SoVRMLAudioClip Class Reference

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SoVRMLAudioClip Class Reference
VRML97 Classes | 3D Sound Support Classes

The SoVRMLAudioClip class is used to load and store audio data.Audio data is loaded using the simage library, so make sure you have built the simage library with support for the audio file formats you intend to use (libogg, libvorbis and libvorbisfile for OggVorbis, libsndfile for WAV and several other formats). More...

`#include <Inventor/VRMLnodes/SoVRMLAudioClip.h>`

Inheritance diagram for SoVRMLAudioClip:

## Public Types
typedef void * | open_func(const SbStringList &url, SoVRMLAudioClip *clip, void *userdataptr)
typedef size_t | read_func(void *datasource, void *buffer, int numframes, int &channels, SoVRMLAudioClip *clip, void *userdataptr)
typedef int | seek_func(void *datasource, long offset, int whence, SoVRMLAudioClip *clip, void *userdataptr)
typedef long | tell_func(void *datasource, SoVRMLAudioClip *clip, void *userdataptr)
typedef int | close_func(void *datasource, SoVRMLAudioClip *clip, void *userdataptr)
Public Types inherited from SoNode
enum | NodeType { INVENTOR = 0x0000, VRML1 = 0x0001, VRML2 = 0x0002, INVENTOR_1 = 0x0004, INVENTOR_2_0 = 0x0008, INVENTOR_2_1 = 0x0010, INVENTOR_2_5 = 0x0020, INVENTOR_2_6 = 0x0040, COIN_1_0 = 0x0080, COIN_2_0 = 0x0100, EXTENSION = 0x0200, COIN_2_2 = 0x0400, COIN_2_3 = 0x0800, COIN_2_4 = 0x1000, INVENTOR_5_0 = 0x2000, COIN_2_5 = 0x4000, COIN_3_0 = 0x8000, INVENTOR_6_0 = 0x10000 }

## Public Member Functions
virtual SoType | getTypeId (void) const
| SoVRMLAudioClip (void)
int | getSampleRate ()
void * | open (const SbStringList &url)
size_t | read (void *datasource, void *buffer, int numframes, int &channels)
int | seek (void *datasource, long offset, int whence)
long | tell (void *datasource)
int | close (void *datasource)
void | setCallbacks (open_func *opencb, read_func *readcb, seek_func *seekcb, tell_func *tellcb, close_func *closecb, void *userdataptr)
Public Member Functions inherited from SoNode
void | setOverride (const SbBool state)
SbBool | isOverride (void) const
void | setNodeType (const NodeType type)
NodeType | getNodeType (void) const
virtual SoNode * | copy (SbBool copyconnections=FALSE) const
virtual SbBool | affectsState (void) const
virtual void | doAction (SoAction *action)
virtual void | GLRender (SoGLRenderAction *action)
virtual void | GLRenderBelowPath (SoGLRenderAction *action)
virtual void | GLRenderInPath (SoGLRenderAction *action)
virtual void | GLRenderOffPath (SoGLRenderAction *action)
virtual void | callback (SoCallbackAction *action)
virtual void | getBoundingBox (SoGetBoundingBoxAction *action)
virtual void | getMatrix (SoGetMatrixAction *action)
virtual void | handleEvent (SoHandleEventAction *action)
virtual void | pick (SoPickAction *action)
virtual void | rayPick (SoRayPickAction *action)
virtual void | search (SoSearchAction *action)
virtual void | write (SoWriteAction *action)
virtual void | audioRender (SoAudioRenderAction *action)
virtual void | getPrimitiveCount (SoGetPrimitiveCountAction *action)
virtual void | grabEventsSetup (void)
virtual void | grabEventsCleanup (void)
virtual void | startNotify (void)
virtual void | notify (SoNotList *l)
uint32_t | getNodeId (void) const
virtual SoChildList * | getChildren (void) const
virtual void | writeInstance (SoOutput *out)
virtual SoNode * | addToCopyDict (void) const
virtual void | copyContents (const SoFieldContainer *from, SbBool copyconnections)
virtual SoFieldContainer * | copyThroughConnection (void) const
Public Member Functions inherited from SoFieldContainer
void | setToDefaults (void)
SbBool | hasDefaultValues (void) const
SbBool | fieldsAreEqual (const SoFieldContainer *container) const
void | copyFieldValues (const SoFieldContainer *container, SbBool copyconnections=FALSE)
SbBool | set (const char *const fielddata)
void | get (SbString &fielddata)
virtual int | getFields (SoFieldList &l) const
virtual int | getAllFields (SoFieldList &l) const
virtual SoField * | getField (const SbName &name) const
virtual SoField * | getEventIn (const SbName &name) const
virtual SoField * | getEventOut (const SbName &name) const
SbBool | getFieldName (const SoField *const field, SbName &name) const
SbBool | enableNotify (const SbBool flag)
SbBool | isNotifyEnabled (void) const
SbBool | set (const char *fielddata, SoInput *input)
void | get (SbString &fielddata, SoOutput *out)
virtual SbBool | validateNewFieldValue (SoField *field, void *newval)
virtual void | addWriteReference (SoOutput *out, SbBool isfromfield=FALSE)
SbBool | getIsBuiltIn (void) const
virtual void | getFieldsMemorySize (size_t &managed, size_t &unmanaged) const
void | setUserData (void *userdata) const
void * | getUserData (void) const
Public Member Functions inherited from SoBase
void | ref (void) const
void | unref (void) const
void | unrefNoDelete (void) const
int32_t | getRefCount (void) const
void | touch (void)
SbBool | isOfType (SoType type) const
virtual SbName | getName (void) const
virtual void | setName (const SbName &newname)
void | addAuditor (void *const auditor, const SoNotRec::Type type)
void | removeAuditor (void *const auditor, const SoNotRec::Type type)
const SoAuditorList & | getAuditors (void) const
SbBool | shouldWrite (void)
void | assertAlive (void) const

## Static Public Member Functions
static SoType | getClassTypeId (void)
static void | initClass (void)
static void | setSubdirectories (const SbList< SbString > &subdirectories)
static const SbStringList & | getSubdirectories ()
static void | setDefaultPauseBetweenTracks (SbTime pause)
static SbTime | getDefaultPauseBetweenTracks ()
static void | setDefaultIntroPause (SbTime pause)
static SbTime | getDefaultIntroPause ()
static void | setDefaultSampleRate (int samplerate)
static int | getDefaultSampleRate ()
static void | setDefaultTimerInterval (SbTime interval)
static SbTime | getDefaultTimerInterval ()
Static Public Member Functions inherited from SoNode
static uint32_t | getCompatibilityTypes (const SoType &nodetype)
static SoType | getClassTypeId (void)
static SoNode * | getByName (const SbName &name)
static int | getByName (const SbName &name, SoNodeList &l)
static void | initClass (void)
static void | initClasses (void)
static uint32_t | getNextNodeId (void)
static int | getActionMethodIndex (const SoType type)
static void | getBoundingBoxS (SoAction *action, SoNode *node)
static void | GLRenderS (SoAction *action, SoNode *node)
static void | callbackS (SoAction *action, SoNode *node)
static void | getMatrixS (SoAction *action, SoNode *node)
static void | handleEventS (SoAction *action, SoNode *node)
static void | pickS (SoAction *action, SoNode *node)
static void | rayPickS (SoAction *action, SoNode *node)
static void | searchS (SoAction *action, SoNode *node)
static void | writeS (SoAction *action, SoNode *node)
static void | audioRenderS (SoAction *action, SoNode *node)
static void | getPrimitiveCountS (SoAction *action, SoNode *node)
Static Public Member Functions inherited from SoFieldContainer
static void | initClass (void)
static SoType | getClassTypeId (void)
static void | cleanupClass (void)
static void | initCopyDict (void)
static void | addCopy (const SoFieldContainer *orig, const SoFieldContainer *copy)
static SoFieldContainer * | checkCopy (const SoFieldContainer *orig)
static SoFieldContainer * | findCopy (const SoFieldContainer *orig, const SbBool copyconnections)
static void | copyDone (void)
Static Public Member Functions inherited from SoBase
static void | initClass (void)
static SoType | getClassTypeId (void)
static void | addName (SoBase *const base, const char *const name)
static void | removeName (SoBase *const base, const char *const name)
static void | incrementCurrentWriteCounter (void)
static void | decrementCurrentWriteCounter (void)
static SoBase * | getNamedBase (const SbName &name, SoType type)
static int | getNamedBases (const SbName &name, SoBaseList &baselist, SoType type)
static SbBool | read (SoInput *input, SoBase *&base, SoType expectedtype)
static void | setInstancePrefix (const SbString &c)
static void | setTraceRefs (SbBool trace)
static SbBool | getTraceRefs (void)
static SbBool | connectRoute (SoInput *input, const SbName &fromnodename, const SbName &fromfieldname, const SbName &tonodename, const SbName &tofieldname)
static SbBool | readRoute (SoInput *input)

## Public Attributes
SoSFString | description
SoSFBool | loop
SoSFFloat | pitch
SoSFTime | startTime
SoSFTime | stopTime
SoMFString | url

## Protected Member Functions
virtual const SoFieldData * | getFieldData (void) const
virtual | ~SoVRMLAudioClip ()
Protected Member Functions inherited from SoNode
| SoNode (void)
virtual | ~SoNode ()
virtual SbBool | readInstance (SoInput *in, unsigned short flags)
Protected Member Functions inherited from SoFieldContainer
| SoFieldContainer (void)
virtual | ~SoFieldContainer ()
Protected Member Functions inherited from SoBase
| SoBase (void)
virtual | ~SoBase ()
virtual void | destroy (void)
SbBool | hasMultipleWriteRefs (void) const
SbBool | writeHeader (SoOutput *out, SbBool isgroup, SbBool isengine) const
void | writeFooter (SoOutput *out) const
virtual const char * | getFileFormatName (void) const

## Static Protected Member Functions
static const SoFieldData ** | getFieldDataPtr (void)
Static Protected Member Functions inherited from SoNode
static const SoFieldData ** | getFieldDataPtr (void)
static void | setNextActionMethodIndex (int index)
static int | getNextActionMethodIndex (void)
static void | incNextActionMethodIndex (void)
static void | setCompatibilityTypes (const SoType &nodetype, const uint32_t bitmask)
Static Protected Member Functions inherited from SoBase
static uint32_t | getCurrentWriteCounter (void)
static void | staticDataLock (void)
static void | staticDataUnlock (void)

## Protected Attributes
SoSFTime | duration_changed
SoSFBool | isActive
Protected Attributes inherited from SoNode
uint32_t | uniqueId
Protected Attributes inherited from SoFieldContainer
SbBool | isBuiltIn

## Additional Inherited Members
Protected Types inherited from SoBase
enum | BaseFlags { IS_ENGINE = 0x01, IS_GROUP = 0x02 }
Static Protected Attributes inherited from SoNode
static uint32_t | nextUniqueId = 1
static int | nextActionMethodIndex = 0

## Detailed Description

The SoVRMLAudioClip class is used to load and store audio data.

Audio data is loaded using the simage library, so make sure you have built the simage library with support for the audio file formats you intend to use (libogg, libvorbis and libvorbisfile for OggVorbis, libsndfile for WAV and several other formats).

The detailed class documentation is taken verbatim from the VRML97 standard (ISO/IEC 14772-1:1997). It is copyright The Web3D Consortium, and is used by permission of the Consortium:

    AudioClip {
      exposedField   SFString description      ""
      exposedField   SFBool   loop             FALSE
      exposedField   SFFloat  pitch            1.0        # (0, inf)
      exposedField   SFTime   startTime        0          # (-inf, inf)
      exposedField   SFTime   stopTime         0          # (-inf, inf)
      exposedField   MFString url              []
      eventOut       SFTime   duration_changed
      eventOut       SFBool   isActive
    }

An AudioClip node specifies audio data that can be referenced by Sound nodes. The description field specifies a textual description of the audio source. A browser is not required to display the description field but may choose to do so in addition to playing the sound. The url field specifies the URL from which the sound is loaded. Browsers shall support at least the wavefile format in uncompressed PCM format (see http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/bibliography.html#[WAV]). It is recommended that browsers also support the MIDI file type 1 sound format (see http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/references.html#[MIDI]); MIDI files are presumed to use the General MIDI patch set. Subclause 4.5, VRML and the World Wide Web (http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.5), contains details on the url field. The results are undefined when no URLs refer to supported data types.

The loop, startTime, and stopTime exposedFields and the isActive eventOut, and their effects on the AudioClip node, are discussed in detail in 4.6.9, Time-dependent nodes (http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.6.9). The "cycle" of an AudioClip is the length of time in seconds for one playing of the audio at the specified pitch. The pitch field specifies a multiplier for the rate at which sampled sound is played. Values for the pitch field shall be greater than zero. Changing the pitch field affects both the pitch and playback speed of a sound. A set_pitch event to an active AudioClip is ignored and no pitch_changed eventOut is generated. If pitch is set to 2.0, the sound shall be played one octave higher than normal and played twice as fast. For a sampled sound, the pitch field alters the sampling rate at which the sound is played. The proper implementation of pitch control for MIDI (or other note sequence sound clips) is to multiply the tempo of the playback by the pitch value and adjust the MIDI Coarse Tune and Fine Tune controls to achieve the proper pitch change. A duration_changed event is sent whenever there is a new value for the "normal" duration of the clip. Typically, this will only occur when the current url in use changes and the sound data has been loaded, indicating that the clip is playing a different sound source. The duration is the length of time in seconds for one cycle of the audio for a pitch set to 1.0. Changing the pitch field will not trigger a duration_changed event. A duration value of "-1" implies that the sound data has not yet loaded or the value is unavailable for some reason. A duration_changed event shall be generated if the AudioClip node is loaded when the VRML file is read or the AudioClip node is added to the scene graph. The isActive eventOut may be used by other nodes to determine if the clip is currently active. If an AudioClip is active, it shall be playing the sound corresponding to the sound time (i.e., in the sound's local time system with sample 0 at time 0):

    t = (now - startTime) modulo (duration / pitch)

## Constructor & Destructor Documentation

SoVRMLAudioClip::SoVRMLAudioClip | ( | void |  | ) |

Constructor.

SoVRMLAudioClip::~SoVRMLAudioClip | ( |  | ) |
| protectedvirtual

Destructor.

## Member Function Documentation

SoType SoVRMLAudioClip::getTypeId | ( | void |  | ) | const
| virtual

Returns the type identification of an object derived from a class inheriting SoBase. This is used for run-time type checking and "downward" casting.

Usage example:

void foo(SoNode * node)
{
if (node->getTypeId() == SoFile::getClassTypeId()) {
SoFile * filenode = (SoFile *)node; // safe downward cast, knows the type
}
}

For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: this method needs to be overridden in all subclasses. This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the pre-defined macros available through for instance Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine.h (for engine classes) and so on.

For more information on writing Coin extensions, see the class documentation of the toplevel superclasses for the various class groups.

Implements SoBase.

const SoFieldData * SoVRMLAudioClip::getFieldData | ( | void |  | ) | const
| protectedvirtual

Returns a pointer to the class-wide field data storage object for this instance. If no fields are present, returns `NULL`.

Reimplemented from SoFieldContainer.

void * SoVRMLAudioClip::open | ( | const SbStringList & | urlref | ) |

Opens an audio source with the given url. Returns a handle to the datasource.

size_t SoVRMLAudioClip::read | ( | void * | datasource,
|  | void * | buffer,
|  | int | numframes,
|  | int & | channels
| ) |  |

Reads numframes frames of audio with channels channels from datasource into buffer. Buffer must be allocated by the caller, and must be able to hold all the audio data (size = numframes * channels * sizeof(int16_t)). The function must always fill the buffer completely unless buffer == NULL.

When an error occurs, or when end-of-file has been reached, this function returns 0. Otherwise, the function should return numframes.

When the caller receives a return value of 0, it will queue the returned buffer for playing. When this buffer is finished playing, the caller will call read() one final time, with buffer == NULL. The read() function can then set the isActive field to FALSE, free any resources allocated, etc.

int SoVRMLAudioClip::seek | ( | void * | datasource,
|  | long | offset,
|  | int | whence
| ) |  |

Moves the "filepointer" in the datasource, returns -1L on error.

long SoVRMLAudioClip::tell | ( | void * | datasource | ) |

Returns the current position of the "filepointer" in the datasource, or -1L on error.

int SoVRMLAudioClip::close | ( | void * | datasource | ) |

Closes datasource.

void SoVRMLAudioClip::setCallbacks | ( | open_func * | opencb,
|  | read_func * | readcb,
|  | seek_func * | seekcb,
|  | tell_func * | tellcb,
|  | close_func * | closecb,
|  | void * | userdataptr
| ) |  |

Sets callbacks for opening, reading, seeking, telling and closing an audio source. Specifying NULL for a function is OK, except for the read function. If a function set to NULL is later called, a default implementation doing nothing is called in it's place.

## Member Data Documentation

SoSFString SoVRMLAudioClip::description

Description of the audio clip. Default value is an empty string.

SoSFBool SoVRMLAudioClip::loop

Specifies whether sound should be looped. Is FALSE by default.

SoSFFloat SoVRMLAudioClip::pitch

Specifies the pitch. The default value is 1.0.

Alters the sampling rate at which the sound is played. A pitch of 2.0 means that the sound should be played twice as fast and one octave higher than normal.

SoSFTime SoVRMLAudioClip::startTime

Specifies the start time. Default value is 0.

SoSFTime SoVRMLAudioClip::stopTime

Specifies the stop time. Default value is 0.

SoMFString SoVRMLAudioClip::url

The audio data URL.

SoVRMLAudioClip::duration_changed
| protected

An eventOut sent when a new sound starts playing.

SoVRMLAudioClip::isActive
| protected

This eventOut is sent when the sound starts/stops playing.

The documentation for this class was generated from the following files:

- SoVRMLAudioClip.h
- AudioClip.cpp

Copyright © 1998-2010 by Kongsberg Oil & Gas Technologies. All rights reserved.