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FIlm in DV to be compressed for Web Streaming

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Nicolas Ayerbe
FIlm in DV to be compressed for Web Streaming
on May 9, 2011 at 11:27:28 pm

So I have a client that supplied me with footage shot in film, then transferred to (SD) Quicktime DV - NTSC files at 29.97fps.

This is for web streaming (Vimeo), so it has to be deinterlaced. Now the part that I am confused over is whether I should just use the "(Best) motion compensated" setting in Compressor, or if the footage has to be Reverse Telecined?

I don't know anything about reverse telecine since I've always worked with video, but I read somewhere else that if the film footage is at 29.97, it has to be reverse telecined to return it to its original 24fps. It makes sense, but since this is just going up on the web I also wonder if its necessary?

Essentially all we want is for the ugly teeth to go away as much as possible.

Thanks


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Craig Seeman
Re: FIlm in DV to be compressed for Web Streaming
on May 10, 2011 at 2:26:57 am

[Nicolas Ayerbe] "So I have a client that supplied me with footage shot in film, then transferred to (SD) Quicktime DV - NTSC files at 29.97fps."

Yuck. Take nice film and use a horrible standard def codec and add unneeded pull down. The should have edited in Uncompressed, ProRes, DNxHD or some such high resolution codec.

[Nicolas Ayerbe] "I don't know anything about reverse telecine since I've always worked with video,"

People shot and edit video in 24fps (23.98) all the time these days. Video has nothing to do with it.

[Nicolas Ayerbe] "This is for web streaming (Vimeo), so it has to be deinterlaced. Now the part that I am confused over is whether I should just use the "(Best) motion compensated" setting in Compressor, or if the footage has to be Reverse Telecined?"

Reverse Telecine will give you 24fps (23.98) Progressive. Having fewer frames will also meet greater bits per frame at the same data rate which usually results in better quality video.

An issue may be when the telecine was originally added in the process. If the film dailies were telecined individually, editing would cause a "broken" cadence which Compressor might not detect properly. On the other hand if the telecine pull down was added after editing then it would be easier to detect. Of course if they have a 23.98 editing sequence (ideally in a higher quality codec), that's the source they should have given you.



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Nicolas Ayerbe
Re: FIlm in DV to be compressed for Web Streaming
on May 10, 2011 at 3:12:04 am

Yeah DV is what it is, but sadly is what I have to work with. I came later in the project and so I couldn't have advised them any better. They're not really going to spend anymore in transfers.

Just to make sure though: You are saying I should do Reverse Telecine right?

Also just adding to what you said: How can I tell if the telecine was added before during the process? As far as I can see all the footage is at 29.97.


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Craig Seeman
Re: FIlm in DV to be compressed for Web Streaming
on May 10, 2011 at 4:59:16 am

[Nicolas Ayerbe] "They're not really going to spend anymore in transfers."

They went straight from film to DV?
Wow, almost any other standard def codec would be better. I can't imagine someone having the budget to shoot on film, even if it was 16mm short ends, and transferring to DV both for edit and delivery.

[Nicolas Ayerbe] "Just to make sure though: You are saying I should do Reverse Telecine right?"
Try it. The result depends on how they got there and if they edited with Telecine source, whether Compressor detects the changes in the cadence at the edit points.

[Nicolas Ayerbe] "Also just adding to what you said: How can I tell if the telecine was added before during the process? As far as I can see all the footage is at 29.97."

You can jog through the source frame by frame and spot the cadence by eye. If it changes after and edit (check several) then you know they Telecine'd the source.



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Nicolas Ayerbe
Re: FIlm in DV to be compressed for Web Streaming
on May 10, 2011 at 11:17:19 pm

Just to make sure I asked how they had done all their post work. Turns out what happened was from Film to Tape to DVCam and then captured via FCP. It turns out the footage is not recent but already a few years old and that was the way they told them to do it back then. I was told the 3:2 pulldown had been done, but obviosuly capturing from the DVcam is the reason why all the footage is 29.97.

Now I don't know if that's how it was done back then, but I'm guessing that means I can just de-interlace with "(Best) Motion Compensated"?


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Craig Seeman
Re: FIlm in DV to be compressed for Web Streaming
on May 11, 2011 at 5:14:36 am

I'd still test reverse telecine first. If Compressor guesses the cadence and removes it correctly, you'll have the potential of better quality frames at the same encoded bit rate. If reverse telecine doesn't work then do try deinterlace.

The problem is when the pull down was added. One can import DV and remove the pull down on the source clips and edit in 23.98/24 native and then once edited, can add the pull down to the entire edited sequence. This makes the pull down easy to reverse.

If the clips were edited 29.97 then each edit point, depending on where the edit point is in the source clips cadence, will change the cadence. This may be harder to detect and reverse because the cadence is not consistent.



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Jeff Greenberg
Re: FIlm in DV to be compressed for Web Streaming
on May 18, 2011 at 1:59:12 pm

You're going to deinterlace - and ignore the reverse telecine.

You perform reverse telecine when you first get video at 29.97 and needs to be converted back to 23.98 - to match what it was shot at.

But after the editorial process? Each cut starts a different cadence of the 3:2 pulldown. Just deinterlace (best) and move on.

Best,

Jeff G

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