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Remove the biquad filter code.

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This commit is contained in:
Mike Brady
2014-05-19 17:48:08 +01:00
parent 64788fa5de
commit 26992acf95
1 changed files with 2 additions and 91 deletions
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player.c
+2 -91
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@@ -283,95 +283,6 @@ static inline short dithered_vol(short sample) {
return out>>16;
}
typedef struct {
double hist[2];
double a[2];
double b[3];
} biquad_t;
static void biquad_init(biquad_t *bq, double a[], double b[]) {
bq->hist[0] = bq->hist[1] = 0.0;
memcpy(bq->a, a, 2*sizeof(double));
memcpy(bq->b, b, 3*sizeof(double));
}
static void biquad_lpf(biquad_t *bq, double freq, double Q) {
double w0 = 2.0 * M_PI * freq * frame_size / (double)sampling_rate;
double alpha = sin(w0)/(2.0*Q);
double a_0 = 1.0 + alpha;
double b[3], a[2];
b[0] = (1.0-cos(w0))/(2.0*a_0);
b[1] = (1.0-cos(w0))/a_0;
b[2] = b[0];
a[0] = -2.0*cos(w0)/a_0;
a[1] = (1-alpha)/a_0;
biquad_init(bq, a, b);
}
static double biquad_filt(biquad_t *bq, double in) {
double w = in - bq->a[0]*bq->hist[0] - bq->a[1]*bq->hist[1];
double out = bq->b[1]*bq->hist[0] + bq->b[2]*bq->hist[1] + bq->b[0]*w;
bq->hist[1] = bq->hist[0];
bq->hist[0] = w;
return out;
}
static double bf_playback_rate = 1.0;
static double bf_est_drift = 0.0; // local clock is slower by
static biquad_t bf_drift_lpf;
static double bf_est_err = 0.0, bf_last_err;
static biquad_t bf_err_lpf, bf_err_deriv_lpf;
static double desired_fill;
static int fill_count;
static void bf_est_reset(short fill) {
biquad_lpf(&bf_drift_lpf, 1.0/180.0, 0.3);
biquad_lpf(&bf_err_lpf, 1.0/10.0, 0.25);
biquad_lpf(&bf_err_deriv_lpf, 1.0/2.0, 0.2);
fill_count = 0;
bf_playback_rate = 1.0;
bf_est_err = bf_last_err = 0;
desired_fill = fill_count = 0;
}
static void bf_est_update(short fill) {
// the rate-matching system needs to decide how full to keep the buffer.
// the initial fill is present when the system starts to output samples,
// but most output chains will instantly gobble their own buffer's worth of
// data. we average for a while to decide where to draw the line.
if (fill_count < 1000) {
desired_fill += (double)fill/1000.0;
fill_count++;
return;
} else if (fill_count == 1000) {
// this information could be used to help estimate our effective latency?
debug(1, "established desired fill of %f frames, "
"so output chain buffered about %f frames\n", desired_fill,
config.buffer_start_fill - desired_fill);
fill_count++;
}
#define CONTROL_A (1e-4)
#define CONTROL_B (1e-1)
double buf_delta = fill - desired_fill;
bf_est_err = biquad_filt(&bf_err_lpf, buf_delta);
double err_deriv = biquad_filt(&bf_err_deriv_lpf, bf_est_err - bf_last_err);
double adj_error = CONTROL_A * bf_est_err;
bf_est_drift = biquad_filt(&bf_drift_lpf, CONTROL_B*(adj_error + err_deriv) + bf_est_drift);
debug(3, "bf %d err %f drift %f desiring %f ed %f estd %f\n",
fill, bf_est_err, bf_est_drift, desired_fill, err_deriv, err_deriv + adj_error);
bf_playback_rate = 1.0 + adj_error + bf_est_drift;
bf_last_err = bf_est_err;
}
// get the next frame, when available. return 0 if underrun/stream reset.
static abuf_t *buffer_get_frame(void) {
int16_t buf_fill;
@@ -768,8 +679,8 @@ static void *player_thread_func(void *arg) {
accumulated_buffers_in_use += seq_diff(ab_read, ab_write);
if (play_number%print_interval==0) {
current_latency=accumulated_delay/print_interval;
if ((play_number/print_interval)%40==0)
{ // only print every fiftieth one, in verbose mode
if ((play_number/print_interval)%100==0)
{ // only print every hundredth one, in verbose mode
//debug(1,"Valid frames: %lld; overall frames added/subtracted %lld; frames added + frames deleted %lld; average D/A delay, average latency (frames): %llu, %llu; average buffers in use: %llu, moving average delay (number of delays): %llu (%lu).\n",
// frames-(additions-deletions), additions-deletions, additions+deletions, accumulated_da_delay/print_interval,current_latency,accumulated_buffers_in_use/print_interval,moving_average_delay,number_of_delays);