Phonon: only one output device

skoczo

Hi,
I have usb sound cards and i want to play music on this cards. Unfortunetly phonon don't see my card.

When i'm waiting on notify signal:
@connect(Phonon::BackendCapabilities::notifier(), SIGNAL(availableAudioOutputDevicesChanged()), this, SLOT(devicesChanged()));@
I got only 1 device.

In console i can see two cards: pactl list
@Card #1
Name: alsa_card.pci-0000_00_1b.0
Driver: module-alsa-card.c
Owner Module: 26
Properties:
alsa.card = "0"
alsa.card_name = "HDA Intel PCH"
alsa.long_card_name = "HDA Intel PCH at 0xd3610000 irq 46"
alsa.driver_name = "snd_hda_intel"
device.bus_path = "pci-0000:00:1b.0"
sysfs.path = "/devices/pci0000:00/0000:00:1b.0/sound/card0"
......

Card #2
Name: alsa_card.usb-C-Media_Electronics_Inc._USB_PnP_Sound_Device-00-Device
Driver: module-alsa-card.c
Owner Module: 29
Properties:
alsa.card = "1"
alsa.card_name = "USB PnP Sound Device"
alsa.long_card_name = "C-Media Electronics Inc. USB PnP Sound Device at usb-0000:00:14.0-2.2, full spe"
alsa.driver_name = "snd_usb_audio"
device.bus_path = "pci-0000:00:14.0-usb-0:2.2:1.0"
sysfs.path = "/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2.2/1-2.2:1.0/sound/card1"
.....
@

Can you help?

SGaist

Hi and welcome to devnet,

What Distribution/Desktop environment are you running ?

skoczo

Arch linux, XFCE with pulseaudio.

When i call "QAudioDeviceInfo::availableDevices(QAudio::AudioOutput)" i got 3 devices. This is ok but how to connect this with phonon?

Any ideas?

skoczo

How to use multiple sound cards to play mp3 or internet radio in QT? Can anyone help?

SGaist

IIRC, using phonon, you'll use what the backend is setup to use e.g. pulseaudio.

If you want to play with several outputs at the same time, you should rather look at QtMultimedia

skoczo

Do you have some examples how to do that? I know how to play (raw formats)wave but how to play mp3 or internet radio using QtMultimedia?

SGaist

QMediaPlayer comes to mind

skoczo

In QMediaPlayer i can't found way to set output device.
Do you know how to set it? I even looked at the code but i don't know how it works :/

SGaist

AFAIK, you can't just simply set it. You have to get a QAudioEndpointSelector from QMediaPlayer. However it might not be implement in all backends

skoczo

I have Qt 5.3.1 and can't find QAudioEndpointSelector class.
About what version Qt you are talking about? Do you have an example?

SGaist

Sorry, my bad it's a class from QtMobility, it's QAudioOutputSelectorControl that I was thinking about

skoczo

What the qt-mobility is? It sounds like lib for mobile devices. Can i use it in desktop app?

SGaist

It was for the Qt 4 series, some of the classes have been integrated in Qt 5 others might need porting.

Yes you can,

skoczo

I don't know how to do that.
Maybe you know some other C++ library than qt where can i play music on multiple sound cards? I use it on linux and want play music from internet radio.

SGaist

You can have a look at GStreamer and QGStreamer