Add center_video.cpp

src/center_video.cpp

@@ -0,0 +1,177 @@
+#include <opencv2/opencv.hpp>
+
+#define WIDTH 1920
+#define HEIGHT 1080
+#define ACCEPTED_BLANK 20
+#define ACCEPTED_NON_BG 10
+#define SHOW_PROGRESS
+
+using namespace std;
+
+cv::Scalar backgroundColor(255, 255, 255);
+cv::Scalar blue(249, 0, 0);
+
+
+bool is_background (const cv::Vec3b& pixel) {
+    // Upper bound: 195075
+    return abs((pixel[0] - backgroundColor[0])*(pixel[1] - backgroundColor[1])*(pixel[2] - backgroundColor[2])) < 5000;
+};
+
+cv::Rect get_pos(const cv::Mat& frame) {
+    bool no_break = true;
+    int left_margin = -1;
+    int right_margin = -1;
+
+    for (int i=0; i < frame.cols; i++) {
+        bool contains_non_white = false;
+        for (int j=0; j < frame.rows; j++) {
+            int non_bg = 0;
+            if (!is_background(frame.at<cv::Vec3b>(j, i))) {
+                contains_non_white = true;
+                break;
+            }
+        }
+
+        if (no_break && !contains_non_white) {
+            left_margin += 1;
+        } else if (contains_non_white) {
+            no_break = false;
+        }
+
+        if (contains_non_white) {
+            right_margin = i+1;
+        }
+    }
+
+    right_margin = min(right_margin, frame.cols-1);
+
+    // Iterate over the lines and find the tallest block of non-white lines, this will give us
+    // the vertical size of the rectangle, i.e the top and bottom margins
+    int top_margin = -1;
+    int bottom_margin = -1;
+    int max_height = 0;
+
+    int cur_height = -1;
+    int cur_top_margin = 0;
+
+    int echecs = 0;
+
+    for (int i=0; i < frame.rows; i++) {
+        bool contains_non_white = false;
+        int non_bg = 0;
+        for (int j=0; j < frame.cols; j++) {
+            if (!is_background(frame.at<cv::Vec3b>(i, j))) {
+                if (++non_bg >= ACCEPTED_NON_BG) {
+                    contains_non_white = true;
+                    break;
+                }
+            }
+        }
+
+        if (!contains_non_white) {
+            if (++echecs >= ACCEPTED_BLANK) {
+                if (cur_height >= max_height) {
+                    max_height = cur_height;
+                    top_margin = cur_top_margin;
+                    bottom_margin = cur_top_margin + cur_height;
+                }
+
+                cur_height = -1;
+            }
+        } else {
+            cur_height += 1;
+            if (cur_height == 0) {
+                cur_top_margin = i;
+            }
+            echecs = 0;
+        }
+    }
+
+    if (cur_height >= max_height) {
+        max_height = cur_height;
+        top_margin = cur_top_margin;
+        bottom_margin = cur_top_margin + cur_height;
+    }
+
+    //cout << "top: " << top_margin << ", bottom: " << bottom_margin << ", height: " << max_height << endl;
+    bottom_margin = min(bottom_margin, frame.rows-1);
+
+
+    cv::Rect rect = cv::Rect(left_margin, top_margin, right_margin-left_margin, bottom_margin-top_margin);
+    // Return a rectangle covering all the frame except the left margin
+    //cv::Rect rect = cv::Rect(left_margin, 0, right_margin-left_margin, frame.rows-1);
+    //cout << rect << endl;
+    return rect;
+}
+
+int main(int argc, char** argv) {
+    if (argc != 3) {
+        cerr << "Usage: " << argv[0] << " <input_video_file> <output_video_file>" << endl;
+        return 1;
+    }
+
+    // Open the input video file
+    cv::VideoCapture inputVideo(argv[1]);
+    if (!inputVideo.isOpened()) {
+        cerr << "Error: Could not open input video file." << endl;
+        return 1;
+    }
+
+    // Get input video properties
+    int inputWidth = inputVideo.get(cv::CAP_PROP_FRAME_WIDTH);
+    int inputHeight = inputVideo.get(cv::CAP_PROP_FRAME_HEIGHT);
+    int totalFrames = static_cast<int>(inputVideo.get(cv::CAP_PROP_FRAME_COUNT));
+
+    // Create video writer for the output video
+    cv::VideoWriter outputVideo(argv[2], cv::VideoWriter::fourcc('X', '2', '6', '4'), inputVideo.get(cv::CAP_PROP_FPS),
+                                cv::Size(WIDTH, HEIGHT), true);
+
+    if (!outputVideo.isOpened()) {
+        cerr << "Error: Could not open output video file for writing." << endl;
+        return 1;
+    }
+
+    // Process each frame
+    cv::Mat frame;
+    int currentFrame = 0;
+    int last_progress = -1;
+    while (inputVideo.read(frame)) {
+        // Get the rectangle to keep using the get_pos function
+        cv::Rect roi = get_pos(frame);
+
+        cv::Mat resizedFrame(HEIGHT, WIDTH, frame.type(), blue);
+        frame(roi).copyTo(resizedFrame(cv::Rect((WIDTH - roi.width) / 2, (HEIGHT - roi.height) / 2, roi.width, roi.height)));
+
+        // Write the modified frame to the output video
+        outputVideo.write(resizedFrame);
+
+        // Update and display progress bar
+        currentFrame++;
+
+        #ifdef SHOW_PROGRESS
+            float progress = static_cast<float>(currentFrame) / totalFrames;
+            int barWidth = 50;
+            int pos = static_cast<int>(barWidth * progress);
+
+            int progress_percent = static_cast<int>(progress * 100.0);
+            if (progress_percent != last_progress) {
+                cout << "[";
+                for (int i = 0; i < barWidth; ++i) {
+                    if (i < pos) cout << "=";
+                    else if (i == pos) cout << ">";
+                    else cout << " ";
+                }
+                cout << "] " << int(progress * 100.0) << "%    " << roi << "\r";
+                cout.flush();
+            }
+        #endif
+    }
+
+    // Release video capture and writer objects
+    inputVideo.release();
+    outputVideo.release();
+
+    cout << "Video processing complete. Output saved to: " << argv[2] << endl;
+
+    return 0;
+}