We recorded the audio of a rather long meeting of a couple of hours on a phone. Someone forgot to turn off sound recording at the end of the meeting and the phone must have turned off due to low battery at some point. It is an MP4 container file which should contain an AAC stream at 192kbit/s. The file has a total size of 734MB, which would probably mean more than 8 hours of audio. We would like to restore as much as possible of this file, but it is not recognized by common media applications.
ffprobe which says
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000000002602660] moov atom not found recording-20171111-135205.mp4: Invalid data found when processing input
According to what I found via search engines, this means that the header of the container file has not been written properly, which kind of makes sense.
Is there any way to restore the audio from the file? The first couple of hours are probably enough, if that makes things any easier.