Re: TV Glossary

From: Harald Tveit Alvestrand (
Date: Tue, Aug 31 1999

Message-Id: <>
Date: Wed, 01 Sep 1999 00:24:00 +0200
To: "Michael A. Dolan" <>, (WWW TV List)
From: Harald Tveit Alvestrand <>
Subject: Re: TV Glossary

At 07:30 31.08.99 -0700, Michael A. Dolan wrote:
>Hash: SHA1
>Here's a crack at some definitions.  I suspect there will be a few
>minor variations on this, as these may be a little ATSC-centric.  But
>having these in place will help us all speak the same language at
>least.  If you have comments on these definitions, or have other
>terms to add, lets do it here first, then we can publish the results
>to the W3C site in a little more beautiful form.

I find this incredibly useful. THANKS!
I'll add questions in a few places.

>Program - a collection of related video, audio and/or data in a
>single "file".  This is also generically called "content".

So a Program has a definite, limited size. Right?

>Program Stream - as defined in ISO 13818-1 for MPEG - a streaming
>version of a Program.
>Transport (Stream) - as defined by ISO 13818-1 for MPEG - a
>multiplexed collection of concatenated Program Streams without
>beginning or end.

what does multiplexing mean in this case?
Two possibilities - breaking up a Program Stream to insert other Program 
Streams (like commercials) - and multiple unrelated Program Streams being 
transmitted at the same time (for instance normal programming + teletex)

>Content Author - usually a studio (Disney, ABC Studios) that creates
>video, audio, and "data" or some aggregation of these.
>Channel - a Program Stream.  This is also known in DVB as a

Now I'm confused; I would have thought that a Channel would be a Transport 

>Network - company that authors and aggregates content and distributes
>it (ABC).
>Transport Company - a company that aggregates and emits (usually in
>cable or satellite) a collection of channels (DIRECTV).  This is also
>sometimes referred to as a "network", but usually confuses folks when
>it is.

I'll assume that network-owned transport companies can be described as a 
Transport Company plus a Network, rather than confusing the terms.

>Broadcaster - company that emits radio waves (KABC).

Is a Broadcaster always a special case of Transport Company?

>Affiliate - broadcaster (KABC) that gets most of its content from a
>network, and thus has an affiliation to that network (ABC).
>Feed - the serialized stream of content from a network.

Is a Feed a special case of a Program Stream?

Harald Tveit Alvestrand, Maxware, Norway