WaveManipp is intended to be a C++ library for efficient uncompressed audio data manipulation. At this point, it supports WAV files only up to two channels. It does not support audio recording or playback on its own, and there are no plans to implement that. However, in the future, some functionalities should be incorporated into it to facilitate the cooperation with third-party playback/recording libraries.
In order to use the library classes and methods in our code, we have to include the necessary headers. This can be done by including the WaveManipp.h header file somewhere at the top of the header/source file.
#include <WaveManipp.h>The easiest way to load an uncompressed audio file into memory is to do it from within the constructor by providing the path to the file (filename). All of the WaveManipp classes reside in the wm namespace.
wm::Wave wave("D:/AudioSamples/test.wav");Alternatively, one can load a file by calling the empty constructor first and then using open().
wm::Wave wave;
wave.open("D:/AudioSamples/test.wav");The overloaded std::ostream operator lets us display the basic information about the opened file fairly easily.
std::cout << wave << std::endl;The line above should ouput something along the lines of:
ChunkID: RIFF
ChunkSize: 351966
Format: WAVE
----------
Subchunk1ID: fmt
Subchunk1Size: 16
AudioFormat: 1
NumChannels: 2
SampleRate: 44100
ByteRate: 176400
BlockAlign: 4
BitsPerSample: 16
----------
Subchunk2ID: data
Subchunk2Size: 351812
For example, we can now generate a sine wave and append it to the existing Wave object.
auto sineWave = wm::Wave::generateSine(220.f, 0.f, 44100, 44100);
wave.append(sineWave);We should be able to see the updated header data.
std::cout << wave << std::endl;ChunkID: RIFF
ChunkSize: 528248
Format: WAVE
----------
Subchunk1ID: fmt
Subchunk1Size: 16
AudioFormat: 1
NumChannels: 2
SampleRate: 44100
ByteRate: 176400
BlockAlign: 4
BitsPerSample: 16
----------
Subchunk2ID: data
Subchunk2Size: 528212
We can easily save the result by calling the save() method with a filename.
wave.save("result.wav");More detailed information can be found below.
The Wave class represents an audio file stored in memory. All audio data within a Wave object is stored using single-precision floating-point values. While in many cases this means using more memory than necessary, it is much more convenient for effective audio data manipulation. Otherwise, every time we called a method to perform some operation on the data, each sample would have to be converted to a floating-point value first and then converted back to whatever its original format was.
So far, WaveManipp supports uncompressed RIFF/RIFX mono and stereo WAV files. The supported audio sample bit depths are 8, 16, 24, and 32. Support for more channels may be added in the future.
Even though internally WaveManipp uses the C functions std::malloc, std::calloc, and std::realloc for memory allocation and reallocation, it may still be suboptimal when merging a large number of Wave objects. The better solution is to use the WaveBuilder class, which stores pointers to the actual Wave objects. Nonetheless, when using this class, it is crucial that the consituent objects be not destroyed before creating the final Wave object using the toWave() method. When used properly, the Wave object is created only once, so there is no need for repeated memory reallocation.