libcv-dev: error: 'ptrdiff_t' does not name a type

[Jose Luis]

Not only the package itself fails to build, but any other package depending on libcv-dev also fails with the new g++ with this error:

error: 'ptrdiff_t' does not name a type

The solution is very simple: to add an #include <stddef.h> to /usr/include/opencv/cxcore.hpp.

Please, could any maintainer patch this package?

An equivalent bug was already reported in Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=624917

Thanks,
Jose Luis

[Gal Shalif (gal-fourier)]

See a proposed fix at: LP: #791527

[Gal Shalif (gal-fourier)]

Note on of testing of fix for LP: #791527 :
 * The new FFmpeg sources from Ubuntu 11.10 Oneiric do NOT compile against the OpenCV package (that is 2.1)
However, testing was OK with:
 * Ubuntu 11.04 Natty gcc 4.5
 * Ubuntu 11.10 Oneiric gcc 4.6 while using the old Ffmpeg sources from Ubuntu 11.04 Natty

[Gal Shalif (gal-fourier)]

More notes on testing of fix for LP: #791527:

After fixing the ptrdiff_t error above - we get more build errors of the OpenCV package on Ubuntu 11.10 Oneiric because of:

1. The OpenCV 2.1 version is used
2. The new FFmpeg 0.7 version is used
3. OpenCV version 2.1 do not compile against the new FFmpeg version 0.7

AFAIK, the latest SVN version of OpenCV do not either compile against the new ffmpeg 0.7 and it is likely that the OpenCV developers will have to modify the OpenCV sources to allow a build against the new ffmpeg 0.7.

[Gal Shalif (gal-fourier)]

Verify that latest OpenCV-2.3.0rc.tar.bz2 (released on 2011-06-21) do also have compilation errors when compiled against Ffmpeg0.7 from Ubuntu 11.10 oneiric (OpenCV-2.3.0rc.tar.bz2 is available from http://sourceforge.net/projects/opencvlibrary/)

[Launchpad Janitor (janitor)]

This bug was fixed in the package opencv - 2.1.0-3ubuntu2

---------------
opencv (2.1.0-3ubuntu2) oneiric; urgency=low

  [ Reinhard Tartler ]
  * enable parallel builds

  [ Gal Shalif (Work at Fourier Systems) ]
  * Add patch ubuntu11.04_no_videodev.h_include_file.patch
    - fix build error on Ubuntu 11.04 Natty (LP: #756154):
    - Backport the upstream 2.2 changeset to void the use
      of the obsolete V4L1 (linux/videodev.h)
  * Add patch ubuntu11.10_oneiric_fix_compilation_error_with_gcc4.6.patch
      - fix build error on Ubuntu 11.10 Oneiric (LP: #791527):
  * Add cvcap_ffmpeg_fix_compile_against_libav0.7.patch
      - fix compilation errors when compiled against libav-0.7
        (as applicable for Ubuntu 11.10 Oneiric) (LP: #756154)
 -- Gal Shalif (Work at Fourier Systems) <email address hidden> Thu, 07 Jul 2011 10:25:00 +0300