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Audio Sync Problems using compressor

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James Bayliss-Smith
Audio Sync Problems using compressor
on Sep 2, 2009 at 9:21:04 pm

Hi There, I am having audio sync problems when using compressor. I am trying to compress a 12 minute film but the output is a bit juddery and the audio is out of sync. I am using the settings as laid out in this vimeo page. http://www.vimeo.com/help/compression

I am starting off with HDV footage I converted to ProRes standard quality when I captured into FCP. In Compresor I am going down from 1920 x 1080 to 1280 x 720 as vimeo recommends. I am also changing the audio from 48 to 44.1. Has anyone got any ideas why it is going out of sync and has juddery playback? I am using a Quicktime referenc file as opposed to a self contained file. Do you think this might have anything to do with it.

Any help would be greatly appreciated

All the best

James Bayliss-Smith


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Daniel Low
Re: Audio Sync Problems using compressor
on Sep 2, 2009 at 9:53:57 pm

Why are you going from 48k to 44.1?

Can you post a link to the clip?

__________________________________________________________________
"There's no chance that the iPhone is going to get any significant market share. No chance."

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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 2, 2009 at 9:57:10 pm

I am going from 48 to 44.1 because Vimeo recommends that. I don't know why but it is for Vimeo so I figure go with the settings they want? I can't post a link yet but will do soon.


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 2, 2009 at 9:55:08 pm

A little more information

I am using Mac OS 10.4.1
I am using compressor version 3.0.5


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Daniel Low
Re: Audio Sync Problems using compressor
on Sep 2, 2009 at 10:08:29 pm

Try it at 48k

__________________________________________________________________
"There's no chance that the iPhone is going to get any significant market share. No chance."

Steve Ballmer To USA Today


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 2, 2009 at 10:19:50 pm

Sure I will do. What is the difference? Why do Vimeo want 44.1 and FCP 48?


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 3, 2009 at 9:57:27 am

I just tried compressing it using 48 kHz and still had the same audio sync problems.

Any ideas?

James


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 3, 2009 at 4:46:36 pm

I have just done a further test, this time leaving the frame at 1920 x 1080. No juddery playback, no audio out of sync. I will use this one. But it still bugs me, why was I having these problems. Is compressor just not very good? Is it a bug?

Any advice and guidance much appreciated

James


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Daniel Low
Re: Audio Sync Problems using compressor
on Sep 3, 2009 at 5:26:08 pm

Compressor is very good, but you have to know how to use it properly.

__________________________________________________________________
"There's no chance that the iPhone is going to get any significant market share. No chance."

Steve Ballmer To USA Today


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 3, 2009 at 5:55:18 pm

Hi Daniel, based on my setting what do you think I wasn't doing properly? I will never learn if I don't understand.

Thanks

James


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Daniel Low
Re: Audio Sync Problems using compressor
on Sep 3, 2009 at 8:49:05 pm

I'd need a compete rundown of your exact settings and complete workflow. But really you should just read the chapter on Frame controls in the compressor user manual.
Can you remind me what version of compressor are you using?

__________________________________________________________________
"There's no chance that the iPhone is going to get any significant market share. No chance."

Steve Ballmer To USA Today


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 4, 2009 at 6:50:38 am

Here Goes:

Settings


Name: Vimeo HD
Description: HD for Vimeo
File Extension: mov
Estimated file size: 2.15 GB/hour of source
Audio Encoder
AAC, Stereo (L R), 44.100 kHz
Video Encoder
Format: QT
Width: 1280
Height: 720
Pixel aspect ratio: Square
Crop: None
Padding: None
Frame rate: (100% of source)
Frame Controls On:
Retiming: (Fast) Nearest Frame
Resize Filter: Linear Filter
Deinterlace Filter: Better (Motion Adaptive)
Adaptive Details: On
Antialias: 0
Detail Level: 0
Field Output: Progressive
Codec Type: H.264
Multi-pass: On, frame reorder: On
Pixel depth: 24
Spatial quality: 75
Min. Spatial quality: 25
Key frame interval: 25
Temporal quality: 50
Min. temporal quality: 25
Average data rate: 5.12 (Mbps)

Workflow

I captured HDV footage as ProRes 422 (Normal Quality) straight into Final Cut Pro.

I am using Compressor version 3.0.5

Why did you suggest I read the chapter on Frame controls? I understand that this is the most important part of compressor but did you have any particular reason in relation to Audio sync issues? I always use frame controls to de-interlace. I will read this chapter. I'm guessing it must have something to do with the 'Retiming control' as the timing of the audio was out?

Thanks for your kind advice


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Daniel Low
Re: Audio Sync Problems using compressor
on Sep 4, 2009 at 7:00:49 am

[James Bayliss-Smith] "Why did you suggest I read the chapter on Frame controls"

Because you said that you were unhappy with the quality of playback

[James Bayliss-Smith] "I captured HDV footage as ProRes 422 (Normal Quality) straight into Final Cut Pro. "

How did you get it to compressor?



__________________________________________________________________
"There's no chance that the iPhone is going to get any significant market share. No chance."

Steve Ballmer To USA Today


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 4, 2009 at 7:15:25 am

I got the video into compressor by exporting a Quicktime Movie "current settings" then dragged that into compressor


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 4, 2009 at 7:14:10 am

I just read the chapter on frame controls and there seems to be nothing in there that would make the audio go out of sync. Still a mystery

James


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 4, 2009 at 7:20:28 am

I have just realised something that may be of interest. Due to capturing a portion of one tape at a later date than all the rest I have realised that there is 1 clip in my sequence that was captured as ProRes (HQ) all the rest is just ProRes. I'm not sure why this would be a problem as I'm sure Final Cut 6 can handle different sources in the time line.


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James Bayliss-Smith
Re: Audio Sync Problems using compressor
on Sep 4, 2009 at 5:42:44 pm

Hi Daniel, any ideas?


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