ore, no less. For example, the term 4:4:4 defines a complete set of digital bits, bytes, and frames from the A/D conversion process ap- plied to the output of CCD sensors in a camera. The typical camera output is almost always stated to be 4:2:2, meaning the signal contains half as many chroma pixels as a 4:4:4 signal. Sometimes this technique is referred to as sub-sampling. Overall, it is part of a signal processing strategy called bitrate reduction (BRR) that reduces the amount of bits in the signal, lowering complexity and cost of camera processing cir- cuitry and the amount of storage required of video tape machines and file servers, as well as transmission channel bandwidth. Compression techniques and standards include algorithms, rules, and procedures used to process content before and after storage, transport, or both. The purpose of using compression is to transform the original information into something representative of the original that is satisfactory to the viewer or listener. Highly effective compres- sion techniques strive to reduce bandwidth or storage capacity while preserving quality or resemblance to the original. Interface standards define physical and electrical properties of con- nectors, voltage levels, signaling protocols, bit framing, and mapping details. Payload bitrate is the data that travels across the interface. This includes all the data or bits resulting from analog to digital conver- sion, and any clocking, framing, control signals, metadata, or other directly related information. It excludes any and all bits or bytes related to network or storage media functions. To a communications network, or storage medium, 27MHz clocking information embed- ded in an MPEG compressed signal is payload. PRACTICAL IP AND TELECOM FOR BROADCAST ENGINEERING AND OPERATIONS Multiplexing techniques and standards are used when digitized audio, video or other source material is mixed or interleaved into a program level serial bitstream. Multiple programs multiplexed into a common bitstream are said to o