Frame Time (0018,1063) is the nominal time (in milliseconds) between individual frames of a Multi-frame image. If the Frame Increment Pointer points to this Attribute, Frame Time shall be used in the following manner to calculate 'the relative time' for each frame:
Frame 'Relative Time' (n) = Frame Delay + Frame Time * (n-1)
where: n = number of frame within the Multi-frame image and the first frame number is one
Note: When there is only one frame present, Frame Time (0018,1063) may have either a value of 0, or a nominal value that would apply if there were multiple frames.
Frame Time Vector (0018,1065) is an array that contains the time increments (in milliseconds) between the nth frame and the previous frame for a Multi-frame image. The first frame always has a time increment of 0. If the Frame Increment Pointer points to this Attribute, the Frame Time Vector shall be used in the following manner to calculate 'relative time' T(n) for frame n :
where Δti is the ith Frame Time Vector component.
During a video acquisition, audio may be used for voice commentary of what is being observed, as well as to record sound-based physiological information such as Doppler audio.
Some Transfer Syntaxes allow for the multiplexing of interleaved audio with video data, and the Attributes of the Cine Module support this encoding paradigm. They are not intended to describe audio acquired simultaneously when it is encoded in other SOP Instances or within Attributes other than Pixel Data (7FE0,0010) of the same SOP Instance.
Synchronization between audio and video is assumed to be encoded at the Transfer Syntax level (i.e. within the encoded bit stream).
Note: If no audio was recorded, the Multiplexed Audio Channels Description Code Sequence (003A,0300) will be present and contain no sequence items.