pulp::audio::BufferingReader Class Reference

Background-thread audio file reader for gapless streaming playback. More...

#include <buffering_reader.hpp>

Public Types
using	ReadCallback = std::function<int(float* dest, int num_frames, int num_channels)>
	Callback that reads audio data from a source (file, network, etc.).

Public Member Functions
	BufferingReader ()=default
	~BufferingReader ()
	BufferingReader (const BufferingReader &)=delete
BufferingReader &	operator= (const BufferingReader &)=delete
void	set_read_callback (ReadCallback cb)
	Set the callback that provides audio data.
void	start (int num_channels, int buffer_frames=44100)
	Start the background reader thread.
void	stop ()
	Stop the background thread and release resources.
int	read (float *dest, int num_frames, int num_channels)
	Read frames from the buffer (audio thread, lock-free on the hot path).
bool	is_finished () const
	Check if the source has been fully read.
bool	is_running () const
	Check if the reader is running.
int	frames_available () const
	Number of frames currently available in the buffer.

Detailed Description

Background-thread audio file reader for gapless streaming playback.

Maintains a ring buffer that is filled from a background thread while the audio thread reads from it. The audio thread never blocks on I/O.

BufferingReader reader;
reader.set_read_callback([&](float* dest, int frames, int channels) {
    return audio_file.read(dest, frames, channels);
});
reader.start(2, 44100); // 2 channels, 1 second buffer
 
// In audio callback:
int got = reader.read(output_buffer, num_frames, num_channels);

Member Typedef Documentation

ReadCallback

using pulp::audio::BufferingReader::ReadCallback = std::function<int(float* dest, int num_frames, int num_channels)>

Callback that reads audio data from a source (file, network, etc.).

Parameters

dest	Destination interleaved buffer.
num_frames	Number of frames to read.
num_channels	Number of channels.

Returns

Number of frames actually read (0 = end of source).

Constructor & Destructor Documentation

BufferingReader() [1/2]

pulp::audio::BufferingReader::BufferingReader ( )

default

~BufferingReader()

pulp::audio::BufferingReader::~BufferingReader ( )

inline

BufferingReader() [2/2]

pulp::audio::BufferingReader::BufferingReader ( const BufferingReader & )

delete

Member Function Documentation

frames_available()

int pulp::audio::BufferingReader::frames_available ( ) const

inline

Number of frames currently available in the buffer.

is_finished()

bool pulp::audio::BufferingReader::is_finished ( ) const

inline

Check if the source has been fully read.

is_running()

bool pulp::audio::BufferingReader::is_running ( ) const

inline

Check if the reader is running.

operator=()

BufferingReader & pulp::audio::BufferingReader::operator= ( const BufferingReader & )

delete

read()

int pulp::audio::BufferingReader::read ( float * dest, int num_frames, int num_channels )

inline

Read frames from the buffer (audio thread, lock-free on the hot path).

Parameters

dest	Destination interleaved buffer.
num_frames	Number of frames requested.
num_channels	Number of channels (must match start()).

Returns

Number of frames actually copied (may be less if buffer underrun).

set_read_callback()

void pulp::audio::BufferingReader::set_read_callback ( ReadCallback cb )

inline

Set the callback that provides audio data.

start()

void pulp::audio::BufferingReader::start ( int num_channels, int buffer_frames = 44100 )

inline

Start the background reader thread.

Parameters

num_channels	Number of audio channels.
buffer_frames	Size of the ring buffer in frames (default: 1 second at 44.1kHz).

stop()

void pulp::audio::BufferingReader::stop ( )

inline

Stop the background thread and release resources.

---

The documentation for this class was generated from the following file:

• /home/runner/work/pulp/pulp/core/audio/include/pulp/audio/buffering_reader.hpp