---
title: Demultiplexer
url: https://doc2.pstreamer.tv/en/manual/streamer/demux.html
lang: en
product: Perfect Streamer
version: 2.0.2.362
---

# Demultiplexer

A demuxer input (the demuxer type) extracts a single program from a multiplex and turns it into a regular SPTS stream. Once extracted, the program is subject to the whole SPTS pipeline processing ([SPTS streams](spts.md#streamer-spts)): filtering and modification, transcoding, OTT delivery and DVR recording. This is the only way to process a received multiplex program by program ([MPTS streams](mpts.md#streamer-mpts)).

To connect a program, an input of the demuxer type is added to an SPTS stream and the following are selected (the field names are as in the interface):

- **Source** (the Source kind and Source id fields) — an MPTS stream of the same node or a DVB adapter ([DVB receiver](dvb.md#streamer-dvb)).
- **Program** (the PNR field) — the program is picked from the list of the services detected, with their names. The list is supplied both by an MPTS stream and by a DVB adapter, as long as the source is running and has been analysed. While there is no list — the source has not been chosen yet, the adapter is stopped, the stream has not been analysed — the number is typed in by hand.

Specifics:

- The demultiplexer receives an already descrambled multiplex: the BISS keys are set on the input of the MPTS stream ([BISS descrambling](mpts.md#streamer-mpts-biss)), while CAM and BISS descrambling at the adapter level is set in the DVB adapter settings ([DVB receiver](dvb.md#streamer-dvb)).
- The source is protected against deletion: as long as at least one demultiplexer references an MPTS stream or a DVB adapter, it cannot be deleted — the node reports which objects reference it.
- For inner T2-MI multiplexes a composite program number is used that combines the carrier number and the PNR within that carrier: carrier number × 65536 + PNR (for example, carrier 1, PNR 7 → 65543; carrier 0 is the outer multiplex, an ordinary PNR). There is no need to work it out by hand: the inner programs stand in the same list, below the outer ones, already under their composite numbers. T2-MI reception is described in [DVB receiver](dvb.md#streamer-dvb).

The same multiplex can be delivered in full (an MPTS stream with transport outputs) and in parts — as individual SPTS streams through demultiplexers — at the same time.