How to insert ffmpeg option to QProcess

[mumulala]

Hi everyone. I have little problem with QProcess.
i can run basic command,

QProcess *vconv = new QProcess;
QString input_file=" /home/gafi/copypastetoroot.avi";
QStrng output_file="/home/gafi/copypastetoroot.mkv ";
QString program = "ffmpeg";
QStringList arguments;

arguments << "-i" << input_file << output_file;

vconv -> start(program, arguments);

but if i add some option i got error "At least one output file must be specified"
arguments <<"-i" << input_file << "-q:v 1" << output_file;

i tried in terminal it run normally
ffmpeg -i /home/gafi/copypastetoroot.avi -q:v 1 /home/gafi/copypastetoroot.mkv

How to insert the options? thank you.

[mumulala]

solved. i have to split each options and value into single string