Nsound::BufferWindowSearch Class Reference

Searches the target Buffer for zero crossings at or after the window_size position. More...

#include <Nsound/BufferWindowSearch.h>

Public Member Functions
	BufferWindowSearch (const Buffer &buffer, uint32 window_size=2048)
	BufferWindowSearch (const BufferWindowSearch &copy)
	~BufferWindowSearch ()
BufferWindowSearch &	operator= (const BufferWindowSearch &rhs)
Buffer	getNextWindow ()
	Searches the target Buffer for a zero crossing at or after the window_size position. More...
uint32	getSamplesLeft () const
	Returns how many samples are left in the target Buffer. More...
void	reset ()
	Resets the search. More...
void	setBuffer (const Buffer &buffer)
	Search a different Buffer. More...

Protected Attributes
const Buffer *	target_buffer_
uint32	window_size_
uint32	position_

Detailed Description

Searches the target Buffer for zero crossings at or after the window_size position.

Definition at line 46 of file BufferWindowSearch.h.

Constructor & Destructor Documentation

BufferWindowSearch::BufferWindowSearch	(	const Buffer &	buffer,
		uint32	window_size = 2048
	)

Definition at line 49 of file BufferWindowSearch.cc.

References M_ASSERT_VALUE, and window_size_.

    :
    target_buffer_(&target),
    window_size_(window_size),
    position_(0)
{
    M_ASSERT_VALUE(window_size_, >=, 2);
};

BufferWindowSearch::BufferWindowSearch

(

const BufferWindowSearch &

copy

)

Definition at line 60 of file BufferWindowSearch.cc.

    :
    target_buffer_(copy.target_buffer_),
    window_size_(copy.window_size_),
    position_(copy.position_)
{
};

Nsound::BufferWindowSearch::~BufferWindowSearch ( )

inline

Definition at line 54 of file BufferWindowSearch.h.

{};

Member Function Documentation

BufferWindowSearch & BufferWindowSearch::operator=

(

const BufferWindowSearch &

rhs

)

Definition at line 71 of file BufferWindowSearch.cc.

References position_, target_buffer_, and window_size_.

{
    if(this == &rhs)
    {
        return *this;
    }

    target_buffer_ = rhs.target_buffer_;
    window_size_   = rhs.window_size_;
    position_      = rhs.position_;

    return *this;
};

Buffer BufferWindowSearch::getNextWindow

(

)

Searches the target Buffer for a zero crossing at or after the window_size position.

Definition at line 87 of file BufferWindowSearch.cc.

References Nsound::Buffer::getLength(), position_, Nsound::Buffer::subbuffer(), target_buffer_, and window_size_.

Referenced by Nsound::Buffer::getResample().

{
    enum State
    {
        INIT,
        POS,
        NEG,
        END,
        DONE
    };

    //~    std::string STRINGS[5] = { "init", "pos", "neg", "end", "done" };

    State s = INIT;

    uint32 next_pos = position_ + window_size_;

    //~    Plotter pylab;
    //~
    //~    boolean debug_plot = false;
    //~
    //~    if(next_pos == 0)
    //~    {
    //~        Buffer x_axis;
    //~        for(uint32 i = next_pos; i < next_pos + 100; ++i)
    //~        {
    //~            x_axis << i;
    //~        }
    //~
    //~        pylab.plot(x_axis, target_buffer_->subbuffer(next_pos, 100));
    //~
    //~        pylab.title("window 26303");
    //~
    //~        pylab.hold(true);
    //~
    //~        debug_plot = true;
    //~    }

    //~    cerr << "position_ = " << position_
    //~         << "    start = " << next_pos;

    uint32 end = target_buffer_->getLength();

    // Are we off the end?
    if(next_pos >= end)
    {
        Buffer w = target_buffer_->subbuffer(position_);
        position_ = end;
        return w;
    }

    // DEBUG
    Buffer x(1);
    Buffer y(1);
    x << next_pos;
    y << (*target_buffer_)[next_pos];


    // Initalize the state.
    if((*target_buffer_)[next_pos] > 0.0)
    {
        s = POS;
        //~        if(debug_plot) pylab.plot(x,y, "g+");
    }
    else if((*target_buffer_)[next_pos] < 0.0)
    {
        s = NEG;
        //~        if(debug_plot) pylab.plot(x,y, "r+");
    }
    else
    {
        s = DONE;
    }

    //~    cerr << "    state = " << STRINGS[s];

    State last_s = s;

    while(last_s == s)
    {
        last_s = s;

        ++next_pos;

        //~        if(next_pos > position_ + window_size_ + 200 ) debug_plot = false;
        //~
        //~        // DEBUG
        //~        x = Buffer(1);
        //~        y = Buffer(1);
        //~        x << next_pos;
        //~        y << (*target_buffer_)[next_pos];

        // Are we off the end?
        if(next_pos >= end)
        {
            Buffer w = target_buffer_->subbuffer(position_);
            position_ = end;
            return w;
        }

        // Update state.
        if((*target_buffer_)[next_pos] > 0.0)
        {
            s = POS;
            //~            if(debug_plot) pylab.plot(x,y, "g+");
        }
        else if((*target_buffer_)[next_pos] < 0.0)
        {
            s = NEG;
            //~            if(debug_plot) pylab.plot(x,y, "r+");
        }
        else
        {
            break;
        }
    }

    // Pick the sample that is closest to zero.
    if( std::fabs((*target_buffer_)[next_pos-1]) <
        std::fabs((*target_buffer_)[next_pos]))
    {
        --next_pos;
    }

    //~    cerr << "    state = " << STRINGS[s];
    //~    cerr << "    n_samples_ = " << next_pos - position_ << endl;

    Buffer w = target_buffer_->subbuffer(position_, next_pos - position_);

    position_ = next_pos;

    return w;
}

uint32 BufferWindowSearch::getSamplesLeft

(

)

const

Returns how many samples are left in the target Buffer.

Definition at line 223 of file BufferWindowSearch.cc.

References Nsound::Buffer::getLength(), position_, and target_buffer_.

Referenced by Nsound::Buffer::getResample().

{
    return target_buffer_->getLength() - position_;
}

void Nsound::BufferWindowSearch::reset ( )

inline

Resets the search.

Definition at line 69 of file BufferWindowSearch.h.

References position_.

Referenced by setBuffer().

    {position_ = 0;};

void Nsound::BufferWindowSearch::setBuffer ( const Buffer &  buffer )

inline

Search a different Buffer.

Definition at line 74 of file BufferWindowSearch.h.

References reset(), and target_buffer_.

    {
        target_buffer_ = &buffer;
        reset();
    }

Member Data Documentation

const Buffer* Nsound::BufferWindowSearch::target_buffer_

protected

Definition at line 82 of file BufferWindowSearch.h.

Referenced by getNextWindow(), getSamplesLeft(), operator=(), and setBuffer().

uint32 Nsound::BufferWindowSearch::window_size_

protected

Definition at line 83 of file BufferWindowSearch.h.

Referenced by BufferWindowSearch(), getNextWindow(), and operator=().

uint32 Nsound::BufferWindowSearch::position_

protected

Definition at line 84 of file BufferWindowSearch.h.

Referenced by getNextWindow(), getSamplesLeft(), operator=(), and reset().

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The documentation for this class was generated from the following files:

• Nsound/BufferWindowSearch.h
• Nsound/BufferWindowSearch.cc