RageSoundReader_SpeedChange_Good.h

/* RageSoundReader_SpeedChange_Good - change the speed of an audio stream without
 * changing its pitch. */
 
#ifndef RAGE_SOUND_READER_SPEED_CHANGE_GOOD_H
#define RAGE_SOUND_READER_SPEED_CHANGE_GOOD_H
 
#include <string>
#include <vector>
 
#include "RageSoundReader_Filter.h"
 
struct SpeedChangeFFT;
 
class RageSoundReader_SpeedChange_Good : public RageSoundReader_Filter
{
  public:
    RageSoundReader_SpeedChange_Good(RageSoundReader* pSource);
 
    virtual int SetPosition(int iFrame);
    virtual int Read(float* pBuf, int iFrames);
    virtual RageSoundReader_SpeedChange_Good* Copy() const
    {
        return new RageSoundReader_SpeedChange_Good(*this);
    }
    virtual bool SetProperty(const std::string& sProperty, float fValue);
    virtual int GetNextSourceFrame() const;
    virtual float GetStreamToSourceRatio() const;
 
    void SetSpeedRatio(float fRatio);
    float GetRatio() const { return m_fRate; }
 
  protected:
 
    float m_fRate = 1.0f;
    double m_dPos = 0.0;
    bool m_bDraining = false;
 
    struct AudioBuffer {
        int64_t iNumChannels = 1;
        int64_t iReadPosition = 0;
        int64_t iWritePosition = 0;
        std::vector<float> Samples;
 
        int64_t Frames() const
        {
            return iWritePosition - iReadPosition;
        }
 
        void Extend(int64_t iFrames) {
            uint64_t iSamples = uint64_t((iWritePosition + iFrames) * iNumChannels);
            Samples.resize(iSamples);
        }
 
        void Shift()
        {
            int64_t iSamples = iReadPosition * iNumChannels;
            Samples.erase(Samples.begin(), Samples.begin() + iSamples);
 
            iWritePosition -= iReadPosition;
            iReadPosition -= iReadPosition;
        }
    };
 
    AudioBuffer m_ReadAhead;
    AudioBuffer m_Mixed;
    std::vector<float> m_Scale;
    std::vector<float> m_Copy;
 
    struct Window
    {
        std::vector<float> Buffer;
        int64_t iSize = 0;
        int64_t iSourceStep = 0;
        double dDestStep = 0.0;
        std::shared_ptr<SpeedChangeFFT> Junk;
 
        static Window Make(int iSampleRate, double dRate);
    };
 
    Window m_Window;
};
 
#endif