How to remove ALL metadata using ffmpeg?

Question

I have an input file: infile.mp3 This file contains metadata (artist, genre, etc.) I am trying to delete all metadata for outputting a wav file.

Yes! I found an option:

-map_metadata -1

But the conclusion is unexpected for me ...

$ ffmpeg -i infile.mp3 -acodec pcm_s16le -ac 2 -ar 44100 -map_metadata -1./outfile.wav

OK!

$ ffprobe outfile.wav
Input #0, wav, from 'inp.wav':
  Metadata:
    encoder         : Lavf56.25.101
  Duration: 00:04:00.47, bitrate: 1411 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 2 channels, s16, 1411 kb/s

You see? encoder metadata exists!

And in the wav header after "subchunk1_id" with the value "fmt" I expect "subchunk2_id" with the value "data" (a clear expected example):

$ strings outfile.wav | more
RIFFFB
WAVEfmt
data

But this is not (LIST, INFOISFT, etc.):

$ strings outfile.wav | more
RIFFFB
WAVEfmt 
LIST
INFOISFT
Lavf56.25.101
data

Well .. How to really delete all metadata for the output file?

Answer 1

-fflags +bitexact -flags:v +bitexact -flags:a +bitexact