Qt嵌入mplayer问题

mini6410中我用qt嵌入mplayer作音频播放器，发现用qprocess启动mplayer根本就无法启动
相反如果用system等函数是可以顺利启动并播放歌曲的？请问这是什么问题？
以下是我的代码：
include <QProcess>
                              |  2
-  test.cpp (/Git/ARICE/demo/Q|  3 int main(int argc, char *argv[])
|-   function                 |  4 {
||     main                   |  5     QProcess *process = new QProcess();
                              |  6     QStringList args;
   ~                          |  7     QString exefile = "/bin/mplayer";
   ~                          |  8     QString fileName = "/usr/local/shi.mp3";
   ~                          |  9     args << " -slave";
   ~                          | 10     args << " -quiet";
   ~                          | 11     args << fileName;
   ~                          | 12     process->setProcessChannelMode(QProcess::MergedChannels);
   ~                          | 13     process->start(exefile, args);
   ~                          | 14     if(!process->waitForFinished(3000)) {
   ~                          | 15
   ~                          | 16     }
   ~                          | 17 }