Archive for January, 2016

Alternative to Video/Audio Mixdown

Tuesday, January 19th, 2016

ama-file-export.jpg

There’s an interesting thread on the Avid Community discussing the speed of exports and when to render effects, etc. As of late, I have been using AMA File export as OP1a as export format as it renders and transcodes all one step as it exports the file to a destination of my choice. This may not work for everyone depending on their needs, but for me, I have found the following:

 Advantages:

  • Single one step export and does render/transcode all in one pass
  • Many applications support MXF OP1a like Premier Pro, Resolve, Assimilate, Adobe Media Encoder, FFMpeg, VLC, Sorenson, etc.
  • Includes timecode of sequence/clip of exported file
    •  Makes it easier to manage than a Mixdown in Media Composer as it now also has a user defined source that can be referenced. Use AMA MXF plug-in to access file back into the project.
  • Supports different audio configurations from mono, stereo, 5.1, and direct out
  • Not affected by MoviePlayer’s idiosyncrasies when it comes to video levels

Disadvantages:

  • Limited to DNxHD codecs
    • This would be considered the master requiring the use any of the third party compression offerings for other deliverables
    • Update 8/23/2016: Using Media Composer 8.6 I am able to export DNxHR with any project type including custom sizes. 
  • Cannot set video levels during export as with other exports (video or data levels)
    • Workaround is to apply LUT as an effect to a top track in the timeline. For example, if sequence is Video levels and you want to have it full range (data levels), then apply “Levels scaling (video levels to full range)” from the LUT selection. Export using “selected tracks” in the AMA output as needed.

Update 1/23/2016:

I did a test of various methods of exporting a sequence to see which one would be the fastest. I created a 10 minute sequence (1080p/23.976) from DNxHD 115 source clips. The sequence has 2 V tracks and every event is a Picture In Picture for the entire 10 minutes. There is no audio, just testing video speeds for now. Some processes required one step and other require two and three steps and the times only reflect export/render times, and not the additional time it might take to set it up (as in the case of a mixdown to a new sequence).

From fastest to slowest:

  • 04:15: Un-rendered sequence directly exported as MXF OP1a DNxHD 115 (one step)
  • 06:24: Export QT Sames as Source from un-rendered timeline (one step)
  • 07:03: Render timeline and export MXF OP1a (05:38 for render, 01:25 for export) (two steps)
  • 08:04: Mixdown of un-rendered sequence and export QT Same as Source (05:31 for mixdown, 02:33 for export SaS) (two steps)
  • 08:05: Render timeline and export QT Same as Source (05:38 for render, 02:27 for export) (two steps)
  • 10:55: Render timeline, then do a mixdown, and export QT SaS (05:38 for render, 03:10 for mixdown, 02:27 for export) (3 steps)

In all cases, the fastest and easiest method is to create an AMA MXF OP1a export. Even with everything rendered, MXF export versus QT SaS is 58% faster. A direct one-step export as MXF OP1a is 66% faster than the next fastest method which is a direct QT Same as Source from the same un-rendered timeline.

Thanks to Bill Busby for correcting my MXF terminology. I also got some great feedback from JC Bond regardingOP1a as the first step in creating a guaranteed single DNxHD coded for .mov (Same as Source). I will just copy/paste what he sent as he said it better than I can:

Use OPAtom1a export to create an MXF file, I then AMA link to that file and do a Same as Source QuickTime export. This is the FASTEST way to get a QuickTime that is guaranteed to be a Single Codec / Resolution. Regular Same As Source QuickTimes can be MIX RESOLUTION QuickTimes since they are truly a SAME AS SOURCE and the user can have different codecs and or resolutions in the timeline. In the past the only way to ensure a single codec / resolution QuickTime was to do a CUSTOM QuickTime at that codec.

JC and I also discussed the ability to use ClipToolz [see update below] to quickly rewrap from MXF to MOV with the DNxHD codec as an alternative.

Update 8/16/2016:  Additional benefit as noted by Jared Zammit on the Avid Editors of Facebook:  One great upside to this workflow - AMA file export will not let you export any sequence with offline media. No more scrubbing a timeline for red clips, only to miss a tiny offline subtitle in an hour long sequence. Rejoice!

Update 1/28/2017. ClipToolz is no longer a product but users can look to Convert4 as an option.