Segmentation Fault on using VideoCapture
**GDB output:**> Starting program: /PWD/a.out>[Thread debugging using libthread_db enabled] Using host libthread_db library "/usr/lib/libthread_db.so.1". [New Thread 0x7fffd9293700 (LWP...
View ArticleDoes cv::VideoCapture support both UTF-8 and traditional codepage-encoded...
Hello, I recently built OpenCV 3.2.0 from the Git repository (I downloaded the current source code in the master-branch, and I think it is somewhat different from the currently available official...
View ArticleVideoCapture
Hi, I would like to use cv::VideoCapture to get images from my camera (Imaging Source camera running under Windows through DirectShow, but other cameras might be used later). But I have a few problems...
View ArticleOpencv 3.2 and Videocapture not work
Hello to all. I'm noob whit opencv. I'm trying to use Windows 7, Opencv 3.2 and Visual Studio. I test example whit VideoCapture and .avi and it is ok. When i test VideoCapture whit cam usb it is not...
View Articlecv2.videoCapture(filename) assigning filename dynamically
I am trying to access `filename` dynamically from user and then pass it to `videoCapture(filename)` and then process it. code : import cv2 import numpy as np import os import sqlite3 import pickle...
View ArticleGetting Vendor Details of a Camera
I am using Logitech HD Cam C525 for image/video streaming through opencv.My functionality includes first detecting the availability of camera and then displaying its vendor details like...
View ArticleCamera upside down (sometimes...)
Hello, I use OpenCV with Qt on Windows. My program takes a capture from a webcam with cv::VideoCapture capture; int test1=capture.open(0); // This returns 1 so it's ok. capture >> frame; It...
View ArticleVideoCapture: partially decoded video data?
I've been following the VideoCapture tutorial http://docs.opencv.org/3.2.0/d5/dc4/tutorial_video_input_psnr_ssim.html and it strikes me that only fully decoded frames are analysed. Is there a way to...
View ArticleVideoCapture captures at low fps
Hello I have a camera that captures video (according to the specifications) at a resolution of 640x480 at 120fps. I use the script below to check the speed I can capture frames with OpenCV on Python,...
View Articlecv2 looks like it is reading but always returns black screen, have confirmed...
import cv2 import numpy as np cap = cv2.VideoCapture(0) ret, frame = cap.read() print ('isOpened(),',cap.isOpened()) """ prints as True """ cv2.imshow('frame',frame) cv2.waitKey(0) cap.release()...
View ArticleNormal projects can not to work suddenly
Hello: I have a issue about my project. I use the OpenCV library (OpenCV 2.4.13) to working on in the Visual studio 2015. (System is Windows 10 64bits) Last 2 weeks ago(May 12th ago), my project it...
View ArticleVideoCapture CAP_PROP_PAN & TILT
Dear all, I am confused about the videoCapture cap(CAP_PROP_PAN & TILT). How could I use them ? IS it to drive a turret ? If yes how please ? Thanks for your support. Chris
View ArticleCorrupt JPEG data error when using yuyv webcam
Hi, I'm using yuyv format webcams. Here is my code. #include #include #include #include #define FPS 30 using namespace std; int main(int argc, char** argv){ std::cout << "stereo_cam_node"...
View Articleobject of class VideoCapture cannot be constructed
It is put in a sub thread not main thread. I am not sure if capture was constructed, capture.isOpened() return true, but get totally 1 frame. ...
View ArticleIssue with OpenCV and Swing - Video Display
I've been messing around with OpenCV, and have an issue with displaying images through Swing. I'm using Swing, and was running into an issue where my JFrame and JPanel would close after I'd finished...
View ArticleUnexpected interaction between Swing and VideoCapture?
I've come across what I believe is a weird interaction between Swing and the VideoCapture class in OpenCV, and I was wondering if anyone either had an explanation or at least could duplicate my issue....
View ArticleHow to record multiple cameras with VideoWriter?
Im having problems with VideoWriter class: I have multiple threads, and every one does: 1. capture frame (VideoCapture) 2. resize 3. write frame (VideoWriter) Every thread captures a different camera....
View ArticleAndroid VideoCapture File Format and Alternatives
Hi all, I'm trying to create an android application that will frame-by-frame process video files taken with a phone camera (.mp4) with openCV. Having looked at previous questions on this subject, I...
View ArticleHow does VideoCapture from USB Webcam on Windows using DirectShow and MJPG work?
Hello everybody, my webcam Logitech BRIO supports MJPEG for higher resolutions or for higher frames per second. Sadly, I'm unable to set the VideoCapture backend to DirectShow and then to...
View ArticleNot able to get frame from the second run (OpenCV on Rasbian)?
Hi everyone, i have the following code to run on Rasbian (Raspberry Pi 3's OS): import cv2 import threading id = 0 cam = cv2.VideoCapture(id) while True: rt = cam.grab() ret,frame = cam.retrieve(rt)...
View ArticleAccessing VideoCapture settings
Hello guys! I have problem setting my default format for camera access to RGB. The thing is, I have a camera (FLIR) which has its own open source code (running on STM). I can manupulate this code, so I...
View ArticleVideoCapture not working in opencv android
I'm trying to use VideoCapture() in an android application. The app makes a JNI call to the cpp file which has the videocapture() call and passes it a video path. - I have provided the storage read...
View ArticleWhy is stream from usb camera frozen?
I ran my example in Raspberry Pi 3 (Raspbian OS). I got frames from 2-3 cams. When running first, my example was ok. Then, sometimes, one of cams could not get frame. I think stream from usb camera...
View ArticleGetting a TeleDyne Line Scan Camera to open with VideoCapture
I am trying to create a program that opens up different brands of cameras with opencv, I have had success with one brand of camera, but have had trouble opening up a TeleDyne Dalsa camera, but when I...
View ArticleCheck, is FFmpeg or GStreamer available
What's the easiest way to check in OpenCV code, is FFmpeg or GStreamer (or both) available. I've understood that in VideoCapture class FFmpeg requires filename or device ID, but GStreamer a pipeline,...
View ArticleChanging Exposure with Windows Forms
Hello, Every time I run this bit of code meant to change the value of the exposure with a trackbar and I am getting an error saying System Access Violation, attempted to read or write to protected...
View ArticleHow to properly set up VideoCapture Tags
I am having trouble setting up opencv in C++ to manually change these properties, but every time I try I get the warning "An unhandled exception of type 'System.AccessViolationException' occurred in...
View Articlecv::VideoCapture::open(file) causes fatal memory error
Hello. After upgrading Ubuntu to trusty, a simple video-load code became producing fatal memory error. The code is just opening an video file: #include #include int main(int argc, char**argv) {...
View ArticleWhat are some known backends that work well with a TeleDyne Dalsa Linea Camera?
I have not been able to find one that works with this camera and wanted to know if anyone has had success opening this type of camera.
View ArticleOpenCV V3.3 64bit Video Capture Memory Leak
Dear community, with this simple peace of code a get a memory leak using opencv v3.3 64bit with Visual Studio 2015. int i = 0; while (i++ < 50) { VideoCapture test; test = VideoCapture(0); } Can...
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