Loading video using QMediaPlayer and UNC paths - qt

I'm trying to load a video from a network using UNC paths thanks to Qt 5.5 QMediaPlayer.
The code snippet is the following one:
projectDirectory = QFileDialog::getExistingDirectory (this,
tr ("Choose project folder (sensor + video data"),
QDir::homePath(), QFileDialog::ShowDirsOnly);
QDir dir(projectDirectory);
QStringList test = dir.entryList();
qDebug () << projectDirectory << "contains:" << endl << test;
mediaPlayer.setMedia(QUrl::fromLocalFile(projectDirectory+"/video.mov"));
The code snippet works for a local file but doesn't work when the path begins with //.
Example output:
"//m4800/Partage/111" contains:
(".", "..", "HandBrake.txt", "sensors.csv", "video.mov")
DirectShowPlayerService::doSetUrlSource: Unresolved error code 80004005
Note that I am able to read the sensors.csv text file and that video.mov has the same permissions.

Instead of
mediaPlayer.setMedia(QUrl::fromLocalFile(projectDirectory+"/video.mov"));
remove ::fromLocalFile and try
mediaPlayer.setMedia(QUrl(projectDirectory+"/video.mov"));
This seems to solve the problem. In the codebase I am working on, we have added a check for "//" at the start of the raw path before creating the URL to check it is a UNC path and still use the fromLocalFile if it is not.

The DirectShow library does not appear to correctly support UNC paths.
You either have to copy the file to a local temp folder or load the file into a QByteArray and stream from there.
Neither is a great solution and Microsoft depreciated DirectShow in favour of Media Foundation (which has limited playback support at this time).

Related

QT - Where is config.ini

I wanted to save db's conenction in Config.ini file. I created it and added to project (as "other file") - suitable record appered in .pro file.
I started in code with this:
QSettings settings(QDir::currentPath()+"/"+fileName, QSettings::IniFormat);
Then i created 2 functions
for savng settings:
settings.beginGroup("DB");
settings.setValue("HostName",_hostName);
//_hostName is attribute I can access, so that's not an issue
settings.endGroup();
for reading settings
settings.beginGroup("DBSettings");
_hostName =settings.value("HostName", "Unknown").toString();
// hostName is attribute i can access
settings.endGroup();
I initially called 1. and then 2.
It seems like that the .ini file is created and I could read from it, but it's not that I added to project and i can't find it in the folder it supposed to be.
It works, but I need to include it into the project and I need to be able to "control" it.
I resolved this problem myself. Turned out, that line :
QSettings settings(QDir::currentPath()+"/"+fileName, QSettings::IniFormat);
just has to be repalced with
settings = new QSettings(QDir::currentPath()+"/"+fileName, QSettings::IniFormat);

Qt WinRT App cannot access file permission denied

I need to develop WinRT App using Qt and FFMPEG, I build the ffmpeg for WinRT based on the instruction here and I am able to link the library with my project. Now I need to open a video file using avformat_open_input but it always giving me the output
video decode error "Permission denied"
Below is the relevant part of the code,
int ret = avformat_open_input(&pFormatCtx, hls, NULL, NULL);
if(ret != 0)
{
char errbuf[128];
av_strerror(ret, errbuf, 128);
qDebug()<<"video decode error"<<QString::fromLatin1(errbuf);
}
From the above error it seems some permission issue, do I need to add any additional permission on AppxManifest.xml currently I am using default manifest which is created by Qt creator.
Try to add a file protocol to the manifest page, contains your file extension you want to access/ create or play with..
for example, .xml, .txt, .etc..
I always face this 'unknown' error when try to access files without adding the ext file protocol..
UPDATE:
More Information: https://msdn.microsoft.com/library/windows/apps/hh464906.aspx#file_activation
Do it by: Package.appxmanifest > Declarations > Add a 'File Type Association' > your type name and ext. is required.
Example in a code:
<Extensions>
<uap:Extension Category="windows.fileTypeAssociation">
<uap:FileTypeAssociation Name="myfile">
<uap:SupportedFileTypes>
<uap:FileType>.config</uap:FileType>
</uap:SupportedFileTypes>
</uap:FileTypeAssociation>
</uap:Extension>
</Extensions>
Change 'myfile' and '.config'
Good luck!

Setting Jetty resourcebase to static file embedded in the same jar file

I am trying to access static resource (eg. first.html) packed inside the same .jar file (testJetty.jar), which also has a class which starts the jetty (v.8) server (MainTest.java). I am unable to set the resource base correctly.
The structure of my jar file (testJetty.jar):
testJetty.jar
first.html
MainTest.java
==
Works fine on local machine, but when I wrap it in jar file and then run it, it doesn't work, giving "404: File not found" error.
I tried to set the resourcebase with the following values, all of which failed:
a) Tried setting it to .
resource_handler.setResourceBase("."); // Results in directory containing the jar file, D:\Work\eclipseworkspace\testJettyResult
b) Tried getting it from getResource
ClassLoader loader = this.getClass().getClassLoader();
File indexLoc = new File(loader.getResource("first.html").getFile());
String htmlLoc = indexLoc.getAbsolutePath();
resource_handler.setResourceBase(htmloc); // Results in D:\Work\eclipseworkspace\testJettyResult\file:\D:\Work\eclipseworkspace\testJettyResult\testJetty1.jar!\first.html
c) Tried getting the webdir
String webDir = this.getClass().getProtectionDomain()
.getCodeSource().getLocation().toExternalForm();
resource_handler.setResourceBase(webdir); // Results in D:/Work/eclipseworkspace/testJettyResult/testJetty1.jar
None of these 3 approaches worked.
Any help or alternative would be appreciated
Thanks
abbas
The solutions provided in this thread work but I think some clarity to the solution could be useful.
If you are building a fat jar and use the ProtectionDomain way you may hit some issues because you are loading the whole jar!
class.getProtectionDomain().getCodeSource().getLocation().toExternalForm();
So the better solution is the other provided solution
contextHandler.setResourceBase(
YourClass.class
.getClassLoader()
.getResource("WEB-INF")
.toExternalForm());
The problem here is if you are building a fat jar you are not really dumping your webapp resources into WEB-INF but are probably going into the root of the jar, so a simple workaround is to create a folder XXX and use the second approach as follows:
contextHandler.setResourceBase(
YourClass.class
.getClassLoader()
.getResource("XXX")
.toExternalForm());
Or change your build tool to export the webapp files into that given directory. Maybe Maven does this on a Jar for you but gradle does not.
Not unusually, I found a solution to my problem. The 3rd approach mentioned by Stephen in Embedded Jetty : how to use a .war that is included in the .jar from which Jetty starts? worked!
So, I changed from Resource_handler to WebAppContext, where WebAppContext is pointing to the same jar (testJetty.jar) and it worked!
String webDir = MainTest.class.getProtectionDomain()
.getCodeSource().getLocation().toExternalForm(); ; // Results in D:/Work/eclipseworkspace/testJettyResult/testJetty.jar
WebAppContext webappContext = new WebAppContext(webDir, "/");
It looks like ClassLoader.getResource does not understand an empty string or . or / as an argument. In my jar file I had to move all stuf to WEB-INF(any other wrapping dir will do). So the code looks like
contextHandler.setResourceBase(EmbeddedJetty.class.getClassLoader().getResource("WEB-INF").toExternalForm());
so the context looks like this then:
ContextHandler:744 - Started o.e.j.w.WebAppContext#48b3806{/,jar:file:/Users/xxx/projects/dropbox/ui/target/ui-1.0-SNAPSHOT.jar!/WEB-INF,AVAILABLE}

Qt-application only works correctly if started from the command line

I made a pretty simple application with Qt Creator on Ubuntu 12.04. The application reads an xml-file and shows a couple of images. But when I try to start the application by double clicking the icon on a different machine (running Lubuntu), the images are not shown, and the xml-file is not read. The application does work properly when it is started from the command line by typing ./App.
Why does it behave like this and how do I fix it?
edit: The method that reads the xml:
QDomDocument doc("document");
QString path = "datastorage.xml"; // xml is in same directory as the executable
QFile xmlFile(path);
if (!xmlFile.open(QIODevice::ReadOnly))
throw QString("Error with XML: Could not open file " + path);
if (!doc.setContent(&xmlFile)) {
xmlFile.close();
throw QString("Error with XML: Could not set QDomDocument content from " + path);
}
xmlFile.close();
QDomElement root = doc.documentElement();
return root;
Simply you are using relative paths to read files and those paths are always relative to "working directory". If you're launching your app from console, and all required files are within app directory then everything works. When launching from desktop working directory may be different. Just prepend QCoreApplication::applicationDirPath() to all paths you're using.

QSettings - where is the location of the ini file?

I'm using QSettings to store some data as ini file in Windows.
I want to see the ini file, but I don't know what is the location of the ini file.
This is my code:
QSettings *set = new QSettings(QSettings::IniFormat, QSettings::UserScope, "bbb", "aaa");
set->setValue("size", size());
set->setValue("pos", pos());
Where do I have to look? Or may be I miss the code which write it to the file?
When does the QSettings write its values?
To print out the exact location of your settings file use method fileName method of QSettings class.
QSettings settings("folderName", "fileName");
qDebug() << settings.fileName();
Console output looks then like:
/home/user/.config/folderName/fileName.conf
I think you'll find everything you're looking for here : http://doc.qt.io/archives/qt-4.7/qsettings.html
It's plateform specific, see under :
Platform-Specific Notes
Locations Where Application Settings Are Stored
You can store Settings in files as well :
QSettings settings("/home/petra/misc/myapp.ini",
QSettings::IniFormat);
QSettings save location changes to the QSettings.Scope enum. QSettings save to the Local scope by default. On Linux, I found my local settings in:
~/.config/CompanyName/ApplicationName.conf
If you create a QSettings without giving any specific path, the ini file will be located in the application path.
QSettings Settings("myapp.ini", QSettings::IniFormat);
Settings.setValue("Test", "data");
//...
qDebug() << QApplication::applicationDirPath();
Be careful though : the application path might change : for instance, if you are developping your app with Qt Creator, in debug mode, the application path is in the /debug subfolder.
If you are running it in release mode, the application path is in the /release subfolder.
And when your application is deployed, by default, the application path is in the same folder as the executable (at least for Windows).
Check out the QStandardPaths class, it links to multiple standard paths including configuration on all supported platforms. https://doc.qt.io/qt-5/qstandardpaths.html
QT >= 5.5:
QString path = QStandardPaths::writableLocation(QStandardPaths::AppConfigLocation);
QT < 5.5:
QString path = QStandardPaths::writableLocation(QStandardPaths::ConfigLocation);
There are paths for config files in shared config directories, application data directories, and more.
In linux you can use this snippet or insert this lines into your main code for find location of your file with python.
from PyQt5.QtCore import QSettings
settings = QSettings("Organization Name", "App name")
print(QSettings.fileName(settings))
It should return an output like this.
/$HOME/.config/Organization Name/App name.conf
Source
in windows path is like below:
C:\Users\user_name\AppData\Roaming\bbb
On Mac OSX, I found the file under at ~/Library/Preferences
The QSettings class provides persistent platform-independent application settings.
Users normally expect an application to remember its settings (window sizes and positions, options, etc.) across sessions. This information is often stored in the system registry on Windows, and in XML preferences files on Mac OS X. On Unix systems, in the absence of a standard, many applications (including the KDE applications) use INI text files
http://doc.qt.io/archives/qt-4.7/qsettings.html
On Windows without providing an ini filename, you'll find the data in the registry.
Using this code snippet:
int red = color.red();
int green = color.green();
int blue = color.blue();
QSettings settings("Joe", "SettingsDemo");
qDebug() << settings.fileName();
settings.beginGroup("ButtonColor");
settings.setValue("button1r", red);
settings.setValue("button1g", green);
settings.setValue("button1b", blue);
settings.endGroup();
After running this code, you'll see the output:
"\\HKEY_CURRENT_USER\\Software\\Joe\\SettingsDemo"
Now, opening the regedit tool and following the path list you got: 1

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