MetadataTimeStamps structure (mfapi.h)

The MetadataTimeStamps structure describes the blob format for the MF_CAPTURE_METADATA_FACEROITIMESTAMPS attribute.

Syntax

typedef struct tagMetadataTimeStamps {
  ULONG    Flags;
  LONGLONG Device;
  LONGLONG Presentation;
} MetadataTimeStamps;

Members

Flags

Bitwise OR of the MF_METADATATIMESTAMPS_* flags.

Device

QPC time for the sample the face rectangle is derived from (in 100ns).

Presentation

PTS for the sample the face rectangle is derived from (in 100ns).

Remarks

The MF_CAPTURE_METADATA_FACEROITIMESTAMPS attribute contains the time stamp information for the face ROIs identified in MF_CAPTURE_METADATA_FACEROIS. For a device that cannot provide the time stamp for face ROIs, this attribute should be omitted.

For the Flags field, the following bit flags indicate which time stamp is valid:

#define MF_METADATATIMESTAMPS_DEVICE        0x00000001
#define MF_METADATATIMESTAMPS_PRESENTATION  0x00000002

MFT0 must set Flags to MF_METADATATIEMSTAMPS_DEVICE and the appropriate QPC time for Device, if the driver provides the timestamp metadata for the face ROIs.

The MetadataTimeStamps structure only describes the blob format for the MF_CAPTURE_METADATA_FACEROITIMESTAMPS attribute. The metadata item structure for timestamp (KSCAMERA_METADATA_ITEMHEADER + timestamp metadata payload) is up to driver and must be 8-byte aligned.

Requirements