daisy::WavWriter¶

#include <WavWriter.h>

Public Classes¶

	Name
struct	Config

Public Types¶

	Name
enum class	Result
enum class	BufferState

Public Functions¶

	Name
	WavWriter()
	~WavWriter()
void	Init(const Config & cfg)
void	Sample(const float * in)
void	Write()
void	SaveFile()
void	OpenFile(const char * name)
bool	IsRecording() const
uint32_t	GetLengthSamps()
float	GetLengthSeconds()

Detailed Description¶

template <size_t transfer_size>
class daisy::WavWriter;

Audio Recording Module

Record audio into a working buffer that is gradually written to a WAV file on an SD Card.

Recordings are made with floating point input, and will be converted to the specified bits per sample internally

For now only 16-bit and 32-bit (signed int) formats are supported f32 and s24 formats will be added next

The transfer size determines the amount of internal memory used, and can have an effect on the performance of the streaming behavior of the WavWriter. Memory use can be calculated as: (2 * transfer_size) bytes Performance optimal with sizes: 16384, 32768

To use:

Create a WavWriter object (e.g. WavWriter<32768> writer)
Configure the settings as desired by creating a WavWriter<32768>::Config struct and setting the settings.
Initialize the object with the configuration struct.
Open a new file for writing with: writer.OpenFile("FileName.wav")
Write to it within your audio callback using: writer.Sample(value)
Fill the Wav File on the SD Card with data from your main loop by running: writer.Write()
When finished with the recording finalize, and close the file with: writer.SaveFile();

Public Types Documentation¶

enum Result¶

Enumerator	Value	Description
OK
ERROR

Return values for write related functions

enum BufferState¶

Enumerator	Value	Description
IDLE
FLUSH0
FLUSH1

State of the internal Writing mechanism. When the buffer is a certain amount full one section will write its contents while the other is still being written to. This is performed circularly so that audio will be uninterrupted during writing.

Public Functions Documentation¶

function WavWriter¶

inline WavWriter()

function ~WavWriter¶

inline ~WavWriter()

function Init¶

inline void Init(
    const Config & cfg
)

Initializes the WavFile header, and prepares the object for recording.

"RIFF"

"WAVE"

"fmt "

"data"

Also calcs SubChunk2Size

function Sample¶

inline void Sample(
    const float * in
)

Parameters:

in should be a pointer to an array of samples

Records the current sample into the working buffer, queues writes to media when necessary.

function Write¶

inline void Write()

Check buffer state and write

function SaveFile¶

inline void SaveFile()

Finalizes the writing of the WAV file. This overwrites the WAV Header with the correct final size, and closes the fptr.

function OpenFile¶

inline void OpenFile(
    const char * name
)

Opens a file for writing. Writes the initial WAV Header, and gets ready for stream-based recording.

function IsRecording¶

inline bool IsRecording() const

Returns whether recording is currently active or not.

function GetLengthSamps¶

inline uint32_t GetLengthSamps()

Returns the current length in samples of the recording.

function GetLengthSeconds¶

inline float GetLengthSeconds()

Returns the current length of the recording in seconds.

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Updated on 2024-01-03 at 19:41:01 +0000