DNxHD 220 MXF to SD 1:1

Christopher Drews · June 10th, 2008, 02:43 PM

Hey Avid guys, I have a MC Adrenaline with DNxHD. I capture a HD content file (1080i @ 1920x1080 220 MXF) and bring it into my SD project and looks like absolute crap. What am I doing wrong. In FCP you can bring in HD content in your SD timeline and zoom in without it looking like junk- Is this not true for an Avid?

-C

David Parks · June 10th, 2008, 03:18 PM

You're thinking like FCP. Avid works differently.

You don't need to start another SD project. You can work in your HD project and still view SD. Click the format tab in at the top of the main project/bins window to 30i from 1080i. Click the green box at the bottom left near the timeline to full green, then I'm sure your footage will look better. Continue to edit. When you are ready to output to SD, then go to consolidate/transcode and trancode your sequence to 1:1 MXF.

This will create a new timeline.

Cheers.

John Mitchell · June 26th, 2008, 10:00 PM

David - I think Christopher may have wanted to pan and scan around his HD file in SD (which is a different workflow to what you were suggesting). I can confirm this is an issue with the Avid processing architecture for HD.

Unfortunately the only way around this (until Avid address it) may be to go to After Effects to pan and scan your material. I've tried BCC/3D PIP (High and low quality)/and Reformat - Pan and Scan. None of these solutions appears to correctly subsample the original media and upscale. Instead I thinkthe DVE "window" in SD is limited to 720x576, so Avid downscales the HD into it's SD timeline (using RT) then samples back up that reduced image.

A resolution independent architecture like AvidFX/BorisRED plug in may solve this but I suspect you won't be able to use the clips in the Avid timeline but instead will have to reload it into the plug ins. I say this because BCC which uses the same architecture didn't work.

This is true of HDV (which looks terrible in an SD project anyway or at least 720P does) and DnxHD transcoded material, which at least looks good downconverted on the fly to SD.

David Parks · June 27th, 2008, 02:11 PM

Quote:

Originally Posted by John Mitchell

This is true of HDV (which looks terrible in an SD project anyway or at least 720P does) and DnxHD transcoded material, which at least looks good downconverted on the fly to SD.

John, You might be leaving out a step or 2.

For HDV 720p (Before v. 3) you have to open up your 720p bins in a 30i or 1080i/30i project. At that point yes it looks like crap. Then you reformat your timeline (add a track at top) 14:9 or 16:9 and after you render it looks fine but before the render looks like crap. Before you do this yes it looks crappy. Version 3 you can mix HDV 720p, HDV 1080i etc etc and you pick your raster size for the entire timeline.

Until Chris reponds, I'm still not clear as to what his specfic issue is. Avid pan and scan and more importantly Avid Pan and Zoom (Yes there are 2 different pan and scan efx in Avid)
has always worked great at at maintaining the original rez of any stills. So I have not come to the same conslusions. AFX works great as well.

Cheers.

John Mitchell · June 30th, 2008, 03:19 AM

David - I must be particularly thick today, cause either I missed the point of your post or you missed mine! BTW I'm using 25i while you're using 30i, but I doubt that is where the difference is.
My original post in summary: one reason for shooting in HD is to be able to pan and scan around the HD frame in SD without sacrificing SD resolution (not working in HD).
If you can do this using your method let me know how. As of V3 I can't.

The best result I could get was with the Avid Pan and Scan plug in an SD project but it was significantly worse than running the same footage through AE and doing a direct comparison - despite the extra codec generations you have to jump through to export HDV from Avid to AE and back. I reckon it would better again if I used the native HDV clip. The 3D DVE was worse again. ALL Avid methods seemed to introduce significant aliasing errors and resolution was severely compromised. I'm not sure if this is true of 1080i footage as I haven't tested it, but because the errors looked to be field based a 1080i workflow might be OK (no splitting of progressive frames into fields).

Sure I can edit HD and SD in a HD project BUT if I scale up a HD clip and then render out in SD the results will not be as good as placing a HD clip in a SD timeline in say AfterFX or BorisRED or FCP.

I know what the avid pan and zoom tool does (still frame only) which is why I didn't mention it.

So granted that Chris may not have needed to pan and scan around his frame I guess I'm replying just to clarify what I originally said and hope that maybe you do have a way of working around this limitation without third party applications like AE - cause that would be handy!

BTW - I realise I can set my raster type to HDV in a HD project and it will look better but it no longer outputs on the Adrenaline, so critical monitoring is not possible. Of course this is not possible in SD projects.

June 10th, 2008, 02:43 PM	#1
Christopher Drews Major Player Join Date: Jul 2007 Location: Los Angeles, CA Posts: 628	DNxHD 220 MXF to SD 1:1 - What gives?! Hey Avid guys, I have a MC Adrenaline with DNxHD. I capture a HD content file (1080i @ 1920x1080 220 MXF) and bring it into my SD project and looks like absolute crap. What am I doing wrong. In FCP you can bring in HD content in your SD timeline and zoom in without it looking like junk- Is this not true for an Avid? -C

June 10th, 2008, 03:18 PM	#2
David Parks Major Player Join Date: Feb 2006 Location: Houston Posts: 789	You're thinking like FCP. Avid works differently. You don't need to start another SD project. You can work in your HD project and still view SD. Click the format tab in at the top of the main project/bins window to 30i from 1080i. Click the green box at the bottom left near the timeline to full green, then I'm sure your footage will look better. Continue to edit. When you are ready to output to SD, then go to consolidate/transcode and trancode your sequence to 1:1 MXF. This will create a new timeline. Cheers. __________________ David Parks: DP/Editor: Jacobs Aerospace at NASA Johnson Space Center https://www.youtube.com/user/JacobsESCG

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June 26th, 2008, 10:00 PM	#3
John Mitchell Contributor Join Date: Jul 2005 Location: Sydney Australia Posts: 873	David - I think Christopher may have wanted to pan and scan around his HD file in SD (which is a different workflow to what you were suggesting). I can confirm this is an issue with the Avid processing architecture for HD. Unfortunately the only way around this (until Avid address it) may be to go to After Effects to pan and scan your material. I've tried BCC/3D PIP (High and low quality)/and Reformat - Pan and Scan. None of these solutions appears to correctly subsample the original media and upscale. Instead I thinkthe DVE "window" in SD is limited to 720x576, so Avid downscales the HD into it's SD timeline (using RT) then samples back up that reduced image. A resolution independent architecture like AvidFX/BorisRED plug in may solve this but I suspect you won't be able to use the clips in the Avid timeline but instead will have to reload it into the plug ins. I say this because BCC which uses the same architecture didn't work. This is true of HDV (which looks terrible in an SD project anyway or at least 720P does) and DnxHD transcoded material, which at least looks good downconverted on the fly to SD.

June 30th, 2008, 03:19 AM	#5
John Mitchell Contributor Join Date: Jul 2005 Location: Sydney Australia Posts: 873	David - I must be particularly thick today, cause either I missed the point of your post or you missed mine! BTW I'm using 25i while you're using 30i, but I doubt that is where the difference is. My original post in summary: one reason for shooting in HD is to be able to pan and scan around the HD frame in SD without sacrificing SD resolution (not working in HD). If you can do this using your method let me know how. As of V3 I can't. The best result I could get was with the Avid Pan and Scan plug in an SD project but it was significantly worse than running the same footage through AE and doing a direct comparison - despite the extra codec generations you have to jump through to export HDV from Avid to AE and back. I reckon it would better again if I used the native HDV clip. The 3D DVE was worse again. ALL Avid methods seemed to introduce significant aliasing errors and resolution was severely compromised. I'm not sure if this is true of 1080i footage as I haven't tested it, but because the errors looked to be field based a 1080i workflow might be OK (no splitting of progressive frames into fields). Sure I can edit HD and SD in a HD project BUT if I scale up a HD clip and then render out in SD the results will not be as good as placing a HD clip in a SD timeline in say AfterFX or BorisRED or FCP. I know what the avid pan and zoom tool does (still frame only) which is why I didn't mention it. So granted that Chris may not have needed to pan and scan around his frame I guess I'm replying just to clarify what I originally said and hope that maybe you do have a way of working around this limitation without third party applications like AE - cause that would be handy! BTW - I realise I can set my raster type to HDV in a HD project and it will look better but it no longer outputs on the Adrenaline, so critical monitoring is not possible. Of course this is not possible in SD projects.