Annex A
PES | Packetised Elementary Stream: A sequential stream of data bytes |
| that has been converted from original elementary streams of audio |
| and video access units and transported as packets. Each PES |
| packet consists of a header and a payload of variable length and |
| subject to a maximum of 64 kbytes. A time stamp is provided by the |
| |
| related elementary streams at the Decoder. |
PID | Packet Identifier: the header on a packet in an elementary data |
| stream, which identifies that data stream. An |
| standard. |
PIN | Personal Identification Number: A password used to control access |
| to programming and to set purchase limits. Each subscriber |
| household can activate several PINs and may use them to set |
| individual parental rating or spending limits for each family member. |
Pixel | PIX (picture) Element: The digital representation of the smallest |
| area of a television picture capable of being delineated by the |
| |
peak to peak: Measurement of a signal or waveform from its most | |
| negative point to its most positive point. |
PLL | |
| controls the rotation of an object by comparing its rotational position |
| (phase) with another rotating object as in the case of a sine wave or |
| other repeating signal. This type of control system can synchronize |
| not only the speed, but also the angular position of two waveforms |
| that are not derived from the same source. |
PMT | Program Map Table: Part of the |
| Information (PSI) data and is mandatory for |
| Each service has a PMT, which lists the component parts |
| (elementary streams of video, audio, etc.) for the various services |
| being transmitted. |
A picture / frame produced using forward prediction. It contains | |
| predictions from either previous I frames or previous P frames. The |
| P frame is used as a reference for future P or B frames. |
ppm | Parts per million. |
PPV | Pay Per View: A system of payment for viewing services based on a |
| usage / event basis rather than on |
| Subscribers must purchase viewing rights for each PPV event that |
| they wish to view. PPV events may be purchased as IPPV or OPPV. |
Program | PC - A sequence of instructions for a computer. |
| TV - A concept having a precise definition within ISO |
| |
| PCR. The use of the PCR for timing information creates a virtual |
| channel within the stream. |
Programme | A linking of one or more events under the control of a broadcaster. |
| For example, football match, news, film show. In the |
| concept, the collection of elementary streams comprising the |
| programme, have a common start and end time. A series of |
| programmes are referred to as events. |
EN/LZT 790 0005 R1A |