Qmaster, Dedicated Graphics and Core2Duos

[meucifer]

Hi all—

I've been working with HD video at work on an Octo-core 2.8ghz Mac Pro with 4GB of RAM. The footage we've been shooting comes from HV30s, shot in the 24p cine mode, which then has to go through a reverse-telecine pulldown to extract the progressive frames from the 60i envelope. On the Mac Pro, this process takes forever, and since we're working primarily with interviews, we have to treat long stretches of film first before editing.

I, for one, am not really wealthy enough to purchase a new Octo-core Nehalem Mac Pro with a decent screen, but would like to be able to work with this footage at home. Also, as a note, I occasionally travel abroad to work on and complete projects, so I would like to have a laptop in my arsenal. I am due for a computer upgrade, having used a 1.5ghz PowerBook for many years, but am a bit lost given the strange changes Apple has been making lately.

Ideally, I would like to purchase a computer with a dedicated graphics card, since a lot of research and development is being put into finding interesting ways of maximizing the processing capacity in systems with two video cards. The MacBook Pro 15" models at the higher end have dedicated graphics cards, which, in my mind, gives them an edge over the iMac of similar specifications, minus the screen size. However, I was curious to know if any of you had any experience using Qmaster in very small Core2Duo setups— the other option I am considering is the 13" MacBook Pro, which now has FireWire, and a 24" iMac, both at their highest specifications. The smaller, lighter computer is technically more enabling for me, as I don't work exclusively with video and am often on the move.

While dedicated graphics cards definitely can offer an advantage in encoding, these speed gains often seem highly specific— often tuned for H.264 or DivX. In any case, these are basically my options, and I was curious to know if any of you had real world experience trying to work with these more inexpensive systems in networked capacity or had familiarity with dedicated graphics gains in these lower end systems. Any advice, especially statistical advice, is much appreciated.

Thanks!

 

[bigbossbmb]

Are you editing native HDV or are you capturing ProRes? Would you be using an I/O box with the laptop?

GPUs right now do not accelerate video encoding. But Apple is working on software to offload CPU calculations onto the GPU with Snow Leopard (OpenCL). That said, the 9400 (integrated chip) is supported for OpenCL.

I would look at the refurb MBPs right now. Really good prices on the last generation 15" models that still have expresscard and the 9600 GPU.

Qmaster won't give you anything on a dual core machine.

 

[meucifer]

Are you editing native HDV or are you capturing ProRes? Would you be using an I/O box with the laptop?

I'm capturing native HDV and then telecining and converting to ProRes using Compressor. It's this step that takes forever.

GPUs right now do not accelerate video encoding. But Apple is working on software to offload CPU calculations onto the GPU with Snow Leopard (OpenCL). That said, the 9400 (integrated chip) is supported for OpenCL.

I guess I had forgotten that FCS needs to be partly rewritten to take advantage of OpenCL. Does anyone know, practically, what type of boosts could come from GPU-enabled processing? GPUs are good at crunching very specific types of information.

Qmaster won't give you anything on a dual core machine.

Do you mean that Qmaster won't do anything across two dual core units? I meant to suggest that I would buy two dual core computers in my initial post, the 3.06 GHz iMac and the 2.53 GHz MacBook Pro. I'm not sure wether FW800 or Gigabit ethernet is faster for networking them. I'm just wondering if this networked combo would actually be more expedient than the single MBP with the dedicated GPU...

Thanks, bigbossbmb.

 

[bigbossbmb]

converting HDV to ProRes will always be a slow process... no way around that.

nobody knows (besides Apple) what the gains of OpenCL will be for FCP/Compressor.

It is really hard to say how much of a boost networking those 2 computers will give you. GigE would be the best option (since your media would be on a FW drive and both the MBP and iMac have a single FW bus).

What is your actual goal? it sounded like you wanted a 2nd machine to start cutting projects when the MP was tied up with capture/conversions. But the idea of networking a MBP+iMac makes it sound like you don't have access to the MP.

Do you have Qmaster set up on the MP? How many instances are you running?

 

[giffut]

If ...

... the pulldown ProRes processing you do always is part of your workload, you really should consider building a dedicated machine/cluster to offload this from your workstation. Right now OSX does NOT give you the option to use the graphiccard for those tasks - and we yet don´t know when this will be. I certainly believe we will see a completey revamped Final Cut Studio 3 for this, to utilize Grand Central / OpenCL to the best in OSX 10.6.

Yet, are you really sure that the octo Mac Pro you utilize is that slow - may be something other than this is pushing the brakes on it (not enough RAM, other background processes). Another question would be, whether you just should stop using ProRes altogether and avoid the extra step of transcoding. You don´t really gain too much of going to ProRes firsthand, regarding picture quality. You have a wider color space to work with, but this doesn´t give you better quality for HDV, just some minor additional headroom. ProRes is meant to be for using uncompressed quality video with compressed filesizes, so to speak. What you can do, though: In Final Cut Studio do edit HDV material natively. Choose "ProRes" for your sequence render codec, only - you don´t need to render all to ProRes firsthand - just let Final Cut render what needs to be rendered. Do the final export for the master codec of your choice. This at least should speed up your current work flow drammatically.

Now, if you are willing to put some effort into this, you could built yourself a perfectly suitable hackintosh cluster, similar to this: http://helmer.sfe.se/ This definitely would give you much better performance per watt AND dollar compared to purchasing a brandnew Nehalem Mac Pro. Or you just get a Aja capture card or box: http://www.aja.com/products/

PS

I don´t know whether this might apply to the HV30 models, too: http://funwithstuff.com/therules/2007/10/hv20-pal-1080p25-workflow-solution.html

 

[meucifer]

Hi all—

Thanks for your suggestions. After some experimentation, I think that for personal video work, eliminating the ProRes encoding process is probably the best procedure. I did a few experiments on a 2.67 GHz MacBook Pro Unibody; with 8GB of RAM, the transcoding process took a little over 2x longer than the footage to go from HDV 1080i60 to HDV 1080p24, similar times to 1080p24 AIC. So I think that the MBP is definitely the way to go for the time being, with the possibility of acquiring a Mac Pro down the road as other financial options open up.

Thanks to everyone for their advice— reevaluating workflow is the most efficient and cost effective solution, of course!