Mix.h

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/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  Mix.h
 
  Dominic Mazzoni
  Markus Meyer
 
***********************************************************************/
 
#ifndef __AUDACITY_MIX__
#define __AUDACITY_MIX__
 
#include "AudioGraphBuffers.h"
#include "AudioGraphSource.h"
#include "MixerOptions.h"
#include "SampleFormat.h"
#include <functional>
 
class sampleCount;
class BoundedEnvelope;
class TrackList;
class SampleTrack;
using SampleTrackConstArray = std::vector < std::shared_ptr < const SampleTrack > >;
 
class MixerSource;
 
class SAMPLE_TRACK_API Mixer {
 public:
   using WarpOptions = MixerOptions::Warp;
   using MixerSpec = MixerOptions::Downmix;
   using ResampleParameters = MixerOptions::ResampleParameters;
   using TimesAndSpeed = MixerOptions::TimesAndSpeed;
 
   //
   // Constructor / Destructor
   //
 
   Mixer(const SampleTrackConstArray &inputTracks, bool mayThrow,
         const WarpOptions &warpOptions,
         double startTime, double stopTime,
         unsigned numOutChannels, size_t outBufferSize, bool outInterleaved,
         double outRate, sampleFormat outFormat,
         bool highQuality = true,
         MixerSpec *mixerSpec = nullptr,
         bool applytTrackGains = true);
 
   Mixer(const Mixer&) = delete;
   Mixer &operator=(const Mixer&) = delete;
 
   virtual ~ Mixer();
 
   size_t BufferSize() const { return mBufferSize; }
 
   //
   // Processing
   //
 
 
   size_t Process(size_t maxSamples);
 
   void Restart();
 
   void Reposition(double t, bool bSkipping = false);
 
   // Used in scrubbing and other nonuniform playback policies.
   void SetTimesAndSpeed(
      double t0, double t1, double speed, bool bSkipping = false);
   void SetSpeedForKeyboardScrubbing(double speed, double startTime);
 
   double MixGetCurrentTime();
 
   constSamplePtr GetBuffer();
 
   constSamplePtr GetBuffer(int channel);
 
 private:
 
   void Clear();
 
 private:
 
   // Input
   const unsigned   mNumChannels;
 
   // Transformations
   const size_t     mBufferSize;
 
   // Output
   const bool       mApplyTrackGains;
   const bool       mHighQuality; // dithering
   const sampleFormat mFormat; // output format also influences dithering
   const bool       mInterleaved;
 
   // INPUT
 
   const std::shared_ptr<TimesAndSpeed> mTimesAndSpeed;
 
   // BUFFERS
 
   // Resample into these buffers, or produce directly when not resampling
   AudioGraph::Buffers mFloatBuffers;
 
   // Each channel's data is transformed, including application of
   // gains and pans, and then (maybe many-to-one) mixer specifications
   // determine where in mTemp it is accumulated
   std::vector<std::vector<float>> mTemp;
 
   // Final result applies dithering and interleaving
   const std::vector<SampleBuffer> mBuffer;
 
   std::vector<MixerSource> mSources;
};
#endif