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Avid AAF to Resolve clips partially black?

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John Sackey
Avid AAF to Resolve clips partially black?
on Aug 30, 2012 at 5:26:54 pm

Hi all, I've a had a look for this problem on here and the rest of the web but I can't seem to turn up anyone with the same problem.

I've been given few sequences in Avid MC 6, shot on a Canon C300 and EX-3. I'm transcoding the sequences to DNXHD 185 then exporting an AAF fo the transcoded sequence. When I import them in to Resolve the majority of the clips are fine but in a couple of the sequences there are a couple of clips that have black on the end instead of the full image. So they start where they should but around four or five frames before the end of the clip the media goes black. In Avid the transcoded sequences and the exported sequence of the transcode play the clips normally so it is there but in Resolve it's showing up partially black.

Has anyone had this problem? This is the first time I've come across it, worst case scenario I can export a movie and do a preconform but I'd rather get it fixed or at least know what could be the problem.

I should add I've had no control over this project up until it's hit resolve so I have no idea what silly things could have happened during ingest or the editing stage.

Cheers
John


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Joseph Owens
Re: Avid AAF to Resolve clips partially black?
on Aug 30, 2012 at 8:56:40 pm

[John Sackey] "in a couple of the sequences there are a couple of clips that have black on the end instead of the full image. So they start where they should but around four or five frames before the end of the clip the media goes black. "

Frame rate? If they were short clips at 23.98, and might be remapped by absolute frame count on a 29.97 timeline... or a misinterpreted timewarp...?

"I always pass on free advice -- its never of any use to me" Oscar Wilde.


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John Sackey
Re: Avid AAF to Resolve clips partially black?
on Aug 30, 2012 at 9:12:23 pm

Nope, it's all 25fps.

The last frame of picture before it turns black isn't the absolute last frame of the clip, it just turns black before the clip is finished.

I should probably mention I'm using v8.2.2 as well.

Thanks



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Konstantin Melikhov
Re: Avid AAF to Resolve clips partially black?
on Aug 31, 2012 at 7:36:46 am

Would you mind providing few more details:

Which format did you transcode to, if MXF, was it OP-Atom or OP-1A?
What's the duration of a clip in frames and what's its FPS?
If you're able to share a file that could be helpful.

Best regards,
Konstantin


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Fred Ricci
Re: Avid AAF to Resolve clips partially black?
on Aug 31, 2012 at 9:23:26 am

Hi John
I have the same issue every time I get mxf from avid. I work with music shows and if the show is longer than 600 or 700 shots I always end up with some of them partially black. Never could figure out an explanation. What I usually do is I grade what I can see, add a white vignette and save the still so that I can find it and replace it later with a mixdown from avid. Luckily I have avid in my machine and the mxf media is fine within media composer.

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Konstantin Melikhov
Re: Avid AAF to Resolve clips partially black?
on Aug 31, 2012 at 10:55:42 am

This may happen for OP-1A MXF files, particularly XDCAM or other format with variable frame size, due to a tailing frames indexes not being read correctly by Resolve. This bug will be fixed.

However if that happens to DNxHD which is constant frame size, this looks odd, thus I'd appreciate if you could provide us with more details (is it an OP-1A or OP-Atom MXF, FrameRate etc) or a file sample.

Best regards,
Konstantin


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John Sackey
Re: Avid AAF to Resolve clips partially black?
on Aug 31, 2012 at 3:35:30 pm

Thanks

I'm just exporting an AAF of the last four shots from one of the sequences with the media embedded. The problem clip is the last one, in Resolve the clip just goes black at 08:17:19:05 while in Avid it continues to play.

I've just discovered something interesting in Avid though, at 08:17:19:04 when you watch the clip in the viewer there is the little backwards L end of media symbol in the lower right of the window and when you go on to 08:17:19:05 the forwards L start of media symbol appears in the lower left. Could media spanning in the camera be causing problems? In the other sequence with this problem I'm seeing the same phenomena where the clip turns black in Resolve. The only thing I can think of is media spanning in AMA linked files causing these marks to show up in the middle of clips but It's been a long time since I was an Avid editor.

The source material started as a mix of C300 Canon footage and XDCAM which was AMA linked for editing. I transcoded to DNXHD 185 MXFs then created an AAF for the transcoded sequences for Resolve. The shots that are giving me trouble are from the CF300 originally. I'm not sure what this means in terms of being OP-1A or OP-Atom MXFs, my understanding is they would become OP-Atom upon transcoding?

Here's a link to the AAF

https://www.sendthisfile.com/RIFfqcgnrkyJvhtrkblKxsmK

It's just over 2Gb.

I'm staring to think that this is down to AMA linking to shots that span media cards, exporting the clip from Avid as a QT then reimporting it sorts it out but it would be good to get to the bottom of it and to make sure there isn't a better workaround.

Cheers
John



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Konstantin Melikhov
Re: Avid AAF to Resolve clips partially black?
on Sep 3, 2012 at 7:34:13 am

this AAF references AA020001.MXF and AA020201.MXF, any chance to peek at one of those (the one that causes trouble)?

Best regards,
Konstantin


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John Sackey
Re: Avid AAF to Resolve clips partially black?
on Sep 4, 2012 at 6:17:04 am

Hi Konstantin.

Sorry about this but I'm now off that job and in another city for a couple of weeks.

My colleague at the facility I'm working in at the moment has pretty much confirmed that the problem would come from AMA linking to the files and the cameras recording those shots across 2 cards. I have a feeling that these projects have gone too far down the road for the problem to get solved other than to export the problem clip as one piece of media then re-import it. Not a problem on short pieces but not the scenario I want to be in on a 60 or 90 minute show.

I think the best solution in the future is to make sure everyone knows to shoot one card at a time (which frankly they should be doing without being told if they're any good).

If you would still like a look at those files I can get them to you in a couple of weeks but thanks for your interest and help so far.

John



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