Category Archives: Research

Research I have done, or am doing, posted for the benefit of future generations who might do or be doing the same.

Uploaded Facebook videos not playing sound (but do in preview).

I thought I’d share the solution to a puzzling issue I encountered recently with videos uploaded to Facebook. A recorded video (screen capture) had audio that played fine in my local .mov file, and played fine in the Facebook video preview, but once published, it was silent. No sound.

I tried multiple uploads and several videos, and they all did the same thing. Yet, earlier videos recorded with the same screen capture software, the same way (or so I thought) played audio just fine.

It turns out, Facebook does not support multiple tracks of audio in video files. It uses the first set of audio. I’m my case, the change was using a USB microphone to record my narration instead of the built in laptop mic. The capture software was placing the app audio (built in sound from the computer) on the first set of stereo tracks, and then my USB microphone on the second set. Facebook does not honor any tracks beyond the first set.

Had what I was recording had any app audio, I might have noticed this … “hey, my voice is gone but the beeps are still there.”

But my demo was silent, and it took some web searching to figure this out.

Initially, I got it working simply by taking my captured .mov file and importing it into Final Cut Pro X and then exporting it from there. FCP mixes the multiple audio tracks down to stereo for me, per the output file format.

But, a much easier solution (since I was not using audio on the first track) was to use a utility that would just delete the first unused audio track.

My screen capture software does have an option on how it prioritizes audio recording, so there may be an easy fix I can make there.

I thought I’d post this here in case someone else stumbles upon it.