[FFmpeg-user] Conversion wav -> mp3 -> wav

[Reindl Harald]

Am 22.06.2017 um 22:20 schrieb Rodolfo Medina:
> As an experiment, I converted a .wav file to mp3 format and then back into wav
> again, just to see what happens:
> 
>   $ ffmpeg -i file1.wav file1.mp3
>   $ ffmpeg -i file1.mp3 file2.wav
> 
> I've always heard and read that the first step produces a loss in quality.  So
> I would expect that to be seen in a reduction of size.  Instead, I was suprised
> to see that file1.wav and file2.wav are both 154M large.  Also the output of
> `ffmpeg -i' is almost the same for the two: in both cases, there is:
> 
>   Duration: 00:15:10.84, bitrate: 1411 kb/s
>      Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, stereo, s16, 1411 kb/s
> 
> So I wonder, and am asking to you listers, in where that quality loss is shown
> and how it can be detected.  Or maybe should we think and conclude that the
> original quality is restored with the second step...?

common sense - something which got lost in step1 can not be restored in 
step 2 - it's really that simple