audio_file

Overview

audio_file is a set of small and lightweight classes for reading and writing WAV (Waveform Audio File Format) files. It offers a straightforward and intuitive interface for working with WAV audio data. This includes:

wav_reader

For reading WAV files.

wav_writer

For writing WAV files.

Include

#include <q_io/audio_file.hpp>

wav_base

wav_base is the base class with common functionalities for wav_reader and wav_writer.

Declaration

class wav_base
{
public:

                  wav_base();
                  wav_base(wav_base const&) = delete;
                  ~wav_base();

   wav_base&      operator=(wav_base const&) = delete;
   explicit       operator bool() const;
   std::size_t    sps() const;
   std::size_t    num_channels() const;
};

Expressions

Notation

w

Object of wav_base.

Constructors and Assignment

Expression Semantics

wav_base()

Default construct a wav_base.

wav_base is non-copyable.

C++ brace initialization may also be used.

Accessors

Expression Semantics Return Type

bool(w)

Evaluates to true if wav_base is valid. Operations must only be performed on valid wav_base objects.

bool

w.sps()

Get the WAV file’s sampling rate.

float

w.num_channels()

Get the number of channels in the WAV file.

std::size_t

wav_reader

wav_reader is a class for reading WAV files with the typical read-only input mechanisms, such as incrementally reading a chunk of audio data from a position starting at the beginning of the file, and being able to move a certain position in the file.

Declaration

class wav_reader : public wav_base
{
public:
                  wav_reader(std::string filepath);
                  wav_reader(char const* filepath);

   std::uint64_t  length() const;
   std::uint64_t  position();
   bool           restart();
   bool           seek(std::uint64_t target);

   std::size_t    read(float* data, std::uint32_t len);
   std::size_t    read(concepts::IndexableContainer auto& buffer);
};

The IndexableContainer concept is declared in Basic Concepts.

Expressions

wav_reader is derived from wav_base. In addition to valid expressions for wav_base, wav_reader allows these expressions.

Notation

r

Object of type wav_reader.

f

Object of type convertible to std::string or char const* representing a file path.

d

Pointer to a buffer of float elements with size len.

s

Size buffer of d.

b

Object of type that conforms to the IndexableContainer concept.

p

Position in the wav file (std::uint64_t).

Constructors and Assignment

Expression Semantics

wav_reader(f)

Construct a wav_reader given a file path.
C++ brace initialization may also be used.

Mutators

Expression Semantics Return Type

r.restart()

Reset the read position to the start. Returns false if r is not valid.

bool

r.seek(p)

Set the read position to the p. Returns false if r is not valid.

bool

r.read(d, s)

Read a chunk of data given a raw buffer, float*, d, with size s. Returns the actual size read.

std::size_t.

r.read(b)

Read a chunk of data given a buffer, b. Returns the actual size read.

std::size_t.

Accessors

Expression Semantics Return Type

r.length()

Get the length of the WAV file.

std::uint64_t.

r.position()

Get the current read position.

std::uint64_t.

wav_writer

wav_writer is a class for writing WAV files with the typical write-only output mechanisms, such as incrementally writing a chunk of audio data from a position starting at the beginning of the file. wav_writer writes WAV files with one or more channels and 32-bit floating point samples.

Declaration

class wav_writer : public wav_base
{
public:
                  wav_writer(
                     std::string filename
                   , std::uint32_t num_channels, float sps);

                  wav_writer(
                     char const* filename
                     , std::uint32_t num_channels, float sps);

   std::size_t    write(float const* data, std::uint32_t len);
   std::size_t    write(concepts::IndexableContainer auto const& buffer);
};

The IndexableContainer concept is declared in Basic Concepts.

Expressions

wav_writer is derived from wav_base. In addition to valid expressions for wav_base, wav_writer allows these expressions.

Notation

w

Object of type wav_writer.

f

Object of type convertible to std::string or char const* representing a file path.

d

Pointer to a buffer of float elements with size len.

s

Size buffer of d.

b

Object of type that conforms to the IndexableContainer concept.

ch

Integer value representing number of channels.

sps

Floating point value representing samples per second.

Constructors and Assignment

Expression Semantics

wav_writer(f, ch, sps)

Construct a wav_writer given a file path, f, number of channels, ch, and sampling rate, sps.

Mutators

Expression Semantics Return Type

w.write(d, s)

Write a chunk of data given a raw buffer, float*, d, with size s. Returns the actual size written.

std::size_t.

w.write(b)

Write a chunk of data given a buffer, b. Returns the actual size written.

std::size_t.