“Undefined reference to `avcodec_alloc_frame” Error when compile and install...
I am compiling and installing OpenCV using the steps in http://docs.opencv.org/2.4/doc/tutorials/introduction/linux_install/linux_install.html But during "making" it, it has error when it reaches 45%....
View ArticleError when compiling videoio/src/cap_ffmpeg_impl.hpp
I am compiling opencv 3.0.0 but I get multiple "xxx was not declared in this scope" errors when compiling cap_ffmpeg_impl.hpp file. (E.g pix_fmt_yuv422p, codec_pix_fmt) I have built ffmpeg using the...
View ArticleUsing custom opencv_ffmpeg*.dll version on Windows
From `opencv/3rdparty/ffmpeg/readme.txt`: > On Windows OpenCV uses pre-built> ffmpeg binaries, built with proper> flags (without GPL components) and> wrapped with simple, stable>...
View ArticleHow to send opencv video's to ffmpeg
I m trying to send the processed opencv Mat as video to ffmpeg. I m encoding the frame and writing it to std output and then piping it to ffmpeg. Here is my code. **C++:** if(!cap.isOpened()) { cout...
View Articlesave png with imwrite() - read access violation
Hey there, I already searched everything I could but only found similar problems, not a single proper solution. What I'm using: Win7 x64, QT 5.5.1 x64, VS2013 as compiler, opencv 3.1 x64 (precompiled...
View ArticleCannot build OpenCV 3.1.0 from source with FFMPEG
### Short version **UPDATED MAY 28:** I've tried several more build configurations with FFMPEG. What I've discovered is that when configured with the `--enable-static` option, `make` generates all the...
View ArticleProcessing Camera stream in Opencv, pushing it over RTMP (NGINX RTMP Module)...
Output video: https://youtu.be/VxfoBQjoY6E **Explanation:** I want to: Process camera stream in Opencv and push it over to RTMP server. I already have NGINX (RTMP module) set up and I have tested...
View ArticleWhich one does Opencv supports libav(FFmpeg fork) or FFmpeg
For ubuntu 14.04, which one does OpenCV ( 2.4.9 / 3.0) supports, libav or FFmpeg. Also how to compile OpenCV with FFmpeg/libav enabled. Right now I have installed Opencv 2.4.9 which gives error while...
View ArticleOpencv IP Camera Error
I am using andriod app (IP webcam) as ip camera. i'm running below code in separate thread. because if i run in main thread it crashes the program. VideoCapture cap; Mat img;...
View ArticleCannot compile OpenCV 3.1.0 with FFmpeg using shared libraries in Centos 7
Hello, I am trying to compile OpenCV 3.1.0 with FFmpeg with Centos 7, and I'm getting the following error: Linking CXX shared library ../../lib/libopencv_videoio.so /usr/bin/ld:...
View ArticleOpenCV VideoCapture does not work as pointer or member variable
I have a very strange hevaviour with opencv3.0.0 c++ in visual studio 2010 on windows7. I simply want to open a video file to grab/extract frames from it. When i create a local variable in my cpp,...
View ArticleOpenCV 3.1 VideoCapture ffmpeg
Hello every one. I'm using opencv 3.1 how can I using ffmpeg explicity? std::string filename = "1440x1072.avi"; capture.open(filename, CAP_FFMPEG); does not work... //internally it invoke follow code...
View ArticleTracking an object via OpenCV
I am trying to track an object and mask (a CODE in this case) using OpenCV and Python. As example I am using this video: https://www.dropbox.com/s/eu01hxoxmd3ns5f/capture-3.mp4?dl=0 What I need is to...
View ArticleControl VideoCapture Multithreading
Is there a way to limit the number of threads (or even just cpu cores) that VideoCapture().read() can use? I am processing h264 encoded videos in a parallelized program and want to be able to control...
View ArticleError “sys/videoio.h - not found” OpenCV 3.1.0
I using Elementary OS and I'm trying to install OpenCV 3.1.0, I follow the instructions of http://docs.opencv.org/3.0-beta/doc/tutorials/introduction/linux_install/linux_install.html Also, I have...
View Articleopencv_ffmpeg2413_64.dll gets loaded, VideoCapture still cannot open files
I'm compiling using VS 2015, and I can see in the debug log that the ffmpeg dll gets properly loaded, but when I try to open a file using `VideoCapture` (`VideoCapture::isOpened()` returns false). I do...
View Articleopencv 3.1 ffmpeg should I do shared enable
SO I'm installing opencv 3.1 for c++ use on Ubuntu 16.04 on Rpi 3 opencv with gcc 4.9. In some tutorials they recommend to build ffmpeg from source with shared enable and disable static flag. In others...
View Articleffmpeg DLL not loaded on Windows 7, working on 8 and 10
I need to maintain a project that uses OpenCV 3.0 for its main processing and based on QT. The development environment is based around QT Creator on Windows 10 and Visual C++ 2013 64-bit is used for...
View ArticleVideocapture grab function does not return (blocking call) when IP camera is...
The problem which I am facing is that the grab function of Videocapture object **gets stuck** when my IP cam is disconnected. Ideally, the grab() function or the isOpened() function should return false...
View Articleopencv_ffmpeg module crash (IP Camera)
I'm using IP webcam android app(It converts mobile camera into IP web camera). I'm running below code in Visual Studio 2015 with OpenCV 3.1. VideoCapture cap; Mat img;...
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