DICOM PS3.3 2021a - Information Object Definitions

C.7.6.27 Current Frame Functional Groups Module

Table C.7.6.27-1 defines the Attributes related to the current frame when the IOD is transported using Real-Time Communication. It corresponds to the "per-frame" Attribute for the non-Real-Time IODs.

Note

The group number (0006H) of the Sequence containing the Attributes of the Current Frame Functional Groups Module is used to contain Attributes that are specific to real-time transfer. If this information needs to be kept in a persistent object, its contents have to be copied into an Attribute that has a group number of 0008H or higher. The Current Frame Functional Groups Module is relative to the dynamic part of the RTP Payload. Its group number is lower than that of other Attributes in order to be placed before the static part of the RTP Payload, but higher than the Attributes of the RTV Metadata Information, in order to be placed after the header of the RTP Payload, as is done in PS3.10.

Table C.7.6.27-1. Current Frame Functional Groups Module Attributes

Attribute Name

Tag

Type

Attribute Description

Current Frame Functional Groups Sequence

(0006,0001)

1

Sequence that contains the Functional Groups Sequence Attributes corresponding to the current frame or audio sample.

Only a single Item shall be included in this Sequence.

>Include one or more Functional Group Macros that are contained in every frame.

For each IOD that includes this module, a table is defined in which the permitted Functional Group Macros and their usage is specified.


C.7.6.27.1 Current Frame Functional Groups Module Attributes
C.7.6.27.1.1 Frame Origin Timestamp

Frame Origin Timestamp (0034,0007) contains 10 bytes conforming with the IEEE 1588:2008 (PTPv2) standard. IEEE 1588:2008 represents seconds and nanoseconds since Epoch, defined as 1 of January, 1970, at 00:00:00 TAI (International Atomic Time). The first 6 bytes contain the number of seconds, and the last 4 bytes contain the number of nanoseconds. The Time Source and Time Distribution Protocol values defined in Table C.7-7 “Synchronization Module Attributes” describe how the time was obtained.

If the RTP Header extension of a frame contains an PTP Origin Timestamp, that values shall be used for the Frame Origin Timestamp. Otherwise, the Frame Origin Timestamp value can be derived from Flow RTP sampling rate, the RTP Timestamp, and the reference time for the RTP Timestamp.

Frame Origin Timestamp is used to pair content from different Flows (payload flow with metadata flow), through a time alignment mechanism.

DICOM PS3.3 2021a - Information Object Definitions