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What if one wants to encode a non-supported format in DNxHD?  For example double-framerate HD at 1080p 50 fps?  I typically produce such material by double-framerate deinterlacing from HD footage.  Some cameras are also starting to appear that record directly at 1080p 60 fps.  DNxHD config panel doesn’t give options for this - but there appears to be a workaround:

• http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=745821

• <<Because there was not a 59.94 fps Progressive option in the DNxHD config, I thought it was not allowed. I chose the 1080p 25fps option in the DNxHD config & 59.94 fps in the “Quicktime 7″ panel - and it worked like a champ! All the way thru a HandBrake Render @ 59.94 fps.>

• I have not yet confirmed this by experiment.

Summary:

• Cineform copes nicely with non-standard formats but DNxHD does not.

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Summary of my conclusions from my own limited experiments based around Sony Vegas (9.0e 64-bit):

• For HD 1080-50i, in its corresponding mode, DNxHD works as well as or better than Cineform.
• However for non-standard formats (like Vimeo SD-Wide 853×480), DNxHD does not work well while Cineform does.
  • Confirmed by separate experiment, reported separately.
• For my experiments (Sony Vegas 9.0e-64) the following DNxHD settings made no difference:
  • LevelSpace: RGB/709
  • Quality: 50% (default) or 100%

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Avid DS allegedly supports it:

• http://avid.custkb.com/avid/app/selfservice/search.jsp?DocId=273207
  • Avid DS supports a wide variety of HD formats, which yield new bit rates when encoded to DNxHD. DNxHD 440 is the 1080p 59.97 version of DNxHD.
  • Support for 1080p 50 & 1080p 59.94 (including new DNxHD formats: DNxHD 90, 290 & 440)

It is possible to use the open-source ffmpeg to transcode XDCAM-EX files to other formats, such as DNxHD.Information from http://www.dvinfo.net/forum/sony-xdcam-ex-cinealta/112018-mfx-details-compatibility-what-about-ffmpeg.html as of 2010-12-23:

•  ffmpeg -i input.mp4 -vcodec dnxhd -b 60Mb -acodec copy output.mov
  • 60Mbit is a 720p bitrate.
• This is a good ffmpeg for pro users help site:
  • http://www.itbroadcastanddigitalcinema.com/ffmpeg_howto.html
• This is the command line I got from Baptiste who is developing the DNxHD stuff in ffmpeg.
  • Progressive:
    • fmpeg -i inputfile.mp4 -vcodec dnxhd -b 185Mb -acodec pcm_s16le outputfile.mov
  • Interlaced: (The difference is the -flags +ildct)
    • ffmpeg -i inputfile.mp4 -vcodec dnxhd -b 185Mb -flags +ildct -acodec pcm_s16le outputfile.mov
• And this is a link to a DNxHD white paper:
  • http://www.avid.com/resources/whitepapers/DNxHD_WP3.pdf
    • Dead link as of 2010-12-23; use http://www.avid.com/static/resources/documents/solutions/DNxHD.pdf instead.
• We are thinking of using 36Mbit DNxHD but all people we talk to say to use 185Mbit or maybe 120Mbit and that 36Mbit is for offline.
• But if you don’t have a problem using allot of GB on disc then go for Max Mbit for the specific resolution and framerate you use:
  • 1080p/25 DNxHD 185 1920 x 1080 8bit 25fps = -b 185Mb
  • 720p/50 DNxHD 175 1280 x 720 8bit 50fps = -b 90Mb
  • 1080i/50 DNxHD 185 1920 x 1080 8bit 25fps = -b 185Mb
• More settings for other framerates:
  • http://www.itbroadcastanddigitalcine…#Encoding_VC-3
    • Has many commandlines and DNxHD settings, though sadly none for 1080p50 (as I require).

Information from http://forum.doom9.org/showthread.php?t=130781

•  FFmpeg is now providing Avid DNxHD (SMPTE VC-3) encoding and decoding features

http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=736849&Replies=34

• Avid updated/fixed the DNxHD Codec Configuration Window with their Oct (2010) release…
• http://avid.custkb.com/avid/app/selfservice/search.jsp?DocId=372311
• The Avid codec can only exist in a .mov Quicktime wrapper. A big deal on a lower powered computer like my Core2Duo but pretty much a non-issue on any quad core.
  • Not true. However, the FREE version only exists inside an .MOV. And yes, this is a problem for Vegas.
  • (For) a Quicktime codec … you need QT installed.
• I noticed there is no 1080p in 29.97 frame rate with DNxHD. Damn.
  • Sure there is 1080/30p. The things on the list for you to select are SUGGESTIONS. Use 1080/24p. It will work just fine, and won’t change your video to 24p.
• If you need a tool to convert to DNxHD you can tryout Avid’s Metafuze
  • http://www.avid.com/US/industries/workflow/MetaFuze
    • Metafuze will make great MXFs… for Avid. But they won’t work in Vegas. Or Premiere, or FCP.
• Is there a primer of which of the CODEC selections are which? There are 6 formats and each has slightly different setting available.
  • The formats are:
    • Avid DV
    • Avid DV 100
    • Avid Meridien Compressed
    • Avid Meridien Uncompressed
    • Avid Packed
    • Avid RGBPacked
  • Specifications are at http://avid.custkb.com/avid/app/selfservice/search.jsp?DocId=372319#Avid_Codecs
  • …but pragmatically, what are they actually each good for?
    • See http://blog.davidesp.com/archives/134

I installed the (free) LE version of Avid’s DNxHD onto bothWindows and Mac, in order to round-trip between Sony Vegas and FCP.  Having received no responses to my threads on forums for Sony Vegas and for FCP, I tried Avid’s forums.

• The “Avid on Windows” Forum:
  • PC MediaComposer to MAC FCP http://community.avid.com/forums/p/74442/416691.aspx#416691
    • Thread from August 2009.  Might well be out of date now.
    • If you export DVCProHD from your PC Avid you’ll want to check the “Use AvidDV Codec” box.  This will encode the file as AvidDV100 (which is Avid’s DVCProHD codec).  With the Avid codecs installed on your FCP system you’ll be able to read them.
    • Why don’t they mention DNxHD ?
• The “Avid on Mac” Forum:
  • Search on [fcp dnxhd]
    • http://community.avid.com/forums/p/84564/477328.aspx#477328
      • Error while loading DNxHD QT .mov into FCP
      • Someone with same issue as me: they rendered from Sony Vegas to DNxHD to import to FCP, and the media wasn’t recognized.
      • Thus far, that thread is inconclusive, with suspicions focussing on the precise format settings etc. and the fact that the media was rendered from Sony Vegas (as I guess the latter is relatively “unknown territory” to the Avid/DNxHD folks).
      • I copied this info (& thread link) to the Sony Vegas forum http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=720994&Replies=11.  Useful replies:
        • …a smalll but critical point; the codec DNxHD does all the encoding of the video stream, vegas does not touch the encoding process. At most, vegas may update the file headers and starting meta data as it closes the file. If Sony has an issue it will be there, but I would question FCP file handling when it opening the file.
      • ?

Gamma-shift issue:

•  http://forums.creativecow.net/thread/8/1028870
  • “QuickTime movie, created with Avid on a PC, using the DNxHD codec. When I open it in QuickTime Player on a PC, the colours are fine, but when I import it into Final Cut on a Mac, the colours are a lot brighter- gamma shift”.
  • “I have ProRes and DNxHD clips of the same thing on the timeline. When I switch from a frame in one clip to the same frame in the other clip, there is a very visible difference between the two. The DNxHD version is brighter and ‘milky’.  I’ve tried exporting DNxHD from Final Cut and it has the same problem as the DNxHD sourced from the Avid.”
  • “It’s the codec. DNxHD reports RGB values to FCP not Y’CbCr. Therefore FCP applies its internal RGB interpretation which causes the gamma shift you see.”
  • “Any non native codecs to final cut pro should be transcoded first through compressor; best way to check if the gamma has shifted is take an image with tonal ranges which vary over a gradient e.g. sky; look at the scopes in avid for the dnx file; look at the scopes in final cut pro for the dnx file; no guess work”
• x

Problem:

• In Windows I export from Sony Vegas to AVI (CineForm).  In OS X I read the file into FCP and apply the SmoothCam effect, then export to ProRes.  In Windows, Sony Vegas, I replace the original file with the smoothed one.  The levels/gamma are wrong.

Solution (Search):

• Sony Vegas forum http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=718371
  • Use DNxHD
    •  Couple of tips re DNxHD:  709 color level assumes 16-235, and RGB assumes 0-255.
  • Force it back again: www.kenstone.net/fcp_homepage/gamma_mac_pc.html
    • But this presumably implies getting re-quantized twice (the roundtrip issue and the forcing), which for 8-bit footage I imagine could reduce the quality (banding).
• Uncertainties
  • Where and how does this gamma get applied?  In FCP I didn’t (knowingly) alter the levels (eg until it looked right), I just applied the SmoothCam filter.  So I guess it would look wrong on the (pre-SnowLeopard) Mac but I wouldn’t care.  Wouldn’t FCP then export back whatever it got but smoothed?  This one is really confusing.    Experiments needed (when I get time…) I guess.

Some further tips found online:

• [http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=704856]
  • You have more than a dozen choices in the DNxHD codec…  (but you might not see them) because of the little display bug. When you select the Avid DNxHD codec, a window pops up. At the bottom of that window is just a little sliver of a pulldown menu. Click that and all should become clear.
• [http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=701760]
  • DNxHD is a broadcast codec. And types that are not broadcast standards are not included.
  • …in the “Custom Settings” you can … set the Frame rate and the Field order to suit your … footage.
• [http://www.sonycreativesoftware.com/forums/ShowMessage.asp?MessageID=712102&Replies=1]
  • Settings for HD interlaced:
    • Color levels should be RGB
    • Size should be 1920×1080
    • Pixel aspect 1:1
    • Field order Upper
    • DNxHD-TR 175 8-bit template
    • Be sure to click OK (the dialog may fail to display it)
  • Variation for HDV:
    • Thin Raster is supposed to be better for stretched pixels like 1440×1080
• [http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=710761]
  • You will be able to preserve aspect and gamma with DNxHD. Be sure to select the right bit depth and color levels for your originals. (For a) 1440×1080 source, (i.e.) HDV, … you will want 8-bit, 4:2:0 RGB output to match the originals.
  • One user’s experience (not mine):
    • Here’s the file settings for … m2t files (as provided by MediaInfo):
      • 25Mbps, 1440×1080 (16:9), at 29.97fps, MPEG video component version 2,(Main (high @1440)) BVOP
    • Here’s what it reports for the .mov generated by DNxHD:
      • 220Mbps, 1920×1080 (4:3) at 29.97fps, VC-3, DNxHD
    • I’m not sure where it got the 1920×1080 frame setting from, though. In the frame size box, I had custom frame settings of 1440 x 1080 with a PAR of 1.333.
    • Reply:
      • 1440 X 1.333 = 1919.52 which rounds up to 1920.
      • Your render frame size should be set to 1920×1080 to preserve the aspect. As gets mentioned a lot in these forums, MOV does not respect PAR.
• [http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=4&MessageID=709379]
  • Best way to export timeline to FCP for CC:
    • Change your color space to RGB. Click the little pulldown window at the bottom, select 1080i/59.94 DNxHD 220x. And when you say OK to this window, change the slider from the current 50% quality to 100%. Then render out. The file will be slightly less than 2 minutes per gig.
    • Avid 1:1 is an uncompressed codec designed for SD video. DNxHD is an HD codec and the only one Avid uses.