message: videoio(test): test V4L frame size changing manual test
diff: namespace opencv_test { namespace {
  -static void test_readFrames(/*const*/ VideoCapture& capture, const int N = 100)
  +static void test_readFrames(/*const*/ VideoCapture& capture, const int N = 100, Mat* lastFrame = NULL)
  {
  Mat frame;
  int64 time0 = cv::getTickCount();
  @@ -26,6 +26,7 @@ static void test_readFrames(/*const*/ VideoCapture& capture, const int N = 100)
  }
  int64 time1 = cv::getTickCount();
  printf("Processed %d frames on %.2f FPS\n", N, (N * cv::getTickFrequency()) / (time1 - time0 + 1));
  + if (lastFrame) *lastFrame = frame.clone();
  }
  TEST(DISABLED_VideoIO_Camera, basic)
  @@ -55,4 +56,39 @@ TEST(DISABLED_VideoIO_Camera, validate_V4L2_MJPEG)
  capture.release();
  }
  +TEST(DISABLED_VideoIO_Camera, validate_V4L2_FrameSize)
  +{
  + VideoCapture capture(CAP_V4L2);
  + ASSERT_TRUE(capture.isOpened());
  + std::cout << "Camera 0 via " << capture.getBackendName() << " backend" << std::endl;
  + std::cout << "Frame width: " << capture.get(CAP_PROP_FRAME_WIDTH) << std::endl;
  + std::cout << " height: " << capture.get(CAP_PROP_FRAME_HEIGHT) << std::endl;
  + std::cout << "Capturing FPS: " << capture.get(CAP_PROP_FPS) << std::endl;
  + int fourcc = (int)capture.get(CAP_PROP_FOURCC);
  + std::cout << "FOURCC code: " << cv::format("0x%8x", fourcc) << std::endl;
  + test_readFrames(capture, 30);
  +
  + EXPECT_TRUE(capture.set(CAP_PROP_FRAME_WIDTH, 640));
  + EXPECT_TRUE(capture.set(CAP_PROP_FRAME_HEIGHT, 480));
  + std::cout << "Frame width: " << capture.get(CAP_PROP_FRAME_WIDTH) << std::endl;
  + std::cout << " height: " << capture.get(CAP_PROP_FRAME_HEIGHT) << std::endl;
  + std::cout << "Capturing FPS: " << capture.get(CAP_PROP_FPS) << std::endl;
  + Mat frame640x480;
  + test_readFrames(capture, 30, &frame640x480);
  + EXPECT_EQ(640, frame640x480.cols);
  + EXPECT_EQ(480, frame640x480.rows);
  +
  + EXPECT_TRUE(capture.set(CAP_PROP_FRAME_WIDTH, 1280));
  + EXPECT_TRUE(capture.set(CAP_PROP_FRAME_HEIGHT, 720));
  + std::cout << "Frame width: " << capture.get(CAP_PROP_FRAME_WIDTH) << std::endl;
  + std::cout << " height: " << capture.get(CAP_PROP_FRAME_HEIGHT) << std::endl;
  + std::cout << "Capturing FPS: " << capture.get(CAP_PROP_FPS) << std::endl;
  + Mat frame1280x720;
  + test_readFrames(capture, 30, &frame1280x720);
  + EXPECT_EQ(1280, frame1280x720.cols);
  + EXPECT_EQ(720, frame1280x720.rows);
  +
  + capture.release();
  +}
  +
  }} // namespace
  