Minim core
ugens
analysis
Name TickRate
Description The TickRate UGen can be used to control the generation rate of the UGen that is patched to it. It is equivalent to slowing down or speeding up a record player. With a rate of 1, the patched UGen will come through normally, but 0.5 will half as fast and sound an octave lower, whereas 2 will be twice as fast and sound an octave higher. Be aware that increasing the rate comes at the expense of more computation because the patched UGen will be ticked multiple times in one sample frame. Another limitation is that a UGen patched to a TickRate should not be patched to another UGen as well, the audio output will not be what you intend.
Examples
/**
  This is an example of how to use a TickRate UGen to control 
  the tick rate of another UGen, in this case a FilePlayer. <br/>
  A TickRate will tick the UGen patched to it at a rate relative 
  to the normal tick rate. So a TickRate with a value of 1 
  will simply pass the audio. A TickRate with a value of 2 
  will tick the incoming UGen twice as fast as normal. 
  If the value of TickRate is ever set to 0 or lower, 
  it will simply generate silence and not tick its incoming UGen at all. 
  This is because there isn't a way to tell a UGen to tick backwards.
  <p>
  Slide the mouse left and right in the window 
  to control the playback rate of the loop.
  <br/>
  Hold 'i' to make TickRate interpolate between actual sample values 
  (this will remove the "crunch" when at rates less than 1).
  <p>
  For more information about Minim and additional features, 
  visit http://code.compartmental.net/minim/
  <p>
  author: Damien Di Fede
*/

import ddf.minim.*;
import ddf.minim.spi.*; // for AudioRecordingStream
import ddf.minim.ugens.*;

// declare everything we need to play our file and control the playback rate
Minim minim;
TickRate rateControl;
FilePlayer filePlayer;
AudioOutput out;

// you can use your own file by putting it in the data directory of this sketch
// and changing the value assigned to fileName here.
String fileName = "again_loop.aif";

void setup()
{
  // setup the size of the app
  size(640, 200);
  
  // create our Minim object for loading audio
  minim = new Minim(this);
                               
  // this opens the file and puts it in the "play" state.                           
  filePlayer = new FilePlayer( minim.loadFileStream(fileName) );
  // and then we'll tell the recording to loop indefinitely
  filePlayer.loop();
  
  // this creates a TickRate UGen with the default playback speed of 1.
  // ie, it will sound as if the file is patched directly to the output
  rateControl = new TickRate(1.f);
  
  // get a line out from Minim. It's important that the file is the same audio format 
  // as our output (i.e. same sample rate, number of channels, etc).
  out = minim.getLineOut();
  
  // patch the file player through the TickRate to the output.
  filePlayer.patch(rateControl).patch(out);
                        
}

// keyPressed is called whenever a key on the keyboard is pressed
void keyPressed()
{
  if ( key == 'i' || key == 'I' )
  {
    // with interpolation on, it will sound as a record would when slowed down or sped up
    rateControl.setInterpolation( true );
  }
}

void keyReleased()
{
  if ( key == 'i' || key == 'I' )
  {
    // with interpolation off, the sound will become "crunchy" when playback is slowed down
    rateControl.setInterpolation( false );
  }
}

// draw is run many times
void draw()
{
  // change the rate control value based on mouse position
  float rate = map(mouseX, 0, width, 0.0f, 3.f);
  
  rateControl.value.setLastValue(rate);
  
  // erase the window to black
  background( 0 );
  // draw using a white stroke
  stroke( 255 );
  // draw the waveforms
  for( int i = 0; i < out.bufferSize() - 1; i++ )
  {
    // find the x position of each buffer value
    float x1  =  map( i, 0, out.bufferSize(), 0, width );
    float x2  =  map( i+1, 0, out.bufferSize(), 0, width );
    // draw a line from one buffer position to the next for both channels
    line( x1, 50  - out.left.get(i)*50,  x2, 50  - out.left.get(i+1)*50);
    line( x1, 150 - out.right.get(i)*50, x2, 150 - out.right.get(i+1)*50);
  }  
}
Constructors
TickRate();
TickRate(tickRate);
Parameters
tickRate   float: the rate at which to tick a UGen patched to this
Fields
value   The rate that this ticks the UGen patched to it.

Methods
channelCount ( )   Returns the number of channels this UGen has been configured to generate.

getLastValues ( )   Return the last values generated by this UGen. This will most often be used by sub-classes when pulling data from their inputs.

isInterpolating ( )   Returns whether or not this TickRate currently has interpolation on.

patch ( )   Send the output of this UGen to another UGen, UGenInput, or AudioOutput.

printInputs ( )   Prints all inputs connected to this UGen (for debugging)

sampleRate ( )   Returns the sample rate of this UGen.

setChannelCount ( )   Let this UGen know how many channels of audio you will be asking it for.

setInterpolation ( )   Enabled or disable sample interpolation.

setSampleRate ( )   Set the sample rate for this UGen.

tick ( )   Generates one sample frame for this UGen.

unpatch ( )   Unpatch this UGen from an AudioOutput or other UGen.

Usage Web & Application
Related