Compile OpenCV with ffMpeg support - opencv

I'm having problems compiling OpenCV with ffMpeg support under Debian.
I downloaded new ffMpeg and installed it, downloaded opencv-1.1pre1.tar.gz and unpacked it.
then
./configure --enable-apps --enable-shared --with-ffmpeg --with-gnu-ld --without-quicktime CFLAGS=-I/usr/local/include CPPFLAGS=-I/usr/local/include LDFLAGS=-L/usr/local/lib
ffMpeg checked yes and finally when I make it says
../../../otherlibs/highgui/.libs/libhighgui.so: undefined reference to `img_convert'
Now I've been around the forums and tried various stuff but nothing worked.
Can anybody help me get this thing installed?

OpenCV and FFmpeg evolved very much in last months and nowadays its possible to make OpenCV 2.1 work with FFmpeg without much suffering.

There were some changes in FFmpeg API after OpenCV 1.1pre1 was released, so OpenCV might not work properly with new FFMPEG. I'd suggest trying older versions. I was using FFMPEG trunk snapshot of 07/2008 without problems.

Related

Code Blocks OpenCV build failed

Having an issue with trying to build any opencv version with code::blocks.
I've have built opencv successfully before and have no idea what the issue is.
I've tried following many different tutorials on building opencv using mingw 4.9.2 and CMake. I have also tried using mingw32 and mingw64.
But I continue to receive the errors shown in the image above.
My question is; What is the issue? How can I fix this? And, lastly, what am I doing wrong?
Found that the version of OpenCV I was using had issues with MinGW. Tested a whole bunch of OpenCV versions (3.3, 3.2, 3.1, 2.4.13, 2.4.13.3).
I found that OpenCV version 2.4.9 with the latest version of CMake and MinGW worked.
Thought I'd leave this here to help anyone else having issues with creating OpenCV to work with MinGW/Code::Blocks

Does paperclip need FFMPEG to upload videos?

I'm using this gem right now:
Do i need to install FFMPEG like i did for uploading images (imagemagick)?
If I do, i can't seem to figure out how to install FFMPEG since I'm using Nitrous.io, which is a cloud based IDE.
I found out how to install Image magick from a line of code on nitrous.io, but i see nothing for FFMPEG.
So far I have tried googling quite a lot for an alternative encoder that's compatible with nitrous.
Depends on the system you are running and the configuration you need. if on MacOS i suggest using Homebrew.
https://ffmpeg.org/download.html

What do we need to install for developing with JavaCV?

I want to use and learn JavaCV.
• So, I read some articles about how to set up JavaCV development environment in Window 7. At first they download and install OpenCV and adding some directory paths to System Variable, After that ,they extract javacv-0.7-bin.zip and javacv-0.7-cppjars.zip packages to somewhere(probably C:) and add some .jar files to their projects.
My Question : Do I need to install OpenCV for developing in JavaCV? because I wrote some JavaCV programs and my JavaCV programs compile and run properly (without installing OpenCV).
According to a javacv developer, the answer is NO. It comes bundled. Source: javacv issue 406 on GitHub.

Getting webcam to work in OpenCV 2.3 with Cygwin

I have a problem trying to get a webcam in OpenCV 2.3 to work with Cygwin. I have a Windows 7 64-bit system and I use Notepad++ and cygwin compilers to do my C++ programming. I have seen other posts with similar problems:
Getting Webcam to work in OpenCV
Can't access webcam with OpenCV
I first tried installing OpenCV via the Cygwin Ports. This is rather easy to install, but alas I run into the webcam problem (always returns false when trying to find a device). I have also attempted to build OpenCV and install manually using the command line flavor of CMake. I tried adding the HAVE_VIDEOINPUT and HAVE_DSHOW flags, but no dice. All my programs compile nicely and I have all the functionality of OpenCV aside for this webcam thing.
Has anyone successfully built OpenCV 2.3 on Cygwin with webcam working?
It is unlikely that cygwin build of OpenCV will be able to access a webcam. At least it is not possible without hacking OpenCV cmake scripts. Under cygwin OpenCV build always follows the UNIX branch and videoinput/directshow is excluded from build.

About installing the open cv library

sir,
I have tried my level best to install open cv library 2.2.0 version.but it has'nt suceeded
it shows that errors in linking the library hughigh,
whether we wanted to insatll the ipp library prior to install the opencv?
please help me ?..............
I can only recommend the install advice on the OpenCV page. If you are using a unix download the source of the library you want to install and then use cmake to install the library. That usually works fine for me.
Try installing the 1.1 version of OpenCV.
The 2.x version is brand new and as of Nov 1 2009 you will have difficulty finding documentation for that. The 1.1 version of OpenCV, on the other hand, is very well documented and you should have no trouble finding online tutorials for your platform that walk you through the installation process step-by-step.
As an aside: "IPP" refers to Intel's Performance Primitives. In the 1.1 version these are entirely optional. OpenCV does not require them. If you have the Performance Primitives installed, however, your OpenCV code may run faster. (For me it cut down my image processing time by a factor of five.) Once you get everything up and running you can purchase the IPP library from intel here: http://software.intel.com/en-us/intel-ipp/

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