QMediaPlayer::setMedia first call faster than following calls

smart_ptr

Hi all,

I'm using Qt 5.15 on an arm7 system. My code is implemented in C++ 17.

I have a simple class containing a member of QMediaPlayer. The instance of my class and thus also the QMediaPlayer instance lives forever. My class has a method to play a given sound file. In my case, the sound file is a .wav file. The body of the method is quite simple, it just calls:

m_mediaPlayer->setMedia(m_soundFileUrl);
m_mediaPlayer->play();

I have a simple UI with a button. And in onClicked I call the method to play a sound. For test purposes, it is currently (hard coded) always the same sound. I observed, that the first call of setMedia is significantly faster than following calls:

duration of setMedia:  20.8233 ms
c++Sound: 24ms

duration of setMedia:  37.016 ms
c++Sound: 39ms

duration of setMedia:  37.4577 ms
c++Sound: 41ms

duration of setMedia:  35.025 ms
c++Sound: 38ms

My question now is, what is the reason for that?

Regards,
smart_ptr