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Homework #1: Cookin' with Low-level Audio

Due date: 2017.10.3 11:59:59pm, Tuesday.

Let's get cookin'.

Specification (part 1 of 4): Real-time Audio

create a program that is capable of real-time audio input/output
give it name (e.g., sig-gen; creative names are always welcome)
- start with this basic boilerplate: [1]
next, add real-time audio support, using the RtAudio Library (version 4.0.10 or later, included in the boilerplate)
- even though it's useful to briefly look through the package, the only files you'll need are:
  - RtAudio.h (the header file for RtAudio, it contains the class definitions)
  - RtAudio.cpp (the implementation)
  - RtError.h (header containing various error handling constructs for RtAudio)
- it may be useful to browse the RtAudio documentation and the example programs in the RtAudio distribution
implement the callback function to generate the expect number of samples per call for a sine wave at 440Hz
the overall behavior when you run the program should be a continuous sine tone at 440hz...
to quit: press enter

Specification (part 2 of 4): Waveforms

modify your program to take command line arguments and generate different signals, depending on the command line flag you specify:

    sig-gen [type] [frequency] [width]
        [type]: --sine |  --noise | --impulse | --pulse
        [frequency]: (a number > 0, not applicable to noise)
        [width]: pulse width (only applicable to pulse)

where the flags correspond to the following signals:
- --sine : sine wave
- --noise : white noise
- --impulse : impluse train, the frequency should determine the impulse train's fundamental period
- --pulse : rectangular pulse wave, the width ([0.0-1.0]) controls the pulse width (e.g., width=.5 should result in a square wave)

it might be a good idea to output the usage (as show above), if insufficient or incorrect parameters are given
you'll need to implement a simple command line parser, with basic error checking (e.g., what to do when invalid/irrelevant parameters are provided?)
you'll also need to organize your code a bit, to selectively generate the request signal

See Signal generator hints if needed.

Specification (part 3 of 4): One Ring to Modulate Them All

Next, add another command line flag:
- --input : mic/line input (make sure input is enabled in the RtAudio initialization)
if specified, this flag tells the program to take the mic/line input and and multiply it against the signal being generated, and output the result;
test it by talking into it and listening to the result...

Specification (part 4 of 4): add ChucK!

Lastly, add ChucK as a module to your program
download charles boilerplate project that includes ChucK as library and API
in host/charles.cpp, add in your existing code from earlier parts
study chuck.h in core/ -- it contains the chuck API you'll use to add ChucK as a module
make the following modifications to charles.cpp (after you've brought in your code, and verified it still compiles/works):
- instantiate a ChucK object
- set parameters
- initialize the ChucK object (init())
- compile a chuck program (created as a string, according to the specification from the command line)
- start ChucK
- very importantly, drive chuck from your callback function
add the --chuck flag to your program. when it is passed in, you should generate and use a chuck program for the sig-gen functionality, rather than instead of what you wrote in earlier parts
- sine
- pulse wave
- white noise
- impulse train
- ring modulating

Note

have fun with it!!!
comment your code!
choose your own coding conventions - but be consistent
you are welcome to work together, but you must do/turn in your own work (you'll likely get more out of it this way)
some considerations:
- how to organize the code for the various types of signals?
- how much error-checking and error-reporting on the command line arguments?

Hints for ChucK Code

ChucK code for reference

You may want to use a stringstream or other string formatting techniques to construct ChucK programs on-the-fly

Deliverables

turn in all files + readme through coursework

1) Create a zip/tar file and put all the files in there. The required files are:
- source code to the project (*.h, *.cpp, makefile, etc.)
- a short README text section that:
  - instructions on building the project (for example, anyone in the class should be able to download
  - conveys your ideas/comments in constructing each program
  - describes any difficulties you encountered in the process
  - lists any collaborators
2) upload zip/tar file to Canvas!