R5c 8K playback/editing issues

[Ron Wilk]

I have just begun to fiddle with the 8k output from the R5c, and have encountered some issues with playback on my 2019 fairly maxed out Mac Pro Tower.  There is quite a delay before the clips begin to play in Resolve 17 Studio, and there is some stuttering, as if some processing is going on in the background.  I have the clips loaded to an SSD RAID box connected via Thunderbolt, but the same issue occurs if the clips are loaded to the desktop, and the main drive is SSD as well.  4k, on the other hand, plays back a smooth as butter, and since I mainly shoot 4k, it is not a big issue at the present time.  But I am wondering if I have overlooked the proper Resolve settings? Anyone else encountering similar problems?

[Ron Wilk]

Followup to the above post:

Rendering the timeline has resolved the issue.

[Tyler Purcell]

Yea, the R5C Raw files will not playback in real time on a non-Apple Silicon system, no matter how much power you have. It's just not possible sadly. The Raw decode is not hardware accelerated properly. Maybe they'll fix it someday, but for the time being, the Apple Silicon systems are the only ones that play it back flawlessly. 

Rendering the timeline does not solve the problem sadly. You won't be able to edit, having to render it every time you throw a clip in the timeline, it's a horrible way to work. 

[Ron Wilk]

The files in question were MP4 8k, not Canon RAW.  And I understand that the timeline would have to be rendered each time edits are made.  Proxies may be an option.  But despite the impressive files, I plan to stick with 4k, in order to interface with the output from my C300 Mk III.  But I was disappointed to find that my uber costly, maxed out Mac Pro Tower could not handle the 8k files, and I have no intention of working from an M1 laptop, which, BTW, I do own.

But I appreciate your response.

Regards,

Ron

Edited May 20, 2022 by Ron Wilk

[Tyler Purcell]

12 hours ago, Ron Wilk said:

The files in question were MP4 8k, not Canon RAW.  And I understand that the timeline would have to be rendered each time edits are made.  Proxies may be an option.  But despite the impressive files, I plan to stick with 4k, in order to interface with the output from my C300 Mk III.  But I was disappointed to find that my uber costly, maxed out Mac Pro Tower could not handle the 8k files, and I have no intention of working from an M1 laptop, which, BTW, I do own.

But I appreciate your response.

Regards,

Ron

OOOOO You're trying to do 8k in AVC ahhhhh now I get it. Yea that won't work sadly. 

You'll be transcoding for sure. 

The problem is different tho... AVC 8k is not supported on the hardware decoder of ANY AMD GPU. Whoops. 

I don't know if the M1's can do it either. It's not part of the "standard" use of the codec unfortunately. 

[Ron Wilk]

Hello Tyler,

Perhaps my explanation had not been clear, but there is no option for AVC... 8k on the R5c, the only options are for MP4 or RAW. But the best workaround appears to be to use proxies, at least for Resolve Studio 17.  As I've mentioned, it is not a big issue at the moment, since I plan on shooting in 4k, but for the occasional instance where I decide to, or am required to shoot 8k and subsequently edit same, I will be using proxies.

Regards,

Ron

[Tyler Purcell]

Yea, the MP4 is "AVC" actually. MP4 is a wrapper not a codec. AVC is a codec, it refers to variant of .h264. 

[Ron Wilk]

I thought that you'd been referring to XF-AVC, and the R5c does not offer 8k in XF-AVC. Sorry for the confusion.

[Ron Wilk]

FYI, I have been shooting with the R5c—for test purposes—in 8k, and importing the clips into Resolve Studio 17 where Pro Res HQ 422 proxies are made.  The proxies play smoothly, and there is little if any visible degradation on an Eizo 31" 4k monitor, as compared to the original media.  While the transcoding takes a little time, it is worth the wait and seems to represent a reasonable approach to editing 8k clips, at least for my current editing platform.