• Compression Techniques

  Compression time too long- want high (ish) quality for youtube, but <24 hour compression

  Posted by Kirsten Dirksen on October 1, 2013 at 11:11 am

  I am trying to create high enough quality videos for my youtube account (I’m a former tv producer and now create weekly videos for my youtube account). Since I have a production background, the technical side is always an effort for me. Since I switched to Final Cut Pro X (about a year ago), I’ve also switched to using Compressor 4 (instead of Final Cut) to compress my videos. I’m sure the quality is better, but the compression times are now 12-24 hours.

  Right now I’m several hours into compression a half hour piece. I posted below the specs in Compressor 4 in hopes that someone can quickly see where I can shave off time. I film in 1080i (though I’m also wondering if perhaps I should switch to progressive to avoid needing to deinterlace.. though I suppose that is for another forum.. and still filming tape with a Sony HVR-Z5U).

  Thanks, in advance, for any help (this is the first time I’ve ever posted to a forum so I hope this all makes sense). To see any of my videos, those from the past few months (mostly) should all have similar specs. My youtube page is https://www.youtube.com/kirstendirksen

  Current specs:

  File Extension: mov
  Estimated size: 2.33 GB
  AAC, Stereo (L R), 48.000 kHz
  Width: 1920
  Height: 1080
  Pixel aspect ratio: Square
  Frame rate: 30
  Frame Controls Automatically selected:
  Retiming: (Fast) Nearest Frame
  Resize Filter: Linear Filter
  Deinterlace Filter: Better (Motion Adaptive)
  Adaptive Details: Off
  Antialias: 0
  Detail Level: 0
  Field Output: Progressive
  Codec Type: H.264
  Multi-pass: On, frame reorder: Off
  Pixel depth: 24
  Spatial quality: 50
  Min. Spatial quality: 50
  Key frame interval: 30
  Temporal quality: 50
  Min. temporal quality: 50
  Average data rate: 10.24 (Mbps)
  Maximum data rate: 10.24 (Mbps)
  Fast Start: on

  Kirsten Dirksen replied 12 years, 11 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Craig Seeman

  October 1, 2013 at 2:39 pm

  YouTube’s recommended encoding specs
  https://support.google.com/youtube/answer/1722171?rd=1

  Shooting progressive is a major help. Deinterlacing takes time.
  For best quality I’d create my own present based on YouTube’s specs although Compressor can’t do High Profile CABAC encoding.

  You don’t mention your workflow but generally I export from FCPX in ProRes 422 rather than send to Compressor. It’s just an old habit and it gives me a ProRes master.
  Creating an internal cluster in Compressor can help if you haven’t done that.
  I’d have Frame Reorder On but I don’t think that’s going to help your encoding speed. It does help a bit in terms of quality relative to bit rate as it adds B-frames which are more efficient.

  Compressor isn’t very fast though and I’d hope Apple improves GPU assisted encoding on the next upgrade.

  Your computer specs make a big difference. Generally I’d recommend at least a Quad i7 (newer is better) and 2GB RAM per core of the computer.
• 

  Kirsten Dirksen

  October 1, 2013 at 8:04 pm

  Thanks Craig. Though you’ve also helped me realize how limited my tech knowledge is. I realized I”d just skimmed the part of the youtube specs page about CABAC… I won’t even ask.

  Though I am curious as to a few more points. I used to export staright from final cut studio and I just used an automatic data rate and set the quality to best. Within Compressor you still have that option within video settings. My compression times used to be just 2 or 3 hours and now it’s an hour or so to lay off to prores (yes, that is also my workflow) and then another half day or day to compress within Compressor. Would I lose a lot of quality to simple go back to this automatic setting? And is this the same thing as the recommended variable bit rate suggestion?

  I just changed my setting from best quality (multi-pass) to faster encode (single-pass) as I read that this didn’t make a big difference in quality, but does greatly help compression time.

  I think my main issue is my computer is old.. a 2008 MacBook Pro (2.8 GHz Intel Core 2 Duo with 8GB RAM). I need to upgrade, but I’m trying to wait it out for the MacBook Pro with the Hawell chip.

  Thanks for the motivation to switch to progressive for filming. I think I was afraid of all the hundreds of hours of archive tape shot interlaced, but I know you can now mix the 2 in Final Cut when I want to use archived footage.

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