Sneaking Past Heavy-Handed Audio Compression on YouTube

niceone writes "Recently YouTube seems to have started applying extreme compression to the audio of uploaded clips. This is the type of compressions used by radio stations to make everything louder, but in this case applied extremely badly. In quiet passages, breathing and shuffling become overpoweringly loud. A gently plucked guitar chord becomes a distorted thud. Listen to an example here. And here's what it could sound like — still not perfect, but a whole lot better. The fixed version is thanks to a workaround proposed by Sopranoguitar — the idea is to turn down the audio and mix in a high frequency sine wave (I used 19kHz). The sine wave fools YouTube's compressor into thinking that the file is at a uniform level (and does not need the volume changing at all) but is filtered out by the encoding process (so, no need to worry about deafening any dogs)."

Comments

Re:and who came up with it?

[Prune]

I'm one of those silly people that builds their own equipment ^_^

The quiet environment is actually not as necessary as you imagine, since one nice way to listen is by using in-ear-canal headphones, such as Etymotic ones. They provide something like 30 dB isolation from outside sound in mid and high frequencies. Combine this with the fact that the ear can pick out a signal several dB below the noisefloor (because noise is broadband whereas signal generally isn't), and one can begin to see that 24-bit audio may make sense (noise-shaped dithered 16-bit can only manage the ear's 120 dB range in a narrow part of the frequency range). Of course, it's hard to make electronics reach such low distortion, and drivers, be they headphones or speakers, have even higher distortion (though it tends to be predominantly linear distortion, unlike the electronics where the problem is the exponential gain of transistors or the 3/2 power law gain of tubes).