Example #1
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?
	desired_fill = (2*config.buffer_start_fill) - desired_fill;
        debug(1, "established desired fill of %f frames, "
              "so output chain buffered about %f frames\n", desired_fill,
              desired_fill - config.buffer_start_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;
}
Example #2
0
static inline void bf_est_update(short fill) {
    if (fill_count < 1000) {
        desired_fill += (double)fill/1000.0;
        fill_count++;
        return;
    }

#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);

#ifdef DEBUG
    fprintf(stderr, "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);
#endif
    bf_playback_rate = 1.0 + adj_error + bf_est_drift;

    bf_last_err = bf_est_err;
}
Example #3
0
void display(void) {
    if (rptr==wptr) {
        glutSwapBuffers();
        glutPostRedisplay();
        return;
    }

    glDrawBuffer(GL_BACK);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    int n;
    double x, y;
    glBegin(GL_LINES);
    glColor4f(0,1,0,0.7);
    glVertex2f(last_x, last_y);

    n = 0;
again:
    while (rptr != wptr) {
        x = biquad_filt(&lpf_x, ringbuf[rptr*4] / 32768.0);
        y = biquad_filt(&lpf_y, ringbuf[rptr*4+1] / 32768.0);
        if (!fullbright)
            glColor4f(0, ringbuf[rptr*4+2]/32768.0, 0,0.7);
        rptr++;
        if (rptr>=RING_SIZE) {
            rptr = 0;
            fprintf(stderr, "r");
        }
        glVertex2f(x, y);
        glVertex2f(x, y);
        n++;
    }
    if (n < 1000) {
        glutSwapBuffers();
        goto again;
    }
    glVertex2f(x, y);
    last_x = x; last_y = y;
    glEnd();

#define SKIP_ACCUM  // accumulation buffer gives nice smooth decay effect, but is slow as tar on most machines
#ifndef SKIP_ACCUM
    glAccum(GL_MULT, 0.7);
    glAccum(GL_ACCUM, 1.0);

    glDrawBuffer(GL_FRONT);
    glAccum(GL_RETURN, 1.0);
    glFlush();
#else
    //glDrawBuffer(GL_BACK);
    glutSwapBuffers();
#endif

    glutPostRedisplay();
}
Example #4
0
void bf_est_update(short fill) {
    if (fill_count < 1000) {
        desired_fill += (double)fill/1000.0;
        fill_count++;
        return;
    }

#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);

    bf_est_drift = biquad_filt(&bf_drift_lpf, CONTROL_B*(bf_est_err*CONTROL_A + err_deriv) + bf_est_drift);

    if (debug)
        fprintf(stderr, "bf %d err %f drift %f desiring %f ed %f estd %f\r", fill, bf_est_err, bf_est_drift, desired_fill, err_deriv, err_deriv + CONTROL_A*bf_est_err);
    bf_playback_rate = 1.0 + CONTROL_A*bf_est_err + bf_est_drift;

    bf_last_err = bf_est_err;
}