ADSR Audio Envelope: How to get it?

How can I get the ADSR sample points of a audio file...Like:

"Fake" example:

[Amp, SR] = audioread(audio.file);

[a d s r] = get_ADSR(Amp);

% Results: The sample position of the Amp vector:
a = 85 % End of Attack -> Attack start = Amp(0)
d = 300 % End of Decay
s = 2456 % End of Sustain
r = 50000 % End of Release

Answer 1

[Matthew Novick]

Could you please clarify your question? Is 'audio.file' a generic waveform, and you want a function that will automatically characterize the parameters of an ADSR envelope, similar to that in the Wikipedia link below? https://en.wikipedia.org/wiki/Synthesizer#Attack_Decay_Sustain_Release_.28ADSR.29_envelope

[Nycholas Maia]

Yes! I would like to get the ADSR parameters from a generic waveform. The Wikipedia article is correct.

Example: https://en.wikipedia.org/wiki/Synthesizer#/media/File:ADSR_parameter.svg

Is it possible?