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Maximising transcoding speed

gugucom

gugucom

macrumors 68020
Original poster
May 21, 2009
2,136
2
Munich, Germany
Transcoding from mpeg PAL to MP4 1080p in high quality with MPEG Streamclip seems to take a lot of computing power. I observe that the Mac Pro does not use the 12 GB RAM I have and I suspect it cannot utilise the HD3870 capabilities. Does anybody have ideas how I can do this faster with my hardware?
 
Sell it and buy a faster machine. A hard drive RAID setup may also speed things up a little.
 
300D said:
Except the current 2.66 and 2.93 Mac Pros.
Click to expand...

Instead of telling him to buy a very expensive machine when his is perfectly capable of performing this task faster, perhaps a change of software would be in order.

OP, does HandBrake not perform this task properly for you? It can use (at least) eight cores in its transcoding, and it's free.
 
300D said:
Sell it and buy a faster machine.
Click to expand...

Well, one could spend thousands of dollars. But then
one may not have to.

Do you know, for example, that MPEG Streamclip is the
most efficient transcoder? Would a recent FFmpeg fare
better? Etc etc.
 
MPEG Streamclip cannot use all of your cores, or at least it never maxed out all 8 of mine (topped out at 5, once). Handbrake and Compressor should be able to do better, properly configured.

Video cards aren't being tapped for transcoding, yet. Once GPGPU capabilities are further developed, they should be. I think only software can achieve greater speeds with the configuration you have. That is to say, faster CPUs probably wouldn't make much of a difference at that point. Not unless your software's yoking all the cores to the task at hand.
 
Thank you for many good hints. MPEG Streamclip allready uses all eight cores but it does not fully utilize them. It did not cross my mind that handbrake would do this. I will definitely try if I get better results with this. At least MPEG Streamclip is a convenient way to cut adverts out of transport streams.

Hopefully Snow Leopard will give GPU h.264 support.

One open question was about using RAM to speed things up. I was wondering if one could keep the whole project in RAM and only copy the finished product.
 
300D said:
At least I'm not making wild guesses.
Click to expand...

Why is it every time I read a post with your name in it, it seems like you are playing King of the Hill with the forum...

@OP: Is there a test run you could provide maybe for other people to compare with? I don't see why that machine + setup would any issue with any task.
 
gugucom said:
Thank you for many good hints. MPEG Streamclip allready uses all eight cores but it does not fully utilize them. It did not cross my mind that handbrake would do this. I will definitely try if I get better results with this. At least MPEG Streamclip is a convenient way to cut adverts out of transport streams.

Hopefully Snow Leopard will give GPU h.264 support.

One open question was about using RAM to speed things up. I was wondering if one could keep the whole project in RAM and only copy the finished product.
Click to expand...

You could order one of those H.264 usb sticks, that should help considerable.
 
zmttoxics said:
@OP: Is there a test run you could provide maybe for other people to compare with? I don't see why that machine + setup would any issue with any task.
Click to expand...

I was transcoding Men in Black II in a 2,6 GB mpeg2 transport stream to MP4.

My choice of format in MPEG Streamclip wasn't very lucky because I tried to blow it up to 1080p which wasn't very usefull and took much space. I had sychronising issues as well and the cores were only 50% loaded. It ran several hours.

I handbraked the file with large files enabled, keeping original resolution and frame rate and de-interlaced it. It loaded the cores fully and ran in 23 minutes. Quality was superb and no sync issues. It went up to 4,6 GB and I can well live with that.

So you can say that I never did a fair comparison but I will simply use Streamclip for cutting and Handbreak for transcoding due to the higher loading of the octad.

I hearded that the Elgato H.264 HD stick will compromise quality and will only run on dedicated SW. That may be wrong. I am looking for something that would speed up any SW I'm using and obviously using existing HW like the GPU would be much preferred.
 
zmttoxics said:
You could order one of those H.264 usb sticks, that should help considerable.
Click to expand...
That would only help with supported software. Not to mention Quicktime encoding is painfully slow as well. It's not surprising they released such a device.

gugucom you're seriously looking a faster processors or a new machine if you want it to be faster.
 
Import it into iMovie9. Then export (share) to quicktime. In there, you can export to allot of different formats including .mov. There are allot of settings in there too. Mpeg stream clip is a nice app but I have found out it does reduce a little quality.

Just to add, there are not to many apps out there that will use all cores (unfortunately). Snow leopard will help but its the maker of these apps who have to write the code for multi processors. Guess we will see in september.
 
Eidorian said:
gugucom you're seriously looking a faster processors or a new machine if you want it to be faster.
Click to expand...

If I would sell this Mac Pro I would probably get just enough to buy the lowest Nehalem Octad. The platform would be better in terms of bandwidth. But I would have to seriously shell out to buy a much faster pair of processors to actually exceed my present x5365 octad. So I had to find at least 2000€ to make progress and bear a lot of hassle. Not even to mention the Ebay and PayPal charges.
 
gugucom said:
If I would sell this Mac Pro I would probably get just enough to buy the lowest Nehalem Octad. The platform would be better in terms of bandwidth. But I would have to seriously shell out to buy a much faster pair of processors to actually exceed my present x5365 octad. So I had to find at least 2000€ to make progress and bear a lot of hassle. Not even to mention the Ebay and PayPal charges.
Click to expand...
That's my point.
 
bearcatrp said:
Import it into iMovie9. Then export (share) to quicktime. In there, you can export to allot of different formats including .mov. There are allot of settings in there too.
Click to expand...

I decided to transcode as little as possible. I will keep stuff I record without adds (basically DVB-S & DVB-S2 Movies) in the stream version. EyeTV has a nice way to run a repository which can even be called up with their remote.

DVB-S stuff with adds I will clip the adds out and transcode to MP4 with Handbrake. This stuff will also run with EyeTV I found out. The loading of the files it a bit more work.

bearcatrp said:
Snow leopard will help but its the maker of these apps who have to write the code for multi processors. Guess we will see in september.
Click to expand...
I'm looking forward to that.
 
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