acmMetrics
The acmMetrics
function returns various metrics for the ACM or related ACM objects.
MMRESULT acmMetrics(
HACMOBJ hao, |
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UINT uMetric, |
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LPVOID pMetric |
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); |
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Parameters
hao
Handle of the
ACM object to query for the metric specified in uMetric. For some
queries, this parameter can be NULL.
uMetric
Metric index
to be returned in pMetric.
ACM_METRIC_COUNT_CODECS
Returned
value is the number of global ACM compressor or decompressor drivers in the
system. The hao parameter must be NULL for this metric index. The pMetric
parameter must point to a buffer of a size equal to a doubleword value.
ACM_METRIC_COUNT_CONVERTERS
Returned
value is the number of global ACM converter drivers in the system. The hao
parameter must be NULL for this metric index. The pMetric parameter must
point to a buffer of a size equal to a doubleword value.
ACM_METRIC_COUNT_DISABLED
Returned
value is the total number of global disabled ACM drivers (of all support types)
in the system. The hao parameter must be NULL for this metric index. The
pMetric parameter must point to a buffer of a size equal to a doubleword
value. The sum of the ACM_METRIC_COUNT_DRIVERS and ACM_METRIC_COUNT_DISABLED
metric indices is the total number of globally installed ACM drivers.
ACM_METRIC_COUNT_DRIVERS
Returned
value is the total number of enabled global ACM drivers (of all support types)
in the system. The hao parameter must be NULL for this metric index. The
pMetric parameter must point to a buffer of a size equal to a doubleword
value.
ACM_METRIC_COUNT_FILTERS
Returned
value is the number of global ACM filter drivers in the system. The hao
parameter must be NULL for this metric index. The pMetric parameter must
point to a buffer of a size equal to a doubleword value.
ACM_METRIC_COUNT_HARDWARE
Returned
value is the number of global ACM hardware drivers in the system. The hao
parameter must be NULL for this metric index. The pMetric parameter must
point to a buffer of a size equal to a doubleword value.
ACM_METRIC_COUNT_LOCAL_CODECS
Returned
value is the number of local ACM compressor drivers, ACM decompressor drivers,
or both for the calling task. The hao parameter must be NULL for this
metric index. The pMetric parameter must point to a buffer of a size
equal to a doubleword value.
ACM_METRIC_COUNT_LOCAL_CONVERTERS
Returned
value is the number of local ACM converter drivers for the calling task. The hao
parameter must be NULL for this metric index. The pMetric parameter must
point to a buffer of a size equal to a doubleword value.
ACM_METRIC_COUNT_LOCAL_DISABLED
Returned
value is the total number of local disabled ACM drivers, of all support types,
for the calling task. The hao parameter must be NULL for this metric
index. The pMetric parameter must point to a buffer of a size equal to a
doubleword value. The sum of the ACM_METRIC_COUNT_LOCAL_DRIVERS and
ACM_METRIC_COUNT_LOCAL_DISABLED metric indices is the total number of locally
installed ACM drivers.
ACM_METRIC_COUNT_LOCAL_DRIVERS
Returned
value is the total number of enabled local ACM drivers (of all support types)
for the calling task. The hao parameter must be NULL for this metric
index. The pMetric parameter must point to a buffer of a size equal to a
doubleword value.
ACM_METRIC_COUNT_LOCAL_FILTERS
Returned
value is the number of local ACM filter drivers for the calling task. The hao
parameter must be NULL for this metric index. The pMetric parameter must
point to a buffer of a size equal to a doubleword value.
ACM_METRIC_DRIVER_PRIORITY
Returned
value is the current priority for the specified driver. The hao parameter
must be a valid ACM driver identifier of the HACMDRIVERID data type. The
pMetric parameter must point to a buffer of a size equal to a doubleword
value.
ACM_METRIC_DRIVER_SUPPORT
Returned
value is the fdwSupport flags for the specified driver. The hao
parameter must be a valid ACM driver identifier of the HACMDRIVERID data
type. The pMetric parameter must point to a buffer of a size equal to a
doubleword value.
ACM_METRIC_HARDWARE_WAVE_INPUT
Returned
value is the waveform-audio input device identifier associated with the
specified driver. The hao parameter must be a valid ACM driver
identifier of the HACMDRIVERID data type that supports the
ACMDRIVERDETAILS_SUPPORTF_HARDWARE flag. If no waveform-audio input device is
associated with the driver, MMSYSERR_NOTSUPPORTED is returned. The pMetric
parameter must point to a buffer of a size equal to a doubleword value.
ACM_METRIC_HARDWARE_WAVE_OUTPUT
Returned
value is the waveform-audio output device identifier associated with the
specified driver. The hao parameter must be a valid ACM driver
identifier of the HACMDRIVERID data type that supports the
ACMDRIVERDETAILS_SUPPORTF_HARDWARE flag. If no waveform-audio output device is
associated with the driver, MMSYSERR_NOTSUPPORTED is returned. The pMetric
parameter must point to a buffer of a size equal to a doubleword value.
ACM_METRIC_MAX_SIZE_FILTER
Returned
value is the size of the largest WAVEFILTER
ACM_METRIC_MAX_SIZE_FORMAT
Returned
value is the size of the largest WAVEFORMATEX2R_J_MS structure. If hao is NULL, the
return value is the largest WAVEFORMATEX structure in the system. If hao
identifies an open instance of an ACM driver of the HACMDRIVER data type
or an ACM driver identifier of the HACMDRIVERID data type, the largest WAVEFORMATEX
structure for that driver is returned. The pMetric parameter must point
to a buffer of a size equal to a doubleword value. This metric is not allowed
for an ACM stream handle of the HACMSTREAM data type.
pMetric
Address of
the buffer to receive the metric details. The exact definition depends on the uMetric
index.
Return Values
Returns zero
if successful or an error otherwise. Possible error values include the
following:
ACMERR_NOTPOSSIBLE |
The index
specified in uMetric cannot be returned for the specified hao. |
MMSYSERR_INVALHANDLE |
The
specified handle is invalid. |
MMSYSERR_INVALPARAM |
At least
one parameter is invalid. |
MMSYSERR_NOTSUPPORTED |
The index
specified in uMetric is not supported. |
See Also