Tag Archives: 2.9.6

osgART 2.0 RC3 with OpenSceneGraph 2.9.7 or later (including 3.0.0)

Long time ago I had problems using osgART 2.0 RC3 with OpenSceneGraph 2.9.7 or later, I couldn’t get the video feed from the webcam on the background so I only used OpenSceneGraph 2.9.6. Today I found out that my osgART program could work with OpenSceneGraph 2.9.7 or later (current version 3.0.0 works too!), but as I always used 2.9.6 I didn’t know I have founded the solution to this problem!

NOTE: If you want to install OpenSceneGraph 3.0.0 in Ubuntu 11.10 or Ubuntu 12.04 you’ll have to use the patches I’ve created and uploaded to my github repository.

The key of the problem is that when you configure the video backgrounds osgART::VideoGeode you can use TEXTURE_2D or TEXTURE_RECTANGLE. If you use TEXTURE_RECTANGLE it will work on newer versions of OpenSceneGraph. You can look at line 40 of “examples/osgartsimple/osgartsimple.cpp” in osgART 2.0 RC3 source code folder:

osg::Group* createImageBackground(osg::Image* video) {
	osgART::VideoLayer* _layer = new osgART::VideoLayer();
	_layer->setSize(*video);
	osgART::VideoGeode* _geode = new osgART::VideoGeode(osgART::VideoGeode::USE_TEXTURE_2D, video);
	addTexturedQuad(*_geode,video->s(),video->t());
	_layer->addChild(_geode);
	return _layer;
}

If you installed OpenSceneGraph 2.9.7 or later and compiled osgART 2.0 RC3 as it comes in the original code, when you execute this example from “/usr/local/bin/osgartsimple” you will get this as you show the “Hiro” pattern to the camera:

If you change previous code this way:

osg::Group* createImageBackground(osg::Image* video) {
	osgART::VideoLayer* _layer = new osgART::VideoLayer();
	_layer->setSize(*video);
	osgART::VideoGeode* _geode = new osgART::VideoGeode(osgART::VideoGeode::USE_TEXTURE_RECTANGLE, video);
	addTexturedQuad(*_geode,video->s(),video->t());
	_layer->addChild(_geode);
	return _layer;
}

Then compile and install osgART 2.0 RC3 again, “/usr/local/bin/osgartsimple” will work OK.

Install osgART 2.0 RC3 with OpenSceneGraph 2.8.3 or 2.9.6 with Collada support in Ubuntu 12.04

Before installing osgART we need to install ARToolKit, collada-dom and OpenSceneGraph so look at those post before continuing with this:

Once you have installed the dependencies for osgART download osgART 2.0 RC3 code from here and uncompress it. Run the following commands:

mkdir build
cd build
cmake .. -DCMAKE_CXX_FLAGS=-fpermissive -DCMAKE_MODULE_LINKER_FLAGS=-lgstreamer-0.10 -DCMAKE_SHARED_LINKER_FLAGS=-lgstreamer-0.10
make
sudo make install

You can remove the “-DCMAKE_CXX_FLAGS=-fpermissive” option if you add the following includes in the “include/osgART/Utils” file after “#include <iostream>“:

#include <cstdlib>
#include <limits>

Configure the ARTOOLKIT_CONFIG variable (you should have this already configured when installing ARToolKit):

export ARTOOLKIT_CONFIG="v4l2src device=/dev/video0 use-fixed-fps=false ! ffmpegcolorspace ! capsfilter caps=video/x-raw-rgb,bpp=24 ! identity name=artoolkit ! fakesink"

And run the example program while showing the “Hiro” pattern to the camera:

cd /usr/local/bin/
./osgartsimple

If you get this error:

Plugin '-1' unknown!
Could not initialize video plugin!

It is caused because the osgART libraries weren’t correctly copied to the library folder (“/usr/local/lib“) and/or the OSG plugins folder (“/usr/local/lib/osgPlugins-X.X.X“). Verify that a file called “libosgART.so” is in “/usr/local/lib” and that the files “osgdb_osgart.so“, “osgart_tracker_artoolkit2.so” and “osgart_video_artoolkit2.so” are in the OSG plugins folder (that should be “/usr/local/lib/osgPlugins-2.8.3” or “/usr/local/lib/osgPlugins-2.9.6” depending on the version of OSG you installed). Be aware that if you install different versions of OSG at the same time the osgART plugin may no be copied to the plugin folder of the OSG version you want. Also you may run this just in case:

sudo ldconfig /etc/ld.so.conf

If you see a black background it is caused because of a small bug in ARToolKit. It can be fixed in ARToolKit changing “ar2VideoCapNext” function on “lib/SRC/VideoGStreamer/video.c line 378 to return 0 instead of TRUE OR by changing osgART file “src/osgART/Video/ARToolKit/ARToolKitVideo.cpp” on line 310 from this:

if (0 == ar2VideoCapNext(video))

To this:

if (ar2VideoCapNext(video))

If you want to have a smoother marker detection on osgART you can change the source code on file “src/osgART/Traker/ARToolKit/SingleMarker.cpp” and uncomment the line 76 and comment the line 77. I mean changing this:

//arGetTransMatCont(markerInfo, patt_trans, patt_center, patt_width, patt_trans);
arGetTransMat(markerInfo, patt_center, patt_width, patt_trans);

To this:

arGetTransMatCont(markerInfo, patt_trans, patt_center, patt_width, patt_trans);
//arGetTransMat(markerInfo, patt_center, patt_width, patt_trans);

Sources: http://projects.springlobby.info/issues/1575
https://github.com/bitcoin/bitcoin/pull/456
https://code.ros.org/trac/opencv/ticket/1020
http://forum.openscenegraph.org/viewtopic.php?t=7755
http://code.google.com/p/chromium/issues/detail?id=108945

Install OpenSceneGraph 2.9.6 with Collada support in Ubuntu 12.04

Although I usually install OpenSceneGraph 2.8.3 to work with osgART 2.0 RC3 it is also posible to use OpenSceneGraph 2.9.6 (in fact is the latests version compatible with osgART UPDATE: read this post to see how to make osgART 2.0 RC3 work with OpenSceneGraph 2.9.7 and further). You can download it using SVN:

svn checkout http://www.openscenegraph.org/svn/osg/OpenSceneGraph/tags/OpenSceneGraph-2.9.6 OpenSceneGraph-2.9.6

The steps to install OSG 2.9.6 with Collada support in Ubuntu 12.04 are just the same as I explained before in “Install OpenSceneGraph 2.8.3 with Collada support in Ubuntu 12.04“, but you have to do some more changes on the source code because of FFMpeg. So just add those changes to the source code of OSG 2.9.6 and then do just the same as if you were installing OSG 2.8.3:

/src/osgPlugins/ffmpeg/FFmpegDecoderAudio.cpp
– In line 276 change this:

const int bytes_decoded = avcodec_decode_audio2(m_context, reinterpret_cast(buffer), &data_size, m_packet_data, m_bytes_remaining);

To this:

#if LIBAVCODEC_VERSION_MAJOR >= 53 || (LIBAVCODEC_VERSION_MAJOR==52 && LIBAVCODEC_VERSION_MINOR>=32)
            AVPacket avpkt;
            av_init_packet(&avpkt);
            avpkt.data = const_cast<uint8_t *>(m_packet_data);
            avpkt.size = m_bytes_remaining;

            const int bytes_decoded = avcodec_decode_audio3(m_context, reinterpret_cast<int16_t*>(buffer), &data_size, &avpkt);
#else
            // fallback for older versions of ffmpeg that don't have avcodec_decode_audio3.
            const int bytes_decoded = avcodec_decode_audio2(m_context, reinterpret_cast<int16_t*>(buffer), &data_size, m_packet_data, m_bytes_remaining);
#endif

/src/osgPlugins/ffmpeg/FFmpegDecoderVideo.cpp

– In line 168 change this:

const int bytes_decoded = avcodec_decode_video(m_context, m_frame.get(), &frame_finished, m_packet_data, m_bytes_remaining);

To this:

#if LIBAVCODEC_VERSION_MAJOR >= 53 || (LIBAVCODEC_VERSION_MAJOR==52 && LIBAVCODEC_VERSION_MINOR>=32)
            AVPacket avpkt;
            av_init_packet(&avpkt);
            avpkt.data = const_cast<uint8_t *>(m_packet_data);
            avpkt.size = m_bytes_remaining;

            const int bytes_decoded = avcodec_decode_video2(m_context, m_frame.get(), &frame_finished, &avpkt);
#else
            // fallback for older versions of ffmpeg that don't have avcodec_decode_video2.
            const int bytes_decoded = avcodec_decode_video(m_context, m_frame.get(), &frame_finished, m_packet_data, m_bytes_remaining);
#endif

Sources: http://code.metager.de/source/xref/OpenSceneGraph/src/osgPlugins/ffmpeg/FFmpegDecoderAudio.cpp