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Open Source Computer Vision Library
https://opencv.org/
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733 lines
25 KiB
733 lines
25 KiB
Video Analysis |
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============== |
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.. highlight:: cpp |
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gpu::BroxOpticalFlow |
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-------------------- |
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.. ocv:class:: gpu::BroxOpticalFlow |
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Class computing the optical flow for two images using Brox et al Optical Flow algorithm ([Brox2004]_). :: |
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class BroxOpticalFlow |
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{ |
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public: |
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BroxOpticalFlow(float alpha_, float gamma_, float scale_factor_, int inner_iterations_, int outer_iterations_, int solver_iterations_); |
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//! Compute optical flow |
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//! frame0 - source frame (supports only CV_32FC1 type) |
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//! frame1 - frame to track (with the same size and type as frame0) |
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//! u - flow horizontal component (along x axis) |
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//! v - flow vertical component (along y axis) |
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void operator ()(const GpuMat& frame0, const GpuMat& frame1, GpuMat& u, GpuMat& v, Stream& stream = Stream::Null()); |
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//! flow smoothness |
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float alpha; |
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//! gradient constancy importance |
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float gamma; |
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//! pyramid scale factor |
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float scale_factor; |
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//! number of lagged non-linearity iterations (inner loop) |
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int inner_iterations; |
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//! number of warping iterations (number of pyramid levels) |
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int outer_iterations; |
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//! number of linear system solver iterations |
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int solver_iterations; |
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GpuMat buf; |
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}; |
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gpu::GoodFeaturesToTrackDetector_GPU |
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------------------------------------ |
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.. ocv:class:: gpu::GoodFeaturesToTrackDetector_GPU |
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Class used for strong corners detection on an image. :: |
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class GoodFeaturesToTrackDetector_GPU |
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{ |
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public: |
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explicit GoodFeaturesToTrackDetector_GPU(int maxCorners_ = 1000, double qualityLevel_ = 0.01, double minDistance_ = 0.0, |
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int blockSize_ = 3, bool useHarrisDetector_ = false, double harrisK_ = 0.04); |
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void operator ()(const GpuMat& image, GpuMat& corners, const GpuMat& mask = GpuMat()); |
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int maxCorners; |
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double qualityLevel; |
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double minDistance; |
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int blockSize; |
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bool useHarrisDetector; |
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double harrisK; |
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void releaseMemory(); |
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}; |
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The class finds the most prominent corners in the image. |
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.. seealso:: :ocv:func:`goodFeaturesToTrack` |
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gpu::GoodFeaturesToTrackDetector_GPU::GoodFeaturesToTrackDetector_GPU |
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--------------------------------------------------------------------- |
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Constructor. |
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.. ocv:function:: gpu::GoodFeaturesToTrackDetector_GPU::GoodFeaturesToTrackDetector_GPU(int maxCorners = 1000, double qualityLevel = 0.01, double minDistance = 0.0, int blockSize = 3, bool useHarrisDetector = false, double harrisK = 0.04) |
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:param maxCorners: Maximum number of corners to return. If there are more corners than are found, the strongest of them is returned. |
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:param qualityLevel: Parameter characterizing the minimal accepted quality of image corners. The parameter value is multiplied by the best corner quality measure, which is the minimal eigenvalue (see :ocv:func:`gpu::cornerMinEigenVal` ) or the Harris function response (see :ocv:func:`gpu::cornerHarris` ). The corners with the quality measure less than the product are rejected. For example, if the best corner has the quality measure = 1500, and the ``qualityLevel=0.01`` , then all the corners with the quality measure less than 15 are rejected. |
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:param minDistance: Minimum possible Euclidean distance between the returned corners. |
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:param blockSize: Size of an average block for computing a derivative covariation matrix over each pixel neighborhood. See :ocv:func:`cornerEigenValsAndVecs` . |
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:param useHarrisDetector: Parameter indicating whether to use a Harris detector (see :ocv:func:`gpu::cornerHarris`) or :ocv:func:`gpu::cornerMinEigenVal`. |
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:param harrisK: Free parameter of the Harris detector. |
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gpu::GoodFeaturesToTrackDetector_GPU::operator () |
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------------------------------------------------- |
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Finds the most prominent corners in the image. |
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.. ocv:function:: void gpu::GoodFeaturesToTrackDetector_GPU::operator ()(const GpuMat& image, GpuMat& corners, const GpuMat& mask = GpuMat()) |
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:param image: Input 8-bit, single-channel image. |
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:param corners: Output vector of detected corners (it will be one row matrix with CV_32FC2 type). |
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:param mask: Optional region of interest. If the image is not empty (it needs to have the type ``CV_8UC1`` and the same size as ``image`` ), it specifies the region in which the corners are detected. |
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.. seealso:: :ocv:func:`goodFeaturesToTrack` |
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gpu::GoodFeaturesToTrackDetector_GPU::releaseMemory |
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--------------------------------------------------- |
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Releases inner buffers memory. |
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.. ocv:function:: void gpu::GoodFeaturesToTrackDetector_GPU::releaseMemory() |
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gpu::FarnebackOpticalFlow |
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------------------------- |
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.. ocv:class:: gpu::FarnebackOpticalFlow |
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Class computing a dense optical flow using the Gunnar Farneback’s algorithm. :: |
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class CV_EXPORTS FarnebackOpticalFlow |
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{ |
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public: |
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FarnebackOpticalFlow() |
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{ |
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numLevels = 5; |
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pyrScale = 0.5; |
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fastPyramids = false; |
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winSize = 13; |
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numIters = 10; |
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polyN = 5; |
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polySigma = 1.1; |
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flags = 0; |
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} |
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int numLevels; |
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double pyrScale; |
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bool fastPyramids; |
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int winSize; |
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int numIters; |
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int polyN; |
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double polySigma; |
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int flags; |
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void operator ()(const GpuMat &frame0, const GpuMat &frame1, GpuMat &flowx, GpuMat &flowy, Stream &s = Stream::Null()); |
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void releaseMemory(); |
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private: |
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/* hidden */ |
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}; |
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gpu::FarnebackOpticalFlow::operator () |
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-------------------------------------- |
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Computes a dense optical flow using the Gunnar Farneback’s algorithm. |
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.. ocv:function:: void gpu::FarnebackOpticalFlow::operator ()(const GpuMat &frame0, const GpuMat &frame1, GpuMat &flowx, GpuMat &flowy, Stream &s = Stream::Null()) |
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:param frame0: First 8-bit gray-scale input image |
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:param frame1: Second 8-bit gray-scale input image |
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:param flowx: Flow horizontal component |
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:param flowy: Flow vertical component |
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:param s: Stream |
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.. seealso:: :ocv:func:`calcOpticalFlowFarneback` |
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gpu::FarnebackOpticalFlow::releaseMemory |
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---------------------------------------- |
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Releases unused auxiliary memory buffers. |
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.. ocv:function:: void gpu::FarnebackOpticalFlow::releaseMemory() |
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gpu::PyrLKOpticalFlow |
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--------------------- |
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.. ocv:class:: gpu::PyrLKOpticalFlow |
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Class used for calculating an optical flow. :: |
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class PyrLKOpticalFlow |
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{ |
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public: |
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PyrLKOpticalFlow(); |
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void sparse(const GpuMat& prevImg, const GpuMat& nextImg, const GpuMat& prevPts, GpuMat& nextPts, |
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GpuMat& status, GpuMat* err = 0); |
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void dense(const GpuMat& prevImg, const GpuMat& nextImg, GpuMat& u, GpuMat& v, GpuMat* err = 0); |
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Size winSize; |
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int maxLevel; |
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int iters; |
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double derivLambda; |
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bool useInitialFlow; |
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float minEigThreshold; |
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bool getMinEigenVals; |
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void releaseMemory(); |
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}; |
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The class can calculate an optical flow for a sparse feature set or dense optical flow using the iterative Lucas-Kanade method with pyramids. |
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.. seealso:: :ocv:func:`calcOpticalFlowPyrLK` |
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gpu::PyrLKOpticalFlow::sparse |
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----------------------------- |
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Calculate an optical flow for a sparse feature set. |
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.. ocv:function:: void gpu::PyrLKOpticalFlow::sparse(const GpuMat& prevImg, const GpuMat& nextImg, const GpuMat& prevPts, GpuMat& nextPts, GpuMat& status, GpuMat* err = 0) |
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:param prevImg: First 8-bit input image (supports both grayscale and color images). |
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:param nextImg: Second input image of the same size and the same type as ``prevImg`` . |
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:param prevPts: Vector of 2D points for which the flow needs to be found. It must be one row matrix with CV_32FC2 type. |
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:param nextPts: Output vector of 2D points (with single-precision floating-point coordinates) containing the calculated new positions of input features in the second image. When ``useInitialFlow`` is true, the vector must have the same size as in the input. |
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:param status: Output status vector (CV_8UC1 type). Each element of the vector is set to 1 if the flow for the corresponding features has been found. Otherwise, it is set to 0. |
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:param err: Output vector (CV_32FC1 type) that contains the difference between patches around the original and moved points or min eigen value if ``getMinEigenVals`` is checked. It can be NULL, if not needed. |
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.. seealso:: :ocv:func:`calcOpticalFlowPyrLK` |
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gpu::PyrLKOpticalFlow::dense |
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----------------------------- |
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Calculate dense optical flow. |
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.. ocv:function:: void gpu::PyrLKOpticalFlow::dense(const GpuMat& prevImg, const GpuMat& nextImg, GpuMat& u, GpuMat& v, GpuMat* err = 0) |
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:param prevImg: First 8-bit grayscale input image. |
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:param nextImg: Second input image of the same size and the same type as ``prevImg`` . |
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:param u: Horizontal component of the optical flow of the same size as input images, 32-bit floating-point, single-channel |
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:param v: Vertical component of the optical flow of the same size as input images, 32-bit floating-point, single-channel |
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:param err: Output vector (CV_32FC1 type) that contains the difference between patches around the original and moved points or min eigen value if ``getMinEigenVals`` is checked. It can be NULL, if not needed. |
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gpu::PyrLKOpticalFlow::releaseMemory |
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------------------------------------ |
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Releases inner buffers memory. |
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.. ocv:function:: void gpu::PyrLKOpticalFlow::releaseMemory() |
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gpu::interpolateFrames |
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---------------------- |
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Interpolates frames (images) using provided optical flow (displacement field). |
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.. ocv:function:: void gpu::interpolateFrames(const GpuMat& frame0, const GpuMat& frame1, const GpuMat& fu, const GpuMat& fv, const GpuMat& bu, const GpuMat& bv, float pos, GpuMat& newFrame, GpuMat& buf, Stream& stream = Stream::Null()) |
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:param frame0: First frame (32-bit floating point images, single channel). |
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:param frame1: Second frame. Must have the same type and size as ``frame0`` . |
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:param fu: Forward horizontal displacement. |
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:param fv: Forward vertical displacement. |
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:param bu: Backward horizontal displacement. |
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:param bv: Backward vertical displacement. |
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:param pos: New frame position. |
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:param newFrame: Output image. |
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:param buf: Temporary buffer, will have width x 6*height size, CV_32FC1 type and contain 6 GpuMat: occlusion masks for first frame, occlusion masks for second, interpolated forward horizontal flow, interpolated forward vertical flow, interpolated backward horizontal flow, interpolated backward vertical flow. |
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:param stream: Stream for the asynchronous version. |
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gpu::VideoWriter_GPU |
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--------------------- |
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Video writer class. |
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.. ocv:class:: gpu::VideoWriter_GPU |
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The class uses H264 video codec. |
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.. note:: Currently only Windows platform is supported. |
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gpu::VideoWriter_GPU::VideoWriter_GPU |
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------------------------------------- |
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Constructors. |
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.. ocv:function:: gpu::VideoWriter_GPU::VideoWriter_GPU() |
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.. ocv:function:: gpu::VideoWriter_GPU::VideoWriter_GPU(const std::string& fileName, cv::Size frameSize, double fps, SurfaceFormat format = SF_BGR) |
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.. ocv:function:: gpu::VideoWriter_GPU::VideoWriter_GPU(const std::string& fileName, cv::Size frameSize, double fps, const EncoderParams& params, SurfaceFormat format = SF_BGR) |
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.. ocv:function:: gpu::VideoWriter_GPU::VideoWriter_GPU(const cv::Ptr<EncoderCallBack>& encoderCallback, cv::Size frameSize, double fps, SurfaceFormat format = SF_BGR) |
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.. ocv:function:: gpu::VideoWriter_GPU::VideoWriter_GPU(const cv::Ptr<EncoderCallBack>& encoderCallback, cv::Size frameSize, double fps, const EncoderParams& params, SurfaceFormat format = SF_BGR) |
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:param fileName: Name of the output video file. Only AVI file format is supported. |
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:param frameSize: Size of the input video frames. |
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:param fps: Framerate of the created video stream. |
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:param params: Encoder parameters. See :ocv:class:`gpu::VideoWriter_GPU::EncoderParams` . |
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:param format: Surface format of input frames ( ``SF_UYVY`` , ``SF_YUY2`` , ``SF_YV12`` , ``SF_NV12`` , ``SF_IYUV`` , ``SF_BGR`` or ``SF_GRAY``). BGR or gray frames will be converted to YV12 format before encoding, frames with other formats will be used as is. |
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:param encoderCallback: Callbacks for video encoder. See :ocv:class:`gpu::VideoWriter_GPU::EncoderCallBack` . Use it if you want to work with raw video stream. |
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The constructors initialize video writer. FFMPEG is used to write videos. User can implement own multiplexing with :ocv:class:`gpu::VideoWriter_GPU::EncoderCallBack` . |
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gpu::VideoWriter_GPU::open |
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-------------------------- |
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Initializes or reinitializes video writer. |
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.. ocv:function:: void gpu::VideoWriter_GPU::open(const std::string& fileName, cv::Size frameSize, double fps, SurfaceFormat format = SF_BGR) |
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.. ocv:function:: void gpu::VideoWriter_GPU::open(const std::string& fileName, cv::Size frameSize, double fps, const EncoderParams& params, SurfaceFormat format = SF_BGR) |
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.. ocv:function:: void gpu::VideoWriter_GPU::open(const cv::Ptr<EncoderCallBack>& encoderCallback, cv::Size frameSize, double fps, SurfaceFormat format = SF_BGR) |
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.. ocv:function:: void gpu::VideoWriter_GPU::open(const cv::Ptr<EncoderCallBack>& encoderCallback, cv::Size frameSize, double fps, const EncoderParams& params, SurfaceFormat format = SF_BGR) |
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The method opens video writer. Parameters are the same as in the constructor :ocv:func:`gpu::VideoWriter_GPU::VideoWriter_GPU` . The method throws :ocv:class:`Exception` if error occurs. |
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gpu::VideoWriter_GPU::isOpened |
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------------------------------ |
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Returns true if video writer has been successfully initialized. |
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.. ocv:function:: bool gpu::VideoWriter_GPU::isOpened() const |
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gpu::VideoWriter_GPU::close |
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--------------------------- |
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Releases the video writer. |
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.. ocv:function:: void gpu::VideoWriter_GPU::close() |
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gpu::VideoWriter_GPU::write |
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--------------------------- |
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Writes the next video frame. |
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.. ocv:function:: void gpu::VideoWriter_GPU::write(const cv::gpu::GpuMat& image, bool lastFrame = false) |
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:param image: The written frame. |
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:param lastFrame: Indicates that it is end of stream. The parameter can be ignored. |
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The method write the specified image to video file. The image must have the same size and the same surface format as has been specified when opening the video writer. |
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gpu::VideoWriter_GPU::EncoderParams |
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----------------------------------- |
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.. ocv:struct:: gpu::VideoWriter_GPU::EncoderParams |
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Different parameters for CUDA video encoder. :: |
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struct EncoderParams |
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{ |
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int P_Interval; // NVVE_P_INTERVAL, |
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int IDR_Period; // NVVE_IDR_PERIOD, |
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int DynamicGOP; // NVVE_DYNAMIC_GOP, |
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int RCType; // NVVE_RC_TYPE, |
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int AvgBitrate; // NVVE_AVG_BITRATE, |
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int PeakBitrate; // NVVE_PEAK_BITRATE, |
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int QP_Level_Intra; // NVVE_QP_LEVEL_INTRA, |
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int QP_Level_InterP; // NVVE_QP_LEVEL_INTER_P, |
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int QP_Level_InterB; // NVVE_QP_LEVEL_INTER_B, |
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int DeblockMode; // NVVE_DEBLOCK_MODE, |
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int ProfileLevel; // NVVE_PROFILE_LEVEL, |
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int ForceIntra; // NVVE_FORCE_INTRA, |
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int ForceIDR; // NVVE_FORCE_IDR, |
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int ClearStat; // NVVE_CLEAR_STAT, |
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int DIMode; // NVVE_SET_DEINTERLACE, |
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int Presets; // NVVE_PRESETS, |
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int DisableCabac; // NVVE_DISABLE_CABAC, |
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int NaluFramingType; // NVVE_CONFIGURE_NALU_FRAMING_TYPE |
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int DisableSPSPPS; // NVVE_DISABLE_SPS_PPS |
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EncoderParams(); |
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explicit EncoderParams(const std::string& configFile); |
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void load(const std::string& configFile); |
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void save(const std::string& configFile) const; |
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}; |
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gpu::VideoWriter_GPU::EncoderParams::EncoderParams |
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-------------------------------------------------- |
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Constructors. |
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.. ocv:function:: gpu::VideoWriter_GPU::EncoderParams::EncoderParams() |
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.. ocv:function:: gpu::VideoWriter_GPU::EncoderParams::EncoderParams(const std::string& configFile) |
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:param configFile: Config file name. |
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Creates default parameters or reads parameters from config file. |
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gpu::VideoWriter_GPU::EncoderParams::load |
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----------------------------------------- |
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Reads parameters from config file. |
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.. ocv:function:: void gpu::VideoWriter_GPU::EncoderParams::load(const std::string& configFile) |
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:param configFile: Config file name. |
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gpu::VideoWriter_GPU::EncoderParams::save |
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----------------------------------------- |
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Saves parameters to config file. |
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.. ocv:function:: void gpu::VideoWriter_GPU::EncoderParams::save(const std::string& configFile) const |
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:param configFile: Config file name. |
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gpu::VideoWriter_GPU::EncoderCallBack |
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------------------------------------- |
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.. ocv:class:: gpu::VideoWriter_GPU::EncoderCallBack |
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Callbacks for CUDA video encoder. :: |
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class EncoderCallBack |
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{ |
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public: |
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enum PicType |
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{ |
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IFRAME = 1, |
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PFRAME = 2, |
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BFRAME = 3 |
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}; |
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virtual ~EncoderCallBack() {} |
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virtual unsigned char* acquireBitStream(int* bufferSize) = 0; |
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virtual void releaseBitStream(unsigned char* data, int size) = 0; |
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virtual void onBeginFrame(int frameNumber, PicType picType) = 0; |
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virtual void onEndFrame(int frameNumber, PicType picType) = 0; |
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}; |
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gpu::VideoWriter_GPU::EncoderCallBack::acquireBitStream |
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------------------------------------------------------- |
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Callback function to signal the start of bitstream that is to be encoded. |
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.. ocv:function:: virtual uchar* gpu::VideoWriter_GPU::EncoderCallBack::acquireBitStream(int* bufferSize) = 0 |
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Callback must allocate buffer for CUDA encoder and return pointer to it and it's size. |
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gpu::VideoWriter_GPU::EncoderCallBack::releaseBitStream |
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------------------------------------------------------- |
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Callback function to signal that the encoded bitstream is ready to be written to file. |
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.. ocv:function:: virtual void gpu::VideoWriter_GPU::EncoderCallBack::releaseBitStream(unsigned char* data, int size) = 0 |
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gpu::VideoWriter_GPU::EncoderCallBack::onBeginFrame |
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--------------------------------------------------- |
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Callback function to signal that the encoding operation on the frame has started. |
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.. ocv:function:: virtual void gpu::VideoWriter_GPU::EncoderCallBack::onBeginFrame(int frameNumber, PicType picType) = 0 |
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:param picType: Specify frame type (I-Frame, P-Frame or B-Frame). |
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gpu::VideoWriter_GPU::EncoderCallBack::onEndFrame |
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------------------------------------------------- |
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Callback function signals that the encoding operation on the frame has finished. |
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.. ocv:function:: virtual void gpu::VideoWriter_GPU::EncoderCallBack::onEndFrame(int frameNumber, PicType picType) = 0 |
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:param picType: Specify frame type (I-Frame, P-Frame or B-Frame). |
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gpu::VideoReader_GPU |
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-------------------- |
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Class for reading video from files. |
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.. ocv:class:: gpu::VideoReader_GPU |
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gpu::VideoReader_GPU::Codec |
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--------------------------- |
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Video codecs supported by ocv:class:`gpu::VideoReader_GPU` . :: |
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enum Codec |
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{ |
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MPEG1 = 0, |
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MPEG2, |
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MPEG4, |
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VC1, |
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H264, |
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JPEG, |
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H264_SVC, |
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H264_MVC, |
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Uncompressed_YUV420 = (('I'<<24)|('Y'<<16)|('U'<<8)|('V')), // Y,U,V (4:2:0) |
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Uncompressed_YV12 = (('Y'<<24)|('V'<<16)|('1'<<8)|('2')), // Y,V,U (4:2:0) |
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Uncompressed_NV12 = (('N'<<24)|('V'<<16)|('1'<<8)|('2')), // Y,UV (4:2:0) |
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Uncompressed_YUYV = (('Y'<<24)|('U'<<16)|('Y'<<8)|('V')), // YUYV/YUY2 (4:2:2) |
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Uncompressed_UYVY = (('U'<<24)|('Y'<<16)|('V'<<8)|('Y')), // UYVY (4:2:2) |
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}; |
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gpu::VideoReader_GPU::ChromaFormat |
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---------------------------------- |
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Chroma formats supported by ocv:class:`gpu::VideoReader_GPU` . :: |
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enum ChromaFormat |
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{ |
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Monochrome=0, |
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YUV420, |
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YUV422, |
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YUV444, |
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}; |
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gpu::VideoReader_GPU::FormatInfo |
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-------------------------------- |
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.. ocv:struct:: gpu::VideoReader_GPU::FormatInfo |
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Struct providing information about video file format. :: |
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struct FormatInfo |
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{ |
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Codec codec; |
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ChromaFormat chromaFormat; |
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int width; |
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int height; |
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}; |
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gpu::VideoReader_GPU::VideoReader_GPU |
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------------------------------------- |
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Constructors. |
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.. ocv:function:: gpu::VideoReader_GPU::VideoReader_GPU() |
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.. ocv:function:: gpu::VideoReader_GPU::VideoReader_GPU(const std::string& filename) |
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.. ocv:function:: gpu::VideoReader_GPU::VideoReader_GPU(const cv::Ptr<VideoSource>& source) |
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:param filename: Name of the input video file. |
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:param source: Video file parser implemented by user. |
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The constructors initialize video reader. FFMPEG is used to read videos. User can implement own demultiplexing with :ocv:class:`gpu::VideoReader_GPU::VideoSource` . |
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gpu::VideoReader_GPU::open |
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-------------------------- |
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Initializes or reinitializes video reader. |
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.. ocv:function:: void gpu::VideoReader_GPU::open(const std::string& filename) |
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.. ocv:function:: void gpu::VideoReader_GPU::open(const cv::Ptr<VideoSource>& source) |
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The method opens video reader. Parameters are the same as in the constructor :ocv:func:`gpu::VideoReader_GPU::VideoReader_GPU` . The method throws :ocv:class:`Exception` if error occurs. |
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gpu::VideoReader_GPU::isOpened |
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------------------------------ |
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Returns true if video reader has been successfully initialized. |
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.. ocv:function:: bool gpu::VideoReader_GPU::isOpened() const |
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gpu::VideoReader_GPU::close |
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--------------------------- |
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Releases the video reader. |
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.. ocv:function:: void gpu::VideoReader_GPU::close() |
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gpu::VideoReader_GPU::read |
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-------------------------- |
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Grabs, decodes and returns the next video frame. |
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.. ocv:function:: bool gpu::VideoReader_GPU::read(GpuMat& image) |
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If no frames has been grabbed (there are no more frames in video file), the methods return ``false`` . The method throws :ocv:class:`Exception` if error occurs. |
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gpu::VideoReader_GPU::format |
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---------------------------- |
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Returns information about video file format. |
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.. ocv:function:: FormatInfo gpu::VideoReader_GPU::format() const |
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The method throws :ocv:class:`Exception` if video reader wasn't initialized. |
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gpu::VideoReader_GPU::dumpFormat |
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---------------------------- |
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Dump information about video file format to specified stream. |
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.. ocv:function:: void gpu::VideoReader_GPU::dumpFormat(std::ostream& st) |
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:param st: Output stream. |
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The method throws :ocv:class:`Exception` if video reader wasn't initialized. |
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gpu::VideoReader_GPU::VideoSource |
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----------------------------------- |
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.. ocv:class:: gpu::VideoReader_GPU::VideoSource |
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Interface for video demultiplexing. :: |
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class VideoSource |
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{ |
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public: |
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VideoSource(); |
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virtual ~VideoSource() {} |
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virtual FormatInfo format() const = 0; |
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virtual void start() = 0; |
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virtual void stop() = 0; |
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virtual bool isStarted() const = 0; |
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virtual bool hasError() const = 0; |
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protected: |
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bool parseVideoData(const unsigned char* data, size_t size, bool endOfStream = false); |
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}; |
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User can implement own demultiplexing by implementing this interface. |
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gpu::VideoReader_GPU::VideoSource::format |
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----------------------------------------- |
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Returns information about video file format. |
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.. ocv:function:: virtual FormatInfo gpu::VideoReader_GPU::VideoSource::format() const = 0 |
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gpu::VideoReader_GPU::VideoSource::start |
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---------------------------------------- |
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Starts processing. |
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.. ocv:function:: virtual void gpu::VideoReader_GPU::VideoSource::start() = 0 |
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Implementation must create own thread with video processing and call periodic :ocv:func:`gpu::VideoReader_GPU::VideoSource::parseVideoData` . |
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gpu::VideoReader_GPU::VideoSource::stop |
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--------------------------------------- |
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Stops processing. |
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.. ocv:function:: virtual void gpu::VideoReader_GPU::VideoSource::stop() = 0 |
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gpu::VideoReader_GPU::VideoSource::isStarted |
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-------------------------------------------- |
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Returns ``true`` if processing was successfully started. |
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.. ocv:function:: virtual bool gpu::VideoReader_GPU::VideoSource::isStarted() const = 0 |
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gpu::VideoReader_GPU::VideoSource::hasError |
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------------------------------------------- |
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Returns ``true`` if error occured during processing. |
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.. ocv:function:: virtual bool gpu::VideoReader_GPU::VideoSource::hasError() const = 0 |
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gpu::VideoReader_GPU::VideoSource::parseVideoData |
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------------------------------------------------- |
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Parse next video frame. Implementation must call this method after new frame was grabbed. |
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.. ocv:function:: bool gpu::VideoReader_GPU::VideoSource::parseVideoData(const unsigned char* data, size_t size, bool endOfStream = false) |
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:param data: Pointer to frame data. Can be ``NULL`` if ``endOfStream`` if ``true`` . |
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:param size: Size in bytes of current frame. |
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:param endOfStream: Indicates that it is end of stream. |
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.. [Brox2004] T. Brox, A. Bruhn, N. Papenberg, J. Weickert. *High accuracy optical flow estimation based on a theory for warping*. ECCV 2004.
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