ILMMCommon Interface
This interface is exposed by the majority of LEAD filters. The interface provides basic functionality and information common to all filters that expose it.
This interface can be obtained using a direct QueryInterface call on the filter object.
When "getting" a BSTR property, the memory containing the string is allocated with SysAllocString. When this string is no longer needed, free this memory by calling SysFreeString if you are working in an environment such as C or C++ that does not automatically delete the memory. VB automatically deletes the memory, so VB programmers do not need to free the memory themselves.
Interface Properties:
Type |
Property name |
Parameter Description |
Description |
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BSTR |
FilterName |
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Contains the friendly name of the filter. A note about BSTR properties. |
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long |
FilterState |
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Indicates the current filter state. Possible values are: |
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Value |
Description |
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0 |
The filter is stopped. |
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1 |
The filter is paused. |
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2 |
The filter is running. |
long |
InputPinsCount |
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Contains the number of input pins on the filter. |
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long |
OutputPinsCount |
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Contains the number of output pins on the filter. |
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BSTR |
InputPinName (long nPinIndex) |
The zero based index of the input pin to retrieve its name. |
Contains the name of the input pin at the specified index. A note about BSTR properties. |
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BSTR |
OutputPinName (long nPinIndex) |
The zero based index of the output pin to retrieve its name. |
Contains the name of the output pin at the specified index. A note about BSTR properties. |
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BOOL |
IsLEADInputPinConnected (long nPinIndex) |
The zero based index of the input pin to check its connection state. |
Indicates whether the input pin at the specified index is connected to another pin. |
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BOOL |
IsLEADOutputPinConnected (long nPinIndex) |
The zero based index of the output pin to check its connection state. |
Indicates whether the output pin at the specified index is connected to another pin. |
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long |
InputPinStreamType (long nPinIndex) |
The zero based index of the input pin to retrieve its stream type. |
Contains the stream type of the input pin at the specified index. Possible values are: |
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Value |
Meaning |
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AudioStream |
[0] The stream type currently used is audio. |
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VideoStream |
[1] The stream type currently used is video. |
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TextStream |
[2] The stream type currently used is text. |
long |
OutputPinStreamType (long nPinIndex) |
The zero based index of the output pin to retrieve its stream type. |
Indicates the stream type of the output pin at the specified index. Possible values are: |
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Value |
Meaning |
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AudioStream |
[0] The stream type currently used is audio. |
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VideoStream |
[1] The stream type currently used is video. |
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TextStream |
[2] The stream type currently used is text. |
long |
InWidth (long nPinIndex) |
The zero based index of the input pin to retrieve its connected video width. |
Indicates the video width for the input pin at the specified index. (Applicable for video streams only). |
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long |
InHeight (long nPinIndex) |
The zero based index of the input pin to retrieve its connected video height. |
Indicates the video height for the input pin at the specified index. (Applicable for video streams only). |
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long |
OutWidth (long nPinIndex) |
The zero based index of the output pin to retrieve its connected video width. |
Indicates the video width for the output pin at the specified index. (Applicable for video streams only). |
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long |
OutHeight (long nPinIndex) |
The zero based index of the output pin to retrieve its connected video height. |
Indicates the video height for the output pin at the specified index. (Applicable for video streams only). |
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long |
InBits (long nPinIndex) |
The zero based index of the input pin to retrieve its connected video bits per pixel. |
Indicates the bits per pixel value of the video stream for the input pin at the specified index. (Applicable for video streams only). |
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long |
OutBits (long nPinIndex) |
The zero based index of the output pin to retrieve its connected video bits per pixel. |
Indicates the bits per pixel value of the video stream for the output pin at the specified index. (Applicable for video streams only). |
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long |
InChannels (long nPinIndex) |
The zero based index of the input pin to retrieve the number of channels for the connected audio stream. |
Indicates the number of channels for the input pin at the specified index (Applicable for audio streams only). |
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long |
OutChannels (long nPinIndex) |
The zero based index of the output pin to retrieve the number of channels for the connected audio stream. |
Indicates the number of channels for the output pin at the specified index (Applicable for audio streams only). |
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long |
InBitsPerSample (long nPinIndex) |
The zero based index of the input pin to retrieve the bits per sample value for the connected audio stream. |
Indicates the bits per sample value for the input pin at the specified index. (Applicable for audio streams only). |
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long |
OutBitsPerSample (long nPinIndex) |
The zero based index of the output pin to retrieve the bits per sample value for the connected audio stream. |
Indicates the bits per sample value for the output pin at the specified index. (Applicable for audio streams only). |
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long |
InSamplesPerSec (long nPinIndex) |
The zero based index of the input pin to retrieve the bits per sample value for the connected audio stream. |
Indicates the samples per second (frequency) value for the input pin at the specified index. (Applicable for audio streams only). |
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long |
OutSamplesPerSec (long nPinIndex) |
The zero based index of the output pin to retrieve the bits per sample value for the connected audio stream. |
Indicates the samples per second (frequency) value for the output pin at the specified index. (Applicable for audio streams only). |
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long |
InputAspectRatioX (long nPinIndex) |
The zero based index of the input pin for which to retrieve the X part of the aspect ratio for the connected video stream. |
Indicates the X (width) part of the aspect ratio of the video stream at the specified index. (Applicable for video streams only). |
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long |
InputAspectRatioY (long nPinIndex) |
The zero based index of the input pin for which to retrieve the Y part of the aspect ratio for the connected video stream. |
Indicates the Y (height) part of the aspect ratio of the video stream at the specified index. (Applicable for video streams only). |
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BSTR |
InputPinStreamSubType (long nPinIndex) |
The zero based index of the input pin to retrieve its stream sub type string. |
Contains the stream sub type CLSID as a string. A note about BSTR properties |
Description
Writes filter settings to the registry. The Multimedia filters save their settings to the registry only at filter destruction. This method will force the filter to save its settings to the registry before it is released. If the filter has no settings to write to the registry, E_NOTIMPL is returned.
Return
S_OK if connected, S_FALSE otherwise.
Parameters
FileName |
character string containing the destination file name. |
Description
Writes filter settings to a file. The destination file can have one or more filters settings, where every filter is identified by its own section as follows:
[Filter 1]
&
&
[Filter m]
&
The file format is the same as windows INI.
If the filter has no settings to expose, E_NOTIMPL is returned.
Return
S_OK if connected, S_FALSE otherwise.
Parameters
FileName |
character string containing the source file name. |
Description
Reads and sets filter settings from a file, written using the ExportSettings method. The ExportSettings method insures that the file is formatted correctly and the right values are written. If the filter has no settings to set, E_NOTIMPL is returned.
Return
S_OK if connected, S_FALSE otherwise.
Parameters
pMem |
pointer to a character string containing the filter settings to load. |
Description
Reads filter settings from a memory buffer. The passed buffer must be filled using the WriteToMemory method.
Return
S_OK if connected, S_FALSE otherwise.
Description
Loads filter settings from the registry. The Multimedia filters import the settings from the registry only at creation time. This method will force the filter to re-load its settings from the registry. If the filter has no settings to load from the registry, E_NOTIMPL is returned.
Return
S_OK if connected, S_FALSE otherwise.
Description
Writes filter settings to the registry. The MM filters save their settings to the registry only at filter destruction. This method will force the filter to save its settings to the registry before its released.
If the filter has no settings to write to the registry, E_NOTIMPL is returned.
Return
S_OK if connected.
Parameters
pMem |
pointer to a character string to be updated with the filter settings. |
lSize |
pointer to a variable to be updated with the size of the written settings, in bytes. |
Description
Writes filter settings to a memory buffer. The filter settings will be written in binary format. Dont try to read individual settings from the buffer; the output buffer can be only used with the LoadFromMemory method.
Return
S_OK if connected, S_FALSE otherwise.