• Avid Media Composer

  DNxHD artifacting?

  Posted by Steve Tomich on July 20, 2011 at 10:27 pm

  Hey all…
  I just ran into a problem with FCP-to-Avid transfers via DNxHD. Here’s the deal:

  DVCPROHD 720p timeline in FCP 7 (aka FCP “Classic”). FCP system has recent DnX codec download, creates a Quicktime in DNxHD 145–all the frame rates and other details seem to line up fine (59.94 fps,etc.)

  Movie imports into Avid version 3.5.9 720p project (on a PC, if that matters) just fine. However, the video has noticeable aliasing, almost as though there is some sort of field-order problem. The movie also has audio stutters every few seconds.

  I double checked the original FCP timeline and it looks and sounds fine. This is so weird–I’ve done plenty of DnxHD exports and imports and they’ve always been clean,

  We are now re-exporting from FCP using the Animation codec, which will hopefully work but is not what I had in mind.

  Any ideas?

  Thanks,

  Steve Tomich
  ABC7 SF

  John Pale replied 14 years, 10 months ago 3 Members · 5 Replies
• 5 Replies

• 

  Shane Ross

  July 20, 2011 at 10:39 pm

  If I were in your shoes, I’d get Automatic Duck Pro Export. It will conver the DVCPRO HD Qt files to DVCPRO HD MXF files with ZERO quality loss. Just take them out of the QT wrapper and break them into the separate parts, and make them available in Avid.

  Again, zero quality loss.

  Shane

  GETTING ORGANIZED WITH FINAL CUT PRO DVD…don’t miss it.
  Read my blog, Little Frog in High Def
• 

  John Pale

  July 20, 2011 at 10:43 pm

  There should be no field ordering problems since this Is progressive footage.

  Are you sure of your settings?

  Did you do this from FCP directly using Quicktime Convsion or using Compressor?

  Compressor gives you more control of your settings, and more reliable results, though you will have to build your own preset.
• 

  Steve Tomich

  July 20, 2011 at 11:10 pm

  Thanks, John. Yer right about the progressive frame/field ordering issue, it is progressive all the way thru, but the kind of artifacting reminds me of field-flipping.

  The FCP editor exported from his timeline, not from Compressor. And I looked over his shoulder at the settings, which were very basic–just defining the type of DNx (145, 8 bit) and the frame rate, and that’s about it. He did have the colors set to millions+, so there was an alpha channel included in his original export, but beyond slowing things down, I can’t imagine that would screw up the video quality.

  Still working the case,

  Steve
• 

  Steve Tomich

  July 20, 2011 at 11:22 pm

  Thanks, Shane. Just checked the Duck website. Since we don’t expect to be doing many of these particular FCP-to-Avid transfers (long story there), the Pro Export software is not an option. What weirds me out is that I was under the impression that once a codec–any codec, not just DNx– is available to any Quicktime-based app, it should be able to make a movie without artifacts, all by itself.

  Perhaps that sounds naive, but I cling to my dreams….

  Steve
• 

  John Pale

  July 21, 2011 at 4:20 pm

  The alpha that shouldn’t be there can cause issues.. Try exporting without it.

  Also, I am not sure QuickTime Conversion within FCP is smart enough to handle the scaling from the thin raster of native DVCPRO HD to full raster square pixel DNX HD properly.

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