• Blackmagic Design

  Transcoding DV50 to 10bit Uncompressed

  Posted by Russell Lasson on July 15, 2005 at 12:12 am

  Here is our situation:

  We’ve shot a feature on the SDX900 in 24PA. Captured firewire removing the pulldown. Edited at 23.98. Now we’re going to online/color correct.

  Originally we planned on going back to the source tapes and capturing them SDI, removing the pulldown with either our decklink extreme or cinema tools (which ever worked better.)

  But then I thought, “The DV50 files that we captured are clones of the tapes. Why not transcode them using Compressor 2 to Blackmagic 10bit? That way, I don’t have to deal with removing the pulldown again.”

  So my questions are:

  1. What’s the difference between how the Decklink Extreme cards transcode video from an SDI source and how Compressor 2 transcodes video, given that the input codec and output codec are the same?

  2. Typically the Blackmagic Codecs use 720×486 frame size, but my DV50 material is 720×480. Is there anything wrong or dangerous about using the Blackmagic 10bit codec at 720×480?

  This is really going to be a big issue when people really start using P2 for aquisition because there is no tape to go back to for the online.

  Let me know what you think.

  Thanks,

  Russ Lasson
  Kaleidoscope Pictures
  http://www.kalpics.com

  Yves De muyter replied 21 years, 1 month ago 2 Members · 2 Replies
• 2 Replies

• 

  Russell Lasson

  July 22, 2005 at 4:25 pm

  nobody want’s to talk geek talk with me?
• 

  Yves De muyter

  July 22, 2005 at 4:39 pm

  [Russell Lasson] “Here is our situation:

  So my questions are:

  1. What’s the difference between how the Decklink Extreme cards transcode video from an SDI source and how Compressor 2 transcodes video, given that the input codec and output codec are the same?
  If the source is DV50, there will not be a big difference IMHO, better yet, going from one codec to another is often a bad idea. SDI is component-video uncompressed and decklink will compress it a little bit again.

  2. Typically the Blackmagic Codecs use 720×486 frame size, but my DV50 material is 720×480. Is there anything wrong or dangerous about using the Blackmagic 10bit codec at 720×480?

  I would’nt do that. I’d try to convert them to 486 height. I don’t know in this situation since we’re using PAL here. I guess your NLE should detect this and force
  a render on the clips, maybe even resizing it, and that is known to be slow. I’d try to add 4 lines black while transcoding. Depends on your transcoding tool if it can do that.

  This is really going to be a big issue when people really start using P2 for aquisition because there is no tape to go back to for the online.”

  Yes. But often the idea is to put those clips on some central terrabyte storage as rushes and keep them there until the project has finished. Diskspace is cheap these days.

  -Yves

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