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alsa-seq: use dll to track queue timer

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Also increase timer resolution to get less jitter.
This commit is contained in:
Wim Taymans 2019-09-24 17:23:39 +02:00
parent 197d2b15b6
commit 387b281f5c
2 changed files with 89 additions and 11 deletions
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89
spa/plugins/alsa/alsa-seq.c
View file

@ -240,6 +240,7 @@ int spa_alsa_seq_open(struct seq_state *state)
int res;
snd_seq_port_subscribe_t *sub;
snd_seq_addr_t addr;
snd_seq_queue_timer_t *timer;
if (state->opened)
return 0;
@ -281,6 +282,16 @@ int spa_alsa_seq_open(struct seq_state *state)
state->sys.source.data = state;
spa_loop_add_source(state->main_loop, &state->sys.source);
/* increase queue timer resolution */
snd_seq_queue_timer_alloca(&timer);
if ((res = snd_seq_get_queue_timer(state->event.hndl, state->event.queue_id, timer)) < 0) {
spa_log_warn(state->log, "failed to get queue timer: %s", snd_strerror(res));
}
snd_seq_queue_timer_set_resolution(timer, INT_MAX);
if ((res = snd_seq_set_queue_timer(state->event.hndl, state->event.queue_id, timer)) < 0) {
spa_log_warn(state->log, "failed to set queue timer: %s", snd_strerror(res));
}
init_ports(state);
if ((res = spa_system_timerfd_create(state->data_system,
@ -585,20 +596,78 @@ static int process_write(struct seq_state *state)
return SPA_STATUS_NEED_DATA;
}
static int update_time(struct seq_state *state)
static void init_loop(struct seq_state *state)
{
state->bw = 0.0;
state->z1 = state->z2 = state->z3 = 0.0;
}
static void set_loop(struct seq_state *state, double bw)
{
double w = 2 * M_PI * bw * state->threshold * state->rate.num / state->rate.denom;
state->w0 = 1.0 - exp (-20.0 * w);
state->w1 = w * 1.5 / state->threshold;
state->w2 = w / 1.5;
state->bw = bw;
}
static int update_time(struct seq_state *state, uint64_t nsec, bool slave)
{
snd_seq_queue_status_t *status;
const snd_seq_real_time_t* queue_time;
uint64_t queue_real, queue_nsec;
double err, corr;
/* take queue time */
snd_seq_queue_status_alloca(&status);
snd_seq_get_queue_status(state->event.hndl, state->event.queue_id, status);
queue_time = snd_seq_queue_status_get_real_time(status);
state->queue_time = SPA_TIMESPEC_TO_NSEC(queue_time);
queue_real = SPA_TIMESPEC_TO_NSEC(queue_time);
spa_log_trace_fp(state->log, "now:%"PRIu64" queue:%"PRIu64" diff:%"PRIu64,
state->current_time, state->queue_time,
state->current_time - state->queue_time);
if (state->queue_start == 0)
state->queue_start = state->current_time - queue_real;
state->queue_time = state->current_time - state->queue_start;
queue_nsec = state->queue_start + queue_real;
err = ((int64_t)state->current_time - (int64_t) queue_nsec) / state->rate.denom;
if (state->bw == 0.0) {
set_loop(state, BW_MAX);
state->next_time = nsec;
state->base_time = nsec;
}
state->z1 += state->w0 * (state->w1 * err - state->z1);
state->z2 += state->w0 * (state->z1 - state->z2);
state->z3 += state->w2 * state->z2;
corr = 1.0 - (state->z2 + state->z3);
if ((state->next_time - state->base_time) > BW_PERIOD) {
state->base_time = state->next_time;
if (state->bw == BW_MAX)
set_loop(state, BW_MED);
else if (state->bw == BW_MED)
set_loop(state, BW_MIN);
spa_log_debug(state->log, NAME" %p: slave:%d rate:%f bw:%f err:%f (%f %f %f)",
state, slave, corr, state->bw, err, state->z1, state->z2, state->z3);
}
state->next_time += state->threshold / corr * 1e9 / state->rate.denom;
if (!slave && state->clock) {
state->clock->nsec = state->current_time;
state->clock->position += state->duration;
state->clock->duration = state->duration;
state->clock->count = state->clock->position;
state->clock->delay = state->duration * corr;
state->clock->rate_diff = corr;
state->clock->next_nsec = state->next_time;
}
spa_log_trace_fp(state->log, "now:%"PRIu64" queue:%"PRIu64" next:%"PRIu64" thr:%d",
state->current_time, queue_nsec, state->next_time, state->threshold);
return 0;
}
@ -610,7 +679,7 @@ int spa_alsa_seq_process(struct seq_state *state)
res = process_recycle(state);
if (state->slaved) {
update_time(state);
update_time(state, state->position->clock.nsec, true);
res |= process_read(state);
}
res = process_write(state);
@ -634,18 +703,15 @@ static void alsa_on_timeout_event(struct spa_source *source)
struct spa_io_clock *clock = &state->position->clock;
state->rate = clock->rate;
state->duration = clock->duration;
state->threshold = (state->duration * clock->rate.num * SPA_NSEC_PER_SEC) /
clock->rate.denom;
state->threshold = state->duration;
}
update_time(state);
update_time(state, state->current_time, false);
res = process_read(state);
if (res > 0)
spa_node_call_ready(&state->callbacks, res);
state->next_time += state->threshold;
set_timeout(state, state->next_time);
}
@ -708,6 +774,7 @@ int spa_alsa_seq_start(struct seq_state *state)
state->source.rmask = 0;
spa_loop_add_source(state->data_loop, &state->source);
init_loop(state);
set_timers(state);
state->started = true;

11
spa/plugins/alsa/alsa-seq.h
View file

@ -105,6 +105,11 @@ struct seq_conn {
struct spa_source source;
};
#define BW_MAX 0.128
#define BW_MED 0.064
#define BW_MIN 0.016
#define BW_PERIOD (3 * SPA_NSEC_PER_SEC)
struct seq_state {
struct spa_handle handle;
struct spa_node node;
@ -139,13 +144,19 @@ struct seq_state {
int timerfd;
uint64_t current_time;
uint64_t next_time;
uint64_t base_time;
uint64_t queue_time;
uint64_t queue_start;
unsigned int opened:1;
unsigned int started:1;
unsigned int slaved:1;
struct seq_stream streams[2];
double bw;
double z1, z2, z3;
double w0, w1, w2;
};
#define VALID_DIRECTION(this,d) ((d) == SPA_DIRECTION_INPUT || (d) == SPA_DIRECTION_OUTPUT)