[Qt-interest] High CPU Usage With QAudioOutput

[Barnes, Clifton A.]

On Wed, 6 Apr 2011, Gabriel M. Beddingfield wrote:

>> format.setCodec("audio/pcm");

> This is line incorrect, since you're actually sending 
> audio/x-wav

I've changed the codec, but there was no change.

> Just curious... did you first check if the format is 
> supported?  

I've checked QAudioFormat::isValid if that's what you mean
by supported.  If not, how can I check if it's supported?

> Also, is it going to PulseAudio instead of your 
> sound card?  My guess is that something is triggering 
> resampling.

There is no sound daemon like PulseAudio.  It's just using
alsa-lib.  Would ALSA try to resample?  Where can I check if 
it is?

> Also, if you're really just wanting phonon-like media 
> playback... you should check out QMediaPlayer.  QAudioOutput 
> is really for low-level stuff (like if you're writing a 
> synthesizer or sampler something).

All I need is to simply play a sound.  Would it make more 
sense to just use a raw audio file with QAudioOutput instead 
of a .wav?  Do I need to use QMediaPlayer for such a simple 
task?  Also, isn't it part of Qt Mobility that uses the 
QAudioOutput underneath?

Clif