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ILMDVRSink Interface

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Interface Properties:

Type	Name	Description
long	FolderCount	Gets or sets the number of buffer folder locations. Use this to determine the number of DVR buffer folder locations on the system.
BSTR	FolderName( long nFolderIndex)	Gets or sets the name of the fully qualified folder path for the specified buffer location. Use this to determine the full pathname of the specified DVR buffer folder location.
BSTR	BaseName	Gets or sets the name of the base file name of the buffer list file and recording chunk files. Use this to determine the file name of the DVR buffer files.
VARIANT_BOOL	IsGrowing	(Read only) Indicates whether the DVR buffer is still growing. If VARIANT_TRUE, the file is still growing and the final duration is unknown. If VARIANT_FALSE, the buffer is not being updated anymore.

Interface Methods:

HRESULT GetAvailabilityInfo(double * pStartOffset, double * pEndOffset, double * pTotalSize)

Parameters

pStartOffset	A pointer to a double type that receives the first offset of available video.
pEndOffset	A pointer to a double type that receives the last offset of available video.
pTotalSize	Total size of all video data available.

Description

Gets the availability information for data for the current playback range.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_UNEXPECTED = Unexpected invalid file handle.

LTMM_E_DVR_NO_RECORDINGS = No .LRC recording files exist.

LTMM_E_DVR_CORRUPT_STUB_FILE = Corrupted .LBL file.

HRESULT SetBufferSize(long nFolderIndex, long nFiles, double fileSize)

Parameters

nFolderIndex	The index of the desired buffer location.
nFiles	The maximum number of .LRC files allowed to be created in this location.
fileSize	The maximum file size (in bytes) of each individual .LRC file.

Description

Sets the number of buffer (.LRC) files and the allowed size per buffer file for the specified buffer location.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_UNEXPECTED = Unexpected invalid file handle

DISP_E_BADINDEX = Index supplied is outside the range of currently valid indexes.

E_INVALIDARG = Either the number of files or file size specified is not valid.

HRESULT GetBufferTotalSize(long nFolderIndex, long uFlags, long * pnFiles, double * pnTotalFileSize)

Parameters

nFolderIndex	The index of the desired buffer location.
uFlags	Flag specifying how to calculate the total size. Values can be: DVRGetTotalSize_Actual = 0x0000 DVRGetTotalSize_Allowed = 0x0001
pnFiles	Total number of files included in the buffer size calculation.
pnTotalFileSize	The total calculated buffer file size.

Description

Sets the number of buffer (.LRC) files and the allowed size per buffer file for the specified buffer location.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_UNEXPECTED = Unexpected invalid file handle

DISP_E_BADINDEX = Index supplied is outside the range of currently valid indexes.

HRESULT CopyBufferToFile(BSTR pszTargetFile, double startOffset, double endOffset)

Parameters

pszTargetFile	Fully qualified pathname of destination file.
startOffset	Starting offset of data to copy.
endOffset	Ending offset of data to copy.

Description

Copies the buffered recording data to the specified fully qualified file pathname.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_UNEXPECTED = Starting offset not found.

DISP_E_BADINDEX = Index supplied is outside the range of currently valid indexes.

LTMM_E_DVR_NO_RECORDINGS = No .LRC recording files exist.

E_INVALIDARG = Either the number of files or file size specified is not valid.

HRESULT GetStatus(DVRStatusConstants * pStatus, long * pnCurrentFolderIndex, long * pnCurrentRecordingIndex, double * pnCurrentRecordingSize)

Parameters

pStatus	A pointer to an enumeration type that will receive the current DVR status. Returned values can be: DVRStatus_Stopped DVRStatus_Paused DVRStatus_Writing
pnCurrentFolderIndex	A pointer to a long type that will receive the current location index.
pnCurrentRecordingIndex	A pointer to a long type that will receive the current recording index. This index is the number of the current LRC file.
pnCurrentRecordingSize	A pointer to double type that will receive the current recording size in bytes.

Description

Gets the DVRSink status, buffer files location and buffer file index, and total current recording size.

Return

S_OK if successful, S_FALSE otherwise.

HRESULT CreateEvents(long nRegistrationID, long TargetProcessID, OLE_HANDLE * pDataWrittenEvent, OLE_HANDLE * pRecordingListChangedEvent)

Parameters

nRegistrationID	A unique identifier for this event registration.
TargetProcessID	The process id of the event subscriber.
pDataWrittenEvent	A handle to the write event.
pRecordingListChangedEvent	A handle to the list changed event.

Description

Creates the windows event objects used to signal data write and recording list changed events.

Note:This method is now deprecated. You should use CreateEvents2 instead.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_OUTOFMEMORY = Memory allocation error was encountered.

HRESULT CreateEvents2(long nRegistrationID, long TargetProcessID, OLE_HANDLE * pDataWrittenEvent, OLE_HANDLE * pRecordingListChangedEvent, OLE_HANDLE *pOffsetReachedEvent)

Parameters

nRegistrationID	A unique identifier for this event registration.
TargetProcessID	The process id of the event subscriber.
pDataWrittenEvent	A handle to the write event.
pRecordingListChangedEvent	A handle to the list changed event.
pOffsetReachedEvent	A handle to the offset reached event.

Description

Creates the windows event objects used to signal data was written, recording list changed and offset reached events. This method is used internally by the LEAD DVR Source Filter.

The offset reached event is designed to work together with the SetOffsetToReach method.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_OUTOFMEMORY = Memory allocation error was encountered.

HRESULT FreeEvents(long nRegistrationID)

Parameters

nRegistrationID

A unique identifier for this event registration.

Description

Frees the windows event objects used by to signal data write and recording list changed events.

Return

S_OK if successful, S_FALSE otherwise.

HRESULT ResetToDefaultsEx(LMDVRSink_APILEVEL ApiLevel)

Parameters

ApiLevel

The desired API Level for reset.

Value can be:
LMDVRSink_APILEVEL_1

Description

Resets the DVRSink interface object to the default settings for the API level specified.

Return

S_OK if successful, S_FALSE otherwise.

HRESULT GetBufferInfo(long nBufferIndex, BSTR * pszFileName, double * pnUsefulSize, double * pnFileSize, long * pnPlayIndex, long * pnFlags)

Parameters

nBufferIndex	The index of the buffer file for which to get information.
pszFileName	A pointer to a string type that will receive the filename of the related buffer recording file.
pnUsefulSize	A pointer to a double type that will receive the used file size of this recording chunk file.
pnFileSize	A pointer to a double type that will receive the physical file size of this recording chunk file.
pnPlayIndex	A pointer to a long type that will receive the index in the play order (the first index might not be 0, but all files should have sequential and incrementing indexes after the first index value)
pnFlags	A pointer to a long type that will receive a DVRBufferFlagConstant setting. Value can be: DVRBuffer_Empty = 0x0001, DVRBuffer_Writing = 0x0002, DVRBuffer_Finished = 0x0004

Description

Gets the buffer information associated with the buffer file index specified.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_INVALIDARG = Buffer index supplied is outside the range of currently valid indexes.

LTMM_E_DVR_NO_RECORDINGS = No .LRC recording files exist.

E_OUTOFMEMORY = A memory allocation error occurred.

Either the number of files or file size specified is not valid.

HRESULT SetOffsetToReach(long nRegistrationID, double Offset)

Parameters

nRegistrationID	The identifier passed to CreateEvents2 when the offset reached event was created.
Offset	The offset to reach (in bytes). The offset reached event will be set when the DVR sink has written data past this offset. Must be > 0.

Description

Use this method to instruct the DVR sink object to set the offset reached event once it has written data past a certain offset. This method is used internally by the DVR source object.

For example, if an application wants to read N bytes from offset X, then it will do the following:

Reset the offset reached event
Call SetOffsetToReach(X + N)
Use a windows waiting function and wait for the offset reached event to be set. (This of course, assumes the event was created through an earlier call to CreateEvents2.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_INVALIDARG = the registration identifier is invalid or the offset is invalid.

HRESULT StartChangingAttributes ()

Description

This method is used to change the DVRSink attributes.

Return

S_OK if successful, S_FALSE otherwise.

HRESULT StopChangingAttributes(VARIANT_BOOL bCancelChanges)

Parameters

bCancelChanges

A BOOL value type specifying whether to cancel or apply the pending attribute changes.

Description

Sets the DVRSink attributes. Set to VARIANT_FALSE to set the attributes. Use VARIANT_TRUE to discard changes and reset the attributes to their previous settings.

Return

S_OK if successful, S_FALSE otherwise.

HRESULT StartBackupToFile(BSTR pszFileName, long Flags)

Parameters

pszFileName	Fully qualified pathname of destination backup file.
Flags	Reserved for future use. Set value to 0.

Description

Starts writing the DVR recording data to the specified fully qualified backup filename.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_UNEXPECTED = Unexpected invalid file handle.

HRESULT StopBackupToFile()

Description

Stops writing the DVR recording data to the backup file.

Return

S_OK if successful, otherwise a return code indicating the reason for failure:

E_UNEXPECTED = Unexpected invalid file handle.

Enums

typedef enum
{
   DVRStatus_Writing       = 0,
   DVRStatus_Paused        = 1,
   DVRStatus_Stopped       = 2
} DVRStatusConstants;

typedef enum
{
LMDVRSink_APILEVEL_1 = 0,
} LMDVRSink_APILEVEL;