#include <IOKit/audio/IOAudioTypes.h>
IOKit/audio/IOAudioTypes.h Kernel.framework
37 enums · 18 typedefs · 10 macros · 10 structs
@enum IOAudioEngineMemory
@abstract Used to identify the type of memory requested by a client process to be mapped into its process space
@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.
@constant kIOAudioSampleBuffer This requests the IOAudioEngine's sample buffer
@constant kIOAudioStatusBuffer This requests the IOAudioEngine's status buffer. It's type is IOAudioEngineStatus.
@constant kIOAudioMixBuffer This requests the IOAudioEngine's mix buffer
underlying type unsigned int
| kIOAudioStatusBuffer | 0 | |
| kIOAudioSampleBuffer | 1 | |
| kIOAudioMixBuffer | 2 | |
| kIOAudioBytesInInputBuffer | 3 | |
| kIOAudioBytesInOutputBuffer | 4 | |
@enum IOAudioEngineCalls
@abstract The set of constants passed to IOAudioEngineUserClient::getExternalMethodForIndex() when making calls
from the IOAudioFamily user client code.
underlying type unsigned int
| kIOAudioEngineCallRegisterClientBuffer | 0 | |
| kIOAudioEngineCallUnregisterClientBuffer | 1 | |
| kIOAudioEngineCallGetConnectionID | 2 | |
| kIOAudioEngineCallStart | 3 | |
| kIOAudioEngineCallStop | 4 | |
| kIOAudioEngineCallGetNearestStartTime | 5 | |
@defined kIOAudioEngineNumCalls The number of elements in the IOAudioEngineCalls enum.
#define kIOAudioEngineNumCalls 6
underlying type unsigned int
| kIOAudioEngineTrapPerformClientIO | 0 | |
underlying type unsigned int
| kIOAudioEngineAllNotifications | 0 | |
| kIOAudioEngineStreamFormatChangeNotification | 1 | |
| kIOAudioEngineChangeNotification | 2 | |
| kIOAudioEngineStartedNotification | 3 | |
| kIOAudioEngineStoppedNotification | 4 | |
| kIOAudioEnginePausedNotification | 5 | |
| kIOAudioEngineResumedNotification | 6 | |
underlying type unsigned int
| kIOAudioEngineStopped | 0 | |
| kIOAudioEngineRunning | 1 | |
| kIOAudioEnginePaused | 2 | |
| kIOAudioEngineResumed | 3 | |
#define kIOAudioEngineCurrentStatusStructVersion 2
#define kFormatExtensionInvalidVersion 0
#define kFormatExtensionCurrentVersion 1
#define kStreamDataDescriptorInvalidVersion 0
#define kStreamDataDescriptorCurrentVersion 1
size 12, align 4
| UInt32 | fVersion | |
| UInt32 | fNumberOfStreams | |
| UInt32[1] | fStreamLength | Array with fNumberOfStreams number of entries |
@struct SMPTETime
@abstract A structure for holding a SMPTE time.
@field fSubframes
The number of subframes in the full message.
@field fSubframeDivisor
The number of subframes per frame (typically 80).
@field fCounter
The total number of messages received.
@field fType
The kind of SMPTE time using the SMPTE time type constants.
@field fFlags
A set of flags that indicate the SMPTE state.
@field fHours
The number of hourse in the full message.
@field fMinutes
The number of minutes in the full message.
@field fSeconds
The number of seconds in the full message.
@field fFrames
The number of frames in the full message.
size 24, align 4
constants describing SMPTE types (taken from the MTC spec), <rdar://11955717>
underlying type unsigned int
| kIOAudioSMPTETimeType24 | 0 | |
| kIOAudioSMPTETimeType25 | 1 | |
| kIOAudioSMPTETimeType30Drop | 2 | |
| kIOAudioSMPTETimeType30 | 3 | |
| kIOAudioSMPTETimeType2997 | 4 | |
| kIOAudioSMPTETimeType2997Drop | 5 | |
| kIOAudioSMPTETimeType60 | 6 | |
| kIOAudioSMPTETimeType5994 | 7 | |
| kIOAudioSMPTETimeType60Drop | 8 | |
| kIOAudioSMPTETimeType5994Drop | 9 | |
| kIOAudioSMPTETimeType50 | 10 | |
| kIOAudioSMPTETimeType2398 | 11 | |
flags describing a SMPTE time stamp
underlying type unsigned int
| kIOAudioSMPTETimeValid | 1 | the full time is valid |
| kIOAudioSMPTETimeRunning | 2 | time is running |
A struct for encapsulating the parts of a time stamp. The flags
say which fields are valid.
size 64, align 8
| UInt64 | fSampleTime | the absolute sample time, was a Float64 |
| UInt64 | fHostTime | the host's root timebase's time |
| UInt64 | fRateScalar | the system rate scalar, was a Float64 |
| UInt64 | fWordClockTime | the word clock time |
| IOAudioSMPTETime | fSMPTETime | the SMPTE time |
| UInt32 | fFlags | the flags indicate which fields are valid |
| UInt32 | fReserved | reserved, pads the structure out to force 8 byte alignment |
flags for the AudioTimeStamp sturcture
underlying type unsigned int
| kIOAudioTimeStampSampleTimeValid | 1 | |
| kIOAudioTimeStampHostTimeValid | 2 | |
| kIOAudioTimeStampRateScalarValid | 4 | |
| kIOAudioTimeStampWordClockTimeValid | 8 | |
| kIOAudioTimeStampSMPTETimeValid | 16 | |
Some commonly used combinations of timestamp flags
underlying type unsigned int
| kIOAudioTimeStampSampleHostTimeValid | 3 | |
underlying type unsigned int
| kIOAudioStreamDirectionOutput | 0 | |
| kIOAudioStreamDirectionInput | 1 | |
underlying type unsigned int
| kIOAudioDeviceCanBeDefaultNothing | 0 | |
| kIOAudioDeviceCanBeDefaultInput | 1 | |
| kIOAudioDeviceCanBeDefaultOutput | 2 | |
| kIOAudioDeviceCanBeSystemOutput | 4 | |
#define kIOAudioEngineDefaultMixBufferSampleSize sizeof(float)
@enum IOAudioControlCalls
@abstract The set of constants passed to IOAudioControlUserClient::getExternalMethodForIndex() when making calls
from the IOAudioFamily user client code.
@constant kIOAudioControlCallSetValue Used to set the value of an IOAudioControl.
@constant kIOAudioControlCallGetValue Used to get the value of an IOAudioControl.
underlying type unsigned int
| kIOAudioControlCallSetValue | 0 | |
| kIOAudioControlCallGetValue | 1 | |
@defined kIOAudioControlNumCalls The number of elements in the IOAudioControlCalls enum.
#define kIOAudioControlNumCalls 2
@enum IOAudioControlNotifications
@abstract The set of constants passed in the type field of IOAudioControlUserClient::registerNotificaitonPort().
@constant kIOAudioControlValueChangeNotification Used to request value change notifications.
@constant kIOAudioControlRangeChangeNotification Used to request range change notifications.
underlying type unsigned int
| kIOAudioControlValueChangeNotification | 0 | |
| kIOAudioControlRangeChangeNotification | 1 | |
@struct IOAudioNotificationMessage
@abstract Used in the mach message for IOAudio notifications.
@field messageHeader Standard mach message header
@field ref The param passed to registerNotificationPort() in refCon.
size 48, align 8
#define kNoIdleAudioPowerDown 0xffffffffffffffffULL
underlying type unsigned int
| kIOAudioPortTypeOutput | 1869968496 | |
| kIOAudioPortTypeInput | 1768845428 | |
| kIOAudioPortTypeMixer | 1835628658 | |
| kIOAudioPortTypePassThru | 1885434739 | |
| kIOAudioPortTypeProcessing | 1886547811 | |
underlying type unsigned int
| kIOAudioOutputPortSubTypeInternalSpeaker | 1769173099 | |
| kIOAudioOutputPortSubTypeExternalSpeaker | 1702064235 | |
| kIOAudioOutputPortSubTypeHeadphones | 1751412846 | |
| kIOAudioOutputPortSubTypeLine | 1818848869 | |
| kIOAudioOutputPortSubTypeSPDIF | 1936745574 | |
| kIOAudioInputPortSubTypeInternalMicrophone | 1768778083 | |
| kIOAudioInputPortSubTypeExternalMicrophone | 1701669219 | |
| kIOAudioInputPortSubTypeCD | 1667506208 | |
| kIOAudioInputPortSubTypeLine | 1818848869 | |
| kIOAudioInputPortSubTypeSPDIF | 1936745574 | |
underlying type unsigned int
| kIOAudioControlTypeLevel | 1818588780 | |
| kIOAudioControlTypeToggle | 1953458028 | |
| kIOAudioControlTypeJack | 1784767339 | |
| kIOAudioControlTypeSelector | 1936483188 | |
<rdar://8325563> Added kIOAudioToggleControlSubTypePhantomPower, kIOAudioToggleControlSubTypePhaseInvert &
kIOAudioSelectorControlSubTypeChannelHighPassFilter
underlying type unsigned int
| kIOAudioLevelControlSubTypeVolume | 1986817381 | |
| kIOAudioLevelControlSubTypeLFEVolume | 1937072758 | |
| kIOAudioLevelControlSubTypePRAMVolume | 1886544237 | |
| kIOAudioToggleControlSubTypeMute | 1836414053 | |
| kIOAudioToggleControlSubTypeSolo | 1936682095 | |
| kIOAudioToggleControlSubTypeLFEMute | 1937072749 | |
| kIOAudioToggleControlSubTypeiSubAttach | 1635017576 | |
| kIOAudioToggleControlSubTypePhantomPower | 1885888878 | |
| kIOAudioToggleControlSubTypePhaseInvert | 1885893481 | |
| kIOAudioSelectorControlSubTypeOutput | 1869968496 | |
| kIOAudioSelectorControlSubTypeInput | 1768845428 | |
| kIOAudioSelectorControlSubTypeClockSource | 1668047723 | |
| kIOAudioSelectorControlSubTypeDestination | 1684370292 | |
| kIOAudioSelectorControlSubTypeChannelNominalLineLevel | 1852597622 | |
| kIOAudioSelectorControlSubTypeChannelLevelPlus4dBu | 878994037 | |
| kIOAudioSelectorControlSubTypeChannelLevelMinus10dBV | 825255010 | |
| kIOAudioSelectorControlSubTypeChannelLevelMinus20dBV | 842032226 | |
| kIOAudioSelectorControlSubTypeChannelLevelMicLevel | 1835623276 | |
| kIOAudioSelectorControlSubTypeChannelLevelInstrumentLevel | 1769174124 | |
| kIOAudioSelectorControlSubTypeChannelHighPassFilter | 1751740518 | |
underlying type unsigned int
| kIOAudioControlUsageOutput | 1869968496 | |
| kIOAudioControlUsageInput | 1768845428 | |
| kIOAudioControlUsagePassThru | 1885434739 | |
| kIOAudioControlUsageCoreAudioProperty | 1886547824 | |
underlying type int
| kIOAudioControlChannelNumberInactive | -1 | |
| kIOAudioControlChannelIDAll | 0 | |
| kIOAudioControlChannelIDDefaultLeft | 1 | |
| kIOAudioControlChannelIDDefaultRight | 2 | |
| kIOAudioControlChannelIDDefaultCenter | 3 | |
| kIOAudioControlChannelIDDefaultLeftRear | 4 | |
| kIOAudioControlChannelIDDefaultRightRear | 5 | |
| kIOAudioControlChannelIDDefaultSub | 6 | |
| kIOAudioControlChannelIDDefaultFrontLeftCenter | 7 | |
| kIOAudioControlChannelIDDefaultFrontRightCenter | 8 | |
| kIOAudioControlChannelIDDefaultRearCenter | 9 | |
| kIOAudioControlChannelIDDefaultSurroundLeft | 10 | |
| kIOAudioControlChannelIDDefaultSurroundRight | 11 | |
underlying type unsigned int
| kIOAudioSelectorControlSelectionValueNone | 1852796517 | |
| kIOAudioSelectorControlSelectionValueInternalSpeaker | 1769173099 | Output-specific selection IDs |
| kIOAudioSelectorControlSelectionValueExternalSpeaker | 1702064235 | |
| kIOAudioSelectorControlSelectionValueHeadphones | 1751412846 | |
| kIOAudioSelectorControlSelectionValueInternalMicrophone | 1768778083 | Input-specific selection IDs |
| kIOAudioSelectorControlSelectionValueExternalMicrophone | 1701669219 | |
| kIOAudioSelectorControlSelectionValueCD | 1667506208 | |
| kIOAudioSelectorControlSelectionValueLine | 1818848869 | Common selection IDs |
| kIOAudioSelectorControlSelectionValueSPDIF | 1936745574 | |
underlying type unsigned int
| kIOAudioStreamSampleFormatLinearPCM | 1819304813 | |
| kIOAudioStreamSampleFormatIEEEFloat | 1768252773 | |
| kIOAudioStreamSampleFormatALaw | 1634492791 | |
| kIOAudioStreamSampleFormatMuLaw | 1970037111 | |
| kIOAudioStreamSampleFormatMPEG | 1836082535 | |
| kIOAudioStreamSampleFormatAC3 | 1633889587 | |
| kIOAudioStreamSampleFormat1937AC3 | 1667326771 | |
| kIOAudioStreamSampleFormat1937MPEG1 | 1836082993 | |
| kIOAudioStreamSampleFormat1937MPEG2 | 1836082994 | |
| kIOAudioStreamSampleFormatTimeCode | 1953066341 | a stream of IOAudioTimeStamp structures that capture any incoming time code information |
underlying type unsigned int
| kIOAudioStreamNumericRepresentationSignedInt | 1936289396 | |
| kIOAudioStreamNumericRepresentationUnsignedInt | 1969843828 | |
| kIOAudioStreamNumericRepresentationIEEE754Float | 1718382452 | |
underlying type unsigned int
| kIOAudioClockSelectorTypeInternal | 1768846368 | |
| kIOAudioClockSelectorTypeExternal | 1702392864 | |
| kIOAudioClockSelectorTypeAESEBU | 1634951797 | |
| kIOAudioClockSelectorTypeTOSLink | 1953461100 | |
| kIOAudioClockSelectorTypeSPDIF | 1936745574 | |
| kIOAudioClockSelectorTypeADATOptical | 1633973359 | |
| kIOAudioClockSelectorTypeADAT9Pin | 1633973305 | |
| kIOAudioClockSelectorTypeSMPTE | 1936552052 | |
| kIOAudioClockSelectorTypeVideo | 1986291055 | |
| kIOAudioClockSelectorTypeControl | 1668182636 | |
| kIOAudioClockSelectorTypeOther | 1869899890 | |
underlying type unsigned int
| kIOAudioStreamAlignmentLowByte | 0 | |
| kIOAudioStreamAlignmentHighByte | 1 | |
underlying type unsigned int
| kIOAudioStreamByteOrderBigEndian | 0 | |
| kIOAudioStreamByteOrderLittleEndian | 1 | |
underlying type unsigned int
| kIOAudioLevelControlNegativeInfinity | 4294967295 | |
underlying type unsigned int
| kIOAudioBuiltInSystemClockDomain | 7567731 | |
| kIOAudioNewClockDomain | 4294967295 | |
<rdar://7130813> Added kIOAudioDeviceTransportTypeDisplayPort
underlying type unsigned int
| kIOAudioDeviceTransportTypeBuiltIn | 1651274862 | |
| kIOAudioDeviceTransportTypePCI | 1885563168 | |
| kIOAudioDeviceTransportTypeUSB | 1970496032 | |
| kIOAudioDeviceTransportTypeFireWire | 825440564 | |
| kIOAudioDeviceTransportTypeNetwork | 1853126507 | |
| kIOAudioDeviceTransportTypeWireless | 2003987571 | |
| kIOAudioDeviceTransportTypeOther | 1869899890 | |
| kIOAudioDeviceTransportTypeBluetooth | 1651275109 | |
| kIOAudioDeviceTransportTypeVirtual | 1986622068 | |
| kIOAudioDeviceTransportTypeDisplayPort | 1685090932 | |
| kIOAudioDeviceTransportTypeHdmi | 1751412073 | |
| kIOAudioDeviceTransportTypeAVB | 1700886114 | <rdar://10874672> |
| kIOAudioDeviceTransportTypeThunderbolt | 1953002862 | <rdar://10874672> |
types that go nowhere
underlying type unsigned int
| OUTPUT_NULL | 256 | |
| INPUT_NULL | 257 | |
Input terminal types
underlying type unsigned int
| INPUT_UNDEFINED | 512 | |
| INPUT_MICROPHONE | 513 | |
| INPUT_DESKTOP_MICROPHONE | 514 | |
| INPUT_PERSONAL_MICROPHONE | 515 | |
| INPUT_OMNIDIRECTIONAL_MICROPHONE | 516 | |
| INPUT_MICROPHONE_ARRAY | 517 | |
| INPUT_PROCESSING_MICROPHONE_ARRAY | 518 | |
| INPUT_MODEM_AUDIO | 519 | |
Output terminal types
underlying type unsigned int
| OUTPUT_UNDEFINED | 768 | |
| OUTPUT_SPEAKER | 769 | |
| OUTPUT_HEADPHONES | 770 | |
| OUTPUT_HEAD_MOUNTED_DISPLAY_AUDIO | 771 | |
| OUTPUT_DESKTOP_SPEAKER | 772 | |
| OUTPUT_ROOM_SPEAKER | 773 | |
| OUTPUT_COMMUNICATION_SPEAKER | 774 | |
| OUTPUT_LOW_FREQUENCY_EFFECTS_SPEAKER | 775 | |
Bi-directional terminal types
underlying type unsigned int
| BIDIRECTIONAL_UNDEFINED | 1024 | |
| BIDIRECTIONAL_HANDSET | 1025 | |
| BIDIRECTIONAL_HEADSET | 1026 | |
| BIDIRECTIONAL_SPEAKERPHONE_NO_ECHO_REDX | 1027 | |
| BIDIRECTIONAL_ECHO_SUPPRESSING_SPEAKERPHONE | 1028 | |
| BIDIRECTIONAL_ECHO_CANCELING_SPEAKERPHONE | 1029 | |
Telephony terminal types
underlying type unsigned int
| TELEPHONY_UNDEFINED | 1280 | |
| TELEPHONY_PHONE_LINE | 1281 | |
| TELEPHONY_TELEPHONE | 1282 | |
| TELEPHONY_DOWN_LINE_PHONE | 1283 | |
External terminal types
underlying type unsigned int
| EXTERNAL_UNDEFINED | 1536 | |
| EXTERNAL_ANALOG_CONNECTOR | 1537 | |
| EXTERNAL_DIGITAL_AUDIO_INTERFACE | 1538 | |
| EXTERNAL_LINE_CONNECTOR | 1539 | |
| EXTERNAL_LEGACY_AUDIO_CONNECTOR | 1540 | |
| EXTERNAL_SPDIF_INTERFACE | 1541 | |
| EXTERNAL_1394_DA_STREAM | 1542 | |
| EXTERNAL_1394_DV_STREAM_SOUNDTRACK | 1543 | |
| EXTERNAL_ADAT | 1544 | |
| EXTERNAL_TDIF | 1545 | |
| EXTERNAL_MADI | 1546 | |
Embedded terminal types
underlying type unsigned int
| EMBEDDED_UNDEFINED | 1792 | |
| EMBEDDED_LEVEL_CALIBRATION_NOISE_SOURCE | 1793 | |
| EMBEDDED_EQUALIZATION_NOISE | 1794 | |
| EMBEDDED_CD_PLAYER | 1795 | |
| EMBEDDED_DAT | 1796 | |
| EMBEDDED_DCC | 1797 | |
| EMBEDDED_MINIDISK | 1798 | |
| EMBEDDED_ANALOG_TAPE | 1799 | |
| EMBEDDED_PHONOGRAPH | 1800 | |
| EMBEDDED_VCR_AUDIO | 1801 | |
| EMBEDDED_VIDEO_DISC_AUDIO | 1802 | |
| EMBEDDED_DVD_AUDIO | 1803 | |
| EMBEDDED_TV_TUNER_AUDIO | 1804 | |
| EMBEDDED_SATELLITE_RECEIVER_AUDIO | 1805 | |
| EMBEDDED_CABLE_TUNER_AUDIO | 1806 | |
| EMBEDDED_DSS_AUDIO | 1807 | |
| EMBEDDED_RADIO_RECEIVER | 1808 | |
| EMBEDDED_RADIO_TRANSMITTER | 1809 | |
| EMBEDDED_MULTITRACK_RECORDER | 1810 | |
| EMBEDDED_SYNTHESIZER | 1811 | |
Processing terminal types
underlying type unsigned int
| PROCESSOR_UNDEFINED | 2048 | |
| PROCESSOR_GENERAL | 2049 | |
#define kIOAudioChannelLabel_Discrete_field_ba 16
underlying type unsigned int
| kIOAudioChannelLabel_Unknown | 4294967295 | unknown or unspecified other use |
| kIOAudioChannelLabel_Unused | 0 | channel is present, but has no intended use or destination |
| kIOAudioChannelLabel_UseCoordinates | 100 | channel is described by the mCoordinates fields. |
| kIOAudioChannelLabel_Left | 1 | |
| kIOAudioChannelLabel_Right | 2 | |
| kIOAudioChannelLabel_Center | 3 | |
| kIOAudioChannelLabel_LFEScreen | 4 | |
| kIOAudioChannelLabel_LeftSurround | 5 | WAVE: "Back Left" |
| kIOAudioChannelLabel_RightSurround | 6 | WAVE: "Back Right" |
| kIOAudioChannelLabel_LeftCenter | 7 | |
| kIOAudioChannelLabel_RightCenter | 8 | |
| kIOAudioChannelLabel_CenterSurround | 9 | WAVE: "Back Center" or plain "Rear Surround" |
| kIOAudioChannelLabel_LeftSurroundDirect | 10 | WAVE: "Side Left" |
| kIOAudioChannelLabel_RightSurroundDirect | 11 | WAVE: "Side Right" |
| kIOAudioChannelLabel_TopCenterSurround | 12 | |
| kIOAudioChannelLabel_VerticalHeightLeft | 13 | WAVE: "Top Front Left" |
| kIOAudioChannelLabel_VerticalHeightCenter | 14 | WAVE: "Top Front Center" |
| kIOAudioChannelLabel_VerticalHeightRight | 15 | WAVE: "Top Front Right" |
| kIOAudioChannelLabel_TopBackLeft | 16 | |
| kIOAudioChannelLabel_TopBackCenter | 17 | |
| kIOAudioChannelLabel_TopBackRight | 18 | |
| kIOAudioChannelLabel_RearSurroundLeft | 33 | |
| kIOAudioChannelLabel_RearSurroundRight | 34 | |
| kIOAudioChannelLabel_LeftWide | 35 | |
| kIOAudioChannelLabel_RightWide | 36 | |
| kIOAudioChannelLabel_LFE2 | 37 | |
| kIOAudioChannelLabel_LeftTotal | 38 | matrix encoded 4 channels |
| kIOAudioChannelLabel_RightTotal | 39 | matrix encoded 4 channels |
| kIOAudioChannelLabel_HearingImpaired | 40 | |
| kIOAudioChannelLabel_Narration | 41 | |
| kIOAudioChannelLabel_Mono | 42 | |
| kIOAudioChannelLabel_DialogCentricMix | 43 | |
| kIOAudioChannelLabel_CenterSurroundDirect | 44 | back center, non diffuse |
| kIOAudioChannelLabel_Haptic | 45 | |
| kIOAudioChannelLabel_LeftTopFront | 13 | |
| kIOAudioChannelLabel_CenterTopFront | 14 | |
| kIOAudioChannelLabel_RightTopFront | 15 | |
| kIOAudioChannelLabel_LeftTopMiddle | 49 | |
| kIOAudioChannelLabel_CenterTopMiddle | 12 | |
| kIOAudioChannelLabel_RightTopMiddle | 51 | |
| kIOAudioChannelLabel_LeftTopRear | 52 | |
| kIOAudioChannelLabel_CenterTopRear | 53 | |
| kIOAudioChannelLabel_RightTopRear | 54 | |
| kIOAudioChannelLabel_Ambisonic_W | 200 | first order ambisonic channels |
| kIOAudioChannelLabel_Ambisonic_X | 201 | |
| kIOAudioChannelLabel_Ambisonic_Y | 202 | |
| kIOAudioChannelLabel_Ambisonic_Z | 203 | |
| kIOAudioChannelLabel_MS_Mid | 204 | Mid/Side Recording |
| kIOAudioChannelLabel_MS_Side | 205 | |
| kIOAudioChannelLabel_XY_X | 206 | X-Y Recording |
| kIOAudioChannelLabel_XY_Y | 207 | |
| kIOAudioChannelLabel_HeadphonesLeft | 301 | other |
| kIOAudioChannelLabel_HeadphonesRight | 302 | |
| kIOAudioChannelLabel_ClickTrack | 304 | |
| kIOAudioChannelLabel_ForeignLanguage | 305 | |
| kIOAudioChannelLabel_Discrete | 400 | generic discrete channel |
| kIOAudioChannelLabel_Discrete_0 | 65536 | numbered discrete channel |
| kIOAudioChannelLabel_Discrete_1 | 65537 | |
| kIOAudioChannelLabel_Discrete_2 | 65538 | |
| kIOAudioChannelLabel_Discrete_3 | 65539 | |
| kIOAudioChannelLabel_Discrete_4 | 65540 | |
| kIOAudioChannelLabel_Discrete_5 | 65541 | |
| kIOAudioChannelLabel_Discrete_6 | 65542 | |
| kIOAudioChannelLabel_Discrete_7 | 65543 | |
| kIOAudioChannelLabel_Discrete_8 | 65544 | |
| kIOAudioChannelLabel_Discrete_9 | 65545 | |
| kIOAudioChannelLabel_Discrete_10 | 65546 | |
| kIOAudioChannelLabel_Discrete_11 | 65547 | |
| kIOAudioChannelLabel_Discrete_12 | 65548 | |
| kIOAudioChannelLabel_Discrete_13 | 65549 | |
| kIOAudioChannelLabel_Discrete_14 | 65550 | |
| kIOAudioChannelLabel_Discrete_15 | 65551 | |
| kIOAudioChannelLabel_Discrete_65535 | 131071 | |