View Full Version : MPEG-2 Encoding acceleration?


Michael Rich
December 20th, 2005, 08:42 AM
Are there any products that work hand-in-hand with FCP or Compressor to speed up the encoding process to MPEG-2? I want good looking video, but its a bit insane to wait 20+ hours to compress ~30 minutes of video in two pass vbr best mode.

I've read the new ATI X1800 cards have a built in encoding accelerator, but I do not know if they work w/ the Mac, nor if they even have drivers if they would.

Thanks!

P.S. I use a G5 PM /w PCI-X.

Daniel Weber
January 21st, 2006, 10:58 PM
I have been fighting this as well. I have heard that it is better to use the single pass encoder instead of the 2 pass and that the quality is just as good but is much faster.

I have been having problems with the footage looking jittery if there is any kind of motion. I understand that there was a Pro Application update that was supposed to fix the problem but I have installed it and the files still look bad.

Even using the single pass encoder, a 2.5 minute clip took over 1 hour to encode.

Let me know if you find anything out.

Dan Weber

Tomas Chinchilla
January 22nd, 2006, 09:35 AM
Here is my workflow:

Edit in FCP5
Change timeline settings to Field D=None
Apply Deinterlace filter to the timeline
Export to compressor
Constant Bit Rate = 8.3MBPS

Leave the frame controls alone!

(If you deinterlace the video, make sure compressor is set to progressive)

Dan Euritt
January 29th, 2006, 01:30 PM
you guys are talking about limiting your mpeg2 encoding capabilities to cbr and single-pass only... that's not the way to create the best quality output, it's a giant step backwards... you might as well just feed the raw avi out thru firewire to a dvd recorder, then rip the disk back into your dvd authoring program... you'd probably get better picture quality.

surely there must be better solutions on the mac side of the fence... how about sorenson squeeze pro?

Ben De Rydt
January 30th, 2006, 08:21 AM
Bitvise gets good reports and MegaPEG too, but Compressor is not so bad at all. Considering your comment on CBR and single pass: 2 pass and VBR encoding only makes sense if you're short on disc space. Otherwise you're just trying to compress more than CBR.

Emre Safak
January 30th, 2006, 10:30 AM
You're both right; VBR yields better quality for a given bit rate, and CBR takes less time.

Guest
January 30th, 2006, 04:33 PM
Get a PC and run procoder..

http://www.canopus.com/products/ProCoderSW/index.php

William Hohauser
January 30th, 2006, 11:10 PM
Better yet skip Compressor and use QuickTime Export in FCP. You can only do one file at a time but it creates MPEG2 files faster and as good quality as Compressor. I have timed this out and found that my G4 Dual 1GHZ compressing MPEG2 with QuickTime Export beat my G5 Dual 2GHZ running Compressor at the same setting with the same video files. My G5 is really fast with QuickTime Export. Test it yourself.

Video cards, to my knowledge, don't provide MPEG2 acceleration.

Compressor, by the way, is faster making H264 files for the internet than QuickTime Export.

And my observations:

High rate CBR is fine for short files.
One-Pass VBR is good for longer files.
Two-Pass VBR provides minor improvements for high bit rate file, better results for lower bit rate files (6bps and lower).

Ben De Rydt
January 31st, 2006, 06:16 AM
You're both right; VBR yields better quality for a given bit rate, and CBR takes less time.

I don't mean to start a flameware here, but please tell me how VBR can yield better quality, provided the encoders VBR upper bitrate limit is the same as the bitrate used for CBR encoding.

Emre Safak
January 31st, 2006, 12:44 PM
It won't under those conditions, of course. The maximum bit rate for the VBR would have to be higher than that of the CBR. The point of VBR is to use your space efficiently.

Tomas Chinchilla
January 31st, 2006, 12:48 PM
I don't mean to start a flameware here, but please tell me how VBR can yield better quality, provided the encoders VBR upper bitrate limit is the same as the bitrate used for CBR encoding.


I was thinking the same but didn't want to start an argument about it either.

I have used both and I can definetly get and see better results with CBR in compressor.