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https://stackoverflow.com/questions/53192627/sometimes-failed-to-read-frame-from-rtsp-with-opencv

I got a strange issue. my code is quite simple, just read frame from RTSP and do some processing.

for (;;) { cap >> frame; if (frame.empty()) { break; } // heavy_processing(frame) // opencv-dnn face detection stuff imshow("cam",frame); } the rtsp streaming is a webcam with 1920x1080P, network traffic is arround 4Mb/s

without "heavy_processing()" function, basically it runs good. CPU is 45% (i7-7700)

with "heavy_processing()" function, it will read an empty frame after couple seconds then exit. I can see CPU surge to 95%+ before it exit.

I built opencv(3.4.3) myself with mostly default option.

so far I suspect the videocap device shutdown when there are too much frames in the buffer, but it doesn't make sense.shouldn't it drop the earliest frame? or is it possible the frame is corrupted inside 'heavy_processing()'?

ffmpeg probably is 4.0(built myself), ubuntu 16.04

https://stackoverflow.com/questions/53192627/sometimes-failed-to-read-frame-from-rtsp-with-opencv

I got a strange issue. my code is quite simple, just read frame from RTSP and do some processing.

for (;;)
{
cap >> frame;
if (frame.empty()) {
break;
}
// heavy_processing(frame) // opencv-dnn face detection stuff
imshow("cam",frame);
}

https://stackoverflow.com/questions/53192627/sometimes-failed-to-read-frame-from-rtsp-with-opencv

I got a strange issue. my code is quite simple, just read frame from RTSP and do some processing.

for (;;)
{
    cap >> frame;
    if (frame.empty()) {
        break;
    }
    // heavy_processing(frame) // opencv-dnn face detection stuff
    imshow("cam",frame);
}

the rtsp streaming is a webcam with 1920x1080P, network traffic is arround 4Mb/s

without "heavy_processing()" function, basically it runs good. CPU is 45% (i7-7700)

with "heavy_processing()" function, it will read an empty frame after couple seconds then exit. I can see CPU surge to 95%+ before it exit.

I built opencv(3.4.3) myself with mostly default option.

so far I suspect the videocap device shutdown when there are too much frames in the buffer, but it doesn't make sense.shouldn't it drop the earliest frame? or is it possible the frame is corrupted inside 'heavy_processing()'?

ffmpeg probably is 4.0(built myself), ubuntu 16.04

void detect(Mat frame, Mat blob, Net &net, Size &inpSize, vector<cv::Rect> &face_rects) {
    Mat detectFrame;
    cv::resize(frame, detectFrame, cv::Size(300, 300), 0, 0, cv::INTER_AREA);
    dnn::blobFromImage(detectFrame, blob, 1.0, inpSize, mean, false, false);
    // if I return here is good
    net.setInput(blob);
    Mat detection = net.forward();   // as long as I add the last two line, it will get read frame empty

https://stackoverflow.com/questions/53192627/sometimes-failed-to-read-frame-from-rtsp-with-opencv

I got a strange issue. my code is quite simple, just read frame from RTSP and do some processing.

for (;;)
{
    cap >> frame;
    if (frame.empty()) {
        break;
    }
    // heavy_processing(frame) // opencv-dnn face detection stuff
    imshow("cam",frame);
}

the rtsp streaming is a webcam with 1920x1080P, network traffic is arround 4Mb/s

without "heavy_processing()" function, basically it runs good. CPU is 45% (i7-7700)

with "heavy_processing()" function, it will read an empty frame after couple seconds then exit. I can see CPU surge to 95%+ before it exit.

I built opencv(3.4.3) myself with mostly default option.

so far I suspect the videocap device shutdown when there are too much frames in the buffer, but it doesn't make sense.shouldn't it drop the earliest frame? or is it possible the frame is corrupted inside 'heavy_processing()'?

ffmpeg probably is 4.0(built myself), ubuntu 16.04

update:

the heavy_processing() function, suspect it is related.

void detect(Mat frame, Mat blob, Net &net, Size &inpSize, vector<cv::Rect> &face_rects) {
    Mat detectFrame;
    cv::resize(frame, detectFrame, cv::Size(300, 300), 0, 0, cv::INTER_AREA);
    dnn::blobFromImage(detectFrame, blob, 1.0, inpSize, mean, false, false);
    // if I return here is good
    net.setInput(blob);
    Mat detection = net.forward();   // as long as I add the last two line, it will get read frame empty