Class PlaybackWav

PlaybackWav Class

Description

A class used for controlling and playback of .wav file format audio data.

Syntax

class PlaybackWav

Members

Public Constructors
PlaybackWav::PlaybackWav	Constructs a PlaybackWav class object.
Public Methods
PlaybackWav::openFile	Open a .wav audio file for playback.
PlaybackWav::closeFile	Close a previously opened audio file.
PlaybackWav::fileOpened	Check if a .wav file is already opened.
PlaybackWav::getSampleRate	Get the sample rate of the .wav file.
PlaybackWav::getChannelCount	Get the number of audio channels in the .wav file.
PlaybackWav::getBitDepth	Get the bit depth of each sample in the .wav file.
PlaybackWav::getLengthMillis	Get the playback length of the .wav file in milliseconds.
PlaybackWav::getPositionMillis	Get the current playback position in milliseconds.
PlaybackWav::setPositionMillis	Set the current playback position in milliseconds.
PlaybackWav::millisToBytes	Convert a playback duration from milliseconds to bytes.
PlaybackWav::bytesToMillis	Convert a playback duration from bytes to milliseconds.
PlaybackWav::readAudioData	Read audio data from the .wav file.

PlaybackWav::PlaybackWav

Syntax

void PlaybackWav(void);

Example Code

Example: PlaybackWavFile

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::openFile

Syntax

void openFile(const char* absFilepath);

Syntax

absFilepath: The filepath of the .wav file that will be opened.

Example Code

Example: PlaybackWavFile

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::closeFile

Syntax

void closeFile(void);

Example Code

NA

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::fileOpened

Syntax

bool fileOpened(void);

Returns

This function returns true if a .wav file is already open, false otherwise.

Example Code

Example: RecordPlaybackWav

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::getSampleRate

Syntax

uint32_t getSampleRate(void);

Returns

The function returns sampling rate encoded in the .wav file header.

Example Code

Example: PlaybackWavFile

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::getChannelCount

Description

Get the number of audio channels in the .wav file.

Syntax

uint16_t getChannelCount(void);

Returns

The function returns channel count encoded in the .wav file header.

Example Code

Example: PlaybackWavFile

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::getBitDepth

Description

Get the bit depth of each sample in the .wav file.

Syntax

uint16_t getBitDepth(void);

Returns

The function returns bit depth encoded in the .wav file header.

Example Code

Example: PlaybackWavFile

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::getLengthMillis

Description

Get the playback length of the .wav file in milliseconds.

Syntax

uint32_t getLengthMillis(void);

Returns

The function returns the total playback length of the currently open .wav file in milliseconds.

Example Code

Example: PlaybackWavFile

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::getPositionMillis

Description

Get the current playback position in milliseconds.

Syntax

uint32_t getPositionMillis(void);

Returns

The function returns the current playback position of the currently open .wav file in milliseconds.

Example Code

Example: PlaybackWavFile

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::setPositionMillis

Description

Set the current playback position in milliseconds.

Syntax

void setPositionMillis(uint32_t pos);

Parameters

pos: The desired playback position expressed in milliseconds.

Any changes to playback position will only take effect on the next call to PlaybackWav::readAudioData. If the desired playback position is beyond the total playback length of the file, the playback position will be set to the end of file, and no audio data will be output on subsequent data reads. “PlaybackWav.h” must be included to use the class function.

PlaybackWav::millisToBytes

Description

Convert a playback duration from milliseconds to bytes.

Syntax

uint32_t millisToBytes(uint32_t ms);

Parameters

ms: playback duration in milliseconds.

Returns

This function returns the number of bytes that is equivalent to the input playback duration in ms, converted using the current sample rate, number of channels and bit depth.

Example Code

NA

Note

“PlaybackWav.h” must be included to use the class function.

PlaybackWav::bytesToMillis

Description

Convert a playback duration from bytes to milliseconds.

Syntax

uint32_t bytesToMillis(uint32_t bytes);

“PlaybackWav.h” must be included to use the class function.

uint32_t readAudioData(int8_t* dst, uint32_t len);
uint32_t readAudioData(int16_t* dst, uint32_t len);

“PlaybackWav.h” must be included to use the class function.