MtFootageData Manual

Table of Contents

• About
• Access
• Footage Data
• Further Reading

About

A MtFootageData object stores information on the video footage loaded by the parent MotionTrackerObject.

Access

The MtFootageData object is obtained from the parent MotionTrackerObject.

• MotionTrackerObject::GetFootageData(): Returns a new MtFootageData object.
• MtFootageData::Free(): Deletes a MtFootageData object.

Warning

The returned object is a copy owned by the caller.

  // This example accesses the Motion Tracker object
  // to print the used footage filename to the console.
 
  // check if an object is selected and if it is a Motion Tracker object
  BaseObject* const obj = doc->GetActiveObject();
  if (obj == nullptr || !obj->IsInstanceOf(Omotiontracker))
    return maxon::IllegalArgumentError(MAXON_SOURCE_LOCATION);
 
  const MotionTrackerObject* const moTrackObject = static_cast<MotionTrackerObject*>(obj);
 
  MtFootageData* footage = moTrackObject->GetFootageData();
  if (footage == nullptr)
    return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
 
  const Filename footageName = footage->GetFootageName();
  ApplicationOutput("Footage: " + footageName.GetString());
 
  // do not forget to free the copy
  MtFootageData::Free(footage);

Footage Data

The MtFootageData object provides read-access to several properties of the loaded video footage.

General information on the loaded footage:

• MtFootageData::GetFootageName(): Returns the Filename of the loaded video file.
• MtFootageData::GetFirstFrameNumber(): Returns the first frame of the loaded video file.
• MtFootageData::GetLastFrameNumber() Returns the last frame of the loaded video file.

Video Resolution and Ratio of the loaded footage:

• MtFootageData::GetResolutionWidthPix(): Returns the resolution width.
• MtFootageData::GetResolutionHeightPix(): Returns the resolution height.
• MtFootageData::GetResolutionAspectRatio(): Returns the resolution aspect ratio.
• MtFootageData::GetPixelAspectRatio(): Returns the pixel aspect ratio.
• MtFootageData::GetImageAspectRatio(): Returns the result aspect ratio.
• MtFootageData::GetDownsamplingFactor(): Returns the used downsampling factor.

  // This example prints various settings of the
  // used footage to the console window.
 
  MtFootageData* footage = moTrackObject->GetFootageData();
  if (footage == nullptr)
    return maxon::UnexpectedError(MAXON_SOURCE_LOCATION);
 
  // AutoFree takes ownership
  AutoFree<MtFootageData> freeFootage;
  freeFootage.Assign(footage);
 
  // access and print footage filename
  const Filename footageName = footage->GetFootageName();
  ApplicationOutput("Footage: " + footageName.GetString());
 
  // access footage resolution
  const Int32 width  = footage->GetResolutionWidthPix(true);
  const Int32 height = footage->GetResolutionHeightPix(true);
 
  // print result
  const String widthStr  = String::IntToString(width);
  const String heightStr = String::IntToString(height);
  ApplicationOutput("Width: " + widthStr + ", Height: " + heightStr);

Further Reading

• Motion Tracker Overview
• MotionTrackerObject Manual
• Mt2dTrackData / Mt2dTrack / MtData Manual
• Entity Creation and Destruction Manual (Classic)