16" MacBook Pro M1 Max displays video with alpha channel as black

meriutta,

Since you are also experiencing difficulties with videos exported using your new MacBook Pro, you’ll want to reach out to Apple Support so they can look into these behaviors further: Contact Apple Support

Regards.

Hello meriutta,

Thanks for reaching out through the Apple Support Communities about that behavior with those videos.

To verify, is this happening with videos in multiple apps, or is this only happening with a particular app?

Do you experience the same behavior with online videos or streaming content?

Hopefully those details will help to further isolate this behavior.

Take care.

I'm also experiencing the same issue. Have you tried viewing your files in Premiere or After Effects? I know this isn't the solution, but I'm curious since those are the only programs on my M1 Max MacBook Pro that are able to properly display ProRes 4444 with Alpha.

On my system, it's not just previews in Finder, or QuickTime that are stripping the alpha channel, but Final Cut Pro 15.4 as well.

I'd also like to point out I've exported ProRes 4444 Alpha straight, and premultiplied. The only difference is the straight alpha displays with a pixelated gray background and rough edges on my keyed subject.

Hoping this can get resolved soon. Video files with alpha channels are a big part of my workflow.

Please post if that works! I'm unfortunately limited by my workplace as to which version of FCP I can use. We're very much behind at the office and I'm using my new MacBook Pro for telework.

It is strange that FCP 10.5.4 is having this problem on a brand new M1 system, but not a 2013 Intel based MacPro. That's what we still have on site.

Same issue here too... good to know I'm not the only one.

M1 MackBook Pro running Mac OS 12.0.1 on M1 Max chip

Intel MacBook Pro running Mac OS 11.6 on Intel i7 chip

I use After Effects to generate animated lower thirds. I then use them in Wirecast as part of live streams. I noticed that when i upgraded to my new M1 MacBook Pro that all the backgrounds on my lower thirds were no longer transparent, but black. The exact same video files would however show transparency on my old intel MacBook Pro.

When running them in Finder as a preview (select file and press Space bar) on both old and new MacBooks I get the same results.... transparent backgrounds on the old intel, black background on the new M1.

I did a test and outputted a video with a straight alpha channel, and another with a premultiplied alpha channel. Neither worked on the new M1 (still black background), but both worked on the old Intel MacBook Pro.

All my videos are being outputted as .mov file using Apple ProRes 4444 as the codec. QuickTime shows that these files have alpha channels in Video Details.

I gave the videos files to my business partner to check too on his M1 MacBook Pro and he got the same results, black background.

So only difference between my two macbooks is OS, and chipset.

I'm reluctant to update my old Intel MacBook Pro to Mac OS 12 in case I loose the ability to run videos with transparency as this is now my back up lpatop for live events that require it. Really had hoped to switch fully over to the new M1 but now I carry two laptops around!

So having not resolved the issue, I'm here to ask if anyone else has?

Hi, we are experiencing this issue as well on M1MAX hardware. What application rendered the files? Im tracking down that the alpha channel bit depth settings and straight./premultiplied settings in After Effects could be a source of an issue on the M1 Max pro res decoders.

Hi everyone, I am experiencing the same issues. I need to export lower thirds for clients, and other stuff, with Apple ProRes 4444 + alpha (on my new specked out and quite expensive MacBook Pro 2021 M1 Max, which are made for motion graphics and video editors?) Hoping for a solution soon. The weird thing is though, when I check an export (with alpha) on an older Intel Macbook the same blackness appears, but when I drag the export in AE it looks alright. Help, anyone?

A quick reply to myself. I first called Apple, they told me to get in touch with Adobe (since I'm having this issue while exporting from After Effects / Media Encoder).

Then I had extensive contact with the Adobe helpdesk. We've tried a few things as checking if an older version of AE (18) had the same issue; it had. Then checking the current beta of AE, to see if that works, it didn't.

But it is a known issue, as you can see here: https://community.adobe.com/t5/after-effects-beta-discussions/after-effects-beta-now-on-apple-silicon/td-p/12474342 (incorrect rendering of ProRes 4444 files).

They said they are currently working on the new version for AE compatible with Apple Silicon, so hopefully this will get resolved in the near future...

No, this is definitly a Problem on Apples side.

I can't encode ProRes 4444 with Alpha via any Program I tried. My workflow relies on ProRes 4444 with Alpha, I'm working with BM Fusion. I can't even select the Alpha export, the option doesn't show up in the saver node.

Yes, I have tried everything, the two workarounds are tif sequences and export to DNxHD with Alpha, and even there the color and alpha channels get jumbled around, so you have to change them before the saver node.

Yes, I have tried to convert the tiff sequences into ProRes 4444 via Compressor, but even there it doesn't work. There is something seriously broken in the encoding system. Same setting on Intel does work as expected.

We utilize a special software for the market we serve, this software dev team has been made aware of the issue and are communicating with the dev support teams at Apple to open and identify that the issue seems to be in the hardware encoder/decoder of the M1 MAX not in the software. That case was opened 2 weeks ago, and I have no further info on status, or acknowledgment from the Apple team that the bug exists. I'll update this post when i hear more.

Im working directly with a third party software dev team who are communicating with Apple about the issue, which is occurring across many other third party apps. Apple is aware that the issue is within the pro res hardware encoder/decoder on the M1 MAX machines, as the regular M1's do not experience this issue. Furthermore we have been able to generate alpha channels using multiple other codecs such as HAP/DNxHD etc.. If i hear of any updates from Apple team Ill post here.

The M1 PRO / MAX both have a hardware chipset for encoding/decoding pro-res. The M1 does not. The issue is concurrent on M1 PRO/MAX machines, but not on M1 , or Intel. When i say its a hardware issue, it doesn't mean that the chip is "bad", it means there is a communication issue in the code between aspects of the way the OS/APP/CHIP talk to one another. This is almost 100% some sort of code issue either in the OS, Rosetta2, or the 3rd party app, or all 3. Hope that helps you to understand.

As long as it's fixable and they are aware, it should be ok. For now, I generate PNG Sequences and encode them on an Intel machine. I know the Pro and Max have the same engine, but since everybody explicitly mentioned the max, I wanted to chime in. :-)