Structs
This structure describes which streams a given AudioDeviceIOProc will use. It is
used in conjunction with kAudioDevicePropertyIOProcStreamUsage.
struct AudioHardwareIOProcStreamUsage {
void* mIOProc;
UInt32 mNumberStreams;
UInt32 mStreamIsOn[kVariableLengthArray];
} ;
Field Descriptions
- mIOProc
- The IOProc whose stream usage is being specified.
- mNumberStreams
- The number of streams being specified.
- mStreamIsOn
- An array of UInt32's whose length is specified by mNumberStreams. Each
element of the array corresponds to a stream. A value of 0 means the stream
is not to be enabled. Any other value means the stream is to be used.
An AudioObjectPropertyAddress collects the three parts that identify a specific
property together in a struct for easy transmission.
struct AudioObjectPropertyAddress {
AudioObjectPropertySelector mSelector;
AudioObjectPropertyScope mScope;
AudioObjectPropertyElement mElement;
} ;
Field Descriptions
- mSelector
- The AudioObjectPropertySelector for the property.
- mScope
- The AudioObjectPropertyScope for the property.
- mElement
- The AudioObjectPropertyElement for the property.
This structure allows a specific sample rate range to be associated with an
AudioStreamBasicDescription that specifies it's sample rate as
kAudioStreamAnyRate.
struct AudioStreamRangedDescription {
AudioStreamBasicDescription mFormat;
AudioValueRange mSampleRateRange;
} ;
Discussion
Note that this structure is only used to desicribe the the available formats
for a stream. It is not used for the current format.
Field Descriptions
- mFormat
- The AudioStreamBasicDescription that describes the format of the stream.
Note that the mSampleRate field of the structure will be the same as the
the values in mSampleRateRange when only a single sample rate is supported.
It will be kAudioStreamAnyRate when there is a range with more elements.
- mSampleRateRange
- The AudioValueRange that describes the minimum and maximum sample rate for
the stream. If the mSampleRate field of mFormat is kAudioStreamAnyRate the
format supports the range of sample rates described by this structure.
Otherwise, the minimum will be the same as the maximum which will be the
same as the mSampleRate field of mFormat.
(Last Updated 12/13/2004)