Aulib Namespace Reference

Classes
class	Decoder
	Abstract base class for audio decoders. More...
class	DecoderAdlmidi
	libADLMIDI decoder. More...
class	DecoderBassmidi
	BASSMIDI decoder. More...
class	DecoderDrflac
	dr_flac decoder. More...
class	DecoderDrmp3
	dr_mp3 decoder. More...
class	DecoderDrwav
	dr_wav decoder. More...
class	DecoderFlac
	libFLAC decoder. More...
class	DecoderFluidsynth
	FluidSynth decoder. More...
class	DecoderModplug
	ModPlug decoder. More...
class	DecoderMpg123
	mpg123 decoder. More...
class	DecoderMusepack
	libmpcdec decoder. More...
class	DecoderOpenmpt
	OpenMPT decoder. More...
class	DecoderOpus
	libopusfile decoder. More...
class	DecoderSndfile
	Libsndfile decoder. More...
class	DecoderVorbis
	libvorbisfile decoder. More...
class	DecoderWildmidi
	WildMIDI decoder. More...
class	DecoderXmp
	XMP decoder. More...
class	Processor
	Abstract base class for audio processors. More...
class	Resampler
	Abstract base class for audio resamplers. More...
class	ResamplerSdl
	SDL_AudioStream resampler. More...
class	ResamplerSox
	Sox resampler. More...
class	ResamplerSpeex
	Speex resampler. More...
class	ResamplerSrc
	SRC (libsamplerate) resampler. More...
class	Stream
	A Stream handles playback for audio produced by a Decoder. More...

Typedefs
using	AudioFormat = Uint16

Functions
auto	init (int freq, AudioFormat format, int channels, int frameSize, const std::string &device={}) -> bool
	Initializes the audio system. More...
auto	initWithoutOutput (int freq, int channels) -> bool
	Initializes the library for decoding and resampling only. More...
void	quit ()
	Shuts down the SDL_audiolib library. More...
auto	sampleFormat () noexcept -> AudioFormat
	Sample format the audio device is actually using. More...
auto	sampleRate () noexcept -> int
	Sample rate the audio device is actually using. More...
auto	channelCount () noexcept -> int
	Number of output channels. More...
auto	frameSize () noexcept -> int
	Number of frames (samples per channel) the audio device is actually using. More...

Typedef Documentation

AudioFormat

using Aulib::AudioFormat = typedef Uint16

Function Documentation

channelCount()

auto Aulib::channelCount ( ) -> int

noexcept

Number of output channels.

This always matches the amount of channels that was requested.

frameSize()

auto Aulib::frameSize ( ) -> int

noexcept

Number of frames (samples per channel) the audio device is actually using.

This can be different than the frame size that was requested.

init()

auto Aulib::init	(	int	freq,
		AudioFormat	format,
		int	channels,
		int	frameSize,
		const std::string &	device = {}
	)		-> bool

Initializes the audio system.

Parameters

freq	Sample rate that the audio device should be opened in. The sample rate that gets actually used might change though if the device does not support the requested rate. Use sampleRate() to find out the actual sample rate.
format	Audio sample format. The most common format is AUDIO_S16SYS. The formats are defined by SDL (SDL_audio.h). The actual format we end up using might be different than the one we request if the audio device does not support it. Use sampleFormat() to find out the actual sample format.
channels	Amount of output channels to use. Can either be 1 (mono) or 2 (stereo.) Lower or higher values will be adjusted. Unlike the other parameters, the channel count is enforced and will not change.
frameSize	Size in frames (samples per channel) of the internal buffer that is used to feed audio samples to SDL. Lower values provide lower latency on audio operations, at the cost of increased CPU usage and risk of audio drop-outs. A good value for 44.1kHz output for music players is 8192 bytes (8kB), while a game that needs to play sound effects without much latency would use something like 2048 instead. The actual frame size we end up using might be different. This depends on the audio device and output driver used by SDL. Use frameSize() to find out the actual frame size.
device	A UTF-8 string reported by SDL_GetAudioDeviceName() or a driver-specific name as appropriate. An empty string requests the most reasonable default device.

Returns

Return values

true	The audio system was initialized successfully.
false	The audio system could not be initialized.

initWithoutOutput()

auto Aulib::initWithoutOutput	(	int	freq,
		int	channels
	)		-> bool

Initializes the library for decoding and resampling only.

Use this instead of the normal init function if you only want to decode and/or resample without actually playing any audio, or if you want to handle audio playback yourself.

SDL_InitSubSystem() will not be called and thus the SDL audio subsystem is left uninitialized.

You cannot use Aulib::Stream objects. Trying to do so will result in undefined behavior.

Parameters

freq	Target sample rate for decoders that generate audio themselves (like the MIDI and MOD decoders.)
channels	Target channel count for decoders that generate audio themselves (like the MIDI and MOD decoders.)

Returns

Return values

true	The library was initialized successfully.
false	The library could not be initialized.

quit()

void Aulib::quit

(

)

Shuts down the SDL_audiolib library.

It is not required to call this function manually, as this happens automatically at program exit, but it is useful in cases where you want to shut down the audio system for some reason.

sampleFormat()

auto Aulib::sampleFormat ( ) -> AudioFormat

noexcept

Sample format the audio device is actually using.

This can be different than the format that was requested.

sampleRate()

auto Aulib::sampleRate ( ) -> int

noexcept

Sample rate the audio device is actually using.

This can be different than the sample rate that was requested.