This effect differs from gradually changing the output volume in that a dedicated effect can change the volume in the smallest possible steps while every other volume control will make more or less noticeable steps.
另请参阅
AudioOutput.volume()
| 参数： | parent – PySide.QtCore.QObject |
|---|
Determines the curve of the volume change.
| 常量 | 描述 |
|---|---|
| Phonon.VolumeFaderEffect.Fade3Decibel | Crossfade curve/fast fade out. This is the default fade curve. |
| Phonon.VolumeFaderEffect.Fade6Decibel | Linear fade out. |
| Phonon.VolumeFaderEffect.Fade9Decibel | Slow fade out. |
| Phonon.VolumeFaderEffect.Fade12Decibel | A more extreme version of the -9dB fade. |
注意事项：
Fade3Decibel is often the best fade for a crossfade, as after half of the time the volume reached -3dB. This means that half the possible power (which is proportional to the square of the voltage) is reached. Summed, the maximum power of two audio signals fading with a -3dB curve will always be equal.
For fading in or out the -3dB curve is too abrupt in the end.
With a -6dB fade curve, a volume of -6dB is reached after half of the fading time. -6dB is equal to half of the voltage meaning that the voltage multiplier changes linearly from the start of the fade to the end.
With the Fade9Decibel fade, a volume of -9dB is reached after half of the fade time, so the fade is fast in the beginning and slow at the end. This is a good fade for ending music.
| 返回类型： | PySide.phonon.Phonon::VolumeFaderEffect.FadeCurve |
|---|
This property holds the fade curve to be used for the PySide.phonon.Phonon::VolumeFaderEffect.fadeIn() , PySide.phonon.Phonon::VolumeFaderEffect.fadeOut() and PySide.phonon.Phonon::VolumeFaderEffect.fadeTo() slots.
默认为 Fade3Decibel .
另请参阅
Phonon.VolumeFaderEffect.FadeCurve
| 参数： | fadeTime – PySide.QtCore.int |
|---|
Tells the Fader to change the volume from the current volume to 100% in fadeTime 毫秒。
Short for fadeTo(1.0, fadeTime) .
fadeTime the fade duration in milliseconds
另请参阅
PySide.phonon.Phonon::VolumeFaderEffect.fadeTo() PySide.phonon.Phonon::VolumeFaderEffect.volume()
| 参数： | fadeTime – PySide.QtCore.int |
|---|
Tells the Fader to change the volume from the current volume to 0% in fadeTime milliseconds. Short for fadeTo(0.0, fadeTime) .
fadeTime the fade duration in milliseconds
| 参数： |
|
|---|
Tells the Fader to change the volume from the current value to volume in fadeTime 毫秒。
另请参阅
PySide.phonon.Phonon::VolumeFaderEffect.fadeIn() PySide.phonon.Phonon::VolumeFaderEffect.fadeOut()
| 参数： | curve – PySide.phonon.Phonon::VolumeFaderEffect.FadeCurve |
|---|
This property holds the fade curve to be used for the PySide.phonon.Phonon::VolumeFaderEffect.fadeIn() , PySide.phonon.Phonon::VolumeFaderEffect.fadeOut() and PySide.phonon.Phonon::VolumeFaderEffect.fadeTo() slots.
默认为 Fade3Decibel .
另请参阅
Phonon.VolumeFaderEffect.FadeCurve
| 参数： | volume – PySide.QtCore.float |
|---|
This is the current volume of the output as voltage factor. Setting this property changes the volume immediately.
1.0 means 100%, 0.5 means 50% voltage/25% power, 0.0 means 0%
另请参阅
PySide.phonon.Phonon::VolumeFaderEffect.volumeDecibel()
| 参数： | volumeDecibel – PySide.QtCore.double |
|---|
This is the current volume of the output in decibel. Setting this property changes the volume immediately.
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.
另请参阅
PySide.phonon.Phonon::VolumeFaderEffect.volume()
| 返回类型： | PySide.QtCore.float |
|---|
This is the current volume of the output as voltage factor. Setting this property changes the volume immediately.
1.0 means 100%, 0.5 means 50% voltage/25% power, 0.0 means 0%
另请参阅
PySide.phonon.Phonon::VolumeFaderEffect.volumeDecibel()
| 返回类型： | PySide.QtCore.double |
|---|
This is the current volume of the output in decibel. Setting this property changes the volume immediately.
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.
另请参阅
PySide.phonon.Phonon::VolumeFaderEffect.volume()
