I used to have a similar problem exporting mpeg files in quicktime pro to either an .mov or other format. Some other programs wouldn’t see it either. I believe it has something to do with the way the audio is multiplexed with the video.
My solution was to use TMPGEnc mpeg encoder to extract the audio from the mpeg file and save it as an uncompressed .wav.
If you think you might want to go this route, you can get a free version of the encoder here:
https://www.tmpgenc.net/en/download.html
This version needs no installation. Unzip to it’s own folder and run.
If you need to read a quicktime file into TMPGEnc, you’ll need to install this plugin for it here:
https://www.moviecodec.com/downloads/363d.html
Unzip the QTReader.zip file and put it in the TMPGEnc folder.
Load in your mpeg file into TMPGEnc and click ES (Audio only) in the STREAM TYPE. Click the SETTINGS tab and choose Linear PCM. OK that, set your output destination, and hit the START button.
I’ve placed a screen grab below to show you. You may need to click it and possibly expand it’s viewing box to see sufficient resolution. This is a screen grab of both the main program window on the left and the audio settings on the right.
After writing all this I didn’t think of whether you are on a MAC or not. Hopefully not. 🙂 Well, hope this helps.
