BufferUtility

<utilities/bufferutility.h>

Utility to provide several time related calculations where musical concepts are translated into buffer units and vice versa.

Public static methods

Size calculation

int bufferToMilliseconds( int bufferSize, int sampleRate )

Returns the time in milliseconds a buffer of given bufferSize lasts for given sampleRate.

int millisecondsToBuffer( int milliSeconds, int sampleRate )

The reverse of bufferToMilliseconds. Calculates the required buffer size to represent given milliSeconds at given sampleRate.

float bufferToSeconds( int bufferSize, int sampleRate )

Returns the time in seconds a buffer of given bufferSize lasts for given sampleRate.

int secondsToBuffer( float seconds, int sampleRate )

The reverse of bufferToSeconds. Calculates the required buffer size to represent given seconds at given sampleRate.

int getBitRate( int sampleRate, int bitDepth, int channels )

Returns the bit rate for an audio stream at given sampleRate, bitDepth and channel amount.

int calculateBufferLength( SAMPLE_RATE minRate )

Calculates the amount of samples a single cycle of a waveform will require at given minRate (in Hertz), for the current engine sample rate.

int calculateBufferLength( int milliSeconds );

Calculates the amount of samples necessary to represent given time in milliSeconds, for the current engine sample rate.

int calculateSamplesPerBeatDivision( int sampleRate, double tempo, int subdivision )

Calculates the amount of samples necessary to render audio at the duration of requested subdivision at the current sampleRate and tempo, where subdivision is a number by which to divide a measure (e.g. 1 = full meausure, 2 = half measure, 4 = quaver, 8 = eight note, etc.)

int getSamplesPerBeat( int sampleRate, double tempo )

Calculates the amount of samples necessary to render audio lasting a single beat for the given tempo at the given sampleRate.

getSamplesPerBar( int sampleRate, double tempo, int beatAmount, int beatUnit )

Calculates the amount of samples necessary to render audio lasting a single measure for the given tempo at the given sampleRate.

Beat calculation

double getBPMbyLength( double length, int amountOfBars )

When given length represents a length in milliseconds and amountOfBars represents the known amount of measures the snippet represents, the resulting value is the tempo in BPM.

double getBPMbySamples( int length, int amountOfBars, int sampleRate )

The same as getBPMbyLength() except that given length represents the size of a buffer in samples and sampleRate the known sampe rate of the snippet.

Buffer generation

std::vector<SAMPLE_TYPE*>* createSampleBuffers( int amountOfChannels, int bufferSize )

Returns a vector of given amountOfChannels in size, containing silent audio buffers at given bufferSize in length.

SAMPLE_TYPE* generateSilentBuffer( int bufferSize )

Creates a silent audio (0.0f) buffer at given bufferSize in length.

void bufferToFile( const char* fileName, SAMPLE_TYPE* buffer, int bufferLength )

Writes the contents of given buffer onto storage under given fileName. The result is a comma separated list of SAMPLE_TYPE values.