opencv cmake didn't find latest ffmpeg libs

Question

Here the output of the ffmpeg command:

ffmpeg version git-2014-01-20-4014b40 Copyright (c) 2000-2014 the FFmpeg developers
built on Jan 20 2014 14:18:13 with gcc 4.8 (Ubuntu/Linaro 4.8.1-10ubuntu9)
configuration: --extra-libs=-ldl --enable-gpl --enable-libass --enable-libfdk-aac --    enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --  enable-libx264 --enable-nonfree --enable-x11grab
libavutil      52. 63.100 / 52. 63.100
libavcodec     55. 48.101 / 55. 48.101
libavformat    55. 25.100 / 55. 25.100
libavdevice    55.  5.102 / 55.  5.102
libavfilter     4.  1.100 /  4.  1.100
libswscale      2.  5.101 /  2.  5.101
libswresample   0. 17.104 /  0. 17.104
libpostproc    52.  3.100 / 52.  3.100
Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

When running CmakeLists.txt for Opencv 2.4.8 installation:

cmake -DCMAKE_BUILD_TYPE=RELEASE -DCMAKE_INSTALL_PREFIX=/usr/local -DBUILD_NEW_PYTHON_SUPPORT=ON -DWITH_TBB=ON -DWITH_V4L=ON -DWITH_QT=ON -DWITH_OPENGL=ON -DWITH_EIGEN=ON -DWITH_OPENEXR=ON ..

I get:

--   Video I/O:
--     DC1394 1.x:                  NO
--     DC1394 2.x:                  YES (ver 2.2.1)
--     FFMPEG:                      YES
--       codec:                     YES (ver 53.35.0)
--       format:                    YES (ver 53.21.1)
--       util:                      YES (ver 51.22.1)
--       swscale:                   YES (ver 2.1.0)
--       gentoo-style:              YES
--     GStreamer:                   
--       base:                      YES (ver 0.10.36)
--       app:                       YES (ver 0.10.36)
--       video:                     YES (ver 0.10.36)

My question: Why opencv didn't link with the lastest libavutil, libavcodec, etc ...

Answer 1

Here is the answer: never forget to rm CMakeCache.txt before running again cmake command.