Compressor and mp4

Are you using one of the Compressor DVD presets?

Do some research on setting up your macpro for "distributed" rendering using qmaster. This will allow you to utiltize the multiple cores on your computer and vastly speed up the rendering. It usually takes a little bit of playing with the settings in the system prefrences: apple qmaster to find the optimal setting. I seem to remember that you need to install qmaster when you did the fcp install. you can always install it now doing a custom install.

Here's an additional thought, I wouldn't ask Compressor to transcode from MP4, assuming it's h.264. Instead, try going to Pro Res and then going from PR to MPEG2.

Russ

Russ, why would there be any quality or speed hit by adding an intermediate step of going to prores?

Because I've found some MP4s to cause Compressor grief and this sounds like it might be an example. A one day MPEG2 encode of a one hour MP4 is off the charts abnormal. First converting the file to an intermediate format is worth a shot.

But if the original file were playing nice with Compressor, then no…I wouldn't recommend it and would expect adding the PR transcode step to double the processing time, more or less.

Did a test tonight...

Converted an one hour h.264 video to DVD and converted the same one hour video from ProRes 422 to DVD. It is faster to convert a ProRes movie to DVD compared to using an h.264 video to DVD. When converting the one hour h.264 to DVD the fans on the iMac sped up indicating to me that the h.264 to DVD placed bigger load on the iMac. The fans ran normal with the ProRes file. Converting the video from h.264 to ProRes, the fans ran normally. Did not look at the final video. I would bet 2 bucks that the ProRes video converted to the DVD format safely.

One hour video...

H.264 to ProRes

4 min 45 sec

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ProRes to DVD

1 pass VBR Best

8 min 16 sec

h.264 to DVD

1 passVBR Best

12 min 10 sec

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ProRes to DVD

2 pass VBR Best

16 min 45 sec

h.264 to DVD

2 passVBR Best

24 min 31 sec

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27" Early iMac

3.4GHz Quad-Core Intel Core i7

16GB 1333MHz DDR3 SDRAM - 4x4GB

2TB Serial ATA Drive + 256GB Solid State Drive

AMD Radeon HD 6970M 2GB GDDR5

Apple Qmaster sharing set to 4 instances...

I always convert convert mp4 or h.264 videos to ProRes LT. Better to use ProRes LT over ProRes 422. The file is smaller and the quality damage has already been done to the mp4/h.264 video. (You won't see the difference between PreRes LT or ProRes 422.)

I used Compressor and Qmaster. What are the specs for your Mac?

Download this free Compressor repair app from Digital Rebellion:

http://www.digitalrebellion.com/compressorrepair/

To setup the Qmaster in Compressor:

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Setup the panel like below

Click on the option button...

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Pick half what is shown for Number of Instances. (After you try the a test video. Max out the number of instances and see which setting works best for you.)

OK.

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In the Inspector window... check Allow Job Segmenting...

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Click Submit...

Pick your cluster... Submit.

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Try a short video, 3 minutes or so that you know that works in Compressor. Compress to h.264 for convenience. You can (should) open Activity Monitor app to see how Compressor is working.