On Thu, Jun 29, 2017 at 12:37 PM, Moritz Barsnick <barsnick@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