[Rx] FFmpeg | Fix M4A Files That Won't Play

FFmpeg | How to “Fix” M4a Audio Files

1. Install FFmpeg (Windows version)

I dumped the FFmpeg.exe and FFprobe.exe into a directory C:\OpenPaths on my main drive. If your FF files are someplace else, change the paths accordingly.

2. Convert Single File

Enter this on the command line:

C:\OpenPaths\ffmpeg.exe -i myAudioFile.m4a -c copy myAudioFile_REMUX.m4a

Again, C:\OpenPaths is where you have your ffmpeg.exe on you computer.

3. Convert Multiple Files in Directory

Create the M4AtoM4A.bat file. All you need to do is to copy the text below into a notepad or equivalent text editor and save it with the .bat extension. Put this in the folder where you have your .m4a files.

MP4toM4A.bat

set thisdir=%1
For /R %thisdir% %%J IN (*.m4a) do (
"C:\OpenPaths\ffmpeg.exe" -i "%%J" -c copy "%%J"_REMUX.m4a
)
pause

Change C:\\OpenPaths\ to where you have your ffmpeg.exe on your computer.

Create a new folder (e.g. M4A) and put all the problem M4As into it.

Now, from the Explorer window, drag the folder ( M4A) with your mouse to the top of the batch file icon  FolderMP4toM4A.bat.

The command/terminal window should open and show the conversions.

The new files in the same directory that have the _REMUX are the “fixed” files and should now be good to play.