The AudioOutput class is used to send data to audio output devices. 更多...
| 头： | #include <Phonon/AudioOutput> |
| Since: | Qt 4.4 |
| 继承： | QObject and MediaNode |
|
|
| AudioOutput (Phonon::Category category , QObject * parent = 0) | |
| AudioOutput (QObject * parent = 0) | |
| Phonon::Category | category () const |
| bool | isMuted () const |
| QString | name () const |
| AudioOutputDevice | outputDevice () const |
| qreal | volume () const |
| qreal | volumeDecibel () const |
| void | setMuted (bool mute ) |
| void | setName (const QString & newName ) |
| bool | setOutputDevice (const Phonon::AudioOutputDevice & newAudioOutputDevice ) |
| void | setVolume (qreal newVolume ) |
| void | setVolumeDecibel (qreal newVolumeDecibel ) |
| void | mutedChanged (bool muted ) |
| void | outputDeviceChanged (const Phonon::AudioOutputDevice & newAudioOutputDevice ) |
| void | volumeChanged (qreal newVolume ) |
The AudioOutput class is used to send data to audio output devices.
The AudioOutput class plays sound over a sound device. The audio output needs to be connected to a MediaObject using createPath(). To start playback, you call play() on the media object.
Phonon::MediaObject *mediaObject = new Phonon::MediaObject(this);
mediaObject->setCurrentSource(Phonon::MediaSource("/mymusic/barbiegirl.wav"));
Phonon::AudioOutput *audioOutput =
new Phonon::AudioOutput(Phonon::MusicCategory, this);
Phonon::Path path = Phonon::createPath(mediaObject, audioOutput);
The class supports changing the volume (). It is also possible to mute the sound.
To find out what AudioOutputDevice s are available for AudioOutput ，可以调用 BackendCapabilities::availableAudioOutputDevices (). A default device is selected by the backend, but it is possible to set the device to be used with setOutputDevice ()。 outputDeviceChanged () signal will be emitted if the device changes.
If an error occurs with the playback, for instance, if no valid output device is found, the media object will receive a stateChanged() signal with the ErrorState .
Note that the default values of properties are dependent on the backend.
另请参阅 Phonon::VolumeSlider , 音乐播放器范例 , BackendCapabilities ，和 Phonon 模块 .
This property tells whether the output is muted.
Muting the output has the same effect as calling setVolume (0.0).
访问函数：
| bool | isMuted () const |
| void | setMuted (bool mute ) |
通知程序信号：
| void | mutedChanged (bool muted ) |
This is the name that appears in Mixer applications that control the volume of this output.
访问函数：
| QString | name () const |
| void | setName (const QString & newName ) |
This property holds the (hardware) destination for the output.
The default device is determined by the Category and the global configuration for that category. Normally you don't need to override this setting - letting the user change the global configuration is the right choice. You can still override the device though, if you have good reasons to do so.
访问函数：
| AudioOutputDevice | outputDevice () const |
| bool | setOutputDevice (const Phonon::AudioOutputDevice & newAudioOutputDevice ) |
另请参阅 outputDeviceChanged ().
This is the current loudness of the output.
(it is using Stevens' law to calculate the change in voltage internally).
访问函数：
| qreal | volume () const |
| void | setVolume (qreal newVolume ) |
通知程序信号：
| void | volumeChanged (qreal newVolume ) |
另请参阅 volumeDecibel .
This is the current volume of the output in decibel.
0 dB means no change in volume, -6dB means an attenuation of the voltage to 50% and an attenuation of the power to 25%, -inf dB means silence.
访问函数：
| qreal | volumeDecibel () const |
| void | setVolumeDecibel (qreal newVolumeDecibel ) |
另请参阅 volume .
创建新的 AudioOutput 采用给定 parent that defines output to a physical device.
The category can be used by mixer applications to group volume controls of applications into categories. That makes it easier for the user to identify the programs. The category is also used for the default output device that is configured centrally. As an example: often users want to have the audio signal of a VoIP application go to their USB headset while all other sounds should go to the internal soundcard.
另请参阅 Phonon::categoryToString() and outputDevice .
创建新的 AudioOutput that defines output to the system default device with the {Phonon::Category::}{ NoCategory } category
另请参阅 Phonon::categoryToString() and outputDevice .
Returns the category of this output.
另请参阅 Phonon::AudioOutput::AudioOutput().
[signal]
void
AudioOutput::
outputDeviceChanged
(const
Phonon::AudioOutputDevice
&
newAudioOutputDevice
)
This signal is emitted when the (hardware) device for the output has changed. newAudioOutputDevice is the new device.
The change can happen either through setOutputDevice or if the global configuration for the used category has changed.
另请参阅 outputDevice .