I found a discussion on rounding through google and here's what someone said in the discussion but this was about going 10 bit to 8 bit in a generic sense it wasn't about video but data in general so I don't know if it's accurate but it made sense to me.:
"If it was me I would read the 10 bits and use a rounding algorithm. If the low two bits are 00 or 01 drop them and take the most significant 8 bits. If the low two bits are 10 or 11, then round up by adding 1 to the most significant eight bits. "
Is there any other way to round? I did read about "double rounding" where the value gets bumped twice on a desktop display but I didn't follow how the double bump actually occurred. Sounds like a question for SUPER CODEC MAN. Mr. Rynderman are you out there? Hollywood is losing 2 bits of data and I'm afraid we're being truncated. Could you explain how Avid rounds 10 bit to 8 bit so tinsel town can rest easy tonight? ;-)
--- In Avid-L2@yahoogroups.com, "Terence Curren" <tcurren@...> wrote:
>
> Depends upon how well the rounding is handled. If not done correctly, you can get a slight shift to green when rounding from 10 to 8.
>
> --- In Avid-L2@yahoogroups.com, "johnrobmoore" <bigfish@> wrote:
> >
> > I was told the avid doesn't truncate but rounds when you lose bits. Not a big deal but my understanding is rounding is better than just loping of the extra bits.
> >
> > --- In Avid-L2@yahoogroups.com, Michael Brockington <brocking@> wrote:
> > >
> > > What was the codec for your original QT? If it was Avid 10-bit media,
> > > and you were able to fast-import it, then you're OK for the first step,
> > > otherwise it was probably truncated on import.
> > >
> > > Cheers,
> > > --Michael
> > >
> > > On 11-09-12 4:15 PM, ripvanmarlowe2000 wrote:
> > > >
> > > > Had an interesting one today which required a bit of grey matter and I
> > > > remember some discussion about this a while back and i think I've
> > > > managed to keep all my bits in place but does this sound right to people?
> > > >
> > > > Client wants a 59.94 10bit uncompressed QT from a 25fps 1920x1080
> > > > 10bit uncompressed master QT.
> > > >
> > > > Starting with the uncompressed 10bit QT I imported into Avid as 1:1X
> > > > MXF. Played out to 50i HDCAM SR with 10bit checked in digicut tool.
> > > > Reconfigured the SR to play back the tape at 23.98 and format convert
> > > > to 59.94 then captured the 59.94 footage back in to a new 59.94
> > > > project as 1:1x MXF then exported as Same as source QT.
> > > >
> > > > Have i kept all my 10 bits using this workflow? Man those SRW-5500s
> > > > are cool!
> > > >
> > > > Andi
> > > >
> > > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
>
If you want to donate to Red Cross quake relief, you can do so through your cell phone. Text redcross to 90999 to make a $10 donation. It will be on your next cell bill.
No comments:
Post a Comment