• Compression Techniques

  How to ensure best quality compression – QuickTime or Compressor?

  Posted by Ben Jones on February 23, 2010 at 1:28 pm

  Hi,

  I’ve got a load of videos online and we need them resized, and I’m not sure how to ensure best quality. We’re running Final Cut Studio 2 (Compressor v3 and FCP v6), also QTPro, on Macs running OSX Leopard 10.5.8. We need the files at frame size 567×319, H264, bitrate limited to 1000kbps for web viewing, and already have the master projects, a 10Mbps 1280×720 H.264 version and a 640×360 1000kbps H264 version. Obviously I’d like the 567×319 files the best quality. The options we have are:

  Reconnecting the original 1080p project and outputting through Compressor at 567×319, bitrate limited to 1000kbps.

  Using Compressor, taking the 10Mbps 1280×720 version and re-outputting at 567×319, bitrate 1000kbps.

  Using QTPro, taking the 1000kbps 640×360 version and resizing to 567×319.

  Would there be a significant difference between these three methods? Reconnecting all the media would be pretty time-consuming, so I’d be keen to avoid that if the quality wasn’t very different. I guess the real question is, is there going to be a visible difference in quality viewing a file resized in QTPro, rather than a recompressed one? Does it make a quality difference at the 567×319 size if it’s been recompressed from a higher bitrate file or just resized from a slightly larger, same bitrate, one.

  Thanks for your help!
  Cheers,
  Ben

  Ben Jones replied 16 years, 6 months ago 3 Members · 3 Replies
• 3 Replies

• 

  Craig Seeman

  February 23, 2010 at 2:23 pm

  Since you use the word “best” I’ll interject my opinions on “best.”

  You should not be using odd frame sizes. Whatever caused you to need them should be changed. Generally speaking most encoders prefer blocks of 16×16, 8×8, 4×4 and even numbers over odd. Basically odd frame sizes is the “worst.”

  For “best” quality use the master files. Re-compressing compressed files is never “best.” H.264 are not “master” files. The output in the sequence codec would be “master” files.

  While Quicktime and Compressor use the same “engine,” Compressor gives you all sorts of processing filters. You don’t give any indication though regarding your needs beyond resizing to a “worst” frame size.
• 

  Daniel Low

  February 23, 2010 at 2:32 pm

  Everything Craig has said is spot on but why on earth/where on earth did you get a frame size of 567×319 from?

  Let me guess, was it the person who designed your webpages/player?

  __________________________________________________________________
  Sent from my iPad Nano.
• 

  Ben Jones

  February 23, 2010 at 3:00 pm

  Thanks guys. And yes, Daniel, how did you guess?! Ha… They were initially online quite happily at 640×360. I’ve gone back to the designers with the frame issues.

  Agreed reconnecting and re-outputting would be best, just curious if you thought there’d be any difference between a QT resize down and a recompress from a higher bitrate. We’ve tried it now and there’s not much difference in the visible video quality, but wherever there’s a text overlay the text looks sharper and brighter on the recompressed ones.

  Thanks again,
  Ben

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