@Cleiton-Bueno thanks for your suggestion. I have disabled audio in my kernel completely now. Now I get the message CameraBin warning: "Could not open audio device for recording." which shows, that I really removed audio support.
Unfortunately, this still doesn't solve my basic issue, which is a extremely sluggish video output when the videoRecorder property is enabled in the Camera. That means, the audio encoding was not causing this problem at all.

Thx, Jens

Hi and welcome to devnet,

You should check what your device support, QAudioDeviceInfo gives you all the various channel counts, sample sizes etc. that are supported by the device you want to use.

The please first update to 5.9.1

I re-built the file system image, this time with Buildroot-2017.02 and Qt version 5.6.2.

I ran, on the target board, the audiooutput example that Qt provides and got a lots of pulseaudio warnings.

Remembering the above QT_DEBUG_PLUGINS hint, I took a look inside the /usr/lib/qt/plugins/audio directory on the target board and found two plugins: libqtmedia_pulse.so and libqtaudio_alsa.so .

Removing the libqtmedia_pulse.so plugin solved the race condition with libqtaudio_alsa.so and solved the problem.

In addition, make sure that alsa-lib builds before qt5multimedia (commit 8d7dd837e5e from mainline Buildroot: "qt5multimedia: conditionally add alsa-lib to dependencies").

Hi and welcome to devnet,

QAudioInput returns a pointer to a QIODevice that will provide the audio data. Connect the readyRead signal from that QIODevice object to a slot of your class, there you can read the audio data received and make what you want with it.

Hope it helps

Hi,

Usually, to play sound effect, the QSoundEffect class is used. Wouldn't that fill your need ?

Hi,

You should take a look at the bug report system to see if it something known.

Hi,

Then that's something you should ask to the QtAV authors. It's not an official Qt module.

Hi,

Might be a bit of short answer but… AFAIK, no you can't.

Is it a paid or free program.

Hi,

Take a look the QAudioInput example.

Then you either have to play your video through QtMultimedia and use a QAudioProbe or you'll have to do it with some additional hardware.

You're welcome !

Since you have what you need now, please mark the thread as solved using the "Topic Tool" button so that other forum users may know a solution has been found :)

@SGaist

Good point about the drawing – that hadn't occurred to me.

@SGaist Well...
I wrote about my solutions to combine Qt and RtAudio and it just works but it is a bit of head breaking for me how to manage this with QIODevice.
Maybe after some time

Then it probably is using the audio plugin which I'm not sure at all is supporting qrc

I see... Had to rebuild the app with 5.5 where WMF backend was present.
And the link doesn't seem to provide any rationale for this very odd decision. Of course, I don't care what backed is used, but I do like classes like QAudioProbe actually working.

Then you should check the bug report system

No problem :)

Since you have it working now, please update the thread title prepending [solved] so other forum users may know that a solution has been found :)

Also, when encountering answer(s) that helped you, please consider up-voting them so that other users may find them more easily.

Happy coding !

Good !

Since you have it working now, please update the thread title prepending [solved] so other forum users may know a solution has been found :)

@SGaist
Thanks! I didn't see any bug reports that looked relevant. I'll file one.

One last thing, apparently this error only occur in IOS devices

Nsound is also a C++ library and can be used in C++ applications, see http://sourceforge.net/p/nsound/code/HEAD/tree/tags/nsound-0.9.3/src/Nsound/.

:)
Nick