ProRes LT to H.264 – How to reduce compression times?

[Jeff Meyer]

What are the limiting hardware features on compression times? Is it CPU/RAM/GPU?
CPU, RAM, and hard disk speed will be the most significant factors. In compressor the hard disk is usually most significant, but with H.264 the CPU/RAM are probably most important.

Would compression times be greatly reduced by buying a beefy Mac Pro?
Yes. With a 12 core box and a RAID-5 I can multi-pass H.264 in anywhere from real time to a quarter of real time.

Any word on virtual clusters? Or even networkingmultiple Macbook Pro’s to use as a cluster?
As far as putting computers together you’ll need a shared storage solution. Shy of shared storage my advice is to stick to a firewire drive, and go for a virtual cluster if you have 6 or more cores allowing you to use three or more segments.

I have had mixed advice on exporting from FCP and then importing to compressor rather than using the ‘send to’ function – I am in the middle of a job so don’t want to experiment with my workflow at the moment.
The main reason to avoid ‘Send to’ is because you can’t use a virtual cluster if you use this workflow. Export a Quicktime movie with Current Settings, then take that QT movie into Compressor.
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Since your MBP doesn’t have a whole lot of cores I think you’ll probably see best results exporting a movie at Current Settings onto your external drive, then going to H.264 through Compressor. In Compressor you should exporting to a either a different external drive or your internal drive for best performance. You might play around with two or three virtual cluster segments on your laptop to see if that is faster, but I suspect this computer from drive to drive will be as fast as it can be.

[Rafael Amador]

[Josh Haggard] “I am compressing a ProRes LT 720p30 sequence to H.264 “
Are you “sending to Compressor”, export a self-contained QT movie and import to Compressor instead.
rafael

http://www.nagavideo.com

[Josh Haggard]

Thank you for the reply. You comment:

I think you’ll probably see best results exporting a movie at Current Settings onto your external drive, then going to H.264 through Compressor. In Compressor you should exporting to a either a different external drive or your internal drive for best performance.

I am currently using my internal HDD as the scratch disk – no external drive is used anywhere in my workflow. Will using an external firewire as you suggest speed up conversion times?

Is it generally advisable to always use an external drive as the scratch disk?

[Jeff Meyer]

Yes. Using an external firewire drive is always recommended. G-Technology sponsors a forum on Creative Cow and makes a few bus powered firewire drives that will help your editing without compromising your portability.

It’s important that you get a firewire drive, not USB.

[Josh Haggard]

I have a 500GB G-Raid Firewire800 drive. I hadn’t been using it as I have ample space on my 500GB internal drive.

Why is using an external drive recommened?