[FFmpeg-user] Error converting .m4a to .mp3

[Bernhard Döbler]

Hi,

I want to convert an mp4 file from iTunes to MP3 using ffmpeg.
For on certain file I get error:

~~~
Program: c:\Program 
Files\ffmpeg-20180121-78e884f-win64-shared\bin\ffmpeg.exe
File: ../../src/lame-3.100/libmp3lame/vbrquantize.c, Line 783

Expression: vbrsf[sfb] >= vbrsfmin[sfb]

This application has requested the Runtime to terminate it in an unusual 
way.
Please contact the application's support team for more information.
~~~

I understand the exceptioon is thrown my lame; not ffmpeg.
I asked this question on the lame page over at sourceforge. They told me 
to convert the .m4a file to .wav and then use LAME.exe to generate the 
.mp3 file and see if this errors comes up.
I tried that and it did not come up.

Can you give me a hint what might be the cause of the error?


Best,
Bernhard Döbler