Editing MPEG-1 (section)

===Multiplexing===
To generate the PS, the multiplexer will interleave the (two or more) packetized elementary streams. This is done so the packets of the simultaneous streams can be transferred over the same [[Communication channel|channel]] and are guaranteed to both arrive at the decoder at precisely the same time. This is a case of [[time-division multiplexing]].

Determining how much data from each stream should be in each interleaved segment (the size of the interleave) is complicated, yet an important requirement. Improper interleaving will result in buffer underflows or overflows, as the receiver gets more of one stream than it can store (e.g. audio), before it gets enough data to decode the other simultaneous stream (e.g. video). The MPEG [[Video Buffering Verifier]] (VBV) assists in determining if a multiplexed PS can be decoded by a device with a specified data throughput rate and buffer size.<ref name=tutorial_vbv>{{Citation |first1=Mark |last1=Fimoff |first2=Wayne E. |last2=Bretl |title=MPEG2 Tutorial |date=December 1, 1999 |url=http://www.bretl.com/mpeghtml/VBV.HTM |access-date=2016-11-11 |url-status=live |archive-url=https://web.archive.org/web/20161112144717/http://www.bretl.com/mpeghtml/VBV.HTM |archive-date=November 12, 2016 }}</ref> This offers feedback to the multiplexer and the encoder, so that they can change the multiplex size or adjust bitrates as needed for compliance.