• Blackmagic Design

  Difference between Blackmagic NTSC Jpeg and 10 Bit Codecs

  Posted by Lee Burrows on November 27, 2006 at 1:22 am

  Difference between Blackmagic NTSC Jpeg and 10 Bit Codecs

  Hello everyone. I hope that everyone had a nice turkey day. I have a Blackmagic extreme capture card and have often wondered the difference between capturing Analog SD beta tapes in eith NTSC-Jpeg or 10 bit codecs? Or even 8 bit for that matter?

  Now I have always been told that 10 bit is as good as it gets and that the BM NTSC Jpeg codec has a 2-1 compression ratio. However if I am capturing it from analog beta will the different codecs really make a difference in quality? Now I know the BM 10 bit files are the biggest in size and look good but I can’t even really tell a difference when comparing it to a BM NTSC Jpeg clip. And if you are cutting features for TV and there isn’t a noticable difference in the quality between the 2 codecs but it saves you space by working in BM NTSC Jpeg…is it the way to go? Am I assuming something wrong?

  I have been told that working in a 10 bit sequence allows more of your effects to be real time and other features that a Jpeg sequence doesn’t offer but I haven’t noticed anything different to this point. Are there? I appreciate anyones thoughts on this subject.

  Happy Holidays

  Lee

  Mac OS X (10.4.7)
  1.5 GB DDR SDRAM
  Dual 2 GHz Processor
  Power PC G5
  FCP 5.1.2
  Black Magic Decklink Extreme
  Sony UVW 1800
  Motion 2

  Accountneedsrealnameupdate replied 19 years, 5 months ago 2 Members · 1 Reply
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  Accountneedsrealnameupdate

  December 6, 2006 at 11:01 pm

  I get where you’re coming from, we usually do everything in 10bit as it’s mostly short form edits but last year we had a project that involved a huge amount of video, we decided to go jpeg with the option of redigitizing 10bit for an “online” if necessary. Anyway we delivered the jpeg as it looked fine, the client came back with complaints about “jpeg compression artifacts” (one of our idiot producers mentioned the workflow to the client… stupid, stupid stupid!!), anyway we did some tests and to cut a long story short in every single case the artifacts were in the source (dBeta), no-one could tell the difference between the jpeg and the 10bit workflow. There are differences if you really look hard, and there is a slight luma shift that may be a problem but I say if you can get away with it go for it, just don’t mention it to your client.
  Glennser

  PS In our case it was a straight edit with no graphics, compositing or effects, working in a compressed timeline with lot of dissolves and effects, or with footage going through a few generations of exports/recompression could start to stress the codec past usability, I’m not sure. Also 75% is the sweet spot for the photojpeg codec and decklink, I’ve heard some nonsense about it being YUV at 75% and RGB at other values which doesn’t make much sense but below 75% it starts to break up and going higher just increases file size with very little benefit.

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