PlaybackWav Class
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
Description
Constructs a PlaybackWav class object.
Syntax
void PlaybackWav(void);
Parameters
NA
Returns
NA
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“PlaybackWav.h” must be included to use the class function.
PlaybackWav::openFile
Description
Open a .wav file for playback.
Syntax
void openFile(const char* absFilepath);
Parameters
absFilepath: The filepath of the .wav file that will be opened.
Returns
NA
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“PlaybackWav.h” must be included to use the class function.
PlaybackWav::closeFile
Description
Close a previously opened audio file.
Syntax
void closeFile(void);
Parameters
NA
Returns
NA
Example Code
NA
Notes and Warnings
“PlaybackWav.h” must be included to use the class function.
PlaybackWav::fileOpened
Description
Check if a .wav file is already opened.
Syntax
bool fileOpened(void);
Parameters
NA
Returns
This function returns true if a .wav file is already open, false otherwise.
Example Code
Example: RecordPlaybackWav
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“PlaybackWav.h” must be included to use the class function.
PlaybackWav::getSampleRate
Description
Get the sample rate of the .wav file.
Syntax
uint32_t getSampleRate(void);
Parameters
NA
Returns
This function returns sampling rate encoded in the .wav file header.
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“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);
Parameters
NA
Returns
This function returns channel count encoded in the .wav file header.
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“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);
Parameters
NA
Returns
This function returns bit depth encoded in the .wav file header.
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“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);
Parameters
NA
Returns
This function returns the total playback length of the currently open .wav file in milliseconds.
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“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);
Parameters
NA
Returns
This function returns the current playback position of the currently open .wav file in milliseconds.
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“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.
Returns
NA
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
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
Notes and Warnings
“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);
Parameters
bytes: playback duration in number of bytes.
Returns
This function returns the time duration in milliseconds that is equivalent to the input number of bytes, converted using the current sample rate, number of channels and bit depth.
Example Code
NA
Notes and Warnings
“PlaybackWav.h” must be included to use the class function.
PlaybackWav::readAudioData
Description
Read audio data from the .wav file.
Syntax
uint32_t readAudioData(int8_t* dst, uint32_t len);
uint32_t readAudioData(int16_t* dst, uint32_t len);
Parameters
dst: Pointer to an array that stores audio data from .wav file to be read .
len: number of audio samples to be read from .wav file.
Returns
This function returns number of audio samples to be read.
Example Code
Example: PlaybackWavFile
(https://github.com/ambiot/ambd_arduino/blob/dev/Arduino_package/hardware/libraries/AudioCodec/examples/PlaybackWavFile/PlaybackWavFile.ino)
Notes and Warnings
“PlaybackWav.h” must be included to use the class function.
