Urgent Issue: Audio Slipping in Open DCP

[Davis Chambers]

The company I work for is assembling a DCP for festival submissions. This is our first time attempting to make a DCP, and we're stuck on an audio issue. The film has a frame rate of 23.98, and we have a 5.1 mix to incorporate. Our problem is that the audio reports more frames than the video in our MXF wrapping stage. Please help. We are at a loss and need some assistance.

Thanks,

Davis

[Agustin Goya]

Picture will not run at 23.98, it runs at 24.00, you need to apply a 0.001% pulldown to audio to compensate the difference form 23.98 to 24.

regards.

Agustin Goya
WANCAMP | POST
+54-11-6545-2427
http://www.wancamp.com.ar/
http://www.linkedin.com/in/agustingoya/

[Yuri Mamaev]

But in this case there will be less audio frames, then video.

What's your current process? Can you confirm, that your video and audio tracks are aligned and of the same duration?

Regards,

Yuri Mamaev

09.10.2012, в 21:39, Agustin Goya <agust...@gmail.com> написал(а):

[Davis Chambers]

Our 5.1 mix is not as long as picture. Just brought all the individual channels into AE to compare to our video. They are the same duration at this point. Is there some change that occurs in OpenDCP that lengthens the audio?

[Yuri Mamaev]

There should not be any changes. What have you exported from AE?

Best regards,

Yuri Mamaev

09.10.2012, в 22:32, Davis Chambers <davis.m....@gmail.com> написал(а):

[Davis Chambers]

We went from ProRes 422 HQ (@ 23.98) to a 16-bit TIFF sequence at the same frame rate.

[Agustin Goya]

I meant 0.001% Pull Up. Check the duration of you dcp video. Hould be different than the original at 23.976, it should be 0.001% shorter. Any audio editor can change the sample rate of audio. I can't rememer the exact numbers now.


Sent from my phone

-----Original Message-----
From: Yuri Mamaev
Sent: 09/10/2012 14:43:59
Subject: Re: Urgent Issue: Audio Slipping in Open DCP

But in this case there will be less audio frames, then video.

What's your current process? Can you confirm, that your video and audio
tracks are aligned and of the same duration?

Regards,
Yuri Mamaev

09.10.2012, в 21:39, Agustin Goya <agust...@gmail.com> написал(а):

[Stephen van Vuuren]

> I meant 0.001%

That math number is wrong. 23.976 vs 24.000 is 100.1% or 99.9% - or 100.001 (without the percent sign)

>. Our problem is that the audio reports more frames than
> the video in our MXF wrapping stage. Please help. We are at a loss and
> need some assistance.

It can be hard to wrap your head around 23.976 to 24.000 conversion. 23.976 is a slower frame rate that 24.000. Material that is 23.976 is played at 24.000 will be sped up (i.e. playback faster or short in overall duration). Audio, however is a set duration, so it will be longer, i.e. OpenDCP will report as more frames if it is longer in duration than the project at 24.000

Audio must be shorted by a 100.1% speedup (some programs used 99.9%) so it is shorter in duration exactly in sync with playing the frames of 23.976 project at 24.000 fps.

However, if you interpolate your frames to get to 24.000, picture duration is identical and audio will there for be unchanged.

stephen van vuuren
336.202.4777

http://www.insaturnsrings.com/
http://www.sv2dcp.com/
http://www.sv2studios.com/

A film is – or should be – more like music than like fiction. It should be a progression of moods and feelings. The theme, what’s behind the emotion, the meaning, all that comes later.
–Stanley Kubrick

[Davis Chambers]

The mathematical conversion worked as you explained! Thanks Stephen.

[Stephen van Vuuren]

Excellent – glad to be of help.

 

stephen van vuuren

336.202.4777

 

http://www.insaturnsrings.com/

http://www.sv2dcp.com/

http://www.sv2studios.com/

 

A film is – or should be – more like music than like fiction. It should be a progression of moods and feelings. The theme, what’s behind the emotion, the meaning, all that comes later.

–Stanley Kubrick

 

From: Davis Chambers [mailto:davis.m....@gmail.com]
Sent: Thursday, October 11, 2012 3:50 PM
To: ope...@googlegroups.com
Cc: ste...@sv2studios.com
Subject: Re: Urgent Issue: Audio Slipping in Open DCP

 

The mathematical conversion worked as you explained! Thanks Stephen.

[php75]

If you have the sound in a quicktime format, you can adjust the associate video frame rate with "atom inspector" ; you don't have to do any change in the sound datas ; opendcp will count frames and in dcp they have to have the same number in everything : picture, sound and subtitle. If not, you'll get errors and not be able to generate dcp.

[marcos rivero]

Hello I have a question, I just made a dcp file, both mxf file match perfectly, but when i play it on easyDCP, the movie seems to be slow down. Can you please help me. 

Thank you