* moved DIS optical flow from opencv_contrib to opencv, moved TVL1 from opencv to opencv_contrib

* fixed compile warning

* TVL1 optical flow example moved to opencv_contrib

* significantly reduced OpenCV binary size by disabling IPP calls in some OpenCV functions: Sobel, Scharr, medianBlur, GaussianBlur, filter2D, mean, meanStdDev, norm, sum, minMaxIdx, sort.

* re-enable IPP in norm, since it's much faster (without adding too much space overhead)

* refined QRCodeDetector API for OpenCV 4.0

* expanded and tested QRCodeDetector::detectAndDecode()

* removed C API in the following modules: photo, video, imgcodecs, videoio

* trying to fix various compile errors and warnings on Windows and Linux

* continue to fix compile errors and warnings

* continue to fix compile errors, warnings, as well as the test failures

* trying to resolve compile warnings on Android

* Update cap_dc1394_v2.cpp

fix warning from the new GCC

G-API GPU-OpenCL backend (#13008)

* gpu/ocl backend core

* accuracy tests added and adjusted + license headers

* GPU perf. tests added; almost all adjusted to pass

* all tests adjusted and passed - ready for pull request

* missing license headers

* fix warning (workaround RGB2Gray)

* fix c++ magic

* precompiled header

* white spaces

* try to fix warning and blur test

* try to fix Blur perf tests

* more alignments with the latest cpu backend

* more gapi tests refactoring + 1 more UB issue fix + more informative tolerance exceed reports

* white space fix

* try workaround for SumTest

* GAPI_EXPORTS instead CV_EXPORTS

- VFW
- QuickTime/QtKit
- Unicap - GPL, no active support: https://github.com/unicap/unicap
- DC1394 (1st version) / CMU1394

https://en.wikipedia.org/wiki/Carbon_(API)

In 2012, with the release of OS X 10.8 Mountain Lion, most Carbon APIs were considered deprecated.

ffmpeg 4.0.2 -> 4.1

This is a workaround for GPU hang on heavy convolution workload (> 10 GFLOPS).
e.g. ResNet101_DUC_HDC

For the long time task, vkWaitForFences() return without error but next call on
vkQueueSubmit() return -4, i.e. "VK_ERROR_DEVICE_LOST" and driver reports GPU hang.

Need more investigation on root cause of GPU hang and need to optimize convolution shader
to reduce process time.

cmake: introduce setup_vars scripts

* GAPI: Sobel 3x3 with FP32 input

* GAPI: Sobel 3x3 with FP32 input, v2

typo in kmeans doc