fairly "dirty" alpha channel, never worked well for me. If I want alpha channels I always export as PNG sequence.

You can however then use QuickTime player to open the PNG sequence and save it in ProRes 4444. That will result in a ProRes .mov file with clean alpha channel.

[synthsin75]

You can however then use QuickTime player to open the PNG sequence and save it in ProRes 4444. That will result in a ProRes .mov file with clean alpha channel.

Just don't use QT player on Windows, as it has security problems.