The Effect class is used to transform audio streams. 更多...
| 頭： | #include <Phonon/Effect> |
| Since: | Qt 4.4 |
| 繼承： | QObject and MediaNode |
| Effect (const EffectDescription & 描述 , QObject * parent = 0) | |
| EffectDescription | description () const |
| QVariant | parameterValue (const EffectParameter & parameter ) const |
| QList<EffectParameter> | 參數 () const |
| void | setParameterValue (const EffectParameter & parameter , const QVariant & value ) |
The Effect class is used to transform audio streams.
An effect is a media node which is inserted into a path between a MediaObject and an audio output node, for instance, an AudioOutput . The Effect transforms the media stream on that path.
Examples may include simple modifiers, such as fading or pitch shifting, and more complex mathematical transformations. You can query the backend for available effects with BackendCapabilities::availableAudioEffects (). Note that the effects available is dependent on the underlying system (DirectDraw, GStreamer, or QuickTime).
In order to use an effect, insert it into the path as follows:
Path path = Phonon::createPath(...); Effect *effect = new Effect(this); path.insertEffect(effect);
The effect will immediately begin applying it's transformations on the path. To stop it, remove the Effect from the path.
To create an effect, you use the EffectDescription class, which you get from availableAudioEffects() . We give a code example below.
QList<Phonon::EffectDescription> effectDescriptions =
Phonon::BackendCapabilities::availableAudioEffects();
Phonon::EffectDescription effectDescription = effectDescriptions.at(4);
Phonon::Path path = Phonon::createPath(mediaObject, audioOutput);
Phonon::Effect *effect = new Phonon::Effect(effectDescription);
path.insertEffect(effect);
An effect can have one or more parameters, which let you alter how the effect works, for instance, by specifying the depth of a reverb effect. See the EffectParameter 類描述瞭解細節。
Phonon also provides EffectWidget , which lets the user modify the parameters of an effect an the fly; e.g., with combo boxes.
另請參閱 Phonon 模塊 and EffectWidget .
Constructs a new effect object with the given 描述 and parent 對象。
The EffectDescription object determines the type of the effect.
另請參閱 Phonon::BackendCapabilities::availableAudioEffects().
Returns the description of this effect. This is the same description that was passed to the constructor.
Returns the value of the given effect parameter . You can fetch the available parameters for an effect with 參數 ().
另請參閱 setParameterValue () 和 EffectParameter .
Returns a list of parameters that this effect provides to control its behavior.
另請參閱 EffectParameter and EffectWidget .
Sets the given effect parameter 到指定 value .
Parameters for an effect are returned by 參數 (). You can check which QVariant::Type an EffectParameter takes with the EffectParameter::type () 函數。
另請參閱 parameterValue () 和 EffectParameter .