This IS the Avid L2: Re: [Avid-L2] Re: QT video levels?

I don't think you would notice much generational loss converting once
between the 2 codecs which have roughly similar datarates.

Note that importing with the 709 setting tells Avid to use the pixel
values without remapping them, it doesn't force them into the 709
range. So I suspect you would wind up with DNxHD files in the full RBB
range after doing what you describe. Don't know for sure, though --
you'd have to test it.

Also be aware that converting codecs on import or export is much slower
than transcoding. Import/export uses only a single core, whereas
transcoding uses all available cores.

Cheers,
--Michael

On 13-05-09 10:27 PM, michaeljshen76 wrote:
>
> Thanks, Michael! I read the thread you posted. Very helpful.
>
> My end goal is preserve the 709 levels in a Same-As-Source export of a
> ProRes MXF sequence. And for various reasons, I'd like to avoid
> transcoding to DNxHD before export. I'd much prefer to convert the
> exported Quicktime file to 709 somehow.
>
> Could I export Same-As-Source with 709 setting (resulting in a file
> flagged as RGB), then re-import to DNxHD 115 with the 709 setting
> (thereby resetting the levels and gaining access to the original
> detail/information), and then export as 709?
>
> Or would I experience some kind of generational loss as a result of
> this process?
>
> Thanks.
>
> --- In Avid-L2@yahoogroups.com <mailto:Avid-L2%40yahoogroups.com>,
> Michael Brockington <brocking@...> wrote:
> >
> > Hi Mike:
> >
> > I haven't seen it documented, only observed what happens under
> > testing. It looks to me like there is a flag set in the file that
> > indicates it should be interpreted as RGB, rather than a change to
> > underlying pixel values. But the effect is the same (of dropping the
> > blacks and lifting the whites) unless you can force another application
> > to disregard the flag. For instance, in After Effects you can fool
> > around with colour management as I describe at the bottom of this
> thread:
> > http://community.avid.com/forums/p/113013/677905.aspx
> >
> > You could also download a trial version of Avid 6.5 and do your own
> > testing. The belle-nuit test chart can be downloaded here:
> > http://www.belle-nuit.com/test-chart
> >
> > Sounds like a good exercise for one of your students!
> >
> > Cheers,
> > --Michael
> >
> > On 13-05-08 8:15 AM, michaeljshen76 wrote:
> > >
> > > Michael, thank you so much for the reply.
> > >
> > > Does "flagged" mean the same as "converted", i.e., the blacks will go
> > > down, the whites will go up, and the levels will be clipped on a
> video
> > > monitor?
> > >
> > > Does anyone know if 709 Same-As-Source ProRes exports are working in
> > > version 6.5? It would be a lot easier to upgrade one school
> machine to
> > > 6.5 and export all the student sequences using that machine, rather
> > > than convert all the films to DNxHD.
> > >
> > > Sigh.
> > > -Mike
> > >
> > > --- In Avid-L2@yahoogroups.com <mailto:Avid-L2%40yahoogroups.com>
> <mailto:Avid-L2%40yahoogroups.com>,
> > > Michael Brockington <brocking@> wrote:
> > > >
> > > > Yes, I believe your colour levels will be flagged as RGB on export.
> > > >
> > > > I guess one workaround would be to transcode the finished pieces to
> > > > DnxHD at a suitable bitrate, and export that same-as-source using
> > > > 601/709 levels.
> > > >
> > > > Cheers,
> > > > --Michael
> > > >
> > > >
> > > > On 13-05-07 9:48 AM, michaeljshen76 wrote:
> > > > >
> > > > > I have a number of students exporting their finished thesis films.
> > > > > They've been editing in on MC 6.03 in Apple ProRes MXF. The
> plan was
> > > > > to color-correct in the 709 color space, and then have them
> export a
> > > > > Same-As-Source .mov using 601/709 settings. This would be
> their final
> > > > > master.
> > > > >
> > > > > Am I correct in understanding that the 601/709 setting won't
> work,
> > > and
> > > > > that color levels will expand to RGB levels upon export?
> What's the
> > > > > best workaround for this?
> > > > >
> > > > > Thanks for helping my offline editor brain with these online
> > > conundrums!
> > > > >
> > > > > Cheers,
> > > > > Mike
> > > > >
> > > > > --- In Avid-L2@yahoogroups.com
> <mailto:Avid-L2%40yahoogroups.com> <mailto:Avid-L2%40yahoogroups.com>
> > > <mailto:Avid-L2%40yahoogroups.com>,
> > > > > Michael Brockington <brocking@> wrote:
> > > > > >
> > > > > > On 6.0.3 this flag seems to be set properly by Avid for DNxHD
> > > exports.
> > > > > > ProRes exports in that version seem to be always flagged as RGB.
> > > > > >
> > > > > > I reported some testing results here comparing DNxHD vs ProRes
> > > > > > same-as-source exports on Mac:
> > > > > > http://community.avid.com/forums/p/113013/677905.aspx
> > > > > >
> > > > > > I suspect not all applications observe the flag that is set.
> > > > > >
> > > > > > Cheers,
> > > > > > --Michael
> > > > > >
> > > > > > On 13-05-07 3:57 AM, Fabrice Altman wrote:
> > > > > > >
> > > > > > > So... moving on from the goose ;)
> > > > > > >
> > > > > > > Apparently there is an internal flag in the exported DNxHD
> QT file
> > > > > > > that is supposed to be set to either RGB or 709 according
> to the
> > > > > > > export settings.
> > > > > > >
> > > > > > > However, this flag seems always set to 709 on export from
> MC 5.5,
> > > > > > > whatever the export settings are. Can anyone confirm this
> is a
> > > bug
> > > > > and
> > > > > > > has been fixed in later releases?
> > > > > > > (The flag seems to work on export from AFX).
> > > > > > > Does a similar flag exist in ProRes?
> > > > > > >
> > > > > > > Cheers,
> > > > > > > F.
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
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