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Programmer's Guide
- About this Document
- Introduction to OpenAL
- Buffer Functions
- Source Functions
- Listener Functions
- State Functions
- Error Functions
- Extension Functions
- Context Management Functions
- Context Error Functions
- Context Device Functions
- Context Extension Functions
- Context State Functions
- Context Capture Functions
OpenAL is a cross-platform three-dimensional audio API. The API’s primary purpose is to allow an application to position audio sources in a three-dimensional space around a listener, producing reasonable spatialization of the sources for the audio system (headphones, 2.1 speaker output, 5.1 speaker output, etc.) Through extensions, Creative Labs has also enhanced OpenAL with EAX and other capabilities. OpenAL is appropriate for many audio applications, but was designed to be most appropriate for gaming audio.
This reference guide is most appropriate for a programmer. Experience with C or C++ is not required to learn the concepts in OpenAL, but will make understanding the OpenAL source as well as sample code easier. Since there are several sample applications included with the OpenAL SDKs as well as with the source distribution, it is recommended that interested programmers take advantage of those resources.
The two most important resources for additional information on OpenAL are the websites at www.openal.org and http://developer.creative.com. The main OpenAL site hosts the specification, the open source implementations, and sample code. The Creative developer site has a section dedicated to OpenAL with SDKs showing how to use OpenAL as well as various extensions.
Use of OpenAL revolves around the use of three fundamental objects – Buffers, Sources, and a Listener. A buffer can be filled with audio data, and can then be attached to a source. The source can then be positioned and played. How the source is heard is determined by its position and orientation relative to the Listener object (there is only one Listener). Creating a number of sources and buffers and a single listener and then updating the positions and orientations of the sources and listener dynamically can present a convincing 3D audio world.
Here is a diagram showing the fundamental OpenAL objects and their relationships to the context and device objects:
When initializing OpenAL, at least one device has to be opened. Within that device, at least one context will be created. Within that context, one listener object is implied, and a multitude of source objects can be created. Each source can have one or more buffers objects attached to it. Buffer objects are not part of a specific context – they are shared among all contexts on one device.
The function call to open a device, alcOpenDevice, takes a
string as input. The string should contain either the name of a valid OpenAL
rendering device, or NULL
to request the default device.
On PC Systems, a number of different OpenAL renderering devices may co-exist. For example a “native” renderer specific to the user’s high-end soundcard, and a host-based software fallback renderer. On platforms where multiple renderers can be present, an OpenAL application may require the ability to identify the different devices available, in order to give the end-user a choice of device. OpenAL’s Enumeration extension makes this possible.
The Enumeration extension allows the programmer to retrieve a string listing the
names of available devices. It can also provide the name of the default device.
Use alcGetString with the device property set to NULL
, and
the enum property set to ALC_DEVICE_SPECIFIER
to get the list of available
devices. To get the default device name, pass in NULL
and
ALC_DEFAULT_DEVICE_SPECIFIER
.
The Enumeration extension also works with capture devices – the equivalent
values are ALC_CAPTURE_DEVICE_SPECIFIER
and
ALC_CAPTURE_DEFAULT_DEVICE_SPECIFIER
.
The programmer can find out more about the capabilities of each device by querying to see which extensions it supports using alcIsExtensionPresent and alIsExtensionPresent.
As described above, the first step to initializing OpenAL is to open a device. Once that is successfully done, then a context is opened on that device. Now the fundamental OpenAL objects can be managed – the listener, various sources, and various buffers.
To generate a set of buffers for use, use alGetError to reset the error state, call alGenBuffers to generate the number of buffers desired, and then use alGetError again to detect if an error was generated.
Fill the buffers with PCM data using alBufferData.
To generate a set of sources for use, use alGetError to reset the error state, call alGenSources to generate the number of sources desired, and then use alGetError again to detect if an error was generated.
Buffers are attached to sources using alSourcei.
Once a buffer has been attached to a source, the source can play the buffer using alSourcePlay.
Source and Listener properties can be updated dynamically using property set and get calls such as alGetListenerfv, alListener3f, alSourcei, and alGetSource3f.
Example:
// Initialization
Device = alcOpenDevice(NULL); // select the "preferred device"
if (Device) {
Context=alcCreateContext(Device,NULL);
alcMakeContextCurrent(Context);
}
// Check for EAX 2.0 support
g_bEAX = alIsExtensionPresent("EAX2.0");
// Generate Buffers
alGetError(); // clear error code
alGenBuffers(NUM_BUFFERS, g_Buffers);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alGenBuffers :", error);
return;
}
/ Load test.wav
loadWAVFile("test.wav",&format,&data,&size,&freq,&loop);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alutLoadWAVFile test.wav : ", error);
alDeleteBuffers(NUM_BUFFERS, g_Buffers);
return;
}
// Copy test.wav data into AL Buffer 0
alBufferData(g_Buffers[0],format,data,size,freq);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alBufferData buffer 0 : ", error);
alDeleteBuffers(NUM_BUFFERS, g_Buffers);
return;
}
// Unload test.wav
unloadWAV(format,data,size,freq);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alutUnloadWAV : ", error);
alDeleteBuffers(NUM_BUFFERS, g_Buffers);
return;
}
// Generate Sources
alGenSources(1,source);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alGenSources 1 : ", error);
return;
}
// Attach buffer 0 to source
alSourcei(source[0], AL_BUFFER, g_Buffers[0]);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alSourcei AL_BUFFER 0 : ", error);
}
// Exit
Context=alcGetCurrentContext();
Device=alcGetContextsDevice(Context);
alcMakeContextCurrent(NULL);
alcDestroyContext(Context);
alcCloseDevice(Device);
For every context, there is automatically one Listener object. The
alListener[f, 3f, fv, i]
and alGetListener[f, 3f, fv, i]
families of
functions can be used to set or retrieve the following listener properties:
Property | Data Type | Description |
---|---|---|
AL_GAIN |
f , fv
|
Master gain. Value should be positive |
AL_POSITION |
fv , 3f , iv , 3i
|
X, Y, Z position |
AL_VELOCITY |
fv , 3f , iv , 3i
|
Velocity vector |
AL_ORIENTATION |
fv , iv
|
Orientation expressed as “at” and “up” vectors |
Example:
ALfloat listenerPos[]={0.0,0.0,0.0};
ALfloat listenerVel[]={0.0,0.0,0.0};
ALfloat listenerOri[]={0.0,0.0,-1.0, 0.0,1.0,0.0};
// Position ...
alListenerfv(AL_POSITION,listenerPos);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alListenerfv POSITION : ", error);
return;
}
// Velocity ...
alListenerfv(AL_VELOCITY,listenerVel);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alListenerfv VELOCITY : ", error);
return;
}
// Orientation ...
alListenerfv(AL_ORIENTATION,listenerOri);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alListenerfv ORIENTATION : ", error);
return;
}
Each buffer generated by alGenBuffers has properties which can
be retrieved. The alGetBuffer[f, i]
functions can be used to retrieve the
following buffer properties:
Property | Data Type | Description |
---|---|---|
AL_FREQUENCY |
i , iv
|
Frequency of buffer in Hz |
AL_BITS |
i , iv
|
Bit depth of buffer |
AL_CHANNELS |
i , iv
|
Number of channels in buffer. > 1 is valid, but buffer won’t be positioned when played |
AL_SIZE |
i , iv
|
Size of buffer in bytes |
Example:
// Retrieve Buffer Frequency
alGetBufferi(g_Buffers[0], AL_FREQUENCY, &iFreq);
Each source generated by alGenSources has properties which can
be set or retrieved. The alSource[f, 3f, fv, i]
and
alGetSource[f, 3f, fv, i]
families of functions can be used to set or retrieve
the following source properties:
Property | Data Type | Description |
---|---|---|
AL_PITCH |
f , fv
|
Pitch multiplier. Always positive |
AL_GAIN |
f , fv
|
Source gain. Value should be positive |
AL_MAX_DISTANCE |
f , fv , i , iv
|
Used with the Inverse Clamped Distance Model to set the distance where there will no longer be any attenuation of the source |
AL_ROLLOFF_FACTOR |
f , fv , i , iv
|
The rolloff rate for the source. Default is 1.0 |
AL_REFERENCE_DISTANCE |
f , fv , i , iv
|
The distance under which the volume for the source would normally drop by half (before being influenced by rolloff factor or AL_MAX_DISTANCE ) |
AL_MIN_GAIN |
f , fv
|
The minimum gain for this source |
AL_MAX_GAIN |
f , fv
|
The maximum gain for this source |
AL_CONE_OUTER_GAIN |
f , fv
|
The gain when outside the oriented cone |
AL_CONE_INNER_ANGLE |
f , fv , i , iv
|
The gain when inside the oriented cone |
AL_CONE_OUTER_ANGLE |
f , fv , i , iv
|
Outer angle of the sound cone, in degrees. Default is 360 |
AL_POSITION |
fv , 3f
|
X, Y, Z position |
AL_VELOCITY |
fv , 3f
|
Velocity vector |
AL_DIRECTION |
fv , 3f , iv , 3i
|
Direction vector |
AL_SOURCE_RELATIVE |
i , iv
|
Determines if the positions are relative to the listener. Default is AL_FALSE
|
AL_SOURCE_TYPE * |
i , iv
|
The source type – AL_UNDETERMINED , AL_STATIC , or AL_STREAMING
|
AL_LOOPING |
i , iv
|
Turns looping on (AL_TRUE ) or off (AL_FALSE ) |
AL_BUFFER |
i , iv
|
The ID of the attached buffer |
AL_SOURCE_STATE * |
i , iv
|
The state of the source (AL_STOPPED , AL_PLAYING , …) |
AL_BUFFERS_QUEUED * |
i , iv
|
The number of buffers queued on this source |
AL_BUFFERS_PROCESSED * |
i , iv
|
The number of buffers in the queue that have been processed |
AL_SEC_OFFSET |
f , fv , i , iv
|
The playback position, expressed in seconds |
AL_SAMPLE_OFFSET |
f , fv , i , iv
|
The playback position, expressed in samples |
AL_BYTE_OFFSET |
f , fv , i , iv
|
The playback position, expressed in bytes |
* Read Only (alGetSourcei)
Example:
alGetError(); // clear error state
alSourcef(source[0],AL_PITCH,1.0f);
if ((error = alGetError()) != AL_NO_ERROR)
DisplayALError("alSourcef 0 AL_PITCH : \n", error);
alGetError(); // clear error state
alSourcef(source[0],AL_GAIN,1.0f);
if ((error = alGetError()) != AL_NO_ERROR)
DisplayALError("alSourcef 0 AL_GAIN : \n", error);
alGetError(); // clear error state
alSourcefv(source[0],AL_POSITION,source0Pos);
if ((error = alGetError()) != AL_NO_ERROR)
DisplayALError("alSourcefv 0 AL_POSITION : \n", error);
alGetError(); // clear error state
alSourcefv(source[0],AL_VELOCITY,source0Vel);
if ((error = alGetError()) != AL_NO_ERROR)
DisplayALError("alSourcefv 0 AL_VELOCITY : \n", error);
alGetError(); // clear error state
alSourcei(source[0],AL_LOOPING,AL_FALSE);
if ((error = alGetError()) != AL_NO_ERROR)
DisplayALError("alSourcei 0 AL_LOOPING true: \n", error);
To continuously stream audio from a source without interruption, buffer queuing is required. To use buffer queuing, the buffers and sources are generated in the normal way, but alSourcei is not used to attach the buffers to the source. Instead, the functions alSourceQueueBuffers and alSourceUnqueueBuffers are used. The program can attach a buffer or a set of buffers to a source using alSourceQueueBuffers, and then call alSourcePlay on that source. While the source is playing, alSourceUnqueueBuffers can be called to remove buffers which have already played. Those buffers can then be filled with new data or discarded. New or refilled buffers can then be attached to the playing source using alSourceQueueBuffers. As long as there is always a new buffer to play in the queue, the source will continue to play.
Although some 1.0 implementations of OpenAL may not enforce the following restrictions on queuing, it is recommended to observe the following additional rules, which do universally apply to 1.1 implementations:
-
A source that will be used for streaming should not have its first buffer attached using alSourcei – always use alSourceQueueBuffers to attach buffers to streaming sources. Any source can have all buffers detached from it using
alSourcei(..., AL_BUFFER, 0)
, and can then be used for either streaming or non-streaming buffers depending on how data is then attached to the source (with alSourcei or with alSourceQueueBuffers). -
All buffers attached to a source using alSourceQueueBuffers should have the same audio format.
The Doppler effect depends on the velocities of source and listener relative to the medium, and the propagation speed of sound in that medium. The application might want to emphasize or deemphasize the Doppler effect as physically accurate calculation might not give the desired results. The amount of frequency shift (pitch change) is proportional to the speed of listener and source along their line of sight.
The Doppler effect as implemented by OpenAL is described by the formula below. Effects of the medium (air, water) moving with respect to listener and source are ignored.
- SS:
AL_SPEED_OF_SOUND
= speed of sound (default value 343.3) - DF:
AL_DOPPLER_FACTOR
= Doppler factor (default 1.0) - vls: Listener velocity scalar (scalar, projected on source-to-listener vector)
- vss: Source velocity scalar (scalar, projected on source-to-listener vector)
- f: Frequency of sample
- f': Effective Doppler shifted frequency
- SL: Source tt listener vector
- SV: Source velocity vector
- LV: Listener velocity vector
Graphic representation of vls and vss:
3D Mathematical representation of vls and vss:
There are two API calls global to the current context that provide control of
the speed of sound and Doppler factor. AL_DOPPLER_FACTOR
is a simple scaling
of source and listener velocities to exaggerate or deemphasize the Doppler
(pitch) shift resulting from the calculation.
void alDopplerFactor(ALfloat dopplerFactor);
A negative value will result in an AL_INVALID_VALUE
error, the command is then
ignored. The default value is 1. The current setting can be queried using
alGetFloat{v}
and AL_DOPPLER_FACTOR
.
AL_SPEED_OF_SOUND
allows the application to change the reference (propagation)
speed used in the Doppler calculation. The source and listener velocities
should be expressed in the same units as the speed of sound.
void alSpeedOfSound(ALfloat speed);
A negative or zero value will result in an AL_INVALID_VALUE
error, and the
command is ignored. The default value is 343.3 (appropriate for velocity units
of meters and air as the propagation medium). The current setting can be queried
using alGetFloat{v}
and AL_SPEED_OF_SOUND
.
Distance and velocity units are completely independent of one another (so you could use different units for each if desired). If an OpenAL application doesn't want to use Doppler effects, then leaving all velocities at zero will achieve that result.
The error state of OpenAL can be retrieved at any time using alGetError. alGetError clears the error state of OpenAL when it is called, so it is common for an OpenAL application to call alGetError at the beginning of a critical operation to clear the error state, perform the critical operation, and then use alGetError again to test whether or not an error occurred.
Error Codes:
Error Code | Description |
---|---|
AL_NO_ERROR | there is not currently an error |
AL_INVALID_NAME | a bad name (ID) was passed to an OpenAL function |
AL_INVALID_ENUM | an invalid enum value was passed to an OpenAL function |
AL_INVALID_VALUE | an invalid value was passed to an OpenAL function |
AL_INVALID_OPERATION | the requested operation is not valid |
AL_OUT_OF_MEMORY | the requested operation resulted in OpenAL running out of memory |
Example:
alGetError(); // Clear Error Code
// Generate Buffers
alGenBuffers(NUM_BUFFERS, g_Buffers);
if ((error = alGetError()) != AL_NO_ERROR)
{
DisplayALError("alGenBuffers :", error);
exit(-1);
}
OpenAL has an extension mechanism that can be used by OpenAL vendors to add new features to the API. Creative Labs have added a number of extensions including EAX, X-RAM, Multi Channel Buffer playback, and most recently an Effect Extension (EFX). To determine if an extension is available the application can use either alIsExtensionPresent or alcIsExtensionPresent depending on the type of extension. The Appendices contain more details about some of Creative’s extensions to OpenAL.
Property | Data Type | Description |
---|---|---|
AL_FREQUENCY |
i , iv
|
Frequency of buffer in Hz |
AL_BITS |
i , iv
|
Bit depth of buffer |
AL_CHANNELS |
i , iv
|
Number of channels in buffer. > 1 is valid, but buffer won’t be positioned when played |
AL_SIZE |
i , iv
|
Size of buffer in bytes |
- alGenBuffers
- alDeleteBuffers
- alIsBuffer
- alBufferData
- alBufferf
- alBuffer3f
- alBufferfv
- alBufferi
- alBuffer3i
- alBufferiv
- alGetBufferf
- alGetBuffer3f
- alGetBufferfv
- alGetBufferi
- alGetBuffer3i
- alGetBufferiv
This function generates one or more buffers, which contain audio data (see
alBufferData). References to buffers are ALuint
values,
which are used wherever a buffer reference is needed (in calls such as
alDeleteBuffers, alSourcei,
alSourceQueueBuffers, and
alSourceUnqueueBuffers).
void alGenBuffers(
ALsizei n,
ALuint *buffers
);
- n - The number of buffers to be generated
- buffers - Pointer to an array of ALuint values which will store the names of the new buffers
State | Description |
---|---|
AL_INVALID_VALUE | The buffer array isn't large enough to hold the number of buffers requested. |
AL_OUT_OF_MEMORY | There is not enough memory available to generate all the buffers requested. |
OpenAL 1.0 or higher
If the requested number of buffers cannot be created, an error will be generated
which can be detected with alGetError. If an error occurs, no
buffers will be generated. If n
equals zero, alGenBuffers
does nothing and does not return an error.
This function deletes one or more buffers, freeing the resources used by the buffer. Buffers which are attached to a source can not be deleted. See alSourcei and alSourceUnqueueBuffers for information on how to detach a buffer from a source.
void alDeleteBuffers(
ALsizei n,
ALuint *buffers
);
- n - The number of buffers to be deleted
- buffers - Pointer to an array of buffer names identifying the buffers to be deleted
State | Description |
---|---|
AL_INVALID_OPERATION | The buffer is still in use and can not be deleted. |
AL_INVALID_NAME | A buffer name is invalid. |
AL_INVALID_VALUE | The requested number of buffers can not be deleted. |
OpenAL 1.0 or higher
If the requested number of buffers cannot be deleted, an error will be generated
which can be detected with alGetError. If an error occurs, no
buffers will be deleted. If n
equals zero,
alDeleteBuffers does nothing and will not return an error.
This function tests if a buffer name is valid, returning AL_TRUE
if valid,
AL_FALSE
if not.
ALboolean alIsBuffer(
ALuint buffer
);
- buffer - A buffer name to be tested for validity
None
OpenAL 1.0 or higher
The NULL
buffer is always valid (see alSourcei for information on how the NULL buffer is
used).
This function fills a buffer with audio data. All the pre-defined formats are PCM data, but this function may be used by extensions to load other data types as well.
void alBufferData(
ALuint buffer,
ALenum format,
const ALvoid *data,
ALsizei size,
ALsizei freq
);
- buffer - Buffer name to be filled with data
- format - Format type from among the following:
AL_FORMAT_MONO8
AL_FORMAT_MONO16
AL_FORMAT_STEREO8
AL_FORMAT_STEREO16
- data - Pointer to the audio data
- size - The size of the data in bytes
- freq - The frequency of the audio data
State | Description |
---|---|
AL_OUT_OF_MEMORY | There is not enough memory available to create this buffer. |
AL_INVALID_VALUE | The size parameter is not valid for the format specified, the buffer is in use, or the data is a NULL pointer. |
AL_INVALID_ENUM | The specified format does not exist. |
OpenAL 1.0 or higher
8-bit PCM data is expressed as an unsigned value over the range 0 to 255, 128 being an audio output level of zero. 16-bit PCM data is expressed as a signed value over the range -32768 to 32767, 0 being an audio output level of zero. Stereo data is expressed in interleaved format, left channel first. Buffers containing more than one channel of data will be played without 3D spatialization.
This function sets a floating point property of a buffer.
void alBufferf(
ALuint buffer,
ALenum param,
ALfloat value
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be set
- value - The
ALfloat
value to be set
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBuffer3f, alBufferfv, alGetBufferf, alGetBuffer3f, alGetBufferfv
This function sets a floating point property of a buffer.
void alBuffer3f(
ALuint buffer,
ALenum param,
ALfloat v1,
ALfloat v2,
ALfloat v3
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be set
- v1, v2, v3 - The
ALfloat
values to be set
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBufferf, alBufferfv, alGetBufferf, alGetBuffer3f, alGetBufferfv
This function sets a floating point property of a buffer.
void alBuffer3f(
ALuint buffer,
ALenum param,
ALfloat* value
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be set
- values - A pointer to the
ALfloat
values to be set
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBufferf, alBuffer3f, alGetBufferf, alGetBuffer3f, alGetBufferfv
This function sets an integer property of a buffer.
void alBufferi(
ALuint buffer,
ALenum param,
ALint value
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be set
- values - The
ALint
value to be set
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBuffer3i, alBufferiv, alGetBufferi, alGetBuffer3i, alGetBufferiv
This function sets an integer property of a buffer.
void alBuffer3i(
ALuint buffer,
ALenum param,
ALint v1,
ALint v2,
ALint v3,
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be set
- v1, v2, v3 - The
ALint
values to be set
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBufferi, alBufferiv, alGetBufferi, alGetBuffer3i, alGetBufferiv
This function sets an integer property of a buffer.
void alBufferiv(
ALuint buffer,
ALenum param,
ALint* values
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be set
- values - A pointer to the
ALint
values to be set
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBufferi, alBuffer3i, alGetBufferi, alGetBuffer3i, alGetBufferiv
This function retrieves a floating point property of a buffer.
void alGetBufferf(
ALuint buffer,
ALenum pname,
ALfloat* value
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be retrieved
- value - A pointer to an
ALfloat
to hold the retrieved data
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
AL_INVALID_VALUE | The specified value pointer is not valid. |
OpenAL 1.0 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBufferf, alBuffer3f, alBufferfv, alGetBuffer3f, alGetBufferfv
This function retrieves a floating point property of a buffer.
void alGetBuffer3f(
ALuint buffer,
ALenum pname,
ALfloat* v1,
ALfloat* v2,
ALfloat* v3
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be retrieved
- v1, v2, v3 - Pointers to
ALfloat
values to hold the retrieved data
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
AL_INVALID_VALUE | The specified value pointer is not valid. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBufferf, alBuffer3f, alBufferfv, alGetBufferf, alGetBufferfv
This function retrieves a floating point property of a buffer.
void alGetBufferfv(
ALuint buffer,
ALenum pname,
ALfloat* values
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be retrieved
- values - Pointer to an
ALfloat
vector to hold the retrieved data
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
AL_INVALID_VALUE | The specified value pointer is not valid. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be affected by this call, but this function may be used by OpenAL extensions.
alBufferf, alBuffer3f, alBufferfv, alGetBufferf, alGetBuffer3f
This function retrieves an integer property of a buffer.
void alGetBufferi(
ALuint buffer,
ALenum pname,
ALint* value
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be retrieved:
AL_FREQUENCY
AL_BITS
AL_CHANNELS
AL_SIZE
- value - Pointer to an
ALint
to hold the retrieved data
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
AL_INVALID_VALUE | The specified value pointer is not valid. |
OpenAL 1.0 or higher
None
alBufferi, alBuffer3i, alBufferiv, alGetBuffer3i, alGetBufferiv
This function retrieves an integer property of a buffer.
void alGetBuffer3i(
ALuint buffer,
ALenum pname,
ALint* v1,
ALint* v2,
ALint* v3
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be retrieved
- v1, v2, v3 - Pointer to
ALint
values to hold the retrieved data
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
AL_INVALID_VALUE | The specified value pointer is not valid. |
OpenAL 1.1 or higher
There are no relevant buffer properties defined in OpenAL 1.1 which can be retrieved by this call, but this function may be used by OpenAL extensions.
alBufferi, alBuffer3i, alBufferiv, alGetBufferi, alGetBufferiv
This function retrieves an integer property of a buffer.
void alGetBufferiv(
ALuint buffer,
ALenum pname,
ALint* values
);
- buffer - Buffer name whose attribute is being retrieved
- param - The name of the attribute to be retrieved:
AL_FREQUENCY
AL_BITS
AL_CHANNELS
AL_SIZE
- values - Pointer to an
ALint
vector to hold the retrieved data
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified buffer doesn't have parameters (the NULL buffer), or doesn't exist. |
AL_INVALID_VALUE | The specified value pointer is not valid. |
OpenAL 1.1 or higher
None
alBufferi, alBuffer3i, alBufferiv, alGetBufferi, alGetBuffer3i
Property | Data Type | Description |
---|---|---|
AL_PITCH |
f , fv
|
Pitch multiplier. Always positive |
AL_GAIN |
f , fv
|
Source gain. Value should be positive |
AL_MAX_DISTANCE |
f , fv , i , iv
|
Used with the Inverse Clamped Distance Model to set the distance where there will no longer be any attenuation of the source |
AL_ROLLOFF_FACTOR |
f , fv , i , iv
|
The rolloff rate for the source. Default is 1.0 |
AL_REFERENCE_DISTANCE |
f , fv , i , iv
|
The distance under which the volume for the source would normally drop by half (before being influenced by rolloff factor or AL_MAX_DISTANCE ) |
AL_MIN_GAIN |
f , fv
|
The minimum gain for this source |
AL_MAX_GAIN |
f , fv
|
The maximum gain for this source |
AL_CONE_OUTER_GAIN |
f , fv
|
The gain when outside the oriented cone |
AL_CONE_INNER_ANGLE |
f , fv , i , iv
|
The gain when inside the oriented cone |
AL_CONE_OUTER_ANGLE |
f , fv , i , iv
|
Outer angle of the sound cone, in degrees. Default is 360 |
AL_POSITION |
fv , 3f
|
X, Y, Z position |
AL_VELOCITY |
fv , 3f
|
Velocity vector |
AL_DIRECTION |
fv , 3f , iv , 3i
|
Direction vector |
AL_SOURCE_RELATIVE |
i , iv
|
Determines if the positions are relative to the listener. Default is AL_FALSE
|
AL_SOURCE_TYPE |
i , iv
|
The source type: AL_UNDETERMINED , AL_STATIC or AL_STREAMING
|
AL_LOOPING |
i , iv
|
Turns looping on (AL_TRUE ) or off (AL_FALSE ) |
AL_BUFFER |
i , iv
|
The ID of the attached buffer |
AL_SOURCE_STATE |
i , iv
|
The state of the source: AL_STOPPED , AL_PLAYING , ... |
AL_BUFFERS_QUEUED |
i , iv
|
The number of buffers queued on this source |
AL_BUFFERS_PROCESSED |
i , iv
|
The number of buffers in the queue that have been processed |
AL_SEC_OFFSET |
f , fv , i , iv
|
The playback position, expressed in seconds |
AL_SAMPLE_OFFSET |
f , fv , i , iv
|
The playback position, expressed in samples |
AL_BYTE_OFFSET |
f , fv , i , iv
|
The playback position, expressed in bytes |
- alGenSources
- alDeleteSources
- alIsSource
- alSourcef
- alSource3f
- alSourcefv
- alSourcei
- alSource3i
- alSourceiv
- alGetSourcef
- alGetSource3f
- alGetSourcefv
- alGetSourcei
- alGetSource3i
- alGetSourceiv
- alSourcePlay
- alSourcePlayv
- alSourcePause
- alSourcePausev
- alSourceStop
- alSourceStopv
- alSourceRewind
- alSourceRewindv
- alSourceQueueBuffers
- alSourceUnqueueBuffers
This function generates one or more sources. References to sources are
ALuint
values, which are used wherever a source reference is needed (in calls
such as alDeleteSources and alSourcei).
void alGenSources(
ALsizei n,
ALuint *sources
);
- n - The number of sources to be generated
- sources - Pointer to an array of
ALuint
vlaues which will store the names of the new sources
State | Description |
---|---|
AL_OUT_OF_MEMORY | There is not enough memory to generate all the requested sources. |
AL_INVALID_VALUE | There are not enough non-memory resources to create all the requested sources, or the array pointer is not valid. |
AL_INVALID_OPERATION | There is no context to create sources in. |
OpenAL 1.0 or higher
If the requested number of sources cannot be created, an error will be generated
which can be detected with alGetError. If an error occurs, no
sources will be generated. If n
equals zero, alGenSources
does nothing and does not return an error.
This function deletes one or more sources.
void alDeleteSources(
ALsizei n,
ALuint *sources
);
- n - The number of sources to be deleted
- sources - Pointer to an array of source names identifying the sources to be deleted
State | Description |
---|---|
AL_INVALID_NAME | At least one specified source is not valid, or an attempt is being made to delete more sources than exist. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
If the requested number of sources cannot be deleted, an error will be generated
which can be detected with alGetError. If an error occurs, no
sources will be deleted. If n
equals zero,
alDeleteSources does nothing and will not return an error.
A playing source can be deleted – the source will be stopped and then deleted.
This function tests if a source name is valid, returning AL_TRUE
if valid and
AL_FALSE
if not.
boolean alIsSource(
ALuint source
);
- source - A source name to be tested for validity
State | Description |
---|---|
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
This function sets a floating-point property of a source.
void alSourcef(
ALuint source,
ALenum param,
ALfloat value
);
- source - Source name whose attribute is being set
- param - The name of the attribute to set:
AL_PITCH
AL_GAIN
AL_MIN_GAIN
AL_MAX_GAIN
AL_MAX_DISTANCE
AL_ROLLOFF_FACTOR
AL_CONE_OUTER_GAIN
AL_CONE_INNER_ANGLE
AL_CONE_OUTER_ANGLE
AL_REFERENCE_DISTANCE
- value - The value to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is out of range. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alSource3f, alSourcefv, alGetSourcef, alGetSource3f, alGetSourcefv
This function sets a source property requiring three floating point values.
void alSource3f(
ALuint source,
ALenum param,
ALfloat v1,
ALfloat v2,
ALfloat v3
);
- source - Source name whose attribute is being set
- param - The name of the attribute to set:
AL_POSITION
AL_VELOCITY
AL_DIRECTION
- v1, v2, v3 - The three
ALfloat
values to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is out of range. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
This function is an alternative to alSourcefv.
alSourcef, alSourcefv, alGetSourcef, alGetSource3f, alGetSourcefv
This function sets a floating point-vector property of a source.
void alSourcefv(
ALuint source,
ALenum param,
ALfloat* values
);
- source - Source name whose attribute is being set
- param - The name of the attribute to set:
AL_POSITION
AL_VELOCITY
AL_DIRECTION
- values - A pointer to the vector to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is out of range. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
This function is an alternative to alSource3f.
alSourcef, alSource3f, alGetSourcef, alGetSource3f, alGetSourcefv
This function sets an integer property of a source.
void alSourcei(
ALuint source,
ALenum param,
ALint value
);
- source - Source name whose attribute is being set
- param - The name of the attribute to set:
AL_SOURCE_RELATIVE
AL_CONE_INNER_ANGLE
AL_CONE_OUTER_ANGLE
AL_LOOPING
AL_BUFFER
AL_SOURCE_STATE
- value - The value to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is out of range. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The buffer name zero is reserved as a “NULL Buffer" and is accepted by
alSourcei(…, AL_BUFFER, …)
as a valid buffer of zero length. The NULL
Buffer is extremely useful for detaching buffers from a source which were
attached using this call or with alSourceQueueBuffers.
alSource3i, alSourceiv, alGetSourcei, alGetSource3i, alGetSourceiv
This function sets a source property requiring three integer values.
void alSource3i(
ALuint source,
ALenum param,
ALint v1,
ALint v2,
ALint v3
);
- source - Source name whose attribute is being set
- param - The name of the attribute to set:
AL_POSITION
AL_VELOCITY
AL_DIRECTION
- v1, v2, v3 - The three
ALint
values to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is out of range. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
None
alSourcei, alSourceiv, alGetSourcei, alGetSource3i, alGetSourceiv
This function sets an integer-vector property of a source.
void alSourceiv(
ALuint source,
ALenum param,
ALint* values
);
- source - Source name whose attribute is being set
- param - The name of the attribute to set:
AL_POSITION
AL_VELOCITY
AL_DIRECTION
- values - A pointer to the vector to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is out of range. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
None
alSourcei, alSource3i, alGetSourcei, alGetSource3i, alGetSourceiv
This function sets an integer property of a source.
void alGetSourcei(
ALuint source,
ALenum param,
ALint* value
);
- source - Source name whose attribute is being retrieved
- param - The name of the attribute to retrieve:
AL_SOURCE_RELATIVE
AL_BUFFER
AL_SOURCE_STATE
AL_BUFFERS_QUEUED
AL_BUFFERS_PROCESSED
- values - A pointer to the integer value being retrieved
State | Description |
---|---|
AL_INVALID_VALUE | The value pointer given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alSourcei, alSource3i, alSourceiv, alGetSource3i, alGetSourceiv
This function retrieves three integer values representing a property of a source.
void alGetSource3i(
ALuint source,
ALenum param,
ALint* v1,
ALint* v2,
ALint* v3
);
- source - Source name whose attribute is being retrieved
- param - The name of the attribute to retrieve:
AL_POSITION
AL_VELOCITY
AL_DIRECTION
- values - Pointer to the values to retrieve
State | Description |
---|---|
AL_INVALID_VALUE | The value pointer given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
None
alSourcei, alSource3i, alSourceiv, alGetSourcei, alGetSourceiv
This function retrieves an integer property of a source.
void alGetSourceiv(
ALuint source,
ALenum param,
ALint* values
);
- source - Source name whose attribute is being retrieved
- param - The name of the attribute to retrieve:
AL_POSITION
AL_VELOCITY
AL_DIRECTION
- values - Pointer to the vector to retrieve
State | Description |
---|---|
AL_INVALID_VALUE | The value pointer given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alSourcei, alSource3i, alSourceiv, alGetSourcei, alGetSource3i
This function plays a source.
void alSourcePlay(
ALuint source
);
- source - The name of the source to be played
State | Description |
---|---|
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The playing source will have its state changed to AL_PLAYING
. When called on a
source which is already playing, the source will restart at the beginning. When
the attached buffer(s) are done playing, the source will progress to the
AL_STOPPED
state.
alSourcePlayv, alSourcePause, alSourcePausev, alSourceRewind, alSourceRewindv, alSourceStop, alsourcestopv
This function plays a set of sources.
void alSourcePlayv(
ALsizei n,
ALuint *sources
);
- n - The number of sources to be played
- source - A pointer to an array of sources to be played
State | Description |
---|---|
AL_INVALID_VALUE | The value pointer given is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The playing sources will have their state changed to AL_PLAYING
. When called
on a source which is already playing, the source will restart at the beginning.
When the attached buffer(s) are done playing, the source will progress to the
AL_STOPPED
state.
alSourcePlay, alSourcePause, alSourcePausev, alSourceRewind, alSourceRewindv, alSourceStop, alsourcestopv
This function pauses a source.
void alSourcePause(
ALuint source
);
- source - The name of the source to be paused
State | Description |
---|---|
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The paused source will have its state changed to AL_PAUSED
.
alSourcePlay, alSourcePlayv, alSourcePausev, alSourceRewind, alSourceRewindv, alSourceStop, alsourcestopv
This function pauses a set of sources.
void alSourcePausev(
ALsizei n,
ALuint *sources
);
- n - The number of sources to be paused
- source - A pointer to an array of sources to be paused
State | Description |
---|---|
AL_INVALID_VALUE | The value pointer given is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The paused sources will have their state changed to AL_PAUSED
.
alSourcePlay, alSourcePlayv, alSourcePause, alSourceRewind, alSourceRewindv, alSourceStop, alsourcestopv
This function stops a source.
void alSourceStop(
ALuint source
);
- source - The name of the source to be stopped
State | Description |
---|---|
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The paused source will have its state changed to AL_STOPPED
.
alSourcePlay, alSourcePlayv, alSourcePause, alSourcePausev, alSourceRewind, alSourceRewindv, alsourcestopv
This function stops a set of sources.
void alSourceStopv(
ALsizei n,
ALuint *sources
);
- n - The number of sources to stop
- source - A pointer to an array of sources to be stopped
State | Description |
---|---|
AL_INVALID_VALUE | The value pointer given is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The paused sources will have their state changed to AL_STOPPED
.
alSourcePlay, alSourcePlayv, alSourcePause, alSourceRewind, alSourceRewindv, alSourceStop, alsourcestop
This function stops the source and sets its state to AL_INITIAL
.
void alSourceRewind(
ALuint source
);
- source - The name of the source to be rewound
State | Description |
---|---|
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alSourcePlay, alSourcePlayv, alSourcePause, alSourcePausev, alSourceRewindv, alsourcestop, alsourcestopv
his function stops a set of sources and sets all their states to AL_INITIAL
.
void alSourceRewindv(
ALsizei n,
ALuint *sources
);
- n - The number of sources to be rewound
- source - A pointer to an array of sources to be rewound
State | Description |
---|---|
AL_INVALID_VALUE | The value pointer given is not valid. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alSourcePlay, alSourcePlayv, alSourcePause, alSourcePausev, alSourceRewind, alSourceStop, alsourcestop
This function queues a set of buffers on a source. All buffers attached to a
source will be played in sequence, and the number of processed buffers can be
detected using an alGetSourcei call to retrieve
AL_BUFFERS_PROCESSED
.
void alSourceQueueBuffers(
ALuint source,
ALsizei n,
ALuint* buffers
);
- source - The name of the source to queue buffers onto
- n - The number of buffers to be queued
- buffers - A pointer to an array of buffer names to be queued
State | Description |
---|---|
AL_INVALID_NAME | At least one specified buffer name is not valid, or the specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context, an attempt was made to add a new buffer which is not the same format as the buffers already in the queue, or the source already has a static buffer attached. |
OpenAL 1.0 or higher
When first created, a source will be of type AL_UNDETERMINED
. A successful
alSourceQueueBuffers call will change the source type
to AL_STREAMING
.
This function unqueues a set of buffers attached to a source. The number of
processed buffers can be detected using an alSourcei call to
retrieve AL_BUFFERS_PROCESSED
, which is the maximum number of buffers that can
be unqueued using this call.
void alSourceUnqueueBuffers(
ALuint source,
ALsizei n,
ALuint* buffers
);
- source - The name of the source to unqueue buffers from
- n - The number of buffers to be unqueued
- buffers - A pointer to an array of buffer names that were removed
State | Description |
---|---|
AL_INVALID_VALUE | At least one buffer can not be unqueued because it has not been processed yet. |
AL_INVALID_NAME | The specified source name is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The unqueue operation will only take place if all n buffers can be removed from the queue.
Property | Data Type | Description |
---|---|---|
AL_GAIN |
f , fv
|
Master gain. Value should be positive |
AL_POSITION |
fv , 3f , iv , 3i
|
X, Y, Z position |
AL_VELOCITY |
fv , 3f , iv , 3i
|
Velocity vector |
AL_ORIENTATION |
fv , fv
|
Orientation expressed as "at" and "up" vectors |
- alListenerf
- alListener3f
- alListenerfv
- alListeneri
- alListener3i
- alListeneriv
- alGetListenerf
- alGetListener3f
- alGetListenerfv
- alGetListeneri
- alGetListener3i
- alGetListeneriv
This function sets a floating point property for the listener.
void alListenerf(
ALenum param,
ALfloat value
);
- param - The name of the attribute to be set:
AL_GAIN
- value - The ALfloat value to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alListener3f, alListenerfv, alGetListenerf, alGetListener3f, alGetListenerfv
This function sets a floating point property for the listener.
void alListener3f(
ALenum param,
ALfloat v1,
ALfloat v2,
ALfloat v3
);
- param - The name of the attribute to be set:
AL_POSITION
AL_VELOCITY
- v1, v2, v3 - The value to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alListenerf, alListenerfv, alGetListenerf, alGetListener3f, alGetListenerfv
This function sets a floating point-vector property for the listener.
void alListenerfv(
ALenum param,
ALfloat* values
);
- param - The name of the attribute to be set:
AL_POSITION
AL_VELOCITY
AL_ORIENTATION
- values - Pointer to floating point-vector values
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alListenerf, alListener3f, alGetListenerf, alGetListener3f, alGetListenerfv
This function sets an integer property for the listener.
void alListeneri(
ALenum param,
ALint value
);
- param - The name of the attribute to be set
- value - The integer value to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
There are no integer listener attributes defined for OpenAL 1.1, but this function may be used by an extension.
alListener3i, alListeneriv, alGetListeneri, alGetListener3i, alGetListeneriv
This function sets an integer property for the listener.
void alListener3i(
ALenum param,
ALint v1,
ALint v2,
ALint v3
);
- param - The name of the attribute to be set:
AL_POSITION
AL_VELOCITY
- v1, v2, v3 - The integer values to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
None
alListeneri, alListeneriv, alGetListeneri, alGetListener3i, alGetListeneriv
This function sets an integer property for the listener.
void alListeneriv(
ALenum param,
ALint* values
);
- param - The name of the attribute to be set:
AL_POSITION
AL_VELOCITY
AL_ORIENTATION
- values - Pointer to the integer values to set the attribute to
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
None
alListeneri, alListener3i, alGetListeneri, alGetListener3i, alGetListeneriv
This function retrieves a floating point property of the listener.
void alGetListenerf(
ALenum param,
ALfloat* value
);
- param - The name of the attribute to be retrieved:
AL_GAIN
- values - Pointer to the floating-point value being retrieved
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alListenerf, alListener3f, alListenerfv, alGetListener3f, alGetListenerfv
This function retrieves a set of three floating point values from a property of the listener.
void alGetListener3f(
ALenum param,
ALfloat* v1,
ALfloat* v2,
ALfloat* v3
);
- param - The name of the attribute to be retrieved:
AL_POSITION
AL_VELOCITY
- v1, v2, v3 - Pointers to the three floating point being retrieved
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alListenerf, alListener3f, alListenerfv, alGetListenerf, alGetListenerfv
This function retrieves a floating point-vector property of the listener.
void alGetListenerfv(
ALenum param,
ALfloat* values
);
- param - The name of the attribute to be retrieved:
AL_POSITION
AL_VELOCITY
AL_ORIENTATION
- values - Pointers to the three floating point being retrieved
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alListenerf, alListener3f, alListenerfv, alGetListenerf, alGetListener3f
This function retrieves an integer property of the listener.
void alGetListeneri(
ALenum param,
ALint* value
);
- param - The name of the attribute to be retrieved:
- values - Pointer to the integer value being retrieved
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
There are no integer listener attributes defined for OpenAL 1.1, but this function may be used by an extension.
alListeneri, alListener3i, alListeneriv, alGetListener3i, alGetListeneriv
This function retrieves an integer property of the listener.
void alGetListener3i(
ALenum param,
ALint* v1,
ALint* v2,
ALint* v3
);
- param - The name of the attribute to be retrieved:
AL_POSITION
AL_VELOCITY
- v1, v2, v3 - Pointers to the integer values being retrieved
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
None
alListeneri, alListener3i, alListeneriv, alGetListeneri, alGetListeneriv
This function retrieves an integer property of the listener.
void alGetListeneriv(
ALenum param,
ALint* values
);
- param - The name of the attribute to be retrieved:
AL_POSITION
AL_VELOCITY
AL_ORIENTATION
- values - Pointers to the integer values being retrieved
State | Description |
---|---|
AL_INVALID_VALUE | The value given is not valid. |
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
None
alListeneri, alListener3i, alListeneriv, alGetListeneri, alGetListener3i
Property | Data Type | Description |
---|---|---|
AL_DOPPLER_FACTOR | f |
Global Doppler factor |
AL_SPEED_OF_SOUND | f |
Speed of sound in units per second |
AL_DISTANCE_MODEL | f |
Distance model enumeration value |
- alEnable
- alDisable
- alIsEnabled
- alGetBoolean
- alGetDouble
- alGetFloat
- alGetInteger
- alGetBooleanv
- alGetDoublev
- alGetFloatv
- alGetIntegerv
- alGetString
- alDistanceModel
- alDopplerFactor
- alSpeedOfSound
This function enables a feature of the OpenAL driver.
void alEnable(
ALenum capability
);
- capability - the name of a capability to enable
State | Description |
---|---|
AL_INVALID_ENUM | The specified capability is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
There are no capabilities defined in OpenAL 1.1 to be used with this function, but it may be used by an extension.
This function disables a feature of the OpenAL driver.
void alDisable(
ALenum capability
);
- capability - the name of a capability to distable
State | Description |
---|---|
AL_INVALID_ENUM | The specified capability is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
There are no capabilities defined in OpenAL 1.1 to be used with this function, but it may be used by an extension.
This function returns a boolean indicating if a specific feature is enabled in the OpenAL driver.
ALboolean alIsEnabled(
ALenum capability
);
- capability - the name of a capability to check
State | Description |
---|---|
AL_INVALID_ENUM | The specified capability is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
Returns AL_TRUE
if the capability is enabled, AL_FALSE
if the capability is
disabled. There are no capabilities defined in OpenAL 1.1 to be used with this
function, but it may be used by an extension.
This function returns a boolean OpenAL state.
ALboolean alGetBoolean(
ALenum param
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The boolean state described by param
will be returned.
alGetBooleanv, alGetDouble, alGetDoublev, alGetFloat, alGetFloatv, alGetInteger, alGetIntegerv
This function returns a double precision floating point OpenAL state.
ALdouble alGetDouble(
ALenum param
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The double value described by param
will be returned.
alGetBoolean, alGetBooleanv, alGetDoublev, alGetFloat, alGetFloatv, alGetInteger, alGetIntegerv
This function returns a floating point OpenAL state.
ALfloat alGetFloat(
ALenum param
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The floating point state described by param
will be returned.
alGetBoolean, alGetBooleanv, alGetDouble, alGetDoublev, alGetFloatv, alGetInteger, alGetIntegerv
This function returns an integer OpenAL state.
ALint alGetInteger(
ALenum param
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The integer state described by param
will be returned.
alGetBoolean, alGetBooleanv, alGetDouble, alGetDoublev, alGetFloat, alGetFloatv, alGetIntegerv
This function returns an integer OpenAL state.
void alGetBooleanv(
ALenum param,
ALboolean* data
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
- data - A pointer to the location where the state will be stored
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_VALUE | The specified data pointer is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alGetBoolean, alGetDouble, alGetDoublev, alGetFloat, alGetFloatv, alGetInteger, alGetIntegerv
This function retrieves a double precision floating point OpenAL state.
void alGetDoublev(
ALenum param,
ALdouble* data
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
- data - A pointer to the location where the state will be stored
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_VALUE | The specified data pointer is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alGetBoolean, alGetBooleanv, alGetDouble, alGetFloat, alGetFloatv, alGetInteger, alGetIntegerv
This function retrieves a floating point OpenAL state.
void alGetFloatv(
ALenum param,
ALfloat* data
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
- data - A pointer to the location where the state will be stored
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_VALUE | The specified data pointer is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alGetBoolean, alGetBooleanv, alGetDouble, alGetDoublev, alGetFloat, alGetInteger, alGetIntegerv
This function retrieves an integer OpenAL state.
void alGetIntegerv(
ALenum param,
ALint* data
);
- param - the state to be queried:
AL_DOPPLER_FACTOR
AL_SPEED_OF_SOUND
AL_DISTANCE_MODEL
- data - A pointer to the location where the state will be stored
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
AL_INVALID_VALUE | The specified data pointer is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
None
alGetBoolean, alGetBooleanv, alGetDouble, alGetDoublev, alGetFloat, alGetFloatv, alGetInteger
This function retrieves an OpenAL string property.
const ALchar* alGetString(
ALenum param
);
- param - the state to be queried:
AL_VENDOR
AL_VERSION
AL_RENDERER
AL_EXTENSIONS
State | Description |
---|---|
AL_INVALID_ENUM | The specified parameter is not valid. |
OpenAL 1.0 or higher
Returns a pointer to a null-terminated string.
This function selects the OpenAL distance model – AL_INVERSE_DISTANCE
,
AL_INVERSE_DISTANCE_CLAMPED
, AL_LINEAR_DISTANCE
,
AL_LINEAR_DISTANCE_CLAMPED
, AL_EXPONENT_DISTANCE
,
AL_EXPONENT_DISTANCE_CLAMPED
, or AL_NONE
.
The AL_INVERSE_DISTANCE
model works according to the following formula:
gain = AL_REFERENCE_DISTANCE / (AL_REFERENCE_DISTANCE
+ AL_ROLLOFF_FACTOR * (distance - AL_REFERENCE_DISTANCE));
The AL_INVERSE_DISTANCE_CLAMPED
model works according to the following
formula:
distance = max(distance, AL_REFERENCE_DISTANCE);
distance = min(distance, AL_MAX_DISTANCE);
gain = AL_REFERENCE_DISTANCE / (AL_REFERENCE_DISTANCE
+ AL_ROLLOFF_FACTOR * (distance - AL_REFERENCE_DISTANCE));
Here is a graph showing the inverse distance curve:
The AL_LINEAR_DISTANCE
model works according to the following formula:
distance = min(distance, AL_MAX_DISTANCE); // Avoid negative gain
gain = (1 - AL_ROLLOFF_FACTOR * (distance -
AL_REFERENCE_DISTANCE) /
(AL_MAX_DISTANCE - AL_REFERENCE_DISTANCE));
The AL_LINEAR_DISTANCE_CLAMPED
model works according to the following formula:
distance = max(distance, AL_REFERENCE_DISTANCE);
distance = min(distance, AL_MAX_DISTANCE);
gain = (1 - AL_ROLLOFF_FACTOR * (distance -
AL_REFERENCE_DISTANCE) /
(AL_MAX_DISTANCE - AL_REFERENCE_DISTANCE));
Here is a graph showing the linear distance curve:
The AL_EXPONENT_DISTANCE
model works according to the following forumula:
gain = pow(distance / AL_REFERENCE_DISTANCE, -AL_ROLLOFF_FACTOR);
The AL_EXPONENT_DISTANCE_CLAMPED
model works according to the following
forumla:
distance = max(distance, AL_REFERENCE_DISTANCE);
distance = min(distance, AL_MAX_DISTANCE);
gain = pow(distance / AL_REFERENCE_DISTANCE, -AL_ROLLOFF_FACTOR);
Here is a graph showing the exponential distance curve:
The AL_NONE
distance model works according to the following formula:
gain = 1;
void alDistanceModel(
ALenum value
);
- value - The distance model to be set:
AL_INVERSE_DISTANCE
AL_INVERSE_DISTANCE_CLAMPED
AL_LINEAR_DISTANCE
AL_LINEAR_DISTANCE_CLAMPED
AL_EXPONENT_DISTANCE
AL_EXPONENT_DISTANCE_CLAMPED
AL_NONE
State | Description |
---|---|
AL_INVALID_VALUE | The specified distance model is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The default distance model in OpenAL is AL_INVERSE_DISTANCE_CLAMPED
.
This function selects the OpenAL Doppler factor value.
void alDopplerFactor(
ALfloat value
);
- value - The Doppler scale value to set
State | Description |
---|---|
AL_INVALID_VALUE | The specified distance model is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.0 or higher
The default Doppler factor value is 1.0.
This function selects the speed of sound for use in Doppler calculations.
void alSpeedOfSound(
ALfloat value
);
- value - The speed of sound value to set
State | Description |
---|---|
AL_INVALID_VALUE | The specified distance model is not valid. |
AL_INVALID_OPERATION | There is no current context. |
OpenAL 1.1 or higher
The default speed of sound value is 343.3.
Error Code | Description |
---|---|
AL_NO_ERROR | There is not currently an error |
AL_INVALID_NAME | A bad name (ID) was passed to an OpenAL function |
AL_INVALID_ENUM | An invalid enum value was passed to an OpenAL function |
AL_INVALID_VALUE | An invalid value was passed to an OpenAL function |
AL_INVALID_OPERATION | The requested operation is not valid |
AL_OUT_OF_MEMORY | The requested operation resulted in OpenAL running out of memory |
This function returns the current error state and then clears the error state.
ALenum alGetError(ALvoid);
None
None
OpenAL 1.0 or higher
Returns an Alenum
representing the error state. When an OpenAL error occurs,
the error state is set and will not be changed until the error state is
retrieved using alGetError. Whenever alGetError
is called, the error state is cleared and the last state (the current state when
the call was made) is returned. To isolate error detection to a specific
portion of code, alGetError should be called before the isolated
section to clear the current error state.
This function tests if a specific extension is available for the OpenAL driver.
ALboolean alIsExtensionPresent(
const ALchar *extname
);
- extname - A null-terminated string describing the desired extension
State | Description |
---|---|
AL_INVALID_VALUE | The specified extension string is not a valid pointer. |
OpenAL 1.0 or higher
Returns AL_TRUE
if the extension is available, AL_FALSE
if the extension is not
available.
alGetProcAddress, alGetEnumValue
This function returns the address of an OpenAL extension function.
void* alGetProcAddress(
const ALchar *fname
);
- fname - A null-terminated string containing the function name
None
OpenAL 1.0 or higher
The return value is a pointer to the specified function. The return value will
be NULL
if the function is not found.
alIsExtensionPresent, alGetEnumValue
This function returns the enumeration value of an OpenAL enum described by a string.
ALenum alGetEnumValue(
const ALchar *ename
);
- ename - A null-terminated string describing an OpenAL enum
None
OpenAL 1.0 or higher
Returns the actual ALenum
described by a string. Returns NULL
if the string
doesn’t describe a valid OpenAL enum.
alIsExtensionPresent, alGetProcAddress
Property | Data Type | Description |
---|---|---|
ALC_FREQUENCY | i |
Output frequency |
ALC_MONO_SOURCES | i |
Requested number of mono sources |
ALC_STEREO_SOURCES | i |
Requested number of stereo sources |
ALC_REFRESH | i |
Update rate of context processing |
ALC_SYNC | i |
Flag indicating a synchronous context |
- alcCreateContext
- alcMakeContextCurrent
- alcProcessContext
- alcSuspendContext
- alcDestroyContext
- alcGetCurrentContext
- alcGetContextsDevice
This function creates a context using a specified device.
ALCcontext* alcCreateContext(
ALCdevice* device,
ALCint* attrlist
);
- device - A pointer to a device
- attrlist - A pointer to a set of attributes:
ALC_FREQUENCY
ALC_MONO_SOURCES
ALC_REFRESH
ALC_STEREO_SOURCES
ALC_SYNC
State | Description |
---|---|
ALC_INVALID_VALUE | An additional context can not be created for this device. |
ALC_INVALID_DEVICE | The specified device is not a valid output device. |
OpenAL 1.0 or higher
Returns a pointer to the new context (NULL
on failure).
The attribute list can be NULL
, or a zero terminated list of integer pairs
composed of valid ALC attribute tokens and requested values.
alcDestroyContext, alcMakeContextCurrent
This function makes a specified context the current context.
ALCboolean alcMakeContextCurrent(
ALCcontext *context
);
- context - A pointer to the new context
State | Description |
---|---|
ALC_INVALID_CONTEXT | The specified context is invalid. |
OpenAL 1.0 or higher
Returns ALC_TRUE
on success, or ALC_FALSE
on failure.
alcCreateContext, alcDestroyContext
This function tells a context to begin processing.
void alcProcessContext(
ALCcontext *context
);
- context - A pointer to the context
State | Description |
---|---|
ALC_INVALID_CONTEXT | The specified context is invalid. |
OpenAL 1.0 or higher
When a context is suspended, changes in OpenAL state will be accepted but will not be processed. alcSuspendContext can be used to suspend a context, and then all the OpenAL state changes can be applied at once, followed by a call to alcProcessContext to apply all the state changes immediately. In some cases, this procedure may be more efficient than application of properties in a non-suspended state. In some implementations, process and suspend calls are each a NOP.
This function suspends processing on a specified context.
void alcSuspendContext(
ALCcontext *context
);
- context - A pointer to the context to be suspended
State | Description |
---|---|
ALC_INVALID_CONTEXT | The specified context is invalid. |
OpenAL 1.0 or higher
When a context is suspended, changes in OpenAL state will be accepted but will not be processed. A typical use of alcSuspendContext would be to suspend a context, apply all the OpenAL state changes at once, and then call alcProcessContext to apply all the state changes at once. In some cases, this procedure may be more efficient than application of properties in a non-suspended state. In some implementations, process and suspend calls are each a NOP.
This function destroys a context.
void alcDestroyContext(
ALCcontext *context
);
- context - A pointer to the context
State | Description |
---|---|
ALC_INVALID_CONTEXT | The specified context is invalid. |
OpenAL 1.0 or higher
A context which is not current can be destroyed at any time (all sources within
that context will also be deleted).
alcMakeContextCurrent should be used to make sure the
context to be destroyed is not current (NULL
is valid for
alcMakeContextCurrent).
alcCreateContext, alcMakeContextCurrent
This function retrieves the current context.
ALCcontext* alcGetCurrentContext(ALCvoid);
None
None
OpenAL 1.0 or higher
Returns a pointer to the current context.
This function retrieves a context's device pointer.
ALCdevice* alcGetContextsDevice(ALCcontext *context);
- context - A pointer to a context
State | Description |
---|---|
ALC_INVALID_CONTEXT | The specified context is invalid. |
OpenAL 1.0 or higher
Returns a pointer to the specified context's device.
Error Code | Description |
---|---|
ALC_NO_ERROR | There is not currently an error |
ALC_INVALID_DEVICE | A bad device was passed to an OpenAL function |
ALC_INVALID_CONTEXT | A bad context was passed to an OpenAL function |
ALC_INVALID_ENUM | An unknown enum value was passed to an OpenAL function |
ALC_INVALID_VALUE | An invalid value was passed to an OpenAL function |
ALC_OUT_OF_MEMORY | The requested operation resulted in OpenAL running out of memory |
This function retrieves the current context error state.
ALCenum alcGetError(ALCdevice *device);
- device - A pointer to the device to retrieve the error state from
None
OpenAL 1.0 or higher
None
This function opens a device by name.
ALCdevice* alcOpenDevice(
const ALCchar* devicename
);
- devicename - A null-terminated string describing a device
The return value will be NULL
if there is an error.
OpenAL 1.0 or higher
Returns a pointer to the opened device. Will return NULL
if a device can not be opened.
This function closes an opened device.
ALCboolean alcCloseDevice(
ALCdevice* device
);
- device - A pointer to an opened device
State | Description |
---|---|
ALC_INVALID_DEVICE | The specified device name doesn't exist. |
OpenAL 1.0 or higher
ALC_TRUE
will be returned on success or ALC_FALSE
on failure. Closing a
device will fail if the device contains any contexts or buffers.
This function queries if a specified context extension is available.
ALCboolean alcIsExtensionPresent(
ALCdevice *device,
const ALCchar *extName
);
- device - A pointer to the device to be queried for an extension
- extName - A null-terminated string describing the extension
State | Description |
---|---|
ALC_INVALID_VALUE | The string pointer is not valid. |
OpenAL 1.0 or higher
Returns ALC_TRUE
if the extension is available, ALC_FALSE
if the extension
is not available.
alcGetProcAddress, alcGetEnumValue
This function retrieves the address of a specified context extension function.
void* alcGetProcAddress(
ALCdevice* device,
const ALCchar* funcName
);
- device - A pointer to the device to be queried for the function
- funcName - a null-terminated string describing the function
State | Description |
---|---|
ALC_INVALID_VALUE | The string pointer is not valid. |
OpenAL 1.0 or higher
Returns the address of the function, or NULL
if it is not found.
alcIsExtensionPresent, alcGetEnumValue
This function retrieves the enum value for a specified enumeration name.
ALCenum alcGetEnumValue(
ALCdevice* device,
const ALCchar* enumName
);
- device - A pointer to the device to be queried
- enumName - A null terminated string describing the enum value
State | Description |
---|---|
ALC_INVALID_VALUE | The string pointer is not valid. |
OpenAL 1.0 or higher
Returns the enum value described by the enumName string. This is most often used for querying an enum value for an ALC extension.
alcIsExtensionPresent, alcGetProcAddress
This function returns pointers to strings related to the context.
const ALCchar * alcGetString(
ALCdevice *device,
ALenum param
);
- device - A pointer to the device to be queried
- param - An attribute to be retrieved:
ALC_DEFAULT_DEVICE_SPECIFIER
ALC_CAPTURE_DEFAULT_DEVICE_SPECIFIER
ALC_DEVICE_SPECIFIER
ALC_CAPTURE_DEVICE_SPECIFIER
ALC_EXTENSIONS
State | Description |
---|---|
ALC_INVALID_ENUM | The specified parameter is not valid. |
OpenAL 1.0 or higher
ALC_DEFAULT_DEVICE_SPECIFIER
will return the name of the default output
device.
ALC_CAPTURE_DEFAULT_DEVICE_SPECIFIER
will return the name of the default
capture device.
ALC_DEVICE_SPECIFIER
will return the name of the specified output device if a
pointer is supplied, or will return a list of all available devices if a NULL
device pointer is supplied. A list is a pointer to a series of strings
separated by NULL
characters, with the list terminated by two NULL
characters. See Enumeration Extension for more details.
ALC_CAPTURE_DEVICE_SPECIFIER
will return the name of the specified capture
device if a pointer is supplied, or will return a list of all available devices
if a NULL
device pointer is supplied.
ALC_EXTENSIONS
returns a list of available context extensions, with each
extension separated by a space and the list terminated by a NULL
character.
This function returns integers related to the context.
void alcGetIntegerv(
ALCdevice* device,
ALCenum param,
ALCsizei size,
ALCint* data
);
- device - A pointer to the device to be queried
- param - An attribute to be retrieved:
ALC_MAJOR_VERSION
ALC_MINOR_VERSION
ALC_ATTRIBUTES_SIZE
ALC_ALL_ATTRIBUTES
- size - The size of the destination buffer provided
- data - A pointer to the data to be returned
State | Description |
---|---|
ALC_INVALID_VALUE | The specified data pointer or size is not valid. |
ALC_INVALID_ENUM | The specified parameter is not valid. |
ALC_INVALID_DEVICE | The specified device is not valid. |
ALC_INVALID_CONTEXT | The specified context is not valid. |
OpenAL 1.0 or higher
The versions returned refer to the specification version that the implementation meets.
This function opens a capture device by name.
ALCdevice* alcCaptureOpenDevice(
const ALCchar* devicename,
ALCuint frequency,
ALCenum format,
ALCsizei buffersize
);
- devicename - A pointer to a device name string
- frequency - The frequency that the data should be captured at
- format - The requested capture buffer format
- buffersize - The size of the capture buffer
State | Description |
---|---|
ALC_INVALID_VALUE | One of the parameters has an invalid value. |
ALC_OUT_OF_MEMORY | The specified device is invalid, or can not capture audio. |
OpenAL 1.1 or higher
Returns the capture device pointer, or NULL
on failure.
This function closes the specified capture device.
ALCboolean alcCaptureCloseDevice(
ALCdevice* device
);
- device - A pointer to a capture device
State | Description |
---|---|
ALC_INVALID_DEVICE | The specified device is not a valid capture device. |
OpenAL 1.1 or higher
Returns ALC_TRUE
if the close operation was successful, ALC_FALSE
on
failure.
This function begins a capture operation.
void alcCaptureStart(
ALCdevice *device
);
- device - A pointer to a capture device
State | Description |
---|---|
ALC_INVALID_DEVICE | The specified device is not a valid capture device. |
OpenAL 1.1 or higher
alcCaptureStart will begin recording to an internal ring
buffer of the size specified when opening the capture device. The application
can then retrieve the number of samples currently available using the
ALC_CAPTURE_SAMPLES
token with alcGetIntegerv. When the
application determines that enough samples are available for processing, then it
can obtain them with a call to alcCaptureSamples.
alcCaptureStop, alcCaptureSamples
This function stops a capture operation.
void alcCaptureStop(
ALCdevice *device
);
- device - A pointer to a capture device
State | Description |
---|---|
ALC_INVALID_DEVICE | The specified device is not a valid capture device. |
OpenAL 1.1 or higher
None
alcCaptureStart, alcCaptureSamples
This function completes a capture operation, and does not block.
void alcCaptureSamples(
ALCdevice* device,
ALCvoid* buffer,
ALCsizei samples
);
- device - A pointer to a capture device
- buffer - A pointer to a data buffer, which must be large enough to accommodate samples number of samples
- samples - The number of samples to be retrieved
State | Description |
---|---|
ALC_INVALID_VALUE | The specified number of samples is larger than the number of available samples. |
ALC_INVALID_DEVICE | The specified device is not a valid capture device. |
OpenAL 1.1 or higher
None