libcwav

A library for playing (b)cwav files on the 3DS.

Description

The goal of this library is to provide an interface for playing (b)cwav files in 3ds homebrew sofware. The way it is designed allows to play these files in non-application environments, such as 3GX game plugins or applets, as it provides support for the CSND system service. Unlike (b)cstm files which are streamed in chunks from their storage media, (b)cwav files are fully loaded into the linear RAM. Therefore, (b)cwav files are only meant for small sound effects. This library provides support for the ADPCM encodings, which heavily reduce the required memory to play the file.

Supported Features

Supported CWAV Audio Encodings

The following audio encodings are supported.

PCM8/PCM16

Uncompressed 8/16 bit PCM. Useful if memory usage is not a problem.

DSP ADPCM

Lossy compression format, useful if the available memory is limited. Can only be played with DSP.

IMA ADPCM

Lossy compression format, similar to DSP ADPCM. Can only be played with CSND.

Supported System Services

The following system services used to play the audio are supported.

DSP

This system service is used by normal applications. It is recommended to use this system service, as it properly supports suspending applications and sleep mode.

CSND

This system service is used by applets to play audio. It has the advantage of playing audio on top of running/suspended applications, whitout causing any interferences. Use this system service if you want to play audio in applets or 3GX game plugins. Make sure to use cwavDoAptHook() or cwavNotifyAptEvent() to handle apt events (app suspend, sleep or exit)!

Installation and Usage

Make sure you have devkitpro installed and working.
Clone or download the repo and open a command prompt.
Run make install and confirm there aren't any errors.
In your project makefile, add the following to the LIBDIRS line (or similar): $(DEVKITPRO)/libcwav
In your project makefile, add the following to the LIBS line (or similar): -lcwav if the already listed libraries start with -l or just cwav if they don't.
Add #include "cwav.h" and/or #include "cwav_file.h" in your source files to use the library. You can check all the available function calls in the documentation provided in cwav.h and cwav_file.h. Also, you can see an example application in example_libcwav.

Creating (b)cwav files

You can use cwavtool to create (b)cwav files from other audio formats. It supports all possible encodings and loop points.

Credits

libctru: CSND and DSP implementation.
3dbrew.org: (b)cwav file specification.

License

This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions:

The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
This notice may not be removed or altered from any source distribution.