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Daniel Corcoran
conversion issue;
on Oct 16, 2009 at 1:14:04 pm


Hi,

Not sure if this is the right place to ask question;

A client has asked me to fix a video;

I was given a 1h 36m video that has gone through cinema tools to go from 30p to 24p, then it was put into compressor to speed up the audio. This method was taken from the Philip Bloom tutorial,

http://philipbloom.co.uk/tutorials/canon-5dmkii-tutorials/how-to-convert-ca...

The finished result is a (56g 24p Apple Interm Codec) video that is too slow. The video needs to be sped up.

The aduio/ video are in sync its just too slow. I was wondering if anyone had any suggestions as to how to speed up the whole file? The finished video needs to go onto DVD.

None of the original 30p footage is available all I have to work with is the 24p 56g file,

would compressor work if I change the timing from 01.36.13 to 01.05.13?? A bit of trial and error? I presume there must be a much easier way of doing this,

Any suggestions/ help with this would be greatly appreciated;

Cheers,
Daniel


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Chris Blair
Re: conversion issue;
on Oct 17, 2009 at 4:41:01 pm

I don't really have an answer for you, but I have some questions and assumptions for you:

1. Why would someone want to change from 30P originated footage to 24P?

2. If you speed the video back up the fractional amount needed, considering it's already been slowed down once, you're going to start introducing artifacts into the video.

3. Changing video (with synced audio) from one frame rate to the other without adding pull-down or pull-up will certainly either change the speed of the audio or cause it to un-sync with the video.

Maybe I don't understand the goal here, but I believe changing the framerate of source video that has synced audio will almost certainly cause audio issues, either with pitch or syncing.

Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com


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Chris Blair
Re: conversion issue;
on Oct 17, 2009 at 4:52:16 pm

Phillip's tutorial says you MUST have the original 30p audio in a separate timeline to make this work. So I think I do have the answer. Stop wasting your time and try to get the 30p original cut. That's the only way it will work.

His tutorial also says about audio:

As a result this makes the clip longer and slows the audio down which is undesirable where audio is important. At this point you’ve already created a copy of the original clip therefore preserving the original audio which we’ll relink later in Final Cut.

The key phrase is: "where audio is important." I'm very familiar with Phillip Bloom's work from his website and blog, and the short film he references has no sycned audio in it. It's just random street shots (beautifully done) cut to music.




Chris Blair
Magnetic Image, Inc.
Evansville, IN
http://www.videomi.com


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Daniel Low
Re: conversion issue;
on Oct 17, 2009 at 5:59:47 pm

Use Final Cut Pro to do any speed changes to the video and if you are a perfectionist, use Logic to affect the audio to the same degree.

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