

An audio format for creative DJing - ahq
http://www.stems-music.com/

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xiphmont
Why define a new AAC subvariant and not use an existing (and actually
unencumbered) multitrack stem format like mogg that's been around for for a
decade now?

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33degrees
So that the files are playable in any audio player that supports MP4.

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xiphmont
Actually you mean exactly one player: iPod/iPhone. To play nicely with apple,
you have to fork over the $2.50/copy. Ah well.

(Almost everything else currently using stems is mogg-based given the per-unit
royalties for MP4 software support)

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Synaesthesia
AAC is played by many devices, it's not an Apple standard, and the licensing
fees are less than MP3.

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xiphmont
Apple is one of the few vendors that supports AAC in exclusion of other
formats (and, eg, ALAC in exclusion of FLAC, etc). And no, actually, AAC's
declared licensing is considerably more expensive than mp3 (partly because AAC
is a bundle of quite a few different codecs that share the same name).

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im3w1l
According to that description, the format contains 4 separate tracks that
together make up the song. How did you settle on 4 tracks?

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vwelling
Most tracks can be split up into four distinct components: drums, bass,
melody, and vocals. Of course, they could have taken it a step further, by
splitting a track up into its individual instruments, but I doubt that would
be very usable in a live performance setting (although some performers
actually do go this route, usually relying on software such as Ableton Live
for this purpose).

The four channels are also quite similar to the EQ section of a DJ mixer which
generally controls three frequency ranges (low, mid and high). EQ-ing is
heavily used to mix songs together, so by sticking to a similar interface,
DJ's can easily pick up this format.

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soylentcola
I'm more of a "for fun" DJ (occasional parties, events, but mostly just my
basement) but I'm tempted to try mapping the 4 stem tracks to the 4 knobs on
my basic controller (gain, high, mid, low) in Traktor since it apparently
supports the format. Probably not something I'd want to have permanently
enabled but an easy way to play around with it. I guess if I wanted to map a
key to toggle between EQ and stem track levels it might work.

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andybak
1\. Why oh why is 'there are 4 tracks' hard-coded into the format? What a
perverse limitation. I understand there has to be a limit if you want hardware
players to mix in real-time but 4 seems too low and Stem v2 will probably be
needed next year to get round this.

2\. This seems like a wasted opportunity in terms of adding extra features
that wouldn't complicate implementation terribly much. Tracks could allow time
offsets and repeats - you've then got a loop-friendly pseudo-tracker file
format at very little extra cost.

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golergka
1\. When you DJ, your main resource is attention — and while I have experience
with Ableton live sets, trying to juggle more than 4 channels of a track that
you sometimes heard once or twice before is not a very good idea, tbh. Also,
Stems format was created by NI after they already succesfully creates Remix
Packs format, and in my experience, 4 channels that Remix Packs have is quite
a good balance — not to say that all NI Traktor gear is created for 4 channels
in mind.

2\. Once again, extra features not only complicate implementation, but also
user experience. What exactly would you be able to do with time offsets and
repeats that you can't do with Traktor's deck looping and loop recorder
already?

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RubyPinch
> trying to juggle more than 4 channels of a track

sounds more like a tooling problem, stems should be able to be grouped by type
with little effort (e.g., all the drumish things visually represented as one
fake stem)

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golergka
First of all — no, it's an attention problem. I've used APC40 in a live
performance once, but in live perfomance (where you play your own music in
more or less pre-determined fashion), unlike the DJ set (where you play other
people's music, changing the playlist dynamically according to the crowd),
it's easier to manage. Apart from monitoring the crowd, searching the next
track, marking it and pre-listening (because unless it's in the hundred or two
hundreds of tracks you know by heart, you may not know what's the best point
cue it it and how), playing with FX, letting the photographer park his
backpack under your table, answering to some random question by the manager,
you also should have some amount of your attention on reserve, so that when
some unforeseeable shit happens, you won't butcher up the mix and people stay
entertained.

Regardless, if you already want to group the "drummish" stems, then why would
you want to deal with the separately in the first place?

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dharma1
I get it that NI is mostly pushing this for the "creative DJ" market but I
wish it was 8+ tracks and they got majors onboard to release stems of older
music.

There are a bunch of leaked multitracks on the internet, everything from
Metallica to Stevie Wonder and Michael Jackson - and they're really
interesting to listen to and play with.

The original multitrack tapes are fast becoming degraded and lost so would be
fantastic if there was commercial motive to archive/digitise them.

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vwelling
NI's products such as the S8, D2, F1 and X1 are mostly targeted at DJs playing
electronic music, particularly house and techno. Genres where there's a lot of
room for live experimentation with many different layers, due to the easily
quantisable nature of the music. I doubt they had Stevie Wonder and Metallica
in mind while developing this ;)

For production purposes you'd probably want a lossless file format anyway.

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sublimnall
This looks awesome. Ever since I've been DJing, this separation of components
is what I have been wanting to play with.

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blt
The 4-track limitation is stupid. Splitting a track into drums, bass, vocals,
and melody instruments is definitely useful for a lot of purposes, but it's
limiting for real in-depth remixing. Why not make it unlimited?

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gamegod
The 4-track limit means you can build a hardware DJ controller that supports
stems. It also means your software doesn't have to have a crazy unlimited-
track interface. 4 tracks is the sweetspot where you can actually build usable
products around this for live performance.

Clarification: When I say build hardware, I mean design a usable hardware
interface for mixing 4 stems. I don't have to guess what audio is on what
track. Imagine what a nightmare it would be if every stem had a different
number of tracks and you were trying to DJ live with them.

