[FFmpeg-user] Compare quality of 2 audio files

[Harold Tessmann]

On Thu, Jun 29, 2017 at 12:37 PM, Moritz Barsnick <barsnick at gmx.net> wrote:

> And unlike video, it seems there are few, if any, methods to measure
> the *perceived* quality of audio. Check here for some ramblings:
> https://stackoverflow.com/questions/2945531/determining-
> the-best-audio-quality
>
> But I challange you to find an algorithm which can compare two audio
> tracks. (And you need someone with a good ear to confirm its findings.
> Or reference material and encodings such as SQAM.) But if you do find
> it, and it's "free" to use, please implement an ffmpeg filter with it.
> :-)
>

To continue along those lines, I don’t think this is even a problem that
one can precisely define. I will start by acknowledging that there exists a
boundary where you can define audio quality objectively. Clipping, for
instance, destroys sound data, and is objectively bad <
https://en.wikipedia.org/wiki/Loudness_war> (but even then, some musicians
or sound designers may want that, for industrial or other effects). But
there is a difference between objective quality and what people want.
Consider the ability of a display to reproduce an image accurately. You can
make an objective comparison, but if you go by the display section of an
electronics store, you’d find out that people tend to like oversaturated,
objectively worse, color <
http://www.flatpanelshd.com/focus.php?subaction=showfull&id=1328263571>.

And then you have to consider the environment of your audience, which you
can’t necessarily control. Audio played in a car has to contend with road
noise, while pictures on a TV will look significantly different in a bright
store vs. a customer’s home <
https://www.cnet.com/news/why-do-plasma-tvs-look-washed-out-in-the-store/>.

And then there’s the question of how much quality your audience can detect.
The MythBusters did a test with different grades of vodka and determined
that yes, an expert can taste the difference between high end and cheap
liquor, but your average person doesn’t have so discriminating a palate <
http://kwc.org/mythbusters/2006/04/episode_50_bullets_fired_up_vo.html>. So
even if you did come up with a good metric, perhaps you don’t _want_ to
check it against an audiophile, or a recording engineer, or somebody who
has particularly good hearing.

Harold