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#ifndef _AUDIO_H
#define _AUDIO_H
#include <libconfig.h>
#include <stdint.h>
typedef struct {
double current_volume_dB;
int32_t minimum_volume_dB;
int32_t maximum_volume_dB;
} audio_parameters;
typedef struct {
void (*help)(void);
char *name;
// start of program
int (*init)(int argc, char **argv);
// at end of program
void (*deinit)(void);
int (*prepare)(void); // looks and sets stuff in the config data structure
void (*start)(int sample_rate, int sample_format);
// block of samples
int (*play)(void *buf, int samples);
void (*stop)(void);
// may be null if no implemented
int (*is_running)(
void); // if implemented, will return 0 if everything is okay, non-zero otherwise
// may be null if not implemented
void (*flush)(void);
// returns the delay before the next frame to be sent to the device would actually be audible.
// almost certainly wrong if the buffer is empty, so put silent buffers into it to make it busy.
// will change dynamically, so keep watching it. Implemented in ALSA only.
// returns a negative error code if there's a problem
int (*delay)(long *the_delay); // snd_pcm_sframes_t is a signed long
int (*rate_info)(uint64_t *elapsed_time,
uint64_t *frames_played); // use this to get the true rate of the DAC
// may be NULL, in which case soft volume is applied
void (*volume)(double vol);
// may be NULL, in which case soft volume parameters are used
void (*parameters)(audio_parameters *info);
// may be NULL, in which case software muting is used.
// also, will return a 1 if it is actually using the mute facility, 0 otherwise
int (*mute)(int do_mute);
} audio_output;
audio_output *audio_get_output(char *name);
void audio_ls_outputs(void);
void parse_general_audio_options(void);
#endif //_AUDIO_H
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