I try to use libvlc inside my project, so i created a sample project with a few line of code :
libvlc_instance_t *libvlc;
libvlc_media_player_t *mp;
libvlc_media_t *m;
libvlc = libvlc_new (0, NULL);
libvlc_media_t *m = libvlc_media_new_location (libvlc, "rtsp://192.168.1.10:8554");
libvlc_media_player_t *mp;
/* Create a media player playing environement */
mp = libvlc_media_player_new_from_media(m);
Sleep(10000); /* Let it play a bit */
/* Stop playing */
libvlc_media_player_stop (mp);
/* Free the media_player */
libvlc_media_player_release (mp);
libvlc_release(libvlc);
This code compile well with with version 2.1.3 of sdk included in the VLC installer.
My problem is after compile when the program stat, an alert says :
Programm can't start,... it miss DCWRBS00176.O
If i comment out from line libvlc = libvlc_new (0, NULL); to the end, this error doesn't appear.
On time i see DCWRBS00179.O (9 not 6) by commented different lines.
I copy all dll and plugins folder in my project folder same thing...
Whats wrong ? Do i need to include something else ?
Thank you.
EDIT : With last debug version 3.0.0 from git it miss DSZBS00190.O !!!
Ps : I use embarcadero C++ XE3.
So i finally found,
I was using the library included in the vlc installer, after a coff2omf the new .lib generated contains all theses dszb000xxx.o and the problems come from here.
So i used implib :
C:\Program Files (x86)\VideoLAN\VLC>implib -a libvlc.lib libvlc.dll
C:\Program Files (x86)\VideoLAN\VLC>implib -a libvlccore.lib libvlccore.dll
After linking theses libs to my project everything went fine !!!
I hope it helps someones else...
Related
I'm currently facing an issue on a project using libvpx v1.10.0 ( https://github.com/webmproject/libvpx/releases ).
I have successfully built the library for Visual Studio 16 on Windows 10 (PC x64).[I must build libvpx by my own since I need it to run on a Windows 10 ARM64 / VS16 as well (Hololens 2) and a such build is not officially provided]
I've made a C++ DLL that uses the static libs from libvpx (to be used as a native plugin in Unity).
While the VP9 encoding part seems to work correctly in a sample app using my DLL, I cannot initialize the VP9 decoder. Maybe I am missing something in the configuration step of libvpx?
To build the libvpx static libraries, I have launched MSYS2 from the x64 Native Tools Command Prompt of Visual Studio 2019.
Then, I have set the configuration as follows, inspired by what we can find in an ArchLinux AUR package ( https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=libvpx-git ):
./configure --target=x86_64-win64-vs16 --enable-libyuv \
--enable-vp8 --enable-vp9 --enable-postproc --enable-vp9-postproc \
--enable-vp9-highbitdepth --enable-vp9-temporal-denoising
make -j
At the end of the compilation, the build succeeds with 0 error but 2 warnings. The --help of the configure scripts indicates that the --enable-vp9 option enables both the VP9 encoder and decoder.
Then, when I run my app using the C++ DLL that performs the encoding and decoding stuff, I get this error message from libvpx:
Codec does not implement requested capability .
It occurs when I call the vpx_codec_dec_init() function. I don't understand why it cannot be initialized as I think that the VP9 codec is fully built. The error appears as well when I add the --enable-vp9-encoder and --enable-vp9-decoder` options and all other VP9 related options to the configuration.
Is there something to do in the code itself before initializing the VP9 decoder? I have not seen a such thing in the samples of code. Notice that the problem occurs if I use VP8 as well (encoding OK / decoding KO, same error).
Here is the beginning of my function for decoding a frame:
vpx_codec_err_t resultError;
vpx_codec_ctx_t codec;
const vpx_codec_iface_t* decoderInterface = vpx_codec_vp9_cx(); // >>> OK!
if (!decoderInterface)
{
return "libvpx: unsupported codec (decoder)";
}
resultError = vpx_codec_dec_init(&codec, decoderInterface, nullptr, 0); // >>> KO...
if (resultError)
{
std::cout << vpx_codec_error(&codec) << std::endl; // outputs "Codec does not implement requested capability"
return "libvpx: failed to initialize decoder";
}
vpx_codec_iter_t iter = nullptr;
vpx_image_t* yuvFrame = nullptr;
resultError = vpx_codec_decode(&codec, compressedFrame, (unsigned int)compressedFrameSize, nullptr, 0);
if (resultError)
{
return "libvpx: failed to decode frame";
}
// ....
Any help would be great! Thank you. :)
OK, I've figured it out! :)
The line:
const vpx_codec_iface_t* decoderInterface = vpx_codec_vp9_cx();
must be replaced by (+ #include <vpx/vp8dx.h>):
const vpx_codec_iface_t* decoderInterface = vpx_codec_vp9_dx();
The reason I have made this error is due to a previous experience in encoding/decoding videos. I've developed a webcam streaming app using the H.264 codec, which needs a set up "context" structure. So, because of the name of the vpx_codec_vp9_cx() function, I've thought it was creating a such context for VP9. In fact, cx matches for encoding and dx for decoding... Not really obvious though. I don't like this kind of function names.
Anyway, I hope it will help anybody in a same situation. ;)
I am having Problem loading SDL_TTF font.
my program is so big, so there's a piece of code which is creating problem.
TTF_Font *font = NULL;
SDL_Color textColor = {255, 255, 255};
if(SDL_Init() == -1 || TTF_Init() == -1)
return 0;
font = TTF_OpenFont("calibri.ttf", 28);
if(font == NULL)
return 0;
Now please tell me why the funtion TTF_OpenFont is not working.
font remains NULL after the funtion and the program exits...
EDIT:
I cannot cout or printf TTF_GetError() but i used breakpoints to see which function is not working correctly and found the function TTF_OpenFont() returning null every time.
(BTW if there any way to print the Erroe on screen the tell please).
TTF_Init() is working correctly.
FOR PEOPLE WHO ARE ASKING TO INSTALL SDL_TTF SEPARATELY:
I have written the link below from which i am learning SDL in first tutorial it guides how to install SDL and integrate it which project, In 3rd lesson comes the SDL_IMAGE extension library which is to be needed to install separately (which i did and used all image functions easily), In 7th lesson it didn't teach how to install SDL_TFF rather says to do the same steps as for SDL_IMAGE but this time for SDL_TTf so i downloaded SDL_TTF and intalled and you know the rest after....
Windows 8.1, CodeBlocks, MinGW32, SDL1
Here's the link i am learning SDL from
SDL Tutorials
This is how i installed the Extension Library(SDL_TTF)
Setting Up Extention Library
If font is NULL you should use TTF_GetError to know what went wrong.
If the error message is opaque you may want then to take a look at TTF_OpenFont source.
Suggestions:
1) substitute this code for TTF_Init():
if(TTF_Init()==-1) {
printf("TTF_Init: %s\n", TTF_GetError());
exit(2);
}
2) Make sure you call it before any other SDL_ttf functions.
If you're still having problems, please specify
your platform (Windows? Linux?)
how you installed your TTF fonts.
3) See also: https://www.libsdl.org/projects/SDL_ttf/docs/SDL_ttf.html
===================================================================
I'm sorry you're still having problems displaying fonts. A few additional suggestions:
1) I'm sure the tutorial you're using is very good. But you can't assume that just because you followed all the steps, you didn't inadvertantly miss something. To resolve the problem, you're going to have to "look beyond" the tutorial.
2) For starters, we need to confirm whether or not TTF_Init() succeeded. We must be able to see TTF_Init() return status, and TTF_GetError() messages.
Q: What is the return value of TTF_Init?
There are several ways you can display "TTF_GetError":
Start your program from a command prompt ("cmd"):printf("TTF_Init: %s\n", TTF_GetError());
Copy the error to a string and look at it under a debugger: char[80] msg; strcpy (msg, TTF_GetError());
Use a Win32 MessageBox to display the error in a pop-up: MSDN - MessageBox function
3) Make sure you have these .dll's on your filesystem:
libfreetype*.dll
SDL2_ttf*.dll
zlib*.dll
4) Look at the fonts you have installed on your filesystem, for example: C:\Windows\Fonts\*.ttf
See also SDL_ttf - Font directory/Where do fonts go?
PROBLEM SOLVED.
Thanks EveryOne for giving your time...
the problem was program was not recognizing font(candara )
so it copy pasted in my project folder.
I know this was already answerd but i ran into a similar problem with SDL2_ttf under Visual Studio 2015 and want to share my solution to help maybe others in the future.
My problem was that when i started my SDLe application that used SDLe_ttf it could not load the font that was placed in the same directory. But when i executed the the build executable manualy from the command line everything was fine.
I think the problem is that Visual Studio 2015 executes the build executable from a different directory and since i used only the font file name(Sans.ttf) it could not load the font because it treats it as a relative path.
My soultion was to just prefix the font file name with the execution directory which can be optained by calling SDL_GetBasePath.
I'm working on Qt application, that has to compute some data using Scilab's numerical engine. My OS is Ubuntu 14.04 with installed Scilab v.5.5.0 and QtCreator v.3.2.1 (Qt 5.3.2).
I'm using a simple code example provided in scilab help:
/****** INITIALIZATION **********/
#ifdef _MSC_VER
if ( StartScilab(NULL,NULL,NULL) == FALSE )
#else
if ( StartScilab(getenv("SCI"),NULL,NULL) == FALSE )
#endif
{
fprintf(stderr,"Error while calling StartScilab\n");
}
/****** ACTUAL Scilab TASKS *******/
SendScilabJob("myMatrix=['sample','for the help']");
SendScilabJob("disp(myMatrix);"); // Will display !sample for the help !
SendScilabJob("disp([2,3]+[-44,39]);"); // Will display - 42. 42.
/****** TERMINATION **********/
if ( TerminateScilab(NULL) == FALSE ) {
fprintf(stderr,"Error while calling TerminateScilab\n");
}
My problem is that after clicking "Run", I get an alert as follows:
/home/med/Dokumenty/QTWorkspace/build-QTtest-Desktop_Qt_5_3_GCC_32bit-Debug/QTtest: error while loading shared libraries: libscicall_scilab.so.5: cannot open shared object file: No such file or directory
I tried to add following line to qmake .pro file, but without any results:
LIBS += /usr/lib/scilab/libscicall_scilab.so.5
The library already is in specified dir (I've checked this manually). Before that I was trying a lot of another settings - still without success.
Could anyone provide the proper solution of this problem?
try adding the location of your lib to your LD_LIBRARY_PATH
Try to use this in your project file:
LIBS = -L/usr/lib/scilab -lscicall_scilab
You will need to rerun qmake then to regenerate the Makefile(s). Make sure that you have 32 bit library of scilab or change the build to 64 bit should that be the issue.
I'm trying to use LibVLC in a Qt 5 program to open a VLC instance and play a video.
The following code comes from https://wiki.videolan.org/LibVLC_Tutorial/
I'm using Linux.
.pro :
TEMPLATE = app
TARGET = projectLoic
INCLUDEPATH += . vlc
QT += widgets
# Input
HEADERS +=
SOURCES += main.cpp
LIBS +=-lvlc
main :
#include <vlc/vlc.h>
#include <QApplication>
int main(int argc, char* argv[])
{
QApplication app(argc, argv);
libvlc_instance_t * inst;
libvlc_media_player_t *mp;
libvlc_media_t *m;
// Load the VLC engine
inst = libvlc_new(0, NULL);
// Create a new item
m = libvlc_media_new_path (inst, "/home/........mp3");
// Create a media player playing environement
mp = libvlc_media_player_new_from_media (m);
// play the media_player
libvlc_media_player_play (mp);
return app.exec();
}
The compilation is fine. But the program immediatly crashes when I build it (with Qt Creator). Any idea?
Many thanks
Many things could cause this crash. The best is to get VLC source code to trace back the issue. Passing the option '--verbose=2' when initializing libVLC can help as well.
In my case the cause of the crash was due to this bug in the ubuntu package of vlc:
https://bugs.launchpad.net/ubuntu/+source/vlc/+bug/1328466
When calling libvlc_new() vlc modules and their dependent libraries are loaded into memory. The qt module of LibVLC was searching for Qt4 shared objects instead of Qt5 (manually installed).
The solution was to rebuild the module cache which was outdated an pointing to Qt4 binaries. You can reset it on the command line:
sudo /usr/lib/vlc/vlc-cache-gen -f /usr/lib/vlc/plugins/
Or pass to vlc the option:
--reset-plugins-cache
I have never used this library, but Are you using exactly this code?
m = libvlc_media_new_path (inst, "/home/........mp3");
This path may be the problem.
What distribution of Linux are you using?
I ran into this same problem with Qt5 and LibVLC, and the primary cause (Ubuntu 12.04 LTS and 14.04 LTS), was that LibVLC was loading the qt4 interface plugin, which conflicted with Qt5. If you check your call stack, you'll most likely see that at a Qt4 library was being loaded, causing the crash.
If this is the problem, there are only 3 options (tested with LibVLC 2.2 and Qt5 on Ubuntu 12.04 and 14.04 LTS 64 bit).
The first (worst) is to delete the qt4 user interface plugin. You can test this is the problem by moving and running and then setting it back. Deleting will break your regular VLC player most likely.
Second option is to create a copy of the plugins directory and set that in your runtime path using VLC_PLUGIN_PATH, environment variable. but I've had trouble getting that to work without changing the original plugin path folder also (which will break your VLC player unless you modify your shortcuts, etc. to also set VLC_PLUGIN_PATH.
The third option, and what I ended up doing, was to custom build my own static LibVLC binary with a few edits to the source code so that it will not load the qt4 interface plugin installed with VLC. You can follow these steps to do this.
1) Download VLC Source Code for your platforms distribution.
http://download.videolan.org/pub/videolan/vlc/
Make sure you download the version matching your distribution. For
example, match the VLC version to what is installed with Ubuntu.
2) Extract source code to folder
3) Install dependencies for the OS distribution
sudo apt-get build-dep vlc
4) Modify src/modules/bank.c
Edit the module_InitDynamic function
Add the following code at the top of the function:
// HACK TO DISABLE QT4 PLUGIN
if(strstr(path, "qt4") != NULL)
return NULL;
// END HACK
3) From terminal
./bootstrap
./configure --disable-qt --disable-skins2 --enable-xcb --prefix=/home/$USER/vlc-custom_build_output_folder_name
./make
./make install
4) Copy/Save the resulting files in the install folder.
Then just link against this library instead.
I'm trying to install opencv on windows, here are my steps:
downloaded opencv 2.4.3 from website
run the exe, extracted the folder in the same path
opened eclipse (with MinGW previously set and configured)
created new project XYZ
added new folder "src"
added new class "main.cpp"
added the following code:
hash include <cv.h>
hash include <highgui.h>
using namespace cv;
int main(int argc, char** argv) {
Mat image;
image = imread(argv[1], 1);
if (argc != 2 || !image.data) {
printf("No image data \n");
return -1;
}
namedWindow("Display Image", CV_WINDOW_AUTOSIZE);
imshow("Display Image", image);
waitKey(0);
return 0;
}
added the two paths
"E:\Sources\opencv\build\include"
"E:\Sources\opencv\build\include\opencv"
got the compilation error "Symbol 'cv' could not be resolved"
Please advice if any step is missing
you gonna need the latest stable version of openCV 2.4.3 .
Eclipse Juno ! (Eclipse IDE for C/C++ Developers )
And
MinGW - Minimalist GNU for Windows
we will ignore x86/64 choice, since we gonna work with a 32 compiler / and 32 openCV build, even though the system is a 64 one !
Step 1 : Download and Install
Eclipse
Download Eclipse from and decompress the archive . ( I assumed that you already have JRE on your computer , if not ! download and install it ) .
MinGW
Download MinGW . the installer will lead you through the process !
you might have to add the bin directory to the path ! (Default path : C/MinGW/bin )
OpenCV
Download openCV exe from the link , extract the files (in the C:/ directory in this tutorial ) .
Make sure you have the file structure below .
don't forget to add the bin directory => Path !
As I mentioned earlier ! I'll use x86 build even if i have a 64 OS to avoid compiler problems and to keep this tutorial open to x86 OS users !
Step 2 : Create and Configure
Open the Eclipse IDE !
Create a new C++ project : File > New > C++ Project
Choose a Hello Word Project to have a pre structured one !
Don't forget to select the MinGW toolchains
Click Finish and let's get to work !
Now that you have you first Hello word project ! replace the Code in the Soure file .cpp by the code below
///////////////CODE///////////
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
using namespace cv;
using namespace std;
int main(int argc, char** argv)
{
Mat im = imread(argc == 2 ? argv[1] : "lenna.png", 1);
if (im.empty())
{
cout << "Cannot open image!" << endl;
return -1;
}
imshow("image", im);
waitKey(0);
return 0;
}
///////////////CODE///////////
Obviously there are multiple errors on the code , yes ! we have to link the libraries !
Now go to Properties >> C/C++ Build >> Settings
on the Tool Setting tab >> GCC C++ Compiler >> Includes and include opencv path !
[opencvDir\build\include]
Now scroll to MinGW C++ Linker >> Libraries and add the Library search path [opencvDIR\build\x86\mingw\lib]
in the Libraries part ! we add as much librarie as we need for the project !
here I added 4 libraries just for tutorial sake even if well need only the highgui one for our test code to work !
The libraries names can be found on the [opencvDIR\build\x86\mingw\lib]
Example ! for libopencv_video243.dll.a wee add opencv_video243 in the linker !
click OK !
Now we can build our first project !
You figured that you have to add a picture to the project as implied in the source code "lenna.png"
Use lenna for good luck
Build and Run the project !
If you see the beautiful lady :) Congrats :)
have a look here for snapshots!
opencveclipse-on-windows
cv.h is for the old C API. To use the Cpp API try the following:
#include <opencv2/opencv.hpp>