Hi there,

Can anyone recommend the best way for me to downconvert 10TB of 4K footage (yes, it's a lot) to HD, so I can edit it using my old Mac Pro?

I'm thinking I should downconvert to AVC-Intra 100 because that's what I've been using in Media Composer, it seems to me.

I'm hoping there's a software solution that isn't too expensive.

Regards, Malcolm

If you are downconverting so you can offline edit and then conform back to 4K later, why not choose DNX36?
Media Composer can handle 4K it, but you will need a newer version of MC than you have (8.3 or higher).

I don't know if my version of Media Composer (8.9.4) can handle 4K, Dom, but I'm pretty sure my mid-2010 Mac Pro can't. I have 24GB pf RAM, and an SSD startup disk, Radeon 5870 graphics card... maybe those aren't bad, but connectivity is very old USB (not USB 2 or 3 or C) and firewire ports. I've only ever used my four internal SATA drives, and eSATA drives, for editing, and for HD, that's been fine. I can no longer use my eSATA bays because the company stopped updating the firmware a couple of Mac OS releases ago, but I can still use my internal SATA slots.

So that's my thinking. If I can downconvert to HD, and get all of these downconverted HD files onto one of two big-capacity SATA drives, then I'll still be able to use my Mac Pro to edit.

Why not go the proxy DNx36 route? Good questiion, because my client would love to be able to, some day if needed, scale the project back up to 4K.

But two big concerns have been pointed out to me by an editor I know (who has a lot more experience than I do):

1. along with 200-and-some interviews, all 4K (which are currently filling a 10TB USB3 hard drive), I'm going to be given reams of archival 1970s and early 80s video to work with, which won't be 4K of course. That, and the graphics I'll be wanting to add, would be problematic, according to my friend. He says mixing 4K and non-4K isn't fun.

2. He also said that, in his experience, scaling-up after the fact via XML file to 4K isn't always an easy thing to do.

Now, if my client was a tough taskmaster with extremely high technical expectations, I might not be considering downconverting. But the people who've asked me to do this don't have a big budget and never considered 'broadcasting' this project anywhere but youtube. They ended up with a 4K-capable camera only because it wasn't expensive, and a 4K edit only occurred to them when one of them heard the phrase 'future-proof' and they all said 'Yes! Why not?'

Sorry for being long-winded. Frankly, all the technical under-the-hood stuff has always been beyond me and I find it hard to even put into words what steps I should avoid (and why) and what steps I should take instead.

Regards, Malcolm

p.s. Dom, or anyone, if you've read this far and have an opinion on this, please let me know: if I do end up downconverting, should I downconvert to MXF or to AVC-Intra-100? Always in the past when I've shot footage with my Sony camera, I export to MXF, and then import into Avid. In Avid, I noticed recently when I checked that it's AVC-Intra 100. Not sure, if I downconvert, if the process has to be a two-step process, or if it can be a one-step process.

You could go to Blackmagicdesign.com, and download the free version of Resolve, and see if it runs on your old system. If it does, you would drag all your clips into the media pool, go to Media Manager, and transcode everything to HD using a codec of your choosing. Resolve is extremely versatile in it's "dailies" workflow assistance.

If that's not an option, you can use Adobe Media Encoder, or even the $40 version of Compressor if any of those will work on your old machine.

Good luck,

J

Jason, thank you for your advice. Here's my tweak: because all the 4K footage is on a 10TB USB drive—which is USB-3 but because my Mac Pro only has USB-1 any drive connected runs at very slow USB-1 speeds—I'm thinking of connecting the USB-3 drive to my 2013 MacBook Pro, and using the free version of Resolve to transcode (or downconvert?) the 4K files to HD on a 10TB SATA drive in a USB-3 "docking station" that I will also be connected to my MacBook Pro.

Then, once all the files are safely on this SATA drive, I will insert this SATA drive into one of the internal SATA drive bays in my 2010 Mac Pro.

I hope to then be able to start editing.

Two questions, and then I'll try to stop asking.

1. which codec should I transcode (or downconvert) to? Is AVC-Intra 100 a good one? Or... is transcoding a two-step process: do I need to make everything MXF first, and then import into Avid?

2. If I transcode (downconvert) 10TB of 4K, which is 100Mbps bit-rate, to AVC-Intra 100 (which is also 100Mbps bit-rate), will I need a 10TB SATA drive? In other words, do file sizes get larger when I transcode/downconvert, or do they stay the same?

Again, thanks for the help with this. I can't wait to get a firm plan, test it out with a few files, and then get editing.

Malcolm

Malcolm,

Those two questions are very hard for me to answer because I just don't remember that many versions back -- so I don't feel equipped to answer them.

If you have a 2013 MacBook Pro, why not edit on that?

If you're locked into staying on your old MacPro, you could purchase a usb2 (maybe even usb3) PCI card, and you'd have access to that 10TB array at a much better speed -- they're cheap and readily available, and I'd bet it'd run faster than a single SATA drive within your tower if it's accessing an external drive that's setup like a RAID.

What should you transcode to? I'm afraid that depends on a ton of things. If you're striving to edit in the typical offline/online fashion, then I'd say DNxHD36ish mxf files. It's super super fast on slower equipment. If you're not wanting to offline/online, then I'd still stick with a DNxHD codec but go bigger in bitrate (the number depends on your footage, i.e., is it 23.98? 29.97?). The resultant HD footage will definitely be smaller in size than the 4k stuff, but again, it will depend on the material. Sometimes when one transcodes a highly lossy camera codec to something less lossy (but not as taxing on the CPU), the resultant files WILL be larger, but it's probably safe to say, scaling them down to HD, they should be smaller, and especially if you go with DNx36. AVC 100 is just not something I've EVER used, so I really can't comment, and again, I just don't remember what options you'd have that far back in the software.

HOW you get them into AVID (if you're transcoding in Resolve) is, again, a difficulty for me to recall because there's the way I know nowadays which is likely TOTALLY different from the old software. I don't even remember if AMA linking was available that far back. If I AM remembering correctly, on old old equipment, the best way to get material in to AVID was using .mxfs straight into the Mediafiles folder. To do that, you'd transcode in Resolve using one of the DNx mxf options (making sure it's set to render HD), then move those renders into your managed Avid Mediafiles/MXF folder, go into AVID, go into the Media Tool, have it display the .mxf files in the resultant window, then option-drag (control-drag?) them into a bin. Again, it's been a LONG time for me, but this technique will populate your bin with the metadata master clips of the .mxfs from the Mediafiles folder. If I remember correctly, you want to do it this way instead of "importing" them so that you don't re-import files that already properly packaged. Make sense? Just putting them into the Mediafiles folder isn't sufficient enough, you've got to get the 'Master Clip' metadata as well.

Just a heads-up, the free-Resolve version will let you render out rasters as big as UHD, so HD will be no problem. You could even apply a "best-light" look to the clips, but that's another story.

I suggest you download Resolve (not the paid "Studio" version), see if you can make it work, do a test on a clip or two, and bring it into your AVID. This will give you the chance to do a data calculation as well. The codec you choose depends on many factors, not the least of which the workflow you plan on using, and your deliverable.

J

Conversely (and likely more user-friendly) if the USB 1 thing was the only hangup for you, do as I said and buy yourself a USB 2/3 card, then plug that big drive into your MacPro, and just use the transcode options within AVID to get your stuff down to HD (assuming your software version can even support 4k and AMA link).

J

Jason, thank you so much. A USB 3 card that can fit into my Mac Pro sounds like a good place to start. I'll study some of your other advice before acting on it—eg. dragging the mxf files into an Avid bin rather than importing them (which is what I've always done) because, if I'm following your logic properly, this saves all the metadata... which means there's the possibility that some day the whole project could be up-scaled to 4K. Not on my old Mac Pro, but at a place that does this kind of onlining.

So nice of you to help like this.

Malcolm

The BEST way to insure a possilbe future scaling is to edit on a version that has FrameFlex. I usually edit with proxies that are of the original raster size, myself, but even if your proxies are only HD, you can open up that sequence in 4k, link it to the 4k, and it will translate for you.

In a purely HD version of the software, this will be a bit more involved.

Best,

J