MFPKEY_WMAAECMA_DMO_SOURCE_MODE Property
Specifies whether the Voice Capture DSP uses source mode or filter mode.
Constant for IPropertyBag
Available only by using IPropertyStore.
Data Type
VT_BOOL
Default Value
VARIANT_TRUE
Applies To
Remarks
In source mode, the application does not need to send input data to the DSP, because the DSP automatically pulls data from the audio devices. In filter mode, the application must send the input data to the DSP.
This property can have the following values.
| Value | Description |
|---|---|
| VARIANT_FALSE | Filter mode. |
| VARIANT_TRUE | Source mode. |
Note
When the DMO is in source mode, you should only call IMediaObject::SetOutputType to set output stream format, and do not call IMediaObject::SetInputType to set input stream formats. Otherwise DMO initialization will fail.
If the value of this property is VARIANT_TRUE, the DSP has zero inputs. If the value is VARIANT_FALSE, the DSP has one or two inputs, depending on the value of the MFPKEY_WMAAECMA_SYSTEM_MODE property, as shown in the following table.
| Value | Number of inputs |
|---|---|
| OPTIBEAM_ARRAY_AND_AEC | 2 |
| OPTIBEAM_ARRAY_ONLY | 1 |
| SINGLE_CHANNEL_AEC | 2 |
| SINGLE_CHANNEL_NSAGC | 1 |
Note
Only modes with a single input will work with the wrapper filter DMO from the DirectShow 9.0 API.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client |
Windows Vista [desktop apps only] |
| Minimum supported server |
Windows Server 2008 [desktop apps only] |
| Header |
|
See also