Audio Professionals Forum
Change time/pitch
Change time/pitch
by Mats Andersen on Nov 9, 2012 at 8:14:20 pm

I need to convert some audio recordings to sync with
a picture that is shoot in 50 frames per second.

I guess I need to double the length of the audio, but
still keep the original pitch.

Is that possible?

Can anyone recomend a software, preferably with a batch function ?


Re: Change time/pitch
by André Engelhardt on Nov 9, 2012 at 9:15:04 pm

Hi Mats,

I've been using Izotope Radius for time stretching and while it does a great job (so do a lot of other software solutions out there) I wouldn't use it for more than a factor of ±10% the original speed. The more extreme the change to pitch or tempo the more artifacts will be introduced, especially so when slowing things down as the software has to interpolate data that isn't originally there.
The type of source material also plays a major role of how far up or down you can stretch/pitch but generally at anything more than 10% up or down you start getting issues.

For your case, with a factor of two you might want to consider reshooting/re-recording the audio if at all possible.

Good luck!

--
Audio Engineer, Sound Designer,
Composer & Remixer
www.andreengelhardt.net


Re: Change time/pitch
by Ty Ford on Nov 9, 2012 at 10:58:30 pm

Hello Mats and welcome to the Cow Audio Forum.

There is no way you can double the length without problems.

Why do you need to double it?

Regards,

Ty Ford
Cow Audio Forum Leader


Want better production audio?: Ty Ford's Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford's Blog



Re: Change time/pitch
by Eric Toline on Nov 10, 2012 at 12:55:15 am

One minute @50fps is one minute @any other frame rate as long as the playback speed is the same as the record speed. More details about the technical aspects will help in finding a logical solution.

Eric

"I push the RECORD button and hope for the best"


Re: Change time/pitch
by Mats Andersen on Nov 11, 2012 at 10:02:06 pm

Thanks for answers.

This occured because the cinematographer
shoot some scenes with dialogue in 50 fps,
he wanted a dreamy feeling ..

I did convert the soundfiles to the correct length
with Adobe Audition. It sounds horrible, but it
is usable for the editing.

I guess we have to redo these scenes in studio
when the film is edited.


Re: Change time/pitch
by Ty Ford on Nov 11, 2012 at 10:40:12 pm

Hi Mats,

Right. I figured the DP was overcranking for an effect, but you never know. No, you can't really expect to use the sync audio from the camera when you slow it down to 24, 25 or 29.97 fps. YOuhave to do that with ADR.

Regards,

Ty Ford
Cow Audio Forum Leader


Want better production audio?: Ty Ford's Audio Bootcamp Field Guide
Ty Ford Blog: Ty Ford's Blog






© CreativeCOW.net