About

A BaseVideoPost object represents a video post effect in the render settings. Such a video post can be a simple filter or a complete render engine. Custom video posts can be created using the VideoPostData class.

BaseVideoPost objects are an instance of VPbase.

  // This example searches for the "Watermark" post effect and enables it.
  // If it does not exist, it is added.
 
  const Int watermarkID = 1025462;
 
  RenderData* const renderData = doc->GetActiveRenderData();
 
  BaseVideoPost* videoPost = renderData->GetFirstVideoPost();
  BaseVideoPost* watermark = nullptr;
 
  // search for the "Watermark" video post
  while (videoPost != nullptr)
  {
    // check if this is a "Watermark"
    if (videoPost->GetType() == watermarkID)
    {
      watermark = videoPost;
      break;
    }
    videoPost = videoPost->GetNext();
  }
 
  // if not found, create the watermark
  if (watermark == nullptr)
  {
    watermark = BaseVideoPost::Alloc(watermarkID);
    if (watermark == nullptr)
      return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION);
 
    renderData->InsertVideoPost(watermark);
  }
 
  // enable
  watermark->DelBit(BIT_VPDISABLED);

Access

BaseVideoPost elements are stored in an RenderData object:

RenderData::GetFirstVideoPost(): Returns the first BaseVideoPost object.

Allocation/Deallocation

BaseVideoPost object are created with the usual tools:

BaseVideoPost::Alloc(): Creates a new BaseVideoPost object.
BaseVideoPost::Free(): Deletes the given BaseVideoPost object.

Newly created BaseVideoPost objects can be added to the render settings by adding them to the RenderData object:

RenderData::InsertVideoPost(): Adds the given BaseVideoPost element to the list.
RenderData::InsertVideoPostLast(): Adds the given BaseVideoPost element as the last element to the list.

  // This example adds the color correction video post to the current render settings.
 
  RenderData* const renderData = doc->GetActiveRenderData();
  if (renderData == nullptr)
    return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
 
  BaseVideoPost* const colorCorrection = BaseVideoPost::Alloc(VPcolorcorrection);
  if (colorCorrection == nullptr)
    return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION);
 
  renderData->InsertVideoPost(colorCorrection);

Navigation

BaseVideoPost objects are organized in a list. This list can be navigated with:

BaseVideoPost::GetNext(): Returns the next BaseVideoPost in the list.
BaseVideoPost::GetPred(): Returns the previous BaseVideoPost in the list.

  // This example loops through all video posts and prints their names.
 
  RenderData* const renderData = doc->GetActiveRenderData();
 
  BaseVideoPost* videoPost = renderData->GetFirstVideoPost();
 
  while (videoPost != nullptr)
  {
    ApplicationOutput("Video post name: " + videoPost->GetName());
    videoPost = videoPost->GetNext();
  }

Properties

The parameters of a video post can be accessed through C4DAtom::GetParameter() and C4DAtom::SetParameter(). The IDs of these parameters are defined in the header file of the specific video post like vpxmbsampler.h, vppreviewhardware.h, vpwatermark.h etc.

Read-Only Properties

Not every video post can be combined with every render engine. It is needed to ask the BaseVideoPost object if it can be used with the given render engine.

BaseVideoPost::RenderEngineCheck(): Returns true if the video post will work with the given render engine.

  // This example checks if the video post can be added to used render engine
 
  RenderData* const renderData = doc->GetActiveRenderData();
 
  // check render engine
  BaseContainer& bc = renderData->GetDataInstanceRef();
  const Int32    renderEngine = bc.GetInt32(RDATA_RENDERENGINE);
 
  // create new video post
  BaseVideoPost* watermark = BaseVideoPost::Alloc(1025462);
  if (watermark == nullptr)
    return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION);
 
  // check if the video post is compatible with the given render engine
  if (watermark->RenderEngineCheck(renderEngine))
  {
    // insert video post
    renderData->InsertVideoPost(watermark);
  }
  else
  {
    // delete video post
    ApplicationOutput("This video post cannot work with the current render engine.");
    BaseVideoPost::Free(watermark);
  }

Stereo

A video post could also handle stereoscopic related functionality. By default the only existing video post that does handle stereoscopic images is the stereo video post (ID 450000225). To check if a plugin video post handles stereo images check the flag PLUGINFLAG_VIDEOPOST_STEREO_RENDERING. The source and target bitmap data is stored as a BaseBitmap (see BaseBitmap Manual).

BaseVideoPost::StereoMergeImages(): Merges the given images into a single stereo image.
BaseVideoPost::StereoGetCameraCountEditor(): If PLUGINFLAG_VIDEOPOST_STEREO_EDITOR is set the video post returns the number of stereoscopic editor cameras.
BaseVideoPost::StereoGetCameraCountRenderer(): The video post returns the number of stereoscopic cameras used for rendering.
BaseVideoPost::StereoGetCameraInfo(): The video post returns the information structure for a stereoscopic camera.

  // This example merges the two given BaseBitmaps in the src array into a single anaglyph bitmap
 
  AutoAlloc<BaseVideoPost> stereoVP { 450000225 };
  if (stereoVP == nullptr)
    return maxon::OutOfMemoryError(MAXON_SOURCE_LOCATION);
 
  BaseContainer settings;
  settings.SetInt32(RDATA_STEREO_MODE, RDATA_STEREO_MODE_ANAGLYPH);
 
  // merge bitmaps
  if (stereoVP->StereoMergeImages(targetBitmap, src, 2, settings, COLORSPACETRANSFORMATION::NONE) == false)
    return maxon::UnknownError(MAXON_SOURCE_LOCATION);
 
  // show the result image
  ShowBitmap(targetBitmap);

Bits

If a videopost is enabed or not is controlled with a bit:

BIT_VPDISABLED: This bit must be set to disable the video post.

  // This example disables the first video post.
 
  RenderData* const rd = doc->GetActiveRenderData();
  if (rd == nullptr)
    return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
 
  BaseVideoPost* const vp = rd->GetFirstVideoPost();
  if (vp != nullptr)
    vp->SetBit(BIT_VPDISABLED);

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