OpenCV

Hi Krishnan,
I'm not sure about svn version of ffmpeg, but the version shipped with
Ubuntu 9.04 works fine. ffmpeg 0.5.0 hopefully works too. In case of Ubuntu
package the only glitch is that you should install libswscale-dev, otherwise
CMake will report that ffmpeg is found but cvcap_ffmpeg.cpp won't build. So,
CMake build scripts in OpenCV should be fixed. Other than that, it's ok.

Yes, ffmpeg is dynamic indeed, but ffmpeg is fast, cross-platform, has no
dependencies (which is a rare case in open-source world) and actually there
are some pretty stable versions that we could support - currently we use the
version from Ubuntu, our test Linux distro, and ffmpeg 0.5.0 (I guess, these
two are very close if not the same with respect to API).

As for GStreamer, yes, it's stable, but I personally found it very
inconvenient for our purposes. It's quite difficult to organize an open
capturing loop (i.e. loop w/o callbacks and special filters) - just like
DirectShow, GStreamer is targeted for playback, not for video processing.
The proof is that we had to use 3rd-party code, gstappsink.*, to work around
this problem. BTW, gstappsink.* is LGPL code, so, strictly speaking, when
you build highgui with gstreamer support enabled, highgui becomes a subject
to LGPL license, not BSD as the rest of OpenCV. It may be important for some
users. To add to that, gstreamer-based video writer is still not
implemented. If someone provides BSD code for gstappsink.* and the
corresponding module for video writing (gstappsource.* or something like
that), we then can easily make gstreamer the default video I/O backend for
OpenCV on Linux.

Regards,
Vadim

On Wed, Jun 10, 2009 at 9:47 AM, Krishnan V <v.srikrishnan@...> wrote:

> Hi,
> can someone please clarify as to the svn version of ffmpeg being used to
> compile with the SVN 1820 version of opencv? I think that opencv-1.1 had
> some problems with ffmpeg and users may get turned away. this question gets
> constantly asked in the yahoogroup. if ffmpeg is too dynamic, should we use
> gstreamer? any hint from the developers is most welcome.
> thanks
> krishnan
>
>
>
> ------------------------------------------------------------------------------
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>

Il giorno sab, 13/06/2009 alle 00.59 +0400, Vadim Pisarevsky ha scritto:
> 
> Yes, ffmpeg is dynamic indeed, but ffmpeg is fast, cross-platform, has
> no dependencies (which is a rare case in open-source world) and
> actually there are some pretty stable versions that we could support -
> currently we use the version from Ubuntu, our test Linux distro, and
> ffmpeg 0.5.0 (I guess, these two are very close if not the same with
> respect to API).
> 

I think that ffmpeg have a quite stable api now (after 0.5 release).

> As for GStreamer, yes, it's stable, but I personally found it very
> inconvenient for our purposes. It's quite difficult to organize an
> open capturing loop (i.e. loop w/o callbacks and special filters) -
> just like DirectShow, GStreamer is targeted for playback, not for
> video processing. The proof is that we had to use 3rd-party code,
> gstappsink.*, to work around this problem. BTW, gstappsink.* is LGPL
> code, so, strictly speaking, when you build highgui with gstreamer
> support enabled, highgui becomes a subject to LGPL license, not BSD as
> the rest of OpenCV. It may be important for some users. To add to
> that, gstreamer-based video writer is still not implemented. If
> someone provides BSD code for gstappsink.* and the corresponding
> module for video writing (gstappsource.* or something like that), we
> then can easily make gstreamer the default video I/O backend for
> OpenCV on Linux.

appsrc is part of gstreamer, not third-party. It's been in several
releases now.
For video writing features in gstreamer what do you think about
filesink[1]?

http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-plugins/html/gstreamer-plugins-filesink.html

gstreamer is a lgpl framework but i think that for more complex Gui it
could be usefult to use third party library instead of highgui -gtk
based- (full Gtk/cairo, Qt etc.).

So for example some code like this could be very useful in opencv
library for third party integration (GTK):

IplImage *gtkMask; 
GtkWidget *convertOpenCv2Gtk(IplImage *image){ 
  cvCvtColor( image, gtkMask, CV_BGR2RGB ); // Usually opencv image is
BGR, so we need to change it to RGB 
  GtkWidget *gtkImg; 
  GdkPixbuf *pix; 
  pix = gdk_pixbuf_new_from_data ((guchar*)gtkMask->imageData, 
                     GDK_COLORSPACE_RGB, 
                     FALSE, 
                     gtkMask->depth, 
                                     gtkMask->width, 
                     gtkMask->height, 
                     (gtkMask->widthStep), 
                      NULL, 
                      NULL); 
  gtkImg = gtk_image_new_from_pixbuf (pix); 
  return gtkImg; 
} 

Regards,
Ste

Hi all,
i want ask to the WG opencv devel team what they think about GpuCV
project (opencv calls on GPU). Do u Have already evaluated this kind of
solution for opencv library?

[1]https://picoforge.int-evry.fr/cgi-bin/twiki/view/Gpucv/Web/GpuCV#Features

Regards,
Ste

Hi Mr. Vadim and others,
Thank you for the reply. I have spent quite some time now, in fact the
whole day trying to build opencv with ffmpeg. I am not an expert nor a
complete novice and hence hate to bother developers with small
questions. However, I am unable to build opencv with ffmpeg. It is not
the problem with ffmpeg but a build problem.
 I followed the instructions given on the install guide of opencv page
at willow garage.  i got an initially successful compilation of opencv
on Fedora 10 on a quad-core CPU. However, reading video files was
impossible; the program waited forever on opening the video file. I
did ldd for my sample program and found that it links to gstreamer and
not ffmpeg! this is true for highgui also, obviously. with cmake i
found that it is unable to locate libavformat and other ffmpeg headers
and so using gstreamer. i am more acquainted with autotools and
./configure way and so used that to generate the makefiles.
./configure detects ffmpeg. therefore currently i am stuck,
compilation using autotools fails and with cmake i am not ble to link
to ffmpeg.
I viewed the CMakeList.txt and saw gstreamer appearing before ffmpeg;
i doubt this is the problem though. I hope someone can help me out.
Also, cmake generated build fails on fedora 9, obviously the given
"./configure" also fails. I could not rebuild on fedora 9 using
autotools becuase of older versions. one more thing is that the
INSTALL file mentions only the autotools method of building and not
the cmake.
actually, i am a phd student and also do some sysad stuff for the lab.
we have a wide variety of distributions. it would be nice if the build
worked on some older distributions also. I know that this is svn
version and not stable release. please do not take these as criticism
but as some kind of feedback.
Thank you
krishnan


On Sat, Jun 13, 2009 at 2:29 AM, Vadim
Pisarevsky<vadim.pisarevsky@...> wrote:
> Hi Krishnan,
> I'm not sure about svn version of ffmpeg, but the version shipped with
> Ubuntu 9.04 works fine. ffmpeg 0.5.0 hopefully works too. In case of Ubuntu
> package the only glitch is that you should install libswscale-dev, otherwise
> CMake will report that ffmpeg is found but cvcap_ffmpeg.cpp won't build. So,
> CMake build scripts in OpenCV should be fixed. Other than that, it's ok.
> Yes, ffmpeg is dynamic indeed, but ffmpeg is fast, cross-platform, has no
> dependencies (which is a rare case in open-source world) and actually there
> are some pretty stable versions that we could support - currently we use the
> version from Ubuntu, our test Linux distro, and ffmpeg 0.5.0 (I guess, these
> two are very close if not the same with respect to API).
> As for GStreamer, yes, it's stable, but I personally found it very
> inconvenient for our purposes. It's quite difficult to organize an open
> capturing loop (i.e. loop w/o callbacks and special filters) - just like
> DirectShow, GStreamer is targeted for playback, not for video processing.
> The proof is that we had to use 3rd-party code, gstappsink.*, to work around
> this problem. BTW, gstappsink.* is LGPL code, so, strictly speaking, when
> you build highgui with gstreamer support enabled, highgui becomes a subject
> to LGPL license, not BSD as the rest of OpenCV. It may be important for some
> users. To add to that, gstreamer-based video writer is still not
> implemented. If someone provides BSD code for gstappsink.* and the
> corresponding module for video writing (gstappsource.* or something like
> that), we then can easily make gstreamer the default video I/O backend for
> OpenCV on Linux.
> Regards,
> Vadim
> On Wed, Jun 10, 2009 at 9:47 AM, Krishnan V <v.srikrishnan@...> wrote:
>>
>> Hi,
>> can someone please clarify as to the svn version of ffmpeg being used to
>> compile with the SVN 1820 version of opencv? I think that opencv-1.1 had
>> some problems with ffmpeg and users may get turned away. this question gets
>> constantly asked in the yahoogroup. if ffmpeg is too dynamic, should we use
>> gstreamer? any hint from the developers is most welcome.
>> thanks
>> krishnan
>>
>>
>>
>> ------------------------------------------------------------------------------
>> Crystal Reports - New Free Runtime and 30 Day Trial
>> Check out the new simplified licensing option that enables unlimited
>> royalty-free distribution of the report engine for externally facing
>> server and web deployment.
>> http://p.sf.net/sfu/businessobjects
>> _______________________________________________
>> Opencvlibrary-devel mailing list
>> Opencvlibrary-devel@...
>> https://lists.sourceforge.net/lists/listinfo/opencvlibrary-devel
>>
>
>

Hi Krishnan!

please send me the log of the cmake's output+how the make fails+the
location of the libavformat headers on your system.

BR,
  kecsap

On Sat, Jun 13, 2009 at 8:14 PM, Krishnan V<v.srikrishnan@...> wrote:
> Hi Mr. Vadim and others,
> Thank you for the reply. I have spent quite some time now, in fact the
> whole day trying to build opencv with ffmpeg. I am not an expert nor a
> complete novice and hence hate to bother developers with small
> questions. However, I am unable to build opencv with ffmpeg. It is not
> the problem with ffmpeg but a build problem.
>  I followed the instructions given on the install guide of opencv page
> at willow garage.  i got an initially successful compilation of opencv
> on Fedora 10 on a quad-core CPU. However, reading video files was
> impossible; the program waited forever on opening the video file. I
> did ldd for my sample program and found that it links to gstreamer and
> not ffmpeg! this is true for highgui also, obviously. with cmake i
> found that it is unable to locate libavformat and other ffmpeg headers
> and so using gstreamer. i am more acquainted with autotools and
> ./configure way and so used that to generate the makefiles.
> ./configure detects ffmpeg. therefore currently i am stuck,
> compilation using autotools fails and with cmake i am not ble to link
> to ffmpeg.
> I viewed the CMakeList.txt and saw gstreamer appearing before ffmpeg;
> i doubt this is the problem though. I hope someone can help me out.
> Also, cmake generated build fails on fedora 9, obviously the given
> "./configure" also fails. I could not rebuild on fedora 9 using
> autotools becuase of older versions. one more thing is that the
> INSTALL file mentions only the autotools method of building and not
> the cmake.
> actually, i am a phd student and also do some sysad stuff for the lab.
> we have a wide variety of distributions. it would be nice if the build
> worked on some older distributions also. I know that this is svn
> version and not stable release. please do not take these as criticism
> but as some kind of feedback.
> Thank you
> krishnan
>
>
> On Sat, Jun 13, 2009 at 2:29 AM, Vadim
> Pisarevsky<vadim.pisarevsky@...> wrote:
>> Hi Krishnan,
>> I'm not sure about svn version of ffmpeg, but the version shipped with
>> Ubuntu 9.04 works fine. ffmpeg 0.5.0 hopefully works too. In case of Ubuntu
>> package the only glitch is that you should install libswscale-dev, otherwise
>> CMake will report that ffmpeg is found but cvcap_ffmpeg.cpp won't build. So,
>> CMake build scripts in OpenCV should be fixed. Other than that, it's ok.
>> Yes, ffmpeg is dynamic indeed, but ffmpeg is fast, cross-platform, has no
>> dependencies (which is a rare case in open-source world) and actually there
>> are some pretty stable versions that we could support - currently we use the
>> version from Ubuntu, our test Linux distro, and ffmpeg 0.5.0 (I guess, these
>> two are very close if not the same with respect to API).
>> As for GStreamer, yes, it's stable, but I personally found it very
>> inconvenient for our purposes. It's quite difficult to organize an open
>> capturing loop (i.e. loop w/o callbacks and special filters) - just like
>> DirectShow, GStreamer is targeted for playback, not for video processing.
>> The proof is that we had to use 3rd-party code, gstappsink.*, to work around
>> this problem. BTW, gstappsink.* is LGPL code, so, strictly speaking, when
>> you build highgui with gstreamer support enabled, highgui becomes a subject
>> to LGPL license, not BSD as the rest of OpenCV. It may be important for some
>> users. To add to that, gstreamer-based video writer is still not
>> implemented. If someone provides BSD code for gstappsink.* and the
>> corresponding module for video writing (gstappsource.* or something like
>> that), we then can easily make gstreamer the default video I/O backend for
>> OpenCV on Linux.
>> Regards,
>> Vadim
>> On Wed, Jun 10, 2009 at 9:47 AM, Krishnan V <v.srikrishnan@...> wrote:
>>>
>>> Hi,
>>> can someone please clarify as to the svn version of ffmpeg being used to
>>> compile with the SVN 1820 version of opencv? I think that opencv-1.1 had
>>> some problems with ffmpeg and users may get turned away. this question gets
>>> constantly asked in the yahoogroup. if ffmpeg is too dynamic, should we use
>>> gstreamer? any hint from the developers is most welcome.
>>> thanks
>>> krishnan
>>>
>>>
>>>
>>> ------------------------------------------------------------------------------
>>> Crystal Reports - New Free Runtime and 30 Day Trial
>>> Check out the new simplified licensing option that enables unlimited
>>> royalty-free distribution of the report engine for externally facing
>>> server and web deployment.
>>> http://p.sf.net/sfu/businessobjects
>>> _______________________________________________
>>> Opencvlibrary-devel mailing list
>>> Opencvlibrary-devel@...
>>> https://lists.sourceforge.net/lists/listinfo/opencvlibrary-devel
>>>
>>
>>
>
> ------------------------------------------------------------------------------
> Crystal Reports - New Free Runtime and 30 Day Trial
> Check out the new simplified licensing option that enables unlimited
> royalty-free distribution of the report engine for externally facing
> server and web deployment.
> http://p.sf.net/sfu/businessobjects
> _______________________________________________
> Opencvlibrary-devel mailing list
> Opencvlibrary-devel@...
> https://lists.sourceforge.net/lists/listinfo/opencvlibrary-devel
>

forwarded to opencvlibrary-devel@...
2009/6/13 Kertész Csaba <csaba.kertesz@...>:
> Hi Krishnan!
>
> please send me the log of the cmake's output+how the make fails+the
> location of the libavformat headers on your system.
There are at /usr/include/ffmpeg/libavformat/avformat.h, but you
should never have to deal with this particular information since all
which is required is to pass the correct LIBAVFORMAT_CFLAGS when
needed, as provided by the pkg-config --cflags libavformat which will
output -I/usr/include/ffmpeg. Nevertheless that could have been
everything else, including -I/usr/include/ffmpeg4openvcv if a special
system built would be made for opencv

As the opencv package maintainer for Fedora, I plan to enable
gstreamer support for opencv by F-12.
I'm not interested in ffmpeg directly because it is a patent
minefield, as ffmpeg isn't in Fedora.(despite some patentless ffmpeg
version may exists in other distro). But I would like to have a rpm
--with ffmpeg build conditional (along with gstreamer and xine).

At least I was able to built the gstreamer and xine backend once
http://opencvlibrary.svn.sourceforge.net/viewvc/opencvlibrary/trunk/opencv/src/highgui/cvcap_xine.cpp?r1=1172&r2=1382&view=patch
are backported for the xine case with gcc 4.3 and later.

This is the fedora 11 built (gstreamer only):
http://koji.fedoraproject.org/koji/taskinfo?taskID=1478592
I may provide a later snapshot in my kwizart-testing repository for
fedora 11 at rpms.kwizart.net
with ffmpeg enabled opecv.

Nicolas (kwizart)