Qt 4.7: QSound Class Reference

Qt Reference Documentation

# QSound Class Reference

The QSound class provides access to the platform audio facilities. More...

     #include <QSound>

Inherits: QObject.

- List of all members, including inherited members
- Qt 3 support members

## Public Functions

| QSound ( const QString & filename, QObject * parent = 0 )
| ~QSound ()
QString | fileName () const
bool | isFinished () const
int | loops () const
int | loopsRemaining () const
void | setLoops ( int number )

- 29 public functions inherited from QObject

## Public Slots

void | play ()
void | stop ()

- 1 public slot inherited from QObject

## Static Public Members

bool | isAvailable ()
void | play ( const QString & filename )

- 5 static public members inherited from QObject

### Additional Inherited Members

- 1 property inherited from QObject
- 1 signal inherited from QObject
- 7 protected functions inherited from QObject

## Detailed Description

The QSound class provides access to the platform audio facilities.

Qt provides the most commonly required audio operation in GUI applications: asynchronously playing a sound file. This is most easily accomplished using the static play() function:

     QSound::play("mysounds/bells.wav");

Alternatively, create a QSound object from the sound file first and then call the play() slot:

     QSound bells("mysounds/bells.wav");
     bells.play();

Once created a QSound object can be queried for its fileName() and total number of loops() (i.e. the number of times the sound will play). The number of repetitions can be altered using the setLoops() function. While playing the sound, the loopsRemaining() function returns the remaining number of repetitions. Use the isFinished() function to determine whether the sound has finished playing.

Sounds played using a QSound object may use more memory than the static play() function, but it may also play more immediately (depending on the underlying platform audio facilities). Use the static isAvailable() function to determine whether sound facilities exist on the platform. Which facilities that are actually used varies:

Platform | Audio Facility
--- | ---
Microsoft Windows | The underlying multimedia system is used; only WAVE format sound files are supported.
X11 | The Network Audio System is used if available, otherwise all operations work silently. NAS supports WAVE and AU files.
Mac OS X | NSSound is used. All formats that NSSound supports, including QuickTime formats, are supported by Qt for Mac OS X.
Qt for Embedded Linux | A built-in mixing sound server is used, accessing `/dev/dsp` directly. Only the WAVE format is supported.
Symbian | CMdaAudioPlayerUtility is used. All formats that Symbian OS or devices support are supported also by Qt.

Note that QSound does not support resources. This might be fixed in a future Qt version.

## Member Function Documentation

### QSound::QSound ( const QString & filename, QObject * parent = 0 )

Constructs a QSound object from the file specified by the given filename and with the given parent.

This may use more memory than the static play() function, but it may also play more immediately (depending on the underlying platform audio facilities).

See also play().

### QSound::~QSound ()

Destroys this sound object. If the sound is not finished playing, the stop() function is called before the sound object is destructed.

See also stop() and isFinished().

### QString QSound::fileName () const

Returns the filename associated with this QSound object.

See also QSound().

### bool QSound::isAvailable ()`[static]`

Returns true if sound facilities exist on the platform; otherwise returns false.

If no sound is available, all QSound operations work silently and quickly. An application may choose either to notify the user if sound is crucial to the application or to operate silently without bothering the user.

Note: On Windows this always returns true because some sound card drivers do not implement a way to find out whether it is available or not.

### bool QSound::isFinished () const

Returns true if the sound has finished playing; otherwise returns false.

Warning: On Windows this function always returns true for unlooped sounds.

### int QSound::loops () const

Returns the number of times the sound will play.

See also loopsRemaining() and setLoops().

### int QSound::loopsRemaining () const

Returns the remaining number of times the sound will loop (this value decreases each time the sound is played).

See also loops() and isFinished().

### void QSound::play ( const QString & filename )`[static]`

Plays the sound stored in the file specified by the given filename.

See also stop(), loopsRemaining(), and isFinished().

### void QSound::play ()`[slot]`

This is an overloaded function.

Starts playing the sound specified by this QSound object.

The function returns immediately. Depending on the platform audio facilities, other sounds may stop or be mixed with the new sound. The sound can be played again at any time, possibly mixing or replacing previous plays of the sound.

See also fileName().

### void QSound::setLoops ( int number )

Sets the sound to repeat the given number of times when it is played.

Note that passing the value -1 will cause the sound to loop indefinitely.

See also loops().

### void QSound::stop ()`[slot]`

Stops the sound playing.

Note that on Windows the current loop will finish if a sound is played in a loop.

See also play().