OpenCV 2.4.7 with FFMpeg support build with VS 2010 (x86)

Question

I'm fighting with new version of OpenCV 2.4.7 for almost one week (prev. used 2.4.2). My motivation for the new setup is the fact that I run into problems using the Videowriter for uncompressed grayscale videos (http://answers.opencv.org/question/3603/videowriter-videocapture-and-uncompressed-avi/). In https://github.com/Itseez/opencv/pull/1516 "akarsakov" is recommending to build OpenCV without vfw support and open uncompressed video through ffmpeg. That's what I tried to do. I followed basically the instructions mentioned in this video: http://docs.opencv.org/trunk/doc/tutorials/introduction/windows_install/windows_install.html

I had successfully build opencv with Qt 5.1.1 (http://answers.opencv.org/question/24184/how-to-compile-opencv-247-with-qt-and-ffmpeg/). But I'm not able to get the VideoWriter & VideoCapture work for me. So what I did:

1. I downloaded the newest ffmpeg build from http://ffmpeg.zeranoe.com/builds/

2. I generated the vs2010 project disabling VfW and enabling ffmpeg instead:

   Video I/O:
   
   Video for Windows:           NO
   DC1394 1.x:                  NO
   DC1394 2.x:                  NO
   FFMPEG:                      YES (prebuilt binaries)
     codec:                     YES (ver 55.18.102)
     format:                    YES (ver 55.12.100)
     util:                      YES (ver 52.38.100)
     swscale:                   YES (ver 2.3.100)
     gentoo-style:              YES
     OpenNI:                    NO
   OpenNI PrimeSensor Modules:  NO
   PvAPI:                       NO
   GigEVisionSDK:               NO
   DirectShow:                  YES
   Media Foundation:            NO
   XIMEA:                       NO
   

3. I added the include directories and libs for ffmpeg to the highgui module.

I was not able to compile OpenCV without any errors but the behaviour what I see is not what I expect:

1. Build OpenCV 2.4.7 without VfW -> VideoWriter.open () returns always false!
2. Build OpenCV 2.4.7 with VfW -> VideoWriter.open () returns true for the time, calling a release() and an open() on the same object returns always a false.
3. With or without ffmpeg -> An VideoCapture.open () gives a error message asking for libiconv-2dll!

Does some had the same problems and is able to point me to my mistake?

Thank you in advance. cheers

Answer 1

OpenCV 2.4.7 requires a more recent version of FFmpeg to work, but that doesn't seem to the issue since you have that covered.

The cause of your problem could be bug #2281: VideoCapture::read fails on uncompressed video.

As an intermediary solution, I suggest you to downgrade to OpenCV 2.4.5.