How do I sync up slow motion footage correctly with an external audio recorder?

[Mikhail Shapiro]

Hi team,

I am scratching my head... trying to match the audio from the sound recorder to the footage from the red (included above with frame rate) there is no sound recorded on the red since it was shot in slow motion.
The recorder frame rate is 44100htz.

Any advice would help, thank you in advance.

 

[Nick Morrison]

You can do it in Resolve, and pair sound to R3D's in the transcodes. Either by matching timecode, or syncing manually with a slate.

We do it all the the time.

Having a lockit box on the camera, keeping it in sync with sound department, is super convenient for this.

best

 

[Tom Visser]

View attachment 97364

Hi team,

I am scratching my head... trying to match the audio from the sound recorder to the footage from the red (included above with frame rate) there is no sound recorded on the red since it was shot in slow motion.
The recorder frame rate is 44100htz.

Any advice would help, thank you in advance.

There is no such thing as audio framerate. When synching audio, it is possible to set a timecode stamp referencing video framerate, but this is just a metadata tag. In almost all instances, sound recorded for picture should be set to 48Khz. In very rare instances, when you need a pull up or pull down for 24fps (not to be confused with what is commonly known as "24P" which is in fact 23.976 fps) where sound "might" be recorded at 48.048KHz. So your first mistake is likely that your sound is recorded in the wrong sample rate, it likely should not have been done at 44.1KHz. However, if you sample rate convert (SRC) it to 48Khz after the fact, you will likely do no major harm. Then the other equation is what off-frame rate did you shoot and what timebase is your project? If the timebase is 23.976 and you shot double speed, or 47.952 (48fps abbreviated) you can just stretch the audio by 2 and it should match. If you did a fraction thereof, then you'll just have to stretch by that fraction. The easiest way to do this is to get a reference at the head and tail of the clip, so a head and tail slate would have been perfect, then stretch the audio exactly to match those marks. If you don't have marks, will require some experimentation.

 

[Mikhail Shapiro]

The frame rate recorded in was 25fps unfortunately, so I am trying to find a resolution to sync up the audio from the sound recorder. There is NO audio in camera since it was recording at a variable frame rate.

 

[Mikhail Shapiro]

Thank you for your response, unfortunately that is not how the format was filmed. In the above image are the specs, it was shot at 25fps by accident so trying to find a resolution to this crisis, HELPPPPPP

 

[Mikhail Shapiro]

Figured it out!

Slowed down the recording for the external audio recorder to 96% in premier, fits perfectly with the variable speed of 25fps.