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SoundEffect

The SoundEffect element allows playing short-lasting and looping sound effects in wav file format. More...

• List of all members, including inherited members

Properties

• autoPauseInBackground : bool
• autoPlay : bool
• category : string
• loops : int
• loopsRemaining : int
• muted : bool
• playing : bool
• source : url
• status : int
• volume : real

Methods

• isLoaded()
• play()
• stop()

Detailed Description

Playing SoundEffect has a very low latency and is therefore well suited for short notification sounds.

The sound is preloaded as soon as the source property is set and can then be started with low latency by calling play(). You can also set the loops property to implementing looping sounds.

For playing encoded audio files for example in MP3 format or with no latency requirements use the BackgroundMusic component. For videos use the Video component.

Felgo Additions to SoundEffect

SoundEffect enhances the Qt 5 component SoundEffect in the Qt Multimedia 5.0 module with the following additions:

• Allow to pause and resume all SoundEffect objects by setting settings.soundEnabled to true or false.
• Proper application handling: if the app is moved to the background all instances of SoundEffect and BackgroundMusic are paused on mobile platforms. All instances are then resumed when the app gets focus again and comes into foreground. This is especially useful on mobile devices, where the default SoundEffect component would continue playing if the app is moved to the background. On Desktop platforms, the SoundEffect and BackgroundMusic instances keep playing. You can modify this behavior with the autoPauseInBackground property.
• Use the autoPlay property to start playing a SoundEffect when it is loaded, useful if you have a BackgroundMusic type sound that should be loaded when starting your app.

SoundEffect Details

This type allows you to play uncompressed audio files (typically WAV files) in a generally lower latency way, and is suitable for "feedback" type sounds in response to user actions (e.g. virtual keyboard sounds, positive or negative feedback for popup dialogs, or game sounds). If low latency is not important, consider using the MediaPlayer or BackgroundMusic types instead, since they support a wider variety of media formats and are less resource intensive.

Typically the sound effect should be reused, which allows all the parsing and preparation to be done ahead of time, and only triggered when necessary. This is easy to achieve with QML, since you can declare your SoundEffect instance and refer to it elsewhere.

Note: Since SoundEffect requires slightly more resources to achieve lower latency playback, the platform may limit the number of simultaneously playing sound effects.

Finding Sounds

For free sounds, we recommend the following websites:

• http://www.playonloop.com/ - For background music
• http://www.noiseforfun.com/ - For sound effects
• http://freesound.org/ - Another good resource for sound effects
• http://www.audiomicro.com/free-sound-effects - Also for sound effects
• http://raisedbeaches.com/octave/ - For UI sound effects like button click sounds

These sites have a great search feature, as you can search by categories or tags. Most of the sounds are available for free if you add the license to your game. There also are low-price premium version of the sounds, which allows you to use them without any license note.

Supported SoundEffect Formats

The wav format is the single format that is supported on all platforms. Try to follow the same Performance Hints mentioned in the BackgroundMusic component for maximum performance.

Note: If you target the Android platform, ensure that all wav files are 16 bit PCM (or higher) encoded. Convert all 8 bit wav files to 16 bit and rebuild the app.

Example Usage

Here is an example of playing a looping sound on mouse click:

 import Felgo 3.0
 import QtQuick 2.0
 import QtMultimedia 5.0 // required for SoundEffect.Infinite enum value for infinite looping

 GameWindow {

   MouseArea {
     anchors.fill: parent
     onClicked: clickSound.play()
   }

   SoundEffect {
     id: clickSound
     source: "clickSound.wav"
     loops: SoundEffect.Infinite
   }
 }

Property Documentation

Method Documentation