When Ableton started the public beta test for Live 6, we learned about a new audio file format called "Ableton Meta Sound" or ".ams". This article used to start with a link to the Live 6 beta section on the Ableton forum, but since that has vanished, these 3 articles are the most detailed info you will find on this subject anywhere.
I have no doubt that many interested people have a lot of questions. And you can rest assured that we will uncover all the answers. I will also try to get somebody from Ableton to check if my findings are correct.
I originally planned this article out to be much longer, but that would make it too boring to learn about this feature.
This whole process of uncovering the meta files will be broken down into several parts. That way it will be easier to gradually start understanding this format, just like we did.
The Covert Operators have literally made thousands of these files and implemented them in a lot of different ways.
In the next parts, I will talk about the many tricks that we are still learning as we speak.
We will see: How to generate AMS files, How to draw AMS files, How you use these files, Tricks to make lush pads and strings free of aliasing, Tricks to make basslines that thrive on aliasing and many many more things. And I recently discovered that we can generate AMS files with micro-tonal tuning, so we will have a look at that too.
As you can see, there is still a lot of ground to cover.
Lets just begin with looking at what AMS files really are.
The AMS Format
The AMS files are text documents with the .ams extension instead of .txt. They load up in Live 6 as if they were samples and only take up 4 kilobytes of space.
These samples can be used as looping static waveforms in devices such as Simpler and Sampler.
Meta files can also be used as single shots triggered from the Impulse or an audio track.
The audio data in AMS files consists of lines of simple code. We will look at the code later.
Waveforms are generated by means of additive synthesis, which is a technique in audio synthesis to create musical timbres.
The general idea behind AMS files, is that we are able to construct waveforms by adding up sines and cosines.
Imagine a synth with 96 sine oscillators and 96 cosine oscillators. Each oscillator is tuned to a different harmonic. You have control over the amplitude of each oscillator.
By combining even and / or odd harmonics from these sines and cosines, we are able to build different waveforms such as squares or saws.
The result of this imagined synthesizer can be captured inside a AMS file.
A single file represents a single note as outputted by the synthesizer. These outputted files can be used in Simpler and Sampler and the loop points of the waveforms are automatically set.
If you load up 128 AMS files in Sampler that contain data for the 128 notes you can play from the keyboard, the Sampler becomes an emulated oscillator.
A meta file also contains a line of code that will allow you to specify a root key. For example: If the root key is set to 60, then this AMS file will load up in sampler on the note C3 by default.
If this already confused you, don't worry. In the following weeks we will break this down into something that everybody can understand and enjoy. In the next part, we will have a look at the code and some neat tricks you can do with the code. Like micro-tonal tuning.
I hope you found this part useful. Feel free to comment or ask questions.
Meta Files: Uncovering the .ams format, Part 1
