Qprocess: howto run a command consisting of several commands chained together?

[cdwijs]

Hi All,

I'm writing a program that calls raspivid to record a video thru QProcess. This works great like this:

void ExternalCamera::slotStartCapture(QString filename)
{
    if (myProcess->state() == QProcess::Running)
    {
        qDebug()<<"Process already Running, killing";
        myProcess->kill();
        myProcess->waitForFinished(10000);
        //qDebug()<<"Process Killed";
    }
    qDebug()<<myProcess->state();
    filename.append(".h264");
    QStringList arguments;
    //arguments <<"-o" << "file.h264";    //filename
    arguments <<"-o" << filename;    //filename
    arguments <<"-n";                   //no preview
    arguments <<"--bitrate" << "1000000";//bitrate
    arguments <<"-t"<<"300000";          //time


    myProcess->setArguments(arguments);
    myProcess->setProgram("/usr/bin/raspivid");

    myProcess->start();
    qDebug()<<"start movie: "<<filename;
    myProcess->waitForStarted(10000);
    //qDebug()<<"Process started";
}

But now I would like to run the following command line. How can I tell QProcess to do this? Should I place this inside a .sh file, and then call the sh file?

raspivid -t 200000 -o test16.h264 ; avconv -framerate 30 -i test16.h264 -c:v copy test16.mp4

Cheers,
Cedric

[SGaist]

Hi,

So avconv should be called once raspivid is done, correct ?

[JonB]

@cdwijs
You have 3 options!

1. Split into two separate commands at the ;. Run the left-hand side, wait to finish, run the right-hand side, as two different QProcesses.

2. Put that command line into a file. Run QProcess::execute("/bin/sh", QStringList() << "script.sh").

3. Run the whole command-line as an argument to the shell:

QProcess::execute("/bin/sh", QStringList() << "-c" << "raspivid -t 200000 -o test16.h264 ; avconv -framerate 30 -i test16.h264 -c:v copy test16.mp4")`.