RageSoundReader_SpeedChange.h

/* RageSoundReader_SpeedChange - change the speed of an audio stream without
 * changing its pitch. */
 
#ifndef RAGE_SOUND_READER_SPEED_CHANGE_H
#define RAGE_SOUND_READER_SPEED_CHANGE_H
 
#include <string>
#include <vector>
 
#include "RageSoundReader_Filter.h"
 
class RageSoundReader_SpeedChange : public RageSoundReader_Filter
{
  public:
    RageSoundReader_SpeedChange(RageSoundReader* pSource, bool bStepMania);
 
    virtual int SetPosition(int iFrame);
    virtual int Read(float* pBuf, int iFrames);
    virtual RageSoundReader_SpeedChange* Copy() const
    {
        return new RageSoundReader_SpeedChange(*this);
    }
    virtual bool SetProperty(const std::string& sProperty, float fValue);
    virtual int GetNextSourceFrame() const;
    virtual float GetStreamToSourceRatio() const;
 
    void SetSpeedRatio(float fRatio);
 
    /* Return true if the next Read() will start a new block, allowing
     * GetRatio() to be updated to a new value.  Used by
     * RageSoundReader_PitchChange. */
    bool NextReadWillStep() const { return GetCursorAvail() == 0; }
 
    /* Get the ratio last set by SetSpeedRatio. */
    float GetRatio() const { return m_fSpeedRatio; }
 
  protected:
    int FillData(int iMax);
    void EraseData(int iToDelete);
    int Step();
    void Reset();
 
    int GetCursorAvail() const;
 
    int GetWindowSizeFrames() const;
    int GetToleranceFrames() const { return GetWindowSizeFrames() / 4; }
 
    int m_iDataBufferAvailFrames;
    struct ChannelInfo
    {
        std::vector<float> m_DataBuffer;
        int m_iCorrelatedPos;
        int m_iLastCorrelatedPos;
    };
    std::vector<ChannelInfo> m_Channels;
 
    int m_iUncorrelatedPos;
    int m_iPos;
 
    float m_fSpeedRatio;
    float m_fTrailingSpeedRatio;
    float m_fErrorFrames;
 
    const int m_iWindowSize;
    const bool m_bMidSideEncoding;
};
 
#endif