re: HDV motion artifacts -- do solutions exist?

I've been editing a short film shot on HDV 60i and being editing on Avid XPress Pro. The Sequence is set to 29.97fps as far as I can tell -- I didn't set up the project. I just had a first cut yesterday and exported it to a DV NTSC movie file (720 x 480, 29.97fps, interlaced lower field first) for viewing.

This is my first time viewing and cutting HDV so maybe I'm just seeing what so many others are seeing, but the motion artifacts are horrible -- not just during high-speed action shots, but sometimes during even static C-Us in dialogue scenes, and slow-mos done in the Avid XPress itself look even choppier than DV footage in FCP.

So I'm wondering a couple of things:

a) Is there a solution for this? Plugins or applications that can improve the movements? Or was something done wrong in treating this HDV footage? (I will get more tech specs from the producers/directors and DP on camera model, shooting mode etc.)

b) Is it possible that some of the footage was shot differently or captured differently? In some cross-cutting sequences, I'm seeing motion problems on one shot, then not in the next, then in the next shot again. Normal or not?

c) Could something be done in my movie-file export that can improve the playback quality? Did I use OK settings for the export? The motion stuff doesn't look as bad in the Avid XPress monitor (don't have an external monitor, unfortunately, nor a playback/capture device -- this is a very minimal, amateur editing setup owned by the directors), but I thikn it could also be because the image is so small.

HDV is upper odd field...

Magic Bullet Suite 2.1 has been "magic" for me with HDV.



When life gives you dilemmas...make dilemmanade.

> Magic Bullet Suite 2.1 has been "magic" for me with HDV.

Funny you should mention that, Joe, because it was your post about Magic Bullet in the "DV for broadcast" thread that had prompted me to wonder about the film and post this HDV query myself. Thanks for the lead.

Vic's post brings me to another thing: The timeline is set up as HDV as far as I know, but I'm exporting a movie in another codec because I can't do an export in the native format for some reason. Since none of the other practical formats are upper-field-dominant, if I'm to continue using DV NTSC, what should the dominance setting be? Should it follow the timeline or the targeted format?

It should follow the format. Otherwise you WILL introduce intra-frame temporal problems.

And not to nitpick - but filmman uses non standard terminology. Lower field is odd or field one. This is because the fields are counted by the first FULL line of video as field one. Field 2 actualy displays a 1/2 line on top of the field one line - but it is hitting the even numbered lines. (See [docs.info.apple.com])

Derek - one easy way to test if you've got temporal problems and a field flip is to drop a deinterlace on the suspicious shots and see if the motion uglies "clear up" some.

Ian

> It should follow the format. Otherwise you WILL introduce intra-frame
> temporal problems.

Thanks a great deal for the breakdown, Ian -- I'm not a video engineer, so this is new territory. When you say "follow the format" on field-dominance settings, you're talking about adhering to the original timeline, right? The exported format I'm using is DV NTSC, a lower-field-dominant format, but when I export from the timeline, I should use the field dominance setting of the timeline, which is HDV, upper?

> And not to nitpick - but filmman uses non standard terminology. Lower field
> is odd or field one.

So "Upper" is referring to the fact that the half-line at the top belongs to Field Two?

On some of the footage in my exported movie file (DV NTSC), not all, I'm seeing a "silver flickering line" on screen upper left, as if I'm seeing the edges of analog tape. On other shots, it's lower left, I believe. Is that the result of the field dominance problems?

I'll have to look for a de-interlace filter in the Avid XPress Pro...how I wish I were working in Final Cut...there's a high-speed bike scene in the film and it's looking like a drunkard shot it right now.

"The exported format I'm using is DV NTSC, a lower-field-dominant format, but when I export from the timeline, I should use the field dominance setting of the timeline, which is HDV, upper?"

Sorry - I wasn't clear enough -

No. For export you should let the field dominance follow the export format. For DV out let the DV export go to the prefered format for DV (Lower). If you do an HDV or other upper field format export - it should be upper - to match the export format. The export render SHOULD take care of putting things in the proper order for you - assuming that things are not fliped in the timeline.

Look at it this way -- anyone viewing the file in DV ( for example) will see the file played back lower first - then upper. If you force the export to use upper first - they will see the whole magilla field fliped - with all the jerking and ugglies that introduces.

Unfortunately - If stuff gets fliped in the timeline - it's going to stay fliped as you export. That's the bad news. The good is that if you see stuff fliped after export- you know where to go to fix it - - the timeline.

Ian

when I first had to deal with similar problems I didn't know what was happening. But accidentally I found out that at the very end when I was compressing to end up with an MPEG2 for the DVDSP output, there was a choice I had to make: progressive, upper or lower dominance. When I chose lower I always ended up with a good DVD. Since there was no HD DVD and I wasn't making the DVD for progressive output, lower was the only right choice. This is all I know about it. It's not technical knowledge, just experience.

So, I'd say that do whatever you have to do in the timeline to be able to work with your movie, but remember that your target in the end is lower dominance.

Now, I know that doesn't answer the question. The reason I posted this is to learn what I should do with HDV -- now that you guys are getting work in HDV :-) and you have to deal with it. I too have SD and HDV material, so I must figure out at what point to resolve the differences, and I don't kave magic bullet or any other programs besides FCP 5 Studio.

Any helpful comments in the context of this thread would be appreciated.

I'm surprised Wayne hasn't pitched in with an "I told you so" yet. Heh heh. Where are you, my friend? Good thing you'd warned me about this months ago! I tried advising one of the directors, a friend, to not shoot on HDV while discussing tech stuff with her in pre-production, but she went ahead and did her thing! Money reasons, I reckon.

I'll stand in D-man:

"HDV SUCKS". :-D



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>>> I don't kave magic bullet or any other programs besides FCP 5 Studio. <<<

There's no magic miracle cure buried in FC Studio for HDV. You're gonna have to pony up for a plug-in. Start 'a savin'.



When life gives you dilemmas...make dilemmanade.

Could you deinterlace in AE for example? You could do an AAF export to AE using OMF files which AE can read so you're not changing the footage exporting from Avid. Do the deinterlacing in AE and then render and import back to Avid?

Not an informed suggestion (I've not worked in HDV either), just a suggestion.

Andy

> You could do an AAF export to AE using OMF files which AE can read so
> you're not changing the footage exporting from Avid.

I don't know anything about AfterEffects and I have only about 20 days of experience with Avid XPress DV and Avid XPress Pro, with no classes and no training books, so that was Greek to me. |} But I'll bear your suggestions in mind. The previous editor suggested he may be able to do some things, so I'll see what he comes up with.

I seem to recall that xpress has a deinterlacer - in the motion menu/palette maybe? i haven't worked in avid for awhile so I can't recall. maybe look in the help file, but i'm almost certain there is one. look in system settings, or whatever they call that window; i seem to recall it was buried there, somewhere, in one of the settings - not in the effect palette where one might expect it to be (man, I have a bad memory...).



HarryD