U

upstream filter: The filter that passes data from its output pin to the connected input pin of the next filter in the filter graph.
URL moniker filter: A source filter that reads from an Internet server.
userbits: Undefined bits in the SMPTE timecode. These bits can be used for a variety of purposes such as identifying shot and take numbers, calendar date, client code, or any other information the user would like to encode so it travels with the source material throughout the post production process. Often they contain original film and audio tape information. This information is used to generate negative cut lists, so a theatrical film can be edited electronically. Userbits can also store 3/2 pull-down information that describes frame sequencing and repetition when 24 frame per second film is transferred to 30 frame per second video.