/*!

\page CreatingAudioDriver Creating the audio driver

The synthesizer itself does not write any audio to the audio output. This
allows application developers to manage the audio output themselves if they
wish. The next section describes the use of the synthesizer without an audio
driver in more detail.

Creating the audio driver is straightforward: set the
<code>audio.driver</code> settings and create the driver object. Because the
FluidSynth has support for several audio systems, you may want to change
which one you want to use. The list below shows the audio systems that are
currently supported. It displays the name, as used by the fluidsynth library,
and a description. 

- jack: JACK Audio Connection Kit (Linux, Mac OS X, Windows)
- alsa: Advanced Linux Sound Architecture (Linux)
- oss: Open Sound System (Linux, Unix)
- pulseaudio: PulseAudio (Linux, Mac OS X, Windows)
- coreaudio: Apple CoreAudio (Mac OS X)
- dsound: Microsoft DirectSound (Windows)
- portaudio: PortAudio Library (Mac OS 9 & X, Windows, Linux)
- sndman: Apple SoundManager (Mac OS Classic)
- dart: DART sound driver (OS/2)
- opensles: OpenSL ES (Android)
- oboe: Oboe (Android)
- waveout: Microsoft WaveOut, alternative to DirectSound (Windows CE x86,
  Windows Mobile 2003 for ARMv5, Windows 98 SE, Windows NT 4.0, Windows XP
  and later)
- file: Driver to output audio to a file
- sdl2*: Simple DirectMedia Layer (Linux, Windows, Mac OS X, iOS, Android,
  FreeBSD, Haiku, etc.)

The default audio driver depends on the settings with which FluidSynth was
compiled. You can get the default driver with
fluid_settings_getstr_default(). To get the list of available drivers use the
fluid_settings_foreach_option() function. Finally, you can set the driver
with fluid_settings_setstr(). In most cases, the default driver should work
out of the box. 

Additional options that define the audio quality and latency are
\setting{audio_sample-format}, \setting{audio_period-size}, and
\setting{audio_periods}. The details are described later.

You create the audio driver with the new_fluid_audio_driver() function. This
function takes the settings and synthesizer object as arguments. For example: 

\code
void init() 
{
    fluid_settings_t* settings;
    fluid_synth_t* synth;
    fluid_audio_driver_t* adriver;
    settings = new_fluid_settings();

    /* Set the synthesizer settings, if necessary */
    synth = new_fluid_synth(settings);

    fluid_settings_setstr(settings, "audio.driver", "jack");
    adriver = new_fluid_audio_driver(settings, synth);
}
\endcode

As soon as the audio driver is created, it will start playing. The audio
driver creates a separate thread that uses the synthesizer object to generate
the audio.
 
There are a number of general audio driver settings. The audio.driver settings
define the audio subsystem that will be used. The \setting{audio_periods} and
\setting{audio_period-size} settings define the latency and robustness against
scheduling delays. There are additional settings for the audio subsystems used.
For a full list of available <strong>audio driver settings</strong>, please
refer to the \setting{audio} documentation.

<strong>*Note:</strong> In order to use sdl2 as audio driver, the application
is responsible for initializing SDL (e.g. with SDL_Init()). This must be done
<strong>before</strong> the first call to <code>new_fluid_settings()</code>!
Also make sure to call SDL_Quit() after all fluidsynth instances have been
destroyed.

*/