VideoFrameTransfer.h

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/* -LICENSE-START-
 ** Copyright (c) 2012 Blackmagic Design
 **
 ** Permission is hereby granted, free of charge, to any person or organization
 ** obtaining a copy of the software and accompanying documentation covered by
 ** this license (the "Software") to use, reproduce, display, distribute,
 ** execute, and transmit the Software, and to prepare derivative works of the
 ** Software, and to permit third-parties to whom the Software is furnished to
 ** do so, all subject to the following:
 **
 ** The copyright notices in the Software and this entire statement, including
 ** the above license grant, this restriction and the following disclaimer,
 ** must be included in all copies of the Software, in whole or in part, and
 ** all derivative works of the Software, unless such copies or derivative
 ** works are solely in the form of machine-executable object code generated by
 ** a source language processor.
 **
 ** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 ** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 ** FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
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 */
#ifndef __VIDEO_FRAME_TRANSFER_H__
#define __VIDEO_FRAME_TRANSFER_H__

#include "GLExtensions.h"
#include <stdexcept>
#include <map>

// NVIDIA GPU Direct For Video with OpenGL requires the following two headers.
// See the NVIDIA website to check if your graphics card is supported.
#include <DVPAPI.h>
#include <dvpapi_gl.h>

struct SyncInfo;


// Class for performing efficient frame memory transfers between the CPU and GPU,
// using NVIDIA and AMD extensions.
class VideoFrameTransfer
{
public:
  enum Direction
  {
    CPUtoGPU,
    GPUtoCPU
  };

  VideoFrameTransfer(unsigned long memSize, void* address, Direction direction);
  ~VideoFrameTransfer();

  static bool checkFastMemoryTransferAvailable();
  static bool initialize(unsigned width, unsigned height, GLuint captureTexture, GLuint playbackTexture);
  static void beginTextureInUse(Direction direction);
  static void endTextureInUse(Direction direction);
  
  bool performFrameTransfer();
  void waitForTransferComplete();

private:
  static bool isNvidiaDvpAvailable();
  static bool isAMDPinnedMemoryAvailable();
  static bool initializeMemoryLocking(unsigned memSize);

  void*           mBuffer;
  unsigned long       mMemSize;
  Direction         mDirection;
  static bool         mInitialized;
  static bool         mUseDvp;
  static unsigned       mWidth;
  static unsigned       mHeight;
  static GLuint       mCaptureTexture;

  // NVIDIA GPU Direct for Video support
  SyncInfo*         mExtSync;
  SyncInfo*         mGpuSync;
  DVPBufferHandle       mDvpSysMemHandle;

  static DVPBufferHandle    mDvpCaptureTextureHandle;
  static DVPBufferHandle    mDvpPlaybackTextureHandle;
  static uint32_t       mBufferAddrAlignment;
  static uint32_t       mBufferGpuStrideAlignment;
  static uint32_t       mSemaphoreAddrAlignment;
  static uint32_t       mSemaphoreAllocSize;
  static uint32_t       mSemaphorePayloadOffset;
  static uint32_t       mSemaphorePayloadSize;

  // GPU buffer bound to the target GL_EXTERNAL_VIRTUAL_MEMORY_BUFFER_AMD for pinned memory
  GLuint            mBufferHandle;
};

#endif