Ok after a long time of digging round heres a working basic c++ code block :^) don't ask me about what witchcraft got it to work, honestly just kept combining random github results till a few things clicked together as there is not a whole lot of documentation out there for module 3. I learnt basically libcamera and its pre included library is dumb and you have to do a thing before using the code snippet below on newer debian versions. I am using Debian bullseye and to get it to work I uninstalled the base libcam, then compiled the github libcam and ran the pre command for it to work. Dunno if a fresh compile made a difference but I certainly was missing libcamsrc on my build for some reason. If you are using it often I recommend using a script that runs both the compiled program and the required command beforehand.**bump**
I am having the exact same scenario as OP. Only difference is I'm using Rpi 5.
Using Module 3 camera too but can't seem to get openCV to work.
You will also needless to say need opencv dev package.
Compile with g++ using : g++ Camera.cpp -o Camera `pkg-config --cflags --libs opencv4` -lglfw -lGL
Command to use before using the compiled binary : export GST_PLUGIN_PATH=/usr/local/lib/aarch64-linux-gnu/
Code:
#include <opencv2/opencv.hpp>std::string gstreamer_pipeline(int capture_width, int capture_height, int framerate, int display_width, int display_height) { // Simplified pipeline with tuned parameters for latency improvement return " libcamerasrc ! video/x-raw, " " width=(int)" + std::to_string(capture_width) + "," " height=(int)" + std::to_string(capture_height) + "," " framerate=(fraction)" + std::to_string(framerate) +"/1 !" " videoconvert ! videoscale !" " video/x-raw," " width=(int)" + std::to_string(display_width) + "," " height=(int)" + std::to_string(display_height) + " ! queue leaky=downstream max-size-buffers=1 ! appsink sync=false";}int main(){ //pipeline parameters int capture_width = 1024; // Reduced for lower latency, increase this to your desired resolution. int capture_height = 576; // Reduced for lower latency increase this to your desired resolution. int framerate = 50; // Reduced for lower latency increase this to your desired resolution. int display_width = 1080; // Adjusted to match reduced capture size int display_height = 632; // Adjusted to match reduced capture size std::string pipeline = gstreamer_pipeline(capture_width, capture_height, framerate, display_width, display_height); std::cout << "Using pipeline: \n\t" << pipeline << "\n\n\n"; cv::VideoCapture cap(pipeline, cv::CAP_GSTREAMER); if(!cap.isOpened()) { std::cout<<"Failed to open camera."<<std::endl; return (-1); } // Set buffer size to 1 to reduce latency. Not really sure if this is safe to do or if it may cause crashes cap.set(cv::CAP_PROP_BUFFERSIZE, 1); cv::namedWindow("Camera", cv::WINDOW_GUI_NORMAL); cv::resizeWindow("Camera", display_width, display_height); cv::Mat frame; cv::moveWindow("Camera", 1010, 100); // y, x std::cout << "Hit ESC to exit" << "\n" ; while(true) { if (!cap.read(frame)) { std::cout<<"Capture read error"<<std::endl; break; } //show frame cv::imshow("Camera",frame); char esc = cv::waitKey(5); // Quit on esc if(esc == 27) break; } cap.release(); cv::destroyAllWindows() ; return 0;}Statistics: Posted by d0gman — Sun Mar 10, 2024 9:22 am