/*!

\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 (primarily needed on BSD, rarely also Linux and Unix in general)
- pulseaudio: PulseAudio (Linux, Mac OS X, Windows)
- coreaudio: Apple CoreAudio (Mac OS X)
- dsound: Microsoft DirectSound (Windows)
- wasapi: Windows Audio Session API (Windows Vista and later)
- 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)
- 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)
- sdl3*: Simple DirectMedia Layer (Linux, Windows, Mac OS X, iOS, Android,
  FreeBSD, Haiku, etc.)
- pipewire**: PipeWire (Linux)
- file: Driver to output audio to a file

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 audio driver options that define the audio quality and latency include
\setting{audio_sample-format}, \setting{audio_period-size}, and
\setting{audio_periods}. The synthesizer's \setting{synth.sample-rate} is also
involved. The details are described later.

Important: Configure the synthesizer before creating the audio driver.
In particular, set \setting{synth.sample-rate} before instantiating the synth
with new_fluid_synth(). After the synth has been created, changing
\setting{synth.sample-rate} in the settings object may not change the sample
rate used by the synthesizer, while audio drivers created later may
use the updated setting value and cause the audio to be played out of tune. 
If you need to change the sample rate, recreate both the synthesizer and the 
audio driver using settings with the new sample rate.

You can 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 receives audio samples from the
synthesizer object and transfers them to an audio endpoint to generate
sound.
 
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 sdl3 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. A warning may be printed if sdl3 is available, but no such call
has been made.

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

Warnings raised by audio drivers during initialization via new_fluid_settings() can
be suppressed by disabling those audio drivers with fluid_audio_driver_register().
*/
