Dav

Or, “Why 24-bit audio is a load of shit”

I read yesterday that Apple is planning to start selling 24-bit songs on iTunes, and this made me angry. iTunes currently sells 16-bit 256 kb/s AAC files, and will start selling 24-bit 256 kb/s AAC files.

Nobody will be able to tell the difference. Not a single person.

I say this as an audiophile whose entire music collection is stored in lossless FLAC files, because I claim to be able to tell the difference between FLACs and 320 kb/s MP3s. 24-bit is not going to make any difference.

So, let me back up my pessimism with some theory first.

Let’s say you have a 24-bit audio signal. Every sample in the signal is a value between 0 and 2^24 which represents the amplitude of the signal at that point in time. If you were to convert the entire signal to 16-bit, the lowest 8 bits of every sample would be lost — rounded, truncated, whatever. Whatever the true value in the original 24-bit signal was, the 16-bit converted sample will be no more than 2^8 off from the true sample — the difference between the true value and the downsampled value can be no greater than 2^8. This difference of 2^8 represents, at most, 1/65536th of the value of the original sample (2^24 / 2^8 = 2^16, or 65536). This is a difference of about 48 decibels. To put that into perspective, if you played a 16-bit signal at an equivalent volume to rainfall, the lost information in that signal would have the volume of the softest sound your ears could hear if there were complete silence otherwise.

So, that was the theory. Let me also back up my claim with an experiment.

Here is a 5-second clip from a 24-bit FLAC song that I happen to have in my collection. (The song is Progenies of the Great Apocalypse by Dimmu Borgir.)

24-bit Original

Here is the same 5-second clip, but downsampled to 16-bit using Audacity. (Spoiler, it sounds the same).

16-bit downsampled version

I loaded both of them up in Audacity, and subtracted the 16-bit clip from the 24-bit clip to get the difference. This represents the actual loss.

Lost signal

You aren’t supposed to hear anything.

Here is that same clip, except amplified by 48 decibels — that same rainfall-to-practically-silent conversion I mentioned earlier. As another way to look at it, if you play the 16-bit song as loud as a rock concert (~115 decibels according to my earlier link), then this is what you’d be missing.

Lost signal (amplified by 48 decibels)

Aside from the fact that it’s still pretty quiet, I also make the observation that it isn’t particularly interesting — it doesn’t match up to the song.

In conclusion, I think this is a crappy marketing stunt by Apple and nothing more. In the best case, people will end up with 50% larger files that sound no different, and in the worst case people might pay to replace their old 16-bit songs, essentially paying twice for what amounts to the same thing. On top of all that, 24-bit files aren’t supported by many devices. Apple would do far better to start selling higher bitrate (or lossless!) files, rather than 24-bit files.

2010-03-30 update: HD footage of the event
http://vimeo.com/10558068
2010-04-02 update: Gameplay-only footage (both screens)
http://www.youtube.com/user/InstantAwesome

There are too many people to thank to fit in one tweet, so here we go.

Thank you Nick Garner and Stephen Swift for providing color commentary, and extra thanks to Nick for reserving the spot in advance and making sure that the PAX dudes were cool with it. Thank you Joseph Canadas for doing player interviews throughout the match and for bringing in a second copy of Mega Man 2 from home so that we actually had two to use. Thank you Daniel Danger, whom I didn’t even ask for help, but showed up anyway with an HD camcorder and took some amazing footage of the event, and thank you Rob DeVita for also taking video on your camera, not knowing that some dude was wandering around with an HD camcorder. Thank you Casey Malone (whom you might have seen on the Harmonix panel at 10am on Sunday) for both live-tweeting the event and doing pre-game player interviews, which are available here — with me and with John.

A very special thank you to the PAX East Enforcers, particularly the dude with the shaved head and skirt whose name I’m sorry I didn’t get, who not only gave us the go ahead to have the event and bring in our own PA equipment, but also helped us set up the games and surrounding area. You guys embodied the DIY spirit of the gaming community and helped us do something that was both unsanctioned and awesome, and probably bent the rules a little for us.

Thank you, all my friends and coworkers, who showed up to cheer at my victories and gasp at my mistakes.

Thank you John Emhoff for getting wrecked by me at Mega Man 2, and for coming up with the idea to do this in the first place.

And, as always, Thank you for playing!

Over four years ago, I noticed a very striking similarity between The Incredibles and The Fantastic Four.

Looks like collegehumor.com just picked up on it.

Four years too late, guys.

Jacob303: speaking of the guy in regulate
Jacob303: http://www.bombblunts.com/
^Daverd: hahaha
^Daverd: amazing
Jacob303: what i really like is their mission statement, it had to be written by a suit/tie marketting guy
Jacob303: “Not only are the names catchy, they also have your mouth watering in anticipation of firing em up. As an added benefit our unique inner packaging forms a double seal keeping our precious wraps fresh long after the competition is all dry and cracked up.”
^Daverd: wait a minute, the front page says they have 22 flavors
^Daverd: but the flavors page says 20
^Daverd: i’m being robbed of 2 flavors
Jacob303: well, thats the thugg lyfe, son.
^Daverd: true dat.

For anyone who’s been having the same problem with the Ubuntu package pidgin-microblog:

I’ve been using a plugin for Pidgin called pidgin-microblog that allows me to receive twitter updates via a pidgin tab, and post to twitter in that same conversation. It’s pretty sweet. Anyway, recently (possibly since I upgraded to jaunty,) it has been sending me the same messages over and over every 15 seconds or so, to the point where I had to disable the plugin because it was annoying and occasionally crashing pidgin.

The solution was to apt-get purge pidgin-microblog and then reinstall it. The reinstall wasn’t entirely straightforward — I had been using a custom repository in my /etc/apt/sources.list which the upgrade to jaunty automatically commented out for me, which I had to uncomment for the reinstall to work. As an aside, all of my other custom repositories were also commented out from the upgrade (just FYI).

I wrote an RSS feed for our nethack server, which will keep you informed about player deaths and their scores. (Thanks Nick for the brilliant idea). The source is also available.

It does not tell you about deaths by quitting, so feel free to continue spamming new wizards/priests to get that spellbook of identify.

UPDATE: I changed the feed link from http://209.6.168.183:81/nethack_rss.xml to http://sadowl.com/nethack_rss.xml, which is now the preferred location, because the other one is impossible to remember. Both still get updated every hour, so if you’ve already added the former to your feed, you don’t need to change anything. Also, Swifty has already noticed this post and joined our server. RSS for the win!