using namespace ARDOUR;
-nframes_t
-FixedPointLinearInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output)
-{
- // the idea behind phase is that when the speed is not 1.0, we have to
- // interpolate between samples and then we have to store where we thought we were.
- // rather than being at sample N or N+1, we were at N+0.8792922
- // so the "phase" element, if you want to think about this way,
- // varies from 0 to 1, representing the "offset" between samples
- uint64_t the_phase = last_phase[channel];
-
- // acceleration
- int64_t phi_delta;
-
- // phi = fixed point speed
- if (phi != target_phi) {
- phi_delta = ((int64_t)(target_phi - phi)) / nframes;
- } else {
- phi_delta = 0;
- }
-
- // index in the input buffers
- nframes_t i = 0;
-
- for (nframes_t outsample = 0; outsample < nframes; ++outsample) {
- i = the_phase >> 24;
- Sample fractional_phase_part = (the_phase & fractional_part_mask) / binary_scaling_factor;
-
- if (input && output) {
- // Linearly interpolate into the output buffer
- output[outsample] =
- input[i] * (1.0f - fractional_phase_part) +
- input[i+1] * fractional_phase_part;
- }
-
- the_phase += phi + phi_delta;
- }
-
- last_phase[channel] = (the_phase & fractional_part_mask);
-
- // playback distance
- return i;
-}
-
-void
-FixedPointLinearInterpolation::add_channel_to (int /*input_buffer_size*/, int /*output_buffer_size*/)
-{
- last_phase.push_back (0);
-}
-
-void
-FixedPointLinearInterpolation::remove_channel_from ()
-{
- last_phase.pop_back ();
-}
-
-void
-FixedPointLinearInterpolation::reset()
-{
- for (size_t i = 0; i <= last_phase.size(); i++) {
- last_phase[i] = 0;
- }
-}
-
nframes_t
LinearInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output)
}
distance = phase[channel];
- //printf("processing channel: %d\n", channel);
- //printf("phase before: %lf\n", phase[channel]);
for (nframes_t outsample = 0; outsample < nframes; ++outsample) {
i = floor(distance);
Sample fractional_phase_part = distance - i;
fractional_phase_part -= 1.0;
i++;
}
- //printf("I: %u, distance: %lf, fractional_phase_part: %lf\n", i, distance, fractional_phase_part);
if (input && output) {
// Linearly interpolate into the output buffer
input[i] * (1.0f - fractional_phase_part) +
input[i+1] * fractional_phase_part;
}
- //printf("distance before: %lf\n", distance);
distance += _speed + acceleration;
- //printf("distance after: %lf, _speed: %lf\n", distance, _speed);
}
- //printf("before assignment: i: %d, distance: %lf\n", i, distance);
i = floor(distance);
- //printf("after assignment: i: %d, distance: %16lf\n", i, distance);
phase[channel] = distance - floor(distance);
- //printf("speed: %16lf, i after: %d, distance after: %16lf, phase after: %16lf\n", _speed, i, distance, phase[channel]);
return i;
}
-SplineInterpolation::SplineInterpolation()
-{
- // precompute LU-factorization of matrix A
- // see "Teubner Taschenbuch der Mathematik", p. 1105
- m[0] = 4.0;
- for (int i = 0; i <= MAX_PERIOD_SIZE - 2; i++) {
- l[i] = 1.0 / m[i];
- m[i+1] = 4.0 - l[i];
- }
-}
-
nframes_t
-SplineInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output)
+CubicInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output)
{
- // How many input samples we need
- nframes_t n = ceil (double(nframes) * _speed) + 2;
- // |------------------------------------------^
- // this won't be here in the debugged version.
-
- double M[n], t[n-2];
-
- // natural spline: boundary conditions
- M[0] = 0.0;
- M[n - 1] = 0.0;
-
- // solve L * t = d
- // see "Teubner Taschenbuch der Mathematik", p. 1105
- t[0] = 6.0 * (input[0] - 2*input[1] + input[2]);
- for (nframes_t i = 1; i <= n - 3; i++) {
- t[i] = 6.0 * (input[i] - 2*input[i+1] + input[i+2])
- - l[i-1] * t[i-1];
- }
-
- // solve R * M = t
- // see "Teubner Taschenbuch der Mathematik", p. 1105
- M[n-2] = -t[n-3] / m[n-3];
- for (nframes_t i = n-4;; i--) {
- M[i+1] = -(t[i] + M[i+2]) / m[i];
- if ( i == 0 ) break;
- }
-
- // now interpolate
// index in the input buffers
nframes_t i = 0;
}
distance = phase[channel];
- for (nframes_t outsample = 0; outsample < nframes; outsample++) {
+ for (nframes_t outsample = 0; outsample < nframes; ++outsample) {
i = floor(distance);
-
- Sample x = distance - i;
-
- /* this would break the assertion below
- if (x >= 1.0) {
- x -= 1.0;
+ Sample fractional_phase_part = distance - i;
+ if (fractional_phase_part >= 1.0) {
+ fractional_phase_part -= 1.0;
i++;
}
- */
if (input && output) {
- assert (i <= n-1);
- double a0 = input[i];
- double a1 = input[i+1] - input[i] - M[i+1]/6.0 - M[i]/3.0;
- double a2 = M[i] / 2.0;
- double a3 = (M[i+1] - M[i]) / 6.0;
- // interpolate into the output buffer
- output[outsample] = ((a3*x +a2)*x +a1)*x + a0;
+ // Cubically interpolate into the output buffer
+ output[outsample] = cube_interp(fractional_phase_part, input[i-1], input[i], input[i+1], input[i+2]);
}
distance += _speed + acceleration;
}
return i;
}
-
-LibSamplerateInterpolation::LibSamplerateInterpolation() : state (0)
-{
- _speed = 1.0;
-}
-
-LibSamplerateInterpolation::~LibSamplerateInterpolation()
-{
- for (size_t i = 0; i < state.size(); i++) {
- state[i] = src_delete (state[i]);
- }
-}
-
-void
-LibSamplerateInterpolation::set_speed (double new_speed)
-{
- _speed = new_speed;
- for (size_t i = 0; i < state.size(); i++) {
- src_set_ratio (state[i], 1.0/_speed);
- }
-}
-
-void
-LibSamplerateInterpolation::reset_state ()
-{
- printf("INTERPOLATION: reset_state()\n");
- for (size_t i = 0; i < state.size(); i++) {
- if (state[i]) {
- src_reset (state[i]);
- } else {
- state[i] = src_new (SRC_SINC_FASTEST, 1, &error);
- }
- }
-}
-
-void
-LibSamplerateInterpolation::add_channel_to (int input_buffer_size, int output_buffer_size)
-{
- SRC_DATA* newdata = new SRC_DATA;
-
- /* Set up sample rate converter info. */
- newdata->end_of_input = 0 ;
-
- newdata->input_frames = input_buffer_size;
- newdata->output_frames = output_buffer_size;
-
- newdata->input_frames_used = 0 ;
- newdata->output_frames_gen = 0 ;
-
- newdata->src_ratio = 1.0/_speed;
-
- data.push_back (newdata);
- state.push_back (0);
-
- reset_state ();
-}
-
-void
-LibSamplerateInterpolation::remove_channel_from ()
-{
- SRC_DATA* d = data.back ();
- delete d;
- data.pop_back ();
- if (state.back ()) {
- src_delete (state.back ());
- }
- state.pop_back ();
- reset_state ();
-}
-
-nframes_t
-LibSamplerateInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output)
-{
- if (!data.size ()) {
- printf ("ERROR: trying to interpolate with no channels\n");
- return 0;
- }
-
- data[channel]->data_in = input;
- data[channel]->data_out = output;
-
- data[channel]->input_frames = nframes * _speed;
- data[channel]->output_frames = nframes;
- data[channel]->src_ratio = 1.0/_speed;
-
- if ((error = src_process (state[channel], data[channel]))) {
- printf ("\nError : %s\n\n", src_strerror (error));
- exit (1);
- }
-
- //printf("INTERPOLATION: channel %d input_frames_used: %d\n", channel, data[channel]->input_frames_used);
-
- return data[channel]->input_frames_used;
-}
projects / ardour.git / blobdiff