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Instructions for using the auto-tune program yourself.

Installation instructions

This .zip archive contains the main function, autotune.m, as well as the helper routines pitchShift.m, fusionFrames.m, and createFrames.m. To install the program, first you must extract it from the archive. In Windows, this can be done by right-clicking on the .zip and selecting “extract here.” Similar methods exist for other operating systems. Next, copy all of the files to your MATLAB directory, or any other directory in your MATLAB path. If you copy the files as part of a folder, then the folder must be included in your MATLAB path for MATLAB to find the autotune function.

The pitch shifting code is a slight modification of the “Guitar Pitch Shifter” from this site . Note that while it is open-source, there may be legal issues with redistributing this code. Do so at your own risk. These issues can be avoided by substituting the pitch shifter for your own pitch shifting code, replacing the call to pitchShift() in autotune.m.

Using the program

The autotune function takes in five arguments, X, pMin, pMax, w, and Fs.

X is the input signal, which is a matrix of amplitudes in either mono (one column) or stereo (two columns). This matrix can be extracted from a .wav file with the wavread command in MATLAB.

pMin is the minimum frequency in which we expect to find a peak, and pMax is the maximum, in Hz. We suggest passing in 60 for pMin and 1050 for pMax to cover the human vocal range, but this interval may need to be expanded for other instruments. In general, the narrowest possible interval covering all played notes is preferable, as this grants the greatest chance of correctly detecting the correct note.

w is the width of the window to correct as if it were an individual note. Note that the current version of the code rounds w to the next power of two, for simplicity. Theoretically, higher values of w would result in less distortion, but also poorer time resolution, where the boundaries between notes would be less precise. We found that 256 was a good value for this parameter.

Finally, Fs is the sampling frequency, in Hz, of the input signal X. This value can be obtained as the second return value of the wavread command, and is commonly either 22050 or 44100. Here is an example of the proper MATLAB commands to auto-tune a vocal sample:

[X, Fs] = wavread('path to input file'); % Read input from .wavout = autotune(X, 60, 1050, Fs); % Process signal wavwrite(out, Fs, 'path to output file'); % Write output to .wav

Alternatively, the output can be played from the MATLAB command line with the following command:

soundsc(out, Fs);

Note that the current version of the code compresses stereo input to mono output, and that execution time can be greatly reduced by processing only a portion of the input song. Please enjoy our code, and feel free to modify and improve upon it!

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
in a comparison of the stages of meiosis to the stage of mitosis, which stages are unique to meiosis and which stages have the same event in botg meiosis and mitosis
Leah Reply
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Source:  OpenStax, Auto-tune. OpenStax CNX. Dec 20, 2012 Download for free at http://cnx.org/content/col11474/1.1
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