gstreamer library unresolved include - gstreamer

I wrote a simple C code with GStreamer libs (gstreamer example code manual ref)
My GStreamer headers are located at /usr/include/gstreamer-0.10/gst.
Thus, I wrote the following line in my C code:
#include "gstreamer-0.10/gst/gst.h"
When I compiled, I have this error:
there are unresolved includes inside
How can I solve this problem?
Thank you...

If you use the standard C compiler flags given by pkg-config gstreamer-0.10 --cflags, you should need only #include <gst/gst.h> in your source code. To help yourself, you can use a simple Makefile (some simple example here)

in my Qt project-file i use following:
CONFIG += link_pkgconfig
PKGCONFIG += glib-2.0 \
gstreamer-0.10 \
gstreamer-interfaces-0.10
so i suppose you have to tell your compiler to use these pkg-configs (*.pc): glib-2.0, gstreamer-0.10, gstreamer-interfaces-0.10

Related

Running dlib on Qt c++

I'm trying to add dlib library to Qt project to run fhog_object_detector_ex.cpp file on ubuntu. I've built dlib using CMake and now i'm trying to run it in Qt.I have added these lines in myproject.pro
SOURCES += $$PWD/dlib-19.2/dlib/all/source.cpp
INCLUDEPATH += $$PWD/dlib-19.2
LIBS += $$PWD/dlib19.2/examples/build/dlib_build/libdlib.a
LIBS += -pthread
I am including these headers in code:
#include <dlib/svm_threaded.h>
#include <dlib/gui_widgets.h>
#include <dlib/image_processing.h>
#include <dlib/data_io.h>
but when i run the program i got errors, here are some errors:enter image description here
Please help me to deal with it.
You need to link to X11 in addition to pthread.

How to use libltdl on OS X in a Qt project

I try to use libltdl in Qt on OSX. I downloaded the library with brew and i can find it in /usr/local/lib/libltdl.dylib .
I link it in Qt Creator using the assistant and those lines were added to my .pro
macx: LIBS += -lltdl
The problem is when i use :
#include <ltdl.h>
the app doesn't compile and the following error appears :
fatal error: 'ltdl.h' file not found
#include <ltdl.h>
Thanks for your help !

Portaudio example "record_file.c" does not find "min"

First off, I alread got the smaller example paex_record.c to work.
I use MinGW on Windows8 and did compile portaudio from source, that's were I got the used libportaudio-2.dll from.
I set up a project in QtCreator (without gui) with following .pro-file:
TEMPLATE = app
CONFIG += console
CONFIG -= app_bundle
CONFIG -= qt
SOURCES += main.cpp
LIBS += -LC:/Audio/patest/paex_record_file -llibportaudio-2
My folder C:/Audio/patest/paex_record_file looks like:
libportaudio-2.dll
main.cpp
pa_ringbuffer.c
pa_ringbuffer.h
pa_util.h
paex_record_file.pro
paex_record_file.pro.user
portaudio.h
I copied both pa_ringbuffer and pa_util to this folder after they were not found.
Main.cppcontains the whole example file paex_record_file.c from the portaudio source.
There is an error when calling the ringbuffer (line 246 and 271: source):
"min" was not declared in this scope
I thought this example would directly run just like the record.c example.
Do I need to include further packages? I've tried algorithm, math, std and using namespace std, but still the error occurs. But I get the feeling it should work out off box, perhaps my include files or folder setup / linkage is not ok?
EDIT: Ok so I just defined a min-function on my own. Now it throws different error:
undefined reference to "PaUtil_GetRingBufferReadAvailable"
and a couple more of this kind. There is probably a lib missing to be linked, having a look...
I also had this linking error trying to compile paex_record_file.c. Turns out you need to compile pa_ringbuffer.c before compiling the main file. There's also an external dependency on some alloc function, so you need to change 2 lines in the file.
I'm not savvy of qt but you need to do something like:
SOURCES += pa_ringbuffer.c main.cpp
Here's how I compile with MinGW:
Changes inside paex_record_file.c
Line 313 : data.ringBufferData = (SAMPLE *) malloc( numBytes );
Line 443 : free( data.ringBufferData );
Compile with MinGW:
gcc -o p_rec.exe C:\path_to_portaudio\portaudio\common\pa_ringbuffer.c \
paex_record_file.c -lportaudio \
-IC:\path_to_portaudio\portaudio\src\common
I didn't get the min problem, but perhaps you can try to remove the ifdef guard and try to recompile.
#ifdef _WIN32
#include <windows.h>
#include <process.h>
#endif
to
#include <windows.h>
#include <process.h>

Qt shared_ptr not found when including a library

I'm using Qt creator and the yaml-cpp library. I placed yaml-cpp under my source code directory and added it to the Qt project's include path like so:
INCLUDEPATH += Crypto \
Yaml
QMAKE_CXXFLAGS += -std=gnu++0x
DEFINES += __GXX_EXPERIMENTAL_CXX0X__
As you can see, I also told it to use C++ 11 because that is a requirement of this library. However, I get this error on compiling my project (this is the only error):
../ProjectName/Yaml/yaml-cpp/node/ptr.h:11:10: fatal error: 'boost/shared_ptr.hpp' file not found
#include <boost/shared_ptr.hpp>
^
I also tried, at the advice of some online resources, to replace it with #include <memory>, but this does not work. When I try this, it still cannot find shared_ptr.
I probably could compile the library and link Qt creator to it, but I would have to do this on every platform I use and on every machine that every project developer uses. It seems like a more elegant solution to put the source code inside my GitHub directory and compile it along with the project to minimize the overhead of someone compiling the project on their machine, particularly since this is an open source project.
Here is the source code of Yaml-Cpp's file in question:
#include "yaml-cpp/dll.h"
#include <boost/shared_ptr.hpp>
namespace YAML
{
namespace detail {
class node;
class node_ref;
class node_data;
class memory;
class memory_holder;
typedef boost::shared_ptr<node> shared_node;
typedef boost::shared_ptr<node_ref> shared_node_ref;
typedef boost::shared_ptr<node_data> shared_node_data;
typedef boost::shared_ptr<memory_holder> shared_memory_holder;
typedef boost::shared_ptr<memory> shared_memory;
}
}
It seems that you do not have boost installed. You would need to amend that first.
However, you could urge the yaml-cop developers to use the recent C++ standard more and more when their software is built using C++11 or later. C++11 is not a new thing anymore. It should be utilized as much as possible.

OpenCV and convexityDefects

So i am really new to openCV and all the image recognition stuff. So i use monodevelop and i installed OpenCV using apt-getand i included these files
include "opencv2/highgui/highgui.hpp"
include "opencv2/imgproc/imgproc.hpp"
include <opencv2/opencv.hpp>
include <opencv2/imgproc/imgproc.hpp>
include<iostream>
include<vector>
include<algorithm>
include <X11/Xlib.h>
include <X11/Xutil.h>
but this function convexityDefects() shows as undefined
EDIT
So the problem is that the compiler shows that function convexityDefects is not defined in this scope
Here is the full code that i cant get to work -> Code
Could you please point me out!?
Thank you.
So i found the answer i was looking for.....
The libraries i used to compile my project where in wrong location.
so i used pkg-config --libs --cflags opencv to find exactly where are my libs....
After that i included these libraries in Code-Blocks and everything magicly started to work.