> ffmpeg -i input_file.ext -map 0:0 -af "aconvert=flt:auto" -y foo.wav > but it's always converting to s16 I'm not sure why aconvert doesn't seem to be...converting it, as it were. You may be able to work around like -acodec pcm_f32le ref: http://ffmpeg.org/trac/ffmpeg/wiki/audio%20types