PitchDetector Class Reference
#include <PitchDetector.h>
Inheritance diagram for PitchDetector:
Detailed Description
Generates a PitchEvent whenever a notable frequency is detected using FFT.
Definition at line 10 of file PitchDetector.h.
Public Member Functions | |
| PitchDetector () | |
| constructor | |
| ~PitchDetector () | |
| destructor, asserts that pitch_info and pitch_bin have been deleted by DoStop() | |
| virtual void | DoStart () |
| allocates and sets up pitch_info and pitch_bin, relies on EventGeneratorBase to manage event subscriptions | |
| virtual void | DoStop () |
| deletes pitch_info and pitch_bin | |
| virtual void | processEvent (const EventBase &event) |
| if autolistening, will receive EventRouter events concerning our own listeners | |
| virtual std::string | getDescription () const |
| Gives a short description of what this particular instantiation does (in case a more specific description is needed on an individual basis). | |
Static Public Member Functions | |
| static std::string | getClassDescription () |
| Gives a short description of what this class of behaviors does... you should override this (but don't have to). | |
Static Public Attributes | |
| static const unsigned int | fft_frames = 4 |
| number frames to use for fft | |
| static const unsigned int | num_pitches = 60 |
| 5 octaves, 12 pitches per octave | |
| static const float | base_pitch = 110.0f |
| two octaves below tuning A (440) | |
| static const float | half_step = 1.0594630943593f |
twelfth root of two: ![$ \sqrt[12]{2} $](form_22.png) | |
| static const float | sqrt_2_pi = 2.506628274631f |
set to  | |
Protected Member Functions | |
| float | confidence (unsigned int p, float strength) |
| returns a confidence estimate of a pitch in bin p... (actual computation used is not obvious, you'll have to stare at the code /ejt) | |
Static Protected Member Functions | |
| static bool | is_pitch (float conf) |
| returns true if the confidence is above a threshold obtained from configuration | |
| static float | gaussian_pdf (float mu, float sigma, float x) |
| returns the value at x of a gaussian with the parameters mu and sigma | |
| static const char * | pitch_name (unsigned int i) |
| returns a string representing the musical note of a given frequency | |
| static void | hamming (NEWMAT::ColumnVector &v) |
| unknown calculation, does some kind of rescaling of v (/ejt) | |
Protected Attributes | |
| NEWMAT::ColumnVector | left |
| the waveform of the left channel | |
| NEWMAT::ColumnVector | right |
| the waveform of the right channel | |
| NEWMAT::ColumnVector | iml |
| imaginary outputs of the FFT for left channel | |
| NEWMAT::ColumnVector | imr |
| imaginary outputs of the FFT for right channel | |
| NEWMAT::ColumnVector | rel |
| real outputs of the FFT for the left channel | |
| NEWMAT::ColumnVector | rer |
| real outputs of the FFT for the right channel | |
| NEWMAT::ColumnVector | pol |
| absolute value (magnitude) of results of FFT for left channel | |
| NEWMAT::ColumnVector | por |
| absolute value (magnitude) of results of FFT for right channel | |
| NEWMAT::ColumnVector | po |
| average of pol and por for each bin | |
| unsigned int | frame_sz |
| number of samples given by system for each frame (assumed that once started, this won't change) | |
| unsigned int | win_sz |
| number of samples to be recorded before running FFT (frame_sz * fft_frames) | |
| unsigned int | rate |
| sampling frequence (Hz) | |
| unsigned int | cur_frame |
| the current frame index to be filled in next, up to fft_frames, when the FFT is run | |
| unsigned int | local_maxes |
| number of individual peaks | |
| PitchInfo * | pitch_info |
| an array of PitchInfos, one for each of num_pitches, allocated for scope spanning DoStart()/DoStop() | |
| float * | pitch_bin |
| array, holds current amplitude for each num_pitches (mono) | |
| bool | have_fft |
| set to true after FFT has been computed, differentiates first filling of buffers from subsequent rewrites | |
Private Member Functions | |
| PitchDetector (const PitchDetector &) | |
| don't call (copy constructor) | |
| PitchDetector & | operator= (const PitchDetector &) |
| don't call (assignment operator) | |
Classes | |
| struct | PitchInfo |
| stores info about the pitch currently being detected More... | |
Member Function Documentation
| static std::string PitchDetector::getClassDescription | ( | ) | [inline, static] |
Gives a short description of what this class of behaviors does... you should override this (but don't have to).
If you do override this, also consider overriding getDescription() to return it
Reimplemented from BehaviorBase.
Definition at line 34 of file PitchDetector.h.
Referenced by getDescription().
| virtual std::string PitchDetector::getDescription | ( | ) | const [inline, virtual] |
Gives a short description of what this particular instantiation does (in case a more specific description is needed on an individual basis).
By default simply returns getName(), because any calls from a BehaviorBase function to getClassDescription() are going to call BehaviorBase::getClassDescription(), not ~YourSubClass~getClassDescription(), because static functions can't be virtual in C++ (doh!)
This means that getDescription called on a pointer to a BehaviorBase of unknown subtype would always return an empty string, which is pretty useless. So instead we return the name in this situation. If you want getDescription to return getClassDescription, you'll have to override it in your subclass to do so.
Reimplemented from BehaviorBase.
Definition at line 35 of file PitchDetector.h.
| void PitchDetector::processEvent | ( | const EventBase & | event | ) | [virtual] |
if autolistening, will receive EventRouter events concerning our own listeners
This will automatically reduce overhead by eliminating chains of events thrown that don't have any end listeners. However, this might mean your subclass's processEvent will be receiving the events from erouterEGID, and will need to call EventGeneratorBase::processEvent() in order to allow them to be used
Reimplemented from EventGeneratorBase.
Definition at line 66 of file PitchDetector.cc.
The documentation for this class was generated from the following files:
