diff options
| -rw-r--r-- | libs/ardour/ardour/interpolation.h | 17 | ||||
| -rw-r--r-- | libs/ardour/interpolation.cc | 68 |
2 files changed, 70 insertions, 15 deletions
diff --git a/libs/ardour/ardour/interpolation.h b/libs/ardour/ardour/interpolation.h index f417c8c46e..1ba2b5a11e 100644 --- a/libs/ardour/ardour/interpolation.h +++ b/libs/ardour/ardour/interpolation.h @@ -32,7 +32,7 @@ class Interpolation { void remove_channel_from () { phase.pop_back (); } void reset () { - for (size_t i = 0; i <= phase.size(); i++) { + for (size_t i = 0; i < phase.size(); i++) { phase[i] = 0.0; } } @@ -89,6 +89,21 @@ class LinearInterpolation : public Interpolation { public: nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output); }; + +class CubicInterpolation : public Interpolation { + protected: + // shamelessly ripped from Steve Harris' swh-plugins + static inline float cube_interp(const float fr, const float inm1, const float + in, const float inp1, const float inp2) + { + return in + 0.5f * fr * (inp1 - inm1 + + fr * (4.0f * inp1 + 2.0f * inm1 - 5.0f * in - inp2 + + fr * (3.0f * (in - inp1) - inm1 + inp2))); + } + + public: + nframes_t interpolate (int channel, nframes_t nframes, Sample* input, Sample* output); +}; /** diff --git a/libs/ardour/interpolation.cc b/libs/ardour/interpolation.cc index e0035ea11b..244ababb51 100644 --- a/libs/ardour/interpolation.cc +++ b/libs/ardour/interpolation.cc @@ -85,8 +85,6 @@ LinearInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, } 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; @@ -94,7 +92,6 @@ LinearInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, 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 @@ -102,20 +99,52 @@ LinearInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, 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; } +nframes_t +CubicInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output) +{ + // index in the input buffers + nframes_t i = 0; + + double acceleration; + double distance = 0.0; + + if (_speed != _target_speed) { + acceleration = _target_speed - _speed; + } else { + acceleration = 0.0; + } + + distance = phase[channel]; + for (nframes_t outsample = 0; outsample < nframes; ++outsample) { + i = floor(distance); + Sample fractional_phase_part = distance - i; + if (fractional_phase_part >= 1.0) { + fractional_phase_part -= 1.0; + i++; + } + + if (input && output) { + // 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; + } + + i = floor(distance); + phase[channel] = distance - floor(distance); + + return i; +} + SplineInterpolation::SplineInterpolation() { // precompute LU-factorization of matrix A @@ -133,9 +162,10 @@ nframes_t SplineInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output) { // How many input samples we need - nframes_t n = ceil (double(nframes) * _speed + phase[channel]) + 1; - //printf("n = %d\n", n); - + nframes_t n = ceil (double(nframes) * _speed + phase[channel]); + + printf("======== n: %u nframes: %u input: %u, output: %u\n", n, nframes, uint32_t(input), uint32_t(output)); + if (n <= 3) { return 0; } @@ -156,10 +186,16 @@ SplineInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, // solve U * M = t M[n-2] = t[n-3] / m(n-3); + //printf(" M[%d] = %lf \n", n-1 ,M[n-1]); + //printf(" M[%d] = %lf \n", n-2 ,M[n-2]); for (nframes_t i = n-4;; i--) { M[i+1] = (t[i]-M[i+2])/m(i); + //printf(" M[%d] = %lf\n", i+1 ,M[i+1]); if ( i == 0 ) break; } + M[1] = 0.0; + M[n - 2] = 0.0; + //printf(" M[%d] = %lf \n", 0 ,M[0]); } assert (M[0] == 0.0 && M[n-1] == 0.0); @@ -178,15 +214,17 @@ SplineInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, } distance = phase[channel]; + assert(distance >= 0.0 && distance < 1.0); + for (nframes_t outsample = 0; outsample < nframes; outsample++) { i = floor(distance); - Sample x = double(distance) - double(i); + double x = double(distance) - double(i); // if distance is something like 0.999999999999 // it will get rounded to 1 in the conversion to float above - if (x >= 1.0) { - x = 0.0; + while (x >= 1.0) { + x -= 1.0; i++; } @@ -200,6 +238,7 @@ SplineInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, double a0 = input[i]; // interpolate into the output buffer output[outsample] = ((a3*x + a2)*x + a1)*x + a0; + //std::cout << "input[" << i << "/" << i+1 << "] = " << input[i] << "/" << input[i+1] << " distance: " << distance << " output[" << outsample << "] = " << output[outsample] << std::endl; } distance += _speed + acceleration; } @@ -207,6 +246,7 @@ SplineInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, i = floor(distance); phase[channel] = distance - floor(distance); assert (phase[channel] >= 0.0 && phase[channel] < 1.0); + printf("Moved input frames: %u ", i); return i; } |