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#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include "til.h"
#include "til_audio.h"
#include "til_audio_context.h"
#include "til_settings.h"
#include "til_setup.h"
/* "mem" audio backend */
typedef struct mem_audio_setup_t {
til_setup_t til_setup;
} mem_audio_setup_t;
typedef struct mem_audio_t {
til_audio_context_t til_audio_context;
unsigned n_queued;
unsigned n_queued_start_ticks;
unsigned paused:1;
} mem_audio_t;
static int mem_audio_init(til_setup_t *setup, til_audio_context_t **res_context);
static int mem_audio_queue(til_audio_context_t *context, int16_t *frames, int n_frames);;
static unsigned mem_audio_n_queued(til_audio_context_t *context);
static void mem_audio_drop(til_audio_context_t *context);
static void mem_audio_pause(til_audio_context_t *context);
static void mem_audio_unpause(til_audio_context_t *context);
static int mem_audio_setup(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup);
til_audio_ops_t mem_audio_ops = {
.init = mem_audio_init,
.drop = mem_audio_drop,
.pause = mem_audio_pause,
.unpause = mem_audio_unpause,
.queue = mem_audio_queue,
.n_queued = mem_audio_n_queued,
.setup = mem_audio_setup,
};
/* this simulates an audio timer grinding through the queued frames when unpaused,
* returns the remaining n_queued (if any) for convenience, but it's also maintained
* at c->n_queued.
*/
static unsigned mem_refresh_n_queued(mem_audio_t *c)
{
if (!c->paused && c->n_queued) {
unsigned now = til_ticks_now();
unsigned n_played = ((float)(now - c->n_queued_start_ticks) * 44.1f);
c->n_queued -= MIN(c->n_queued, n_played);
}
return c->n_queued;
}
static int mem_audio_init(til_setup_t *setup, til_audio_context_t **res_context)
{
mem_audio_t *c;
assert(setup);
assert(res_context);
c = til_audio_context_new(&mem_audio_ops, sizeof(mem_audio_t), setup);
if (!c)
return -ENOMEM;
c->paused = 1;
*res_context = &c->til_audio_context;
return 0;
}
static void mem_audio_drop(til_audio_context_t *context)
{
mem_audio_t *c = (mem_audio_t *)context;
c->n_queued = 0;
}
static void mem_audio_pause(til_audio_context_t *context)
{
mem_audio_t *c = (mem_audio_t *)context;
if (!c->paused) {
mem_refresh_n_queued(c);
c->paused = 1;
}
}
static void mem_audio_unpause(til_audio_context_t *context)
{
mem_audio_t *c = (mem_audio_t *)context;
if (c->paused) {
c->paused = 0;
c->n_queued_start_ticks = til_ticks_now();
}
}
static int mem_audio_queue(til_audio_context_t *context, int16_t *frames, int n_frames)
{
mem_audio_t *c = (mem_audio_t *)context;
mem_refresh_n_queued(c);
c->n_queued += n_frames;
return 0;
}
static unsigned mem_audio_n_queued(til_audio_context_t *context)
{
mem_audio_t *c = (mem_audio_t *)context;
return mem_refresh_n_queued(c);
}
static int mem_audio_setup(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup)
{
if (res_setup) {
mem_audio_setup_t *setup;
setup = til_setup_new(settings, sizeof(*setup), NULL, &mem_audio_ops);
if (!setup)
return -ENOMEM;
*res_setup = &setup->til_setup;
}
return 0;
}
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