Codec vs. Performance

[Ola Haldor voll]

In my experience, I’ll take Prores any day. DPX is nice, but so far I’ve experienced some frame drops (though at 10-bit 2K), but I’m usually in the green and have good performance.

One frame of DPX takes far more space than one frame of Prores 422HQ or 4444, thus you’ll need faster communication between file -> Resolve. A RAID is the solution, how fast it is depends on what kind and how many disks you make it up of I guess.

I have 4TB RAID0 on eSATA. RED RAW, DPX, Prores 4444.. no problem.. But I experience DPX as the toughest one to chew.

[Jamie Allan]

You’re mixing up processing and bandwidth issues there Ola.

DPX will of course struggle over eSata as the required datarate is alot higher than all the other formats you mention.

It is, however, the easiest to process as each frame is individually presented and not wrapped in any compressed or uncompressed video format.

R3D’s data rate doesnt really go much higher than 40MB/s but is the only currently supported codec that requires co-processing as it requires the most unpacking and debayering out of all compressed RAW codecs at the moment. You do, of course, have the option of lowering your resolution and debayering quality which for most jobs will still give you good enough quality to grade properly.

ProRes is a very efficient i-frame codec with alot less information contained within than R3D which makes it alot easier to unpack. It’s also been written by the same company as Quicktime and as such should be de-coded very well by their hardware. My tests with prores have been very good.

Your worst codecs for creative work (editing & online) are the horrible MPEG2/MPEG4 based acquisition codecs that inhabit most professional cameras as they require alot of CPU processing and have no options for co-processing. All of these codecs (H264, XDCAM, DVCPRO et al) should for the most part be avoided unless your workflow is designed to handle them properly (IE – NRK standardising on IMX50 for their entire broadcast network)

Jamie Allan
Post Production Consultant
DaVinci Specialist (Linux/Mac)
Jamie@Jigsaw24.com

Jigsaw Systems Ltd. – IT & Broadcast specialists for the UK
https://www.jigsaw24.com
https://www.jigsawbroadcast.com

[Sascha Haber]

Also consider Blackmagic or Ajas 10 bit YUV as weapon of choice, and dnxHD as intermediate for AVID people..
And yes, of course nice LOG cins and dpx are what you want if you got a proper raid.

[Ola Haldor voll]

Thanks for the heads up. 🙂

[George Bellias]

I am glad to hear you have had good results with ProRes because I use that codec the most. As I mentioned in my original post, I am use to converting my sequences to other codecs when going to finishing for performance reasons but it would be way more time efficient if I could use the same ProRes media for finishing in the Davinci.

The majority of my projects are shot on either HDCAM SR (4:2:2) or HDCAM, so ProRes has been the codec of choice for many years.

George Bellias
Jade Productions

[Jamie Allan]

If you’re coming from HDCAM SR I would suggest that you conform back to uncompressed QT or DPX as you will retain alot more of the quality from the format here.

ProRes is fine for your offline, and is fine for grading if you’re coming from a format that is more compressed than ProRes (H264, XDCAM et al) but if your aquisition format is higher quality (R3D, HDCAM, ARRI, Film) you should certainly look to online in uncompressed before delivering.

Jamie Allan
Post Production Consultant
DaVinci Specialist (Linux/Mac)
Jamie@Jigsaw24.com

Jigsaw Systems Ltd. – IT & Broadcast specialists for the UK
https://www.jigsaw24.com
https://www.jigsawbroadcast.com

[Margus Voll]

If you populate all 4 internal bays in pro machine you should get some 300 400 MB sec 1tb or 2 tb drives which is a bit faster than esata. I did put my system drive to optical bay as the second device under dvd.

I got DPX SD frames smoothly running even on mbp.

—

Margus

https://iconstudios.eu

[Vladimir Kucherov]

By the numbers it sounds like 400 would be enough for 1080/2k DPXs as well. Am I right in that thinking, that a 4 drive internal raid should handle 2k realtime?

[Margus Voll]

One should test it. On internal raid it will drop faster in speed so if it fills up speed will drop.

I got around 300 mb with internal 4 x 1 tb drives. When you populate with 4 Hitachi enterprise grade 2 TB you should get 4 x 13x MB which is about 500 something, but also this is only my theory. Not tested in practice.

If it works then it is relatively cheap solution but only raid 0. Then you would need 8 tb of timemachine 🙂

Somebody could test it out. My new machine is still in factory still so i can not give any results yet.

—

Margus

https://iconstudios.eu

[Darin Wooldridge]

I’m locked in dpx land. The ability to change one frame or one shot in a sequence is huge.
Dp catches that piece of dirt during final qc, can you frame that up a hair, oh maybe a bit brighter.
No problem.. just render the frame or shot changes, not the entire reel.

I’m done with huge gamma shifts across different systems. The lie that is color sync and several other things i have found to be time killers.

Another bonus is the ability to check your render as its running.

I’m currently running 16 fc 10k drives at raid zero, paired with an atto 8 gb fibre.
My other 16 drives should be showing up any day. (last chassis showed up dead.)

mY 2 cents

Darin Wooldridge
Freelance Colorist / Technical Strategist
818-653-3918-cell
dwooldridge@mac.com
check me out at https://www.facebook.com/pages/Davinci-Resolve-Colorist/117363011609028?ref=ts