audio_loop.h File Reference

Utility function for playing audio on Linux or MacOS. More...

#include "wave_file_reader.h"
#include "tag.h"

Go to the source code of this file.

Macros
#define	AUDIO_BUFFER_SIZE   4410
	Size of the audio buffer.
#define	BUFFER_DURATION_NS   100000000LL
	Duration of the audio buffer.
#define	MAX_AMPLITUDE   32765
	Maximum amplitude for audio playback.
#define	NUM_CHANNELS   1
	Number of channels for audio playback.
#define	NUM_NOTES   8
	Maximum number of notes that can play simultaneously.
#define	SAMPLE_RATE   44100
	Sample rate for audio playback.

Functions
void	add_to_sound (int index_offset, double value)
	Add the given value to the current write buffer at the specified index.
int	lf_play_audio_waveform (lf_waveform_t *waveform, float emphasis, instant_t start_time)
	Play the specified waveform with the specified emphasis at the specified time.
void	lf_start_audio_loop (instant_t start_time)
	Start an audio loop thread that becomes ready to receive audio amplitude samples via add_to_sound().
void	lf_stop_audio_loop ()
	Stop the audio loop thread.

Detailed Description

Utility function for playing audio on Linux or MacOS.

Author

Edward A. Lee

Soroush Bateni

Audio functions for Linux or MacOS. To start an audio loop, call lf_start_audio_loop(), passing it the logical time at which you would like the loop to start. To play a waveform, call lf_play_audio_waveform(). A waveform may be synthesized or read from a .wav file using read_wave_file() (see wave_file_reader.h).

To use this, include the following in your target properties:

files: [
    "/lib/c/reactor-c/util/audio_loop_mac.c",
    "/lib/c/reactor-c/util/audio_loop.h",
    "/lib/c/reactor-c/util/audio_loop_linux.c",
],
cmake-include: [
    "/lib/c/reactor-c/util/audio_loop.cmake"
]

In addition, you need this in your Lingua Franca file:

preamble {=
    #include "audio_loop.h"
=}