![]() ![]() Size frame_size(frame_width, frame_height) Īs previously discussed, the get() method from the VideoCapture() class requires: Int frame_height = static_cast(vid_capture.get(4)) Int frame_width = static_cast(vid_capture.get(3)) Obtain frame size information using get() method In this case, for example, if the user presses the ‘ q’ key, you exit the loop. Calling the waitKey() function lets you monitor the keyboard for user input. If there is a frame to read, you can then use imshow() to display the current frame in a window, otherwise exit the loop. Notice that you also use the waitKey() function to pause for 20ms between video frames. When the first element is True, it indicates the video stream contains a frame to read. The vid_capture.read() method returns a tuple, where the first element is a boolean and the next element is the actual video frame. This is accomplished by creating a loop and reading one frame at a time from the video stream using the vid_capture.read() method. PythonĪfter retrieving the desired metadata associated with the video file, we are now ready to read each image frame from the file. The numeric value or the name can be supplied. In the example below, we provided the numeric values 5 and 7, which correspond to the frame rate ( CAP_PROP_FPS) and frame count ( CAP_PROP_FRAME_COUNT). The get() method takes a single argument from an enumerated list of options documented here. Note that this method does not apply to web cameras. One of them is that the entire video is corrupted, or some frames are corrupted. Assuming the video file was opened successfully, we can use the get() method to retrieve important metadata associated with the video stream. The isOpened() method returns a boolean that indicates whether or not the video stream is valid. Now that we have a video capture object we can use the isOpened() method to confirm the video file was opened successfully. Stopping the video" << endl įor all the examples given below, you can use the same video file that we have used here, which is available in the Downloadable Code folder, or you can use your own video file. wait 20 ms between successive frames and break the loop if key q is pressedĬout << "q key is pressed by the user. Initialize a boolean to check if frames are there or notīool isSuccess = vid_capture.read(frame) Ĭout << "Video camera is disconnected" << endl You can replace 7 with CAP_PROP_FRAME_COUNT as well, they are enumerations Obtain frame_count using opencv built in frame count reading method You can replace 5 with CAP_PROP_FPS as well, they are enumerations Obtain fps and frame count by get() method and print ![]() Print error message if the stream is invalidĬout << "Error opening video stream or file" << endl VideoCapture vid_capture("Resources/Cars.mp4") Namespace to nullify use of cv::function() syntax # 20 is in milliseconds, try to increase the value, say 50 and observe # vid_capture.read() methods returns a tuple, first element is a bool # You can replace 7 with CAP_PROP_FRAME_COUNT as well, they are enumerations # You can replace 5 with CAP_PROP_FPS as well, they are enumerations Vid_capture = cv2.VideoCapture('Resources/Cars.mp4') # Create a video capture object, in this case we are reading the video from a file
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