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IOAudioTypes.h

Includes:
<libkern/OSTypes.h>
<mach/message.h>
<device/device_types.h>
<IOKit/ndrvsupport/IOMacOSTypes.h>

Overview


Typedefs

IOAudioBufferDataDescriptor

typedef struct _IOAudioBufferDataDescriptor { 
    UInt32 fActualDataByteSize; 
    UInt32 fActualNumSampleFrames; 
    UInt32 fTotalDataByteSize; 
    UInt32 fNominalDataByteSize; 
    Byte fData[kVariableLengthArray]; 
} IOAudioBufferDataDescriptor;
Discussion

This structure is used to describe the structure of a sample data buffer

IOAudioControlCalls

The set of constants passed to IOAudioControlUserClient::getExternalMethodForIndex() when making calls from the IOAudioFamily user client code. 

typedef enum _IOAudioControlCalls { 
    kIOAudioControlCallSetValue = 0, 
    kIOAudioControlCallGetValue = 1 
} IOAudioControlCalls;
Constants
kIOAudioControlCallSetValue

Used to set the value of an IOAudioControl.

kIOAudioControlCallGetValue

Used to get the value of an IOAudioControl.

IOAudioControlNotifications

The set of constants passed in the type field of IOAudioControlUserClient::registerNotificaitonPort(). 

typedef enum _IOAudioControlNotifications { 
    kIOAudioControlValueChangeNotification = 0, 
    kIOAudioControlRangeChangeNotification = 1 
} IOAudioControlNotifications;
Constants
kIOAudioControlValueChangeNotification

Used to request value change notifications.

kIOAudioControlRangeChangeNotification

Used to request range change notifications.

IOAudioEngineCalls

The set of constants passed to IOAudioEngineUserClient::getExternalMethodForIndex() when making calls from the IOAudioFamily user client code. 

typedef enum _IOAudioEngineCalls { 
    kIOAudioEngineCallRegisterClientBuffer = 0, 
    kIOAudioEngineCallUnregisterClientBuffer = 1, 
    kIOAudioEngineCallGetConnectionID = 2, 
    kIOAudioEngineCallStart = 3, 
    kIOAudioEngineCallStop = 4, 
    kIOAudioEngineCallGetNearestStartTime = 5 
} IOAudioEngineCalls;

IOAudioEngineMemory

Used to identify the type of memory requested by a client process to be mapped into its process space 

typedef enum _IOAudioEngineMemory { 
    kIOAudioStatusBuffer = 0, 
    kIOAudioSampleBuffer = 1, 
    kIOAudioMixBuffer = 2, 
    kIOAudioBytesInInputBuffer = 3, 
    kIOAudioBytesInOutputBuffer = 4 
} IOAudioEngineMemory;
Constants
kIOAudioSampleBuffer

This requests the IOAudioEngine's sample buffer

kIOAudioStatusBuffer

This requests the IOAudioEngine's status buffer. It's type is IOAudioEngineStatus.

kIOAudioMixBuffer

This requests the IOAudioEngine's mix buffer

Discussion

This is the parameter to the type field of IOMapMemory when called on an IOAudioEngine. This is only intended for use by the Audio Device API library.

IOAudioEngineNotifications

typedef enum _IOAudioEngineNotifications { 
    kIOAudioEngineAllNotifications = 0, 
    kIOAudioEngineStreamFormatChangeNotification = 1, 
    kIOAudioEngineChangeNotification = 2, 
    kIOAudioEngineStartedNotification = 3, 
    kIOAudioEngineStoppedNotification = 4, 
    kIOAudioEnginePausedNotification = 5, 
    kIOAudioEngineResumedNotification = 6 
} IOAudioEngineNotifications;
Discussion

This enum contains constants that can be used to register for notification about changes to the state of an audio engine

IOAudioEngineState

Represents the state of an IOAudioEngine 

typedef enum _IOAudioEngineState { 
    kIOAudioEngineStopped = 0, 
    kIOAudioEngineRunning = 1, 
    kIOAudioEnginePaused = 2, 
    kIOAudioEngineResumed = 3 
} IOAudioEngineState;
Constants
kIOAudioEngineRunning

The IOAudioEngine is currently running - it is transferring data to or from the device.

kIOAudioEngineStopped

The IOAudioEngine is currently stopped - no activity is occurring.

IOAudioEngineStatus

Shared-memory structure giving audio engine status 

typedef struct _IOAudioEngineStatus { 
    UInt32 fVersion; 
    volatile UInt32 fCurrentLoopCount; 
    volatile AbsoluteTime fLastLoopTime; 
    volatile UInt32 fEraseHeadSampleFrame; 
} IOAudioEngineStatus;
Fields
fVersion

Indicates version of this structure

fCurrentLoopCount

Number of times around the ring buffer since the audio engine started

fLastLoopTime

Timestamp of the last time the ring buffer wrapped

fEraseHeadSampleFrame

Location of the erase head in sample frames - erased up to but not including the given sample frame

IOAudioEngineTraps

typedef enum _IOAudioEngineTraps { 
    kIOAudioEngineTrapPerformClientIO = 0 
} IOAudioEngineTraps;
Discussion

This enum contains constants for audio engine traps.

IOAudioNotificationMessage

Used in the mach message for IOAudio notifications. 

typedef struct _IOAudioNotificationMessage { 
    mach_msg_header_t messageHeader; 
    UInt32 type; 
    UInt32 ref; 
    void *sender; 
} IOAudioNotificationMessage;
Fields
messageHeader

Standard mach message header

ref

The param passed to registerNotificationPort() in refCon.

IOAudioSampleIntervalDescriptor

typedef struct _IOAudioSampleIntervalDescriptor { 
    UInt32 sampleIntervalHi; 
    UInt32 sampleIntervalLo; 
} IOAudioSampleIntervalDescriptor;
Discussion

This structure contains information about a sampling interval.

IOAudioSampleRate

typedef struct _IOAudioSampleRate { 
    UInt32 whole; 
    UInt32 fraction; 
} IOAudioSampleRate;
Discussion

Audio Sample Rate (expressed as a whole part and fractional part)

IOAudioSMPTETime

A structure for holding a SMPTE time.

See Also:

SMPTETime

 
typedef struct _IOAudioSMPTETime { 
    SInt16 fSubframes; 
    SInt16 fSubframeDivisor; 
    UInt32 fCounter; 
    UInt32 fType; 
    UInt32 fFlags; 
    SInt16 fHours; 
    SInt16 fMinutes; 
    SInt16 fSeconds; 
    SInt16 fFrames;  
} IOAudioSMPTETime;
Fields
fSubframes

The number of subframes in the full message.

fSubframeDivisor

The number of subframes per frame (typically 80).

fCounter

The total number of messages received.

fType

The kind of SMPTE time using the SMPTE time type constants.

fFlags

A set of flags that indicate the SMPTE state.

fHours

The number of hourse in the full message.

fMinutes

The number of minutes in the full message.

fSeconds

The number of seconds in the full message.

fFrames

The number of frames in the full message.

IOAudioStreamDataDescriptor

typedef struct _IOAudioStreamDataDescriptor { 
    UInt32 fVersion; 
    UInt32 fNumberOfStreams; 
    UInt32 fStreamLength[1]; // Array with fNumberOfStreams number of entries 
} IOAudioStreamDataDescriptor;
Discussion

This structure contains a description of a block of data containing audio data streams.

IOAudioStreamDirection

Represents the direction of an IOAudioStream 

typedef enum _IOAudioStreamDirection { 
    kIOAudioStreamDirectionOutput = 0, 
    kIOAudioStreamDirectionInput = 1 
} IOAudioStreamDirection;
Constants
kAudioOutput

Output buffer

kAudioInput

Input buffer

IOAudioStreamFormat

typedef struct _IOAudioStreamFormat { 
    UInt32 fNumChannels; 
    UInt32 fSampleFormat; 
    UInt32 fNumericRepresentation; 
    UInt8 fBitDepth; 
    UInt8 fBitWidth; 
    UInt8 fAlignment; 
    UInt8 fByteOrder; 
    UInt8 fIsMixable; 
    UInt32 fDriverTag; 
} IOAudioStreamFormat;
Discussion

This structure describes the format of an audio stream.

IOAudioStreamFormatExtension

typedef struct _IOAudioStreamFormatExtension { 
    UInt32 fVersion; 
    UInt32 fFlags; 
    UInt32 fFramesPerPacket; 
    UInt32 fBytesPerPacket; 
} IOAudioStreamFormatExtension;
Discussion

This structure contains an extension to the audio stream format.

IOAudioTimeStamp

typedef struct _IOAudioTimeStamp { 
    UInt64 fSampleTime;
    UInt64 fHostTime;
    UInt64 fRateScalar;
    UInt64 fWordClockTime;
    IOAudioSMPTETime fSMPTETime;
    UInt32 fFlags;
    UInt32 fReserved;
} IOAudioTimeStamp;
Fields
fSampleTime

the absolute sample time, was a Float64

fHostTime

the host's root timebase's time

fRateScalar

the system rate scalar, was a Float64

fWordClockTime

the word clock time

fSMPTETime

the SMPTE time

fFlags

the flags indicate which fields are valid

fReserved

reserved, pads the structure out to force 8 byte alignment

Discussion

A struct for encapsulating the parts of a time stamp. The flags say which fields are valid.

SMPTETime

A structure for holding a SMPTE time.

See Also:

IOAudioSMPTETime

 
typedef struct _IOAudioSMPTETime { 
    SInt16 fSubframes; 
    SInt16 fSubframeDivisor; 
    UInt32 fCounter; 
    UInt32 fType; 
    UInt32 fFlags; 
    SInt16 fHours; 
    SInt16 fMinutes; 
    SInt16 fSeconds; 
    SInt16 fFrames;  
} IOAudioSMPTETime;
Fields
fSubframes

The number of subframes in the full message.

fSubframeDivisor

The number of subframes per frame (typically 80).

fCounter

The total number of messages received.

fType

The kind of SMPTE time using the SMPTE time type constants.

fFlags

A set of flags that indicate the SMPTE state.

fHours

The number of hourse in the full message.

fMinutes

The number of minutes in the full message.

fSeconds

The number of seconds in the full message.

fFrames

The number of frames in the full message.

Enumerations

IOAudioBidirectionalTerminalTypes

enum { 
    BIDIRECTIONAL_UNDEFINED = 0x0400, 
    BIDIRECTIONAL_HANDSET = 0x0401, 
    BIDIRECTIONAL_HEADSET = 0x0402, 
    BIDIRECTIONAL_SPEAKERPHONE_NO_ECHO_REDX = 0x0403, 
    BIDIRECTIONAL_ECHO_SUPPRESSING_SPEAKERPHONE = 0x0404, 
    BIDIRECTIONAL_ECHO_CANCELING_SPEAKERPHONE = 0x0405 
};
Discussion

Bidirectional terminal types

IOAudioClockSelectorTypes

enum { 
    kIOAudioClockSelectorTypeInternal = 'int ', 
    kIOAudioClockSelectorTypeExternal = 'ext ', 
    kIOAudioClockSelectorTypeAESEBU = 'asbu', 
    kIOAudioClockSelectorTypeTOSLink = 'tosl', 
    kIOAudioClockSelectorTypeSPDIF = 'spdf', 
    kIOAudioClockSelectorTypeADATOptical = 'adto', 
    kIOAudioClockSelectorTypeADAT9Pin = 'adt9', 
    kIOAudioClockSelectorTypeSMPTE = 'smpt', 
    kIOAudioClockSelectorTypeVideo = 'vdeo', 
    kIOAudioClockSelectorTypeControl = 'cnrl', 
    kIOAudioClockSelectorTypeOther = 'othr', 
};
Discussion

This enum contains constants related to getting or setting the clock source for an audio interface.

IOAudioControlChannelIDValues

enum { 
    kIOAudioControlChannelNumberInactive = -1, 
    kIOAudioControlChannelIDAll = 0, 
    kIOAudioControlChannelIDDefaultLeft = 1, 
    kIOAudioControlChannelIDDefaultRight = 2, 
    kIOAudioControlChannelIDDefaultCenter = 3, 
    kIOAudioControlChannelIDDefaultLeftRear = 4, 
    kIOAudioControlChannelIDDefaultRightRear = 5, 
    kIOAudioControlChannelIDDefaultSub = 6 
};
Discussion

This enum contains standard audio control channel ID values.

IOAudioControlSubtypes

enum { 
    kIOAudioLevelControlSubTypeVolume = 'vlme', 
    kIOAudioLevelControlSubTypeLFEVolume = 'subv', 
    kIOAudioLevelControlSubTypePRAMVolume = 'pram', 
    kIOAudioToggleControlSubTypeMute = 'mute', 
    kIOAudioToggleControlSubTypeSolo = 'solo', 
    kIOAudioToggleControlSubTypeLFEMute = 'subm', 
    kIOAudioToggleControlSubTypeiSubAttach = 'atch', 
    kIOAudioSelectorControlSubTypeOutput = 'outp', 
    kIOAudioSelectorControlSubTypeInput = 'inpt', 
    kIOAudioSelectorControlSubTypeClockSource = 'clck', 
    kIOAudioSelectorControlSubTypeDestination = 'dest', 
    kIOAudioSelectorControlSubTypeChannelNominalLineLevel = 'nlev', 
    kIOAudioSelectorControlSubTypeChannelLevelPlus4dBu = '4dbu', 
    kIOAudioSelectorControlSubTypeChannelLevelMinus10dBV = '10db', 
    kIOAudioSelectorControlSubTypeChannelLevelMinus20dBV = '20db', 
    kIOAudioSelectorControlSubTypeChannelLevelMicLevel = 'micl', 
    kIOAudioSelectorControlSubTypeChannelLevelInstrumentLevel = 'istl' 
};
Discussion

This enum contains the standard audio control subtypes.

IOAudioControlTypes

enum { 
    kIOAudioControlTypeLevel = 'levl', 
    kIOAudioControlTypeToggle = 'togl', 
    kIOAudioControlTypeJack = 'jack', 
    kIOAudioControlTypeSelector = 'slct' 
};
Discussion

This enum contains the built-in audio controls.

IOAudioControlUsageValues

enum { 
    kIOAudioControlUsageOutput = 'outp', 
    kIOAudioControlUsageInput = 'inpt', 
    kIOAudioControlUsagePassThru = 'pass', 
    kIOAudioControlUsageCoreAudioProperty = 'prop' 
};
Discussion

This enum contains values that represent the intended usage of an IOAudioControl.

IOAudioDeviceTransportTypes

enum { 
    kIOAudioDeviceTransportTypeBuiltIn = 'bltn', 
    kIOAudioDeviceTransportTypePCI = 'pci ', 
    kIOAudioDeviceTransportTypeUSB = 'usb ', 
    kIOAudioDeviceTransportTypeFireWire = '1394', 
    kIOAudioDeviceTransportTypeNetwork = 'ntwk', 
    kIOAudioDeviceTransportTypeWireless = 'wrls', 
    kIOAudioDeviceTransportTypeOther = 'othr', 
    kIOAudioDeviceTransportTypeBluetooth = 'blue', 
    kIOAudioDeviceTransportTypeVirtual = 'virt' 
};
Discussion

Device connection types

IOAudioDeviceUsageFlags

enum { 
    kIOAudioDeviceCanBeDefaultNothing = 0, 
    kIOAudioDeviceCanBeDefaultInput = (
        1L << 0), 
    kIOAudioDeviceCanBeDefaultOutput = (
        1L << 1), 
    kIOAudioDeviceCanBeSystemOutput = (
        1L << 2) 
};
Discussion

Flags that control how an audio device can be used.

IOAudioEmbeddedTerminalTypes

enum { 
    EMBEDDED_UNDEFINED = 0x0700, 
    EMBEDDED_LEVEL_CALIBRATION_NOISE_SOURCE = 0x0701, 
    EMBEDDED_EQUALIZATION_NOISE = 0x0702, 
    EMBEDDED_CD_PLAYER = 0x0703, 
    EMBEDDED_DAT = 0x0704, 
    EMBEDDED_DCC = 0x0705, 
    EMBEDDED_MINIDISK = 0x0706, 
    EMBEDDED_ANALOG_TAPE = 0x0707, 
    EMBEDDED_PHONOGRAPH = 0x0708, 
    EMBEDDED_VCR_AUDIO = 0x0709, 
    EMBEDDED_VIDEO_DISC_AUDIO = 0x070A, 
    EMBEDDED_DVD_AUDIO = 0x070B, 
    EMBEDDED_TV_TUNER_AUDIO = 0x070C, 
    EMBEDDED_SATELLITE_RECEIVER_AUDIO = 0x070D, 
    EMBEDDED_CABLE_TUNER_AUDIO = 0x070E, 
    EMBEDDED_DSS_AUDIO = 0x070F, 
    EMBEDDED_RADIO_RECEIVER = 0x0710, 
    EMBEDDED_RADIO_TRANSMITTER = 0x0711, 
    EMBEDDED_MULTITRACK_RECORDER = 0x0712, 
    EMBEDDED_SYNTHESIZER = 0x0713 
};
Discussion

Embedded terminal types

IOAudioExternalTerminalTypes

enum { 
    EXTERNAL_UNDEFINED = 0x0600, 
    EXTERNAL_ANALOG_CONNECTOR = 0x0601, 
    EXTERNAL_DIGITAL_AUDIO_INTERFACE = 0x0602, 
    EXTERNAL_LINE_CONNECTOR = 0x0603, 
    EXTERNAL_LEGACY_AUDIO_CONNECTOR = 0x0604, 
    EXTERNAL_SPDIF_INTERFACE = 0x0605, 
    EXTERNAL_1394_DA_STREAM = 0x0606, 
    EXTERNAL_1394_DV_STREAM_SOUNDTRACK = 0x0607, 
    EXTERNAL_ADAT = 0x0608, 
    EXTERNAL_TDIF = 0x0609, 
    EXTERNAL_MADI = 0x060A 
};
Discussion

External terminal types

IOAudioInputTerminalTypes

enum { 
    INPUT_UNDEFINED = 0x0200, 
    INPUT_MICROPHONE = 0x0201, 
    INPUT_DESKTOP_MICROPHONE = 0x0202, 
    INPUT_PERSONAL_MICROPHONE = 0x0203, 
    INPUT_OMNIDIRECTIONAL_MICROPHONE = 0x0204, 
    INPUT_MICROPHONE_ARRAY = 0x0205, 
    INPUT_PROCESSING_MICROPHONE_ARRAY = 0x0206, 
    INPUT_MODEM_AUDIO = 0x207 
};
Discussion

Input terminal types

IOAudioNullTerminal Types

enum { 
    OUTPUT_NULL = 0x0100, 
    INPUT_NULL = 0x0101 
};
Discussion

types that go nowhere

IOAudioOutputTerminalTypes

enum { 
    OUTPUT_UNDEFINED = 0x0300, 
    OUTPUT_SPEAKER = 0x0301, 
    OUTPUT_HEADPHONES = 0x0302, 
    OUTPUT_HEAD_MOUNTED_DISPLAY_AUDIO = 0x0303, 
    OUTPUT_DESKTOP_SPEAKER = 0x0304, 
    OUTPUT_ROOM_SPEAKER = 0x0305, 
    OUTPUT_COMMUNICATION_SPEAKER = 0x0306, 
    OUTPUT_LOW_FREQUENCY_EFFECTS_SPEAKER = 0x0307 
};
Discussion

Output terminal types

IOAudioPortSubtypes

enum { 
    kIOAudioOutputPortSubTypeInternalSpeaker = 'ispk', 
    kIOAudioOutputPortSubTypeExternalSpeaker = 'espk', 
    kIOAudioOutputPortSubTypeHeadphones = 'hdpn', 
    kIOAudioOutputPortSubTypeLine = 'line', 
    kIOAudioOutputPortSubTypeSPDIF = 'spdf',  
    kIOAudioInputPortSubTypeInternalMicrophone = 'imic', 
    kIOAudioInputPortSubTypeExternalMicrophone = 'emic', 
    kIOAudioInputPortSubTypeCD = 'cd ', 
    kIOAudioInputPortSubTypeLine = 'line', 
    kIOAudioInputPortSubTypeSPDIF = 'spdf' 
};
Discussion

This enum contains subtypes for audio input and output ports.

IOAudioPortTypes

enum { 
    kIOAudioPortTypeOutput = 'outp', 
    kIOAudioPortTypeInput = 'inpt', 
    kIOAudioPortTypeMixer = 'mixr', 
    kIOAudioPortTypePassThru = 'pass', 
    kIOAudioPortTypeProcessing = 'proc' 
};
Discussion

This enum contains audio port types.

IOAudioProcessingTerminalTypes

enum { 
    PROCESSOR_UNDEFINED = 0x0800, 
    PROCESSOR_GENERAL = 0x0801 
};
Discussion

Processing terminal types

IOAudioSampleFormats

enum { 
    kIOAudioStreamSampleFormatLinearPCM = 'lpcm', 
    kIOAudioStreamSampleFormatIEEEFloat = 'ieee', 
    kIOAudioStreamSampleFormatALaw = 'alaw', 
    kIOAudioStreamSampleFormatMuLaw = 'ulaw', 
    kIOAudioStreamSampleFormatMPEG = 'mpeg', 
    kIOAudioStreamSampleFormatAC3 = 'ac-3', 
    kIOAudioStreamSampleFormat1937AC3 = 'cac3', 
    kIOAudioStreamSampleFormat1937MPEG1 = 'mpg1', 
    kIOAudioStreamSampleFormat1937MPEG2 = 'mpg2', 
    kIOAudioStreamSampleFormatTimeCode = 'time' // a stream of IOAudioTimeStamp structures that capture any incoming time code information 
};
Discussion

This enum contains constants to indicate the sample format for an audio stream.

IOAudioSelectorControlValues

enum { 
    kIOAudioSelectorControlSelectionValueNone = 'none',  
    // Output-specific selection IDs 
    kIOAudioSelectorControlSelectionValueInternalSpeaker = 'ispk', 
    kIOAudioSelectorControlSelectionValueExternalSpeaker = 'espk', 
    kIOAudioSelectorControlSelectionValueHeadphones = 'hdpn',  
    // Input-specific selection IDs 
    kIOAudioSelectorControlSelectionValueInternalMicrophone = 'imic', 
    kIOAudioSelectorControlSelectionValueExternalMicrophone = 'emic', 
    kIOAudioSelectorControlSelectionValueCD = 'cd ',  
    // Common selection IDs 
    kIOAudioSelectorControlSelectionValueLine = 'line', 
    kIOAudioSelectorControlSelectionValueSPDIF = 'spdf' 
};
Discussion

This enum contains standard selector control values. These are primarily used by the audio family itself.

IOAudioSMPTEFlags

enum { 
    kIOAudioSMPTETimeValid = (
        1L << 0),
    kIOAudioSMPTETimeRunning = (
        1L << 1) 
};
Constants
kIOAudioSMPTETimeValid

the full time is valid

kIOAudioSMPTETimeRunning

time is running

Discussion

flags describing a SMPTE time stamp

IOAudioSMPTETypes

enum { 
    kIOAudioSMPTETimeType24 = 0, 
    kIOAudioSMPTETimeType25 = 1, 
    kIOAudioSMPTETimeType30Drop = 2, 
    kIOAudioSMPTETimeType30 = 3, 
    kIOAudioSMPTETimeType2997 = 4, 
    kIOAudioSMPTETimeType2997Drop = 5 
};
Discussion

constants describing SMPTE types (taken from the MTC spec)

IOAudioStreamAlignments

enum { 
    kIOAudioStreamAlignmentLowByte = 0, 
    kIOAudioStreamAlignmentHighByte = 1 
};
Discussion

This enum contains constants to describe whether an audio data format that contains padding (such as a 24-bit stream stored as a series of 32-bit integers) is aligned to the bottom or top of the encapsulating data word

IOAudioStreamByteOrder

enum { 
    kIOAudioStreamByteOrderBigEndian = 0, 
    kIOAudioStreamByteOrderLittleEndian = 1 
};
Discussion

This enum contains byte order constants to describe an audio stream.

IOAudioStreamNumericRepresentations

enum { 
    kIOAudioStreamNumericRepresentationSignedInt = 'sint', 
    kIOAudioStreamNumericRepresentationUnsignedInt = 'uint', 
    kIOAudioStreamNumericRepresentationIEEE754Float = 'flot' 
};
Discussion

This enum contains constants to indicate the underlying numeric data format for an uncompressed audio stream.

IOAudioTelephonyTerminalTypes

enum { 
    TELEPHONY_UNDEFINED = 0x0500, 
    TELEPHONY_PHONE_LINE = 0x0501, 
    TELEPHONY_TELEPHONE = 0x0502, 
    TELEPHONY_DOWN_LINE_PHONE = 0x0503 
};
Discussion

Telephony terminal types

IOAudioTimeStampValidValueCombinations

enum { 
    kIOAudioTimeStampSampleHostTimeValid = (
        kIOAudioTimeStampSampleTimeValid | kIOAudioTimeStampHostTimeValid) 
};
Discussion

Some commonly used combinations of timestamp flags

IOAudioTimeStampValidValues

enum { 
    kIOAudioTimeStampSampleTimeValid = (
        1L << 0), 
    kIOAudioTimeStampHostTimeValid = (
        1L << 1), 
    kIOAudioTimeStampRateScalarValid = (
        1L << 2), 
    kIOAudioTimeStampWordClockTimeValid = (
        1L << 3), 
    kIOAudioTimeStampSMPTETimeValid = (
        1L << 4) 
};
Discussion

flags for the AudioTimeStamp sturcture

#defines

kIOAudioControlNumCalls

#define kIOAudioControlNumCalls 2
Discussion
The number of elements in the IOAudioControlCalls enum.

kIOAudioEngineDefaultMixBufferSampleSize

#define kIOAudioEngineDefaultMixBufferSampleSize sizeof(float)

kIOAudioEngineNumCalls

#define kIOAudioEngineNumCalls 6
Discussion
The number of elements in the IOAudioEngineCalls enum.


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Last Updated: 2008-12-19