AI 146755: am: CL 146754 Fix some problems in the SoundPool docs and add additional text.
Original author: davidsparks
Merged from: //branches/cupcake/...
Automated import of CL 146755
diff --git a/media/java/android/media/SoundPool.java b/media/java/android/media/SoundPool.java
index ab3274b..b13c2e6 100644
--- a/media/java/android/media/SoundPool.java
+++ b/media/java/android/media/SoundPool.java
@@ -46,6 +46,19 @@
* number of streams helps to cap CPU loading and reducing the likelihood that
* audio mixing will impact visuals or UI performance.</p>
*
+ * <p>Sounds can be looped by setting a non-zero loop value. A value of -1
+ * causes the sound to loop forever. In this case, the application must
+ * explicitly call the stop() function to stop the sound. Any other non-zero
+ * value will cause the sound to repeat the specified number of times, e.g.
+ * a value of 3 causes the sound to play a total of 4 times.</p>
+ *
+ * <p>The playback rate can also be changed. A playback rate of 1.0 causes
+ * the sound to play at its original frequency (resampled, if necessary,
+ * to the hardware output frequency). A playback rate of 2.0 causes the
+ * sound to play at twice its original frequency, and a playback rate of
+ * 0.5 causes it to play at half its original frequency. The playback
+ * rate range is 0.5 to 2.0.</p>
+ *
* <p>Priority runs low to high, i.e. higher numbers are higher priority.
* Priority is used when a call to play() would cause the number of active
* streams to exceed the value established by the maxStreams parameter when
@@ -72,6 +85,13 @@
* adjusting the playback rate in real-time for doppler or synthesis
* effects.</p>
*
+ * <p>Note that since streams can be stopped due to resource constraints, the
+ * streamID is a reference to a particular instance of a stream. If the stream
+ * is stopped to allow a higher priority stream to play, the stream is no
+ * longer be valid. However, the application is allowed to call methods on
+ * the streamID without error. This may help simplify program logic since
+ * the application need not concern itself with the stream lifecycle.</p>
+ *
* <p>In our example, when the player has completed the level, the game
* logic should call SoundPool.release() to release all the native resources
* in use and then set the SoundPool reference to null. If the player starts
@@ -104,10 +124,11 @@
}
/**
- * Load the sound from the specified path
- *
+ * Load the sound from the specified path.
+ *
* @param path the path to the audio file
- * @param priority the priority of the sound. Currently has no effect.
+ * @param priority the priority of the sound. Currently has no effect. Use
+ * a value of 1 for future compatibility.
* @return a sound ID. This value can be used to play or unload the sound.
*/
public int load(String path, int priority)
@@ -133,17 +154,18 @@
}
/**
- * Load the sound from the specified APK resource
+ * Load the sound from the specified APK resource.
*
- * <p>Note that the extension is dropped. For example, if you want to load
+ * Note that the extension is dropped. For example, if you want to load
* a sound from the raw resource file "explosion.mp3", you would specify
* "R.raw.explosion" as the resource ID. Note that this means you cannot
* have both an "explosion.wav" and an "explosion.mp3" in the res/raw
- * directory.</p>
+ * directory.
*
* @param context the application context
* @param resId the resource ID
- * @param priority the priority of the sound. Currently has no effect.
+ * @param priority the priority of the sound. Currently has no effect. Use
+ * a value of 1 for future compatibility.
* @return a sound ID. This value can be used to play or unload the sound.
*/
public int load(Context context, int resId, int priority) {
@@ -162,10 +184,11 @@
}
/**
- * Load the sound from an asset file descriptor
+ * Load the sound from an asset file descriptor.
*
* @param afd an asset file descriptor
- * @param priority the priority of the sound. Currently has no effect.
+ * @param priority the priority of the sound. Currently has no effect. Use
+ * a value of 1 for future compatibility.
* @return a sound ID. This value can be used to play or unload the sound.
*/
public int load(AssetFileDescriptor afd, int priority) {
@@ -181,16 +204,17 @@
}
/**
- * Load the sound from a FileDescriptor
+ * Load the sound from a FileDescriptor.
*
- * <p>This version is useful if you store multiple sounds in a single
+ * This version is useful if you store multiple sounds in a single
* binary. The offset specifies the offset from the start of the file
- * and the length specifies the length of the sound within the file.</p>
+ * and the length specifies the length of the sound within the file.
*
* @param fd a FileDescriptor object
* @param offset offset to the start of the sound
* @param length length of the sound
- * @param priority the priority of the sound. Currently has no effect.
+ * @param priority the priority of the sound. Currently has no effect. Use
+ * a value of 1 for future compatibility.
* @return a sound ID. This value can be used to play or unload the sound.
*/
public int load(FileDescriptor fd, long offset, long length, int priority) {
@@ -202,11 +226,11 @@
private native final int _load(FileDescriptor fd, long offset, long length, int priority);
/**
- * Unload a sound from a sound ID
+ * Unload a sound from a sound ID.
*
- * <p>Unloads the sound specified by the soundID. This is the value
+ * Unloads the sound specified by the soundID. This is the value
* returned by the load() function. Returns true if the sound is
- * successfully unloaded, false if the sound was already unloaded.</p>
+ * successfully unloaded, false if the sound was already unloaded.
*
* @param soundID a soundID returned by the load() function
* @return true if just unloaded, false if previously unloaded
@@ -214,66 +238,77 @@
public native final boolean unload(int soundID);
/**
- * Play a sound from a sound ID
+ * Play a sound from a sound ID.
*
- * <p>Play the sound specified by the soundID. This is the value
+ * Play the sound specified by the soundID. This is the value
* returned by the load() function. Returns a non-zero streamID
* if successful, zero if it fails. The streamID can be used to
* further control playback. Note that calling play() may cause
* another sound to stop playing if the maximum number of active
- * streams is exceeded.</p>
+ * streams is exceeded. A loop value of -1 means loop forever,
+ * a value of 0 means don't loop, other values indicate the
+ * number of repeats, e.g. a value of 1 plays the audio twice.
+ * The playback rate allows the application to vary the playback
+ * rate (pitch) of the sound. A value of 1.0 means play back at
+ * the original frequency. A value of 2.0 means play back twice
+ * as fast, and a value of 0.5 means playback at half speed.
*
* @param soundID a soundID returned by the load() function
+ * @param leftVolume left volume value (range = 0.0 to 1.0)
+ * @param rightVolume right volume value (range = 0.0 to 1.0)
+ * @param priority stream priority (0 = lowest priority)
+ * @param loop loop mode (0 = no loop, -1 = loop forever)
+ * @param rate playback rate (1.0 = normal playback, range 0.5 to 2.0)
* @return non-zero streamID if successful, zero if failed
*/
public native final int play(int soundID, float leftVolume, float rightVolume,
int priority, int loop, float rate);
/**
- * Pause a playback stream
+ * Pause a playback stream.
*
- * <p>Pause the stream specified by the streamID. This is the
+ * Pause the stream specified by the streamID. This is the
* value returned by the play() function. If the stream is
* playing, it will be paused. If the stream is not playing
* (e.g. is stopped or was previously paused), calling this
- * function will have no effect.</p>
+ * function will have no effect.
*
* @param streamID a streamID returned by the play() function
*/
public native final void pause(int streamID);
/**
- * Resume a playback stream
+ * Resume a playback stream.
*
- * <p>Resume the stream specified by the streamID. This
+ * Resume the stream specified by the streamID. This
* is the value returned by the play() function. If the stream
* is paused, this will resume playback. If the stream was not
- * previously paused, calling this function will have no effect.</p>
+ * previously paused, calling this function will have no effect.
*
* @param streamID a streamID returned by the play() function
*/
public native final void resume(int streamID);
/**
- * Stop a playback stream
+ * Stop a playback stream.
*
- * <p>Stop the stream specified by the streamID. This
+ * Stop the stream specified by the streamID. This
* is the value returned by the play() function. If the stream
* is playing, it will be stopped. It also releases any native
* resources associated with this stream. If the stream is not
- * playing, it will have no effect.</p>
+ * playing, it will have no effect.
*
* @param streamID a streamID returned by the play() function
*/
public native final void stop(int streamID);
/**
- * Set stream volume
+ * Set stream volume.
*
- * <p>Sets the volume on the stream specified by the streamID.
+ * Sets the volume on the stream specified by the streamID.
* This is the value returned by the play() function. The
* value must be in the range of 0.0 to 1.0. If the stream does
- * not exist, it will have no effect.</p>
+ * not exist, it will have no effect.
*
* @param streamID a streamID returned by the play() function
* @param leftVolume left volume value (range = 0.0 to 1.0)
@@ -283,29 +318,51 @@
float leftVolume, float rightVolume);
/**
- * Change stream priority
+ * Change stream priority.
*
- * <p>Change the priority of the stream specified by the streamID.
+ * Change the priority of the stream specified by the streamID.
* This is the value returned by the play() function. Affects the
- * order in which streams are re-used to play new sounds.
+ * order in which streams are re-used to play new sounds. If the
+ * stream does not exist, it will have no effect.
*
* @param streamID a streamID returned by the play() function
*/
public native final void setPriority(int streamID, int priority);
/**
- * Change stream priority
+ * Set loop mode.
*
- * <p>Change the priority of the stream specified by the streamID.
- * This is the value returned by the play() function. Affects the
- * order in which streams are re-used to play new sounds.
+ * Change the loop mode. A loop value of -1 means loop forever,
+ * a value of 0 means don't loop, other values indicate the
+ * number of repeats, e.g. a value of 1 plays the audio twice.
+ * If the stream does not exist, it will have no effect.
*
* @param streamID a streamID returned by the play() function
+ * @param loop loop mode (0 = no loop, -1 = loop forever)
*/
public native final void setLoop(int streamID, int loop);
+ /**
+ * Change playback rate.
+ *
+ * The playback rate allows the application to vary the playback
+ * rate (pitch) of the sound. A value of 1.0 means playback at
+ * the original frequency. A value of 2.0 means playback twice
+ * as fast, and a value of 0.5 means playback at half speed.
+ * If the stream does not exist, it will have no effect.
+ *
+ * @param streamID a streamID returned by the play() function
+ * @param rate playback rate (1.0 = normal playback, range 0.5 to 2.0)
+ */
public native final void setRate(int streamID, float rate);
+ /**
+ * Release the SoundPool resources.
+ *
+ * Release all memory and native resources used by the SoundPool
+ * object. The SoundPool can no longer be used and the reference
+ * should be set to null.
+ */
public native final void release();
private native final void native_setup(Object mediaplayer_this,
