vtkFFMPEGVideoSource.h

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// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
#ifndef vtkFFMPEGVideoSource_h
#define vtkFFMPEGVideoSource_h
 
#include "vtkIOFFMPEGModule.h" // For export macro
#include "vtkMultiThreader.h"  // for ivar
#include "vtkNew.h"            // for ivar
#include "vtkVideoSource.h"
#include <condition_variable> // for std::condition_variable_any
#include <functional>         // for audio callback
#include <mutex>              // for std::mutex
 
VTK_ABI_NAMESPACE_BEGIN
class vtkFFMPEGVideoSourceInternal;
class vtkFFMPEGVideoSource;
 
// audio callback struct, outside the class so that we
// can forward ref it
struct vtkFFMPEGVideoSourceAudioCallbackData
{
  int NumberOfSamples;
  int BytesPerSample;
  int NumberOfChannels;
  int SampleRate;
  int DataType;
  bool Packed;
  unsigned char** Data;
  vtkFFMPEGVideoSource* Caller;
  void* ClientData;
};
 
// video callback struct, outside the class so that we
// can forward ref it
struct vtkFFMPEGVideoSourceVideoCallbackData
{
  int Height;
  int LineSize[8];
  unsigned char* Data[8]; // nullptr for empty planes
  vtkFFMPEGVideoSource* Caller;
  void* ClientData;
};
 
class VTKIOFFMPEG_EXPORT vtkFFMPEGVideoSource : public vtkVideoSource
{
public:
  static vtkFFMPEGVideoSource* New();
  vtkTypeMacro(vtkFFMPEGVideoSource, vtkVideoSource);
  void PrintSelf(ostream& os, vtkIndent indent) override;
 
  void Record() override;
 
  void Play() override;
 
  void Stop() override;
 
  void Grab() override;
 
 
  void SetFrameSize(int x, int y, int z) override;
  void SetFrameSize(int dim[3]) override { this->SetFrameSize(dim[0], dim[1], dim[2]); }
 
  void SetFrameRate(float rate) override;
 
  void SetOutputFormat(int format) override;
 
  void Initialize() override;
 
  void ReleaseSystemResources() override;
 
 
  vtkSetFilePathMacro(FileName);
  vtkGetFilePathMacro(FileName);
 
  void InternalGrab() override;
 
  // is the video at the end of file?
  // Useful for while loops
  vtkGetMacro(EndOfFile, bool);
 
  // Is the video stream stereo 3d
  vtkGetMacro(Stereo3D, bool);
 
  // we do not use Invoke Observers here because this callback
  // will happen in a different thread that could conflict
  // with events from other threads. In this function you should
  // not block the thread (for example waiting for audio to play)
  // instead you should have enough buffering that you can consume
  // the provided data and return. Typically even 1 second of
  // buffer storage is enough to prevent blocking.
  typedef std::function<void(vtkFFMPEGVideoSourceAudioCallbackData const& data)> AudioCallbackType;
  void SetAudioCallback(AudioCallbackType cb, void* clientData)
  {
    this->AudioCallback = cb;
    this->AudioCallbackClientData = clientData;
  }
 
  // we do not use Invoke Observers here because this callback
  // will happen in a different thread that could conflict
  // with events from other threads. In this function you should
  // not block the thread (for example waiting for video to play)
  // instead you should have enough buffering that you can consume
  // the provided data and return.
  typedef std::function<void(vtkFFMPEGVideoSourceVideoCallbackData const& data)> VideoCallbackType;
  void SetVideoCallback(VideoCallbackType cb, void* clientData)
  {
    this->VideoCallback = cb;
    this->VideoCallbackClientData = clientData;
  }
 
 
  vtkSetMacro(DecodingThreads, int);
  vtkGetMacro(DecodingThreads, int);
 
protected:
  vtkFFMPEGVideoSource();
  ~vtkFFMPEGVideoSource() override;
 
  AudioCallbackType AudioCallback;
  void* AudioCallbackClientData;
 
  int DecodingThreads;
 
  static void* DrainAudioThread(vtkMultiThreader::ThreadInfo* data);
  void* DrainAudio(vtkMultiThreader::ThreadInfo* data);
  int DrainAudioThreadId;
 
  static void* DrainThread(vtkMultiThreader::ThreadInfo* data);
  void* Drain(vtkMultiThreader::ThreadInfo* data);
  int DrainThreadId;
 
  bool EndOfFile;
 
  std::condition_variable_any FeedCondition;
  std::mutex FeedMutex;
  std::condition_variable_any FeedAudioCondition;
  std::mutex FeedAudioMutex;
  static void* FeedThread(vtkMultiThreader::ThreadInfo* data);
  void* Feed(vtkMultiThreader::ThreadInfo* data);
  int FeedThreadId;
 
  char* FileName;
 
  vtkFFMPEGVideoSourceInternal* Internal;
 
  void ReadFrame();
 
  bool Stereo3D;
 
  VideoCallbackType VideoCallback;
  void* VideoCallbackClientData;
 
private:
  vtkFFMPEGVideoSource(const vtkFFMPEGVideoSource&) = delete;
  void operator=(const vtkFFMPEGVideoSource&) = delete;
};
 
VTK_ABI_NAMESPACE_END
#endif