Xinterpolation.*: Add old fixed point and double linear interpolation as alternatives
[ardour.git] / libs / ardour / interpolation.cc
index 444183a2b1d3493fa5f3fffcf117f56afb389728..9b2ff03e2349ba08cd98d2d72cf0d5492ba01ba2 100644 (file)
 
 using namespace ARDOUR;
 
-Interpolation::Interpolation()  : _speed (1.0L), state (0)
+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        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 = phase >> 24;
+               Sample fractional_phase_part = (phase & fractional_part_mask) / binary_scaling_factor;
+               
+               if (input && output) {
+                       // Linearly interpolate into the output buffer
+                       // using fixed point math
+                       output[outsample] = 
+                               input[i] * (1.0f - fractional_phase_part) +
+                               input[i+1] * fractional_phase_part;
+               }
+               
+               phase += phi + phi_delta;
+       }
+
+       last_phase[channel] = (phase & fractional_part_mask);
+       
+       // playback distance
+       return i;
 }
 
-Interpolation::~Interpolation() 
+void 
+FixedPointLinearInterpolation::add_channel_to (int input_buffer_size, int output_buffer_size)
 {
-       state = src_delete (state);
+       last_phase.push_back (0);
+}
+
+void 
+FixedPointLinearInterpolation::remove_channel_from ()
+{
+       last_phase.pop_back ();
 }
 
 void
-Interpolation::set_speed (double new_speed)
+FixedPointLinearInterpolation::reset() 
+{
+       for(int i = 0; i <= last_phase.size(); i++) {
+               last_phase[i] = 0;
+       }
+}
+
+
+nframes_t
+LinearInterpolation::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;
+       }
+       
+       printf("phase before: %lf\n", phase[channel]);
+       distance = phase[channel];
+       for (nframes_t outsample = 0; outsample < nframes; ++outsample) {
+               i = distance;
+               Sample fractional_phase_part = distance - i;
+               if (fractional_phase_part >= 1.0) {
+                       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
+                       output[outsample] = 
+                               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;
+}
+
+void 
+LinearInterpolation::add_channel_to (int input_buffer_size, int output_buffer_size)
+{
+       phase.push_back (0.0);
+}
+
+void 
+LinearInterpolation::remove_channel_from ()
+{
+       phase.pop_back ();
+}
+
+
+void
+LinearInterpolation::reset() 
+{
+       for(int i = 0; i <= phase.size(); i++) {
+               phase[i] = 0.0;
+       }
+}
+
+LibSamplerateInterpolation::LibSamplerateInterpolation() : state (0)
+{
+       _speed = 1.0;
+}
+
+LibSamplerateInterpolation::~LibSamplerateInterpolation() 
+{
+       for (int i = 0; i < state.size(); i++) {
+               state[i] = src_delete (state[i]);
+       }
+}
+
+void
+LibSamplerateInterpolation::set_speed (double new_speed)
 { 
        _speed = new_speed; 
-       src_set_ratio (state, 1.0/_speed); 
+       for (int i = 0; i < state.size(); i++) {
+               src_set_ratio (state[i], 1.0/_speed);
+       }
 }
 
 void
-Interpolation::reset_state ()
+LibSamplerateInterpolation::reset_state ()
 {
-       if (state) {
-               src_reset (state);
-       } else {
-               state = src_new (SRC_LINEAR, 1, &error);
+       printf("INTERPOLATION: reset_state()\n");
+       for (int i = 0; i < state.size(); i++) {
+               if (state[i]) {
+                       src_reset (state[i]);
+               } else {
+                       state[i] = src_new (SRC_SINC_FASTEST, 1, &error);
+               }
        }
 }
 
 void
-Interpolation::add_channel_to (int input_buffer_size, int output_buffer_size) 
+LibSamplerateInterpolation::add_channel_to (int input_buffer_size, int output_buffer_size) 
 {
-       SRC_DATA newdata;
+       SRC_DATA* newdata = new SRC_DATA;
        
        /* Set up sample rate converter info. */
-       newdata.end_of_input = 0 ; 
+       newdata->end_of_input = 0 ; 
 
-       newdata.input_frames  = input_buffer_size;
-       newdata.output_frames = output_buffer_size;
+       newdata->input_frames  = input_buffer_size;
+       newdata->output_frames = output_buffer_size;
 
-       newdata.input_frames_used = 0 ;
-       newdata.output_frames_gen = 0 ;
+       newdata->input_frames_used = 0 ;
+       newdata->output_frames_gen = 0 ;
 
-       newdata.src_ratio = 1.0/_speed;
+       newdata->src_ratio = 1.0/_speed;
        
        data.push_back (newdata);
+       state.push_back (0);
        
        reset_state ();
 }
 
 void
-Interpolation::remove_channel_from () 
+LibSamplerateInterpolation::remove_channel_from () 
 {
+       delete data.back ();
        data.pop_back ();
+       delete state.back ();
+       state.pop_back ();
        reset_state ();
 }
 
 nframes_t
-Interpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output)
+LibSamplerateInterpolation::interpolate (int channel, nframes_t nframes, Sample *input, Sample *output)
 {      
-       data[channel].data_in       = input;
-       data[channel].data_out      = 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; 
+       data[channel]->input_frames  = nframes * _speed;
+       data[channel]->output_frames = nframes;
+       data[channel]->src_ratio         = 1.0/_speed; 
 
-       if ((error = src_process (state, &data[channel]))) {    
+       if ((error = src_process (state[channel], data[channel]))) {    
                printf ("\nError : %s\n\n", src_strerror (error));
                exit (1);
        }
-
-       return data[channel].input_frames_used;
+       
+       //printf("INTERPOLATION: channel %d input_frames_used: %d\n", channel, data[channel]->input_frames_used);
+       
+       return data[channel]->input_frames_used;
 }