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Main Content Last Revised  Tu 2-Dec-98

Programme Delivery Control is an amazing invention that allows the broadcasters to control your video recorder so you get all of the programme on tape, even if the schedule is running late. But why is so little known about it? And just how reliable is the service? As a result of my web guide on the subject, I was fortunate to be able to make a film for Right to Reply all about PDC.

Thanks to Sean Hughes for the images.

From Right to Reply shown on C4 on Sa 25-Oct-97 at 18:30 and on S4C on Mo 27-Oct-97 at 12:00
Copyright © 1997 Channel 4 Television Corporation.



Roger Bolton


In last week’s programme a viewer asked why programmes don’t always start and finish on time. This is particularly annoying when videoing your favourite shows and you can end up like the reader of a detective story who finds out that the last few pages have been torn out.

The broadcasters wouldn’t guarantee to be better timekeepers and suggested that setting the video timer with an extra five minutes before and after the advertised transmission time was the safest way of allowing for their sloppiness.
Following this advice, many of you contacted us to point out that the favoured method of recording television programmes, VideoPlus, whereby a number printed in the listings is entered in to the video recorder instead of the programme time, doesn’t do this.

Some of you also wrote to advise viewers on the joys of PDC. At this point my eyes glaze over. P-D-what?

Piece to Camera P – D – C. Three magical, mysterious letters appearing on video recorders everywhere. They stand for Programme Delivery Control, which is jargon for an amazing invention that allows you to set your video to record a programme, knowing that, even if the programme doesn’t run on time, you’ll still get the whole thing on tape.
But it seems to be one of broadcasting’s best-kept secrets, and I wanted to find out more, so I started my own web site up about it. As it’s been visited over 7 000 times so far, I guess other people are interested too.
Andrew But what exactly is PDC? And how does it work?
Andrew as Einstein

Now this is the technical bit, so pay attention and listen carefully…

Every programme has a PIL, a Programme Ident Label, and that consists of the date, the channel and the time.

Now, just before the programme begins, the broadcaster broadcasts the PDC code, which contains the PIL, which causes the video recorder to begin recording.

Because the video recorder uses the signal and not the clock to decide when to start, it’s completely accurate.

Well we’ve spoken about starts, what about stopping? Some broadcasters transmit a stop code: some broadcasters don’t. (Some video recorders work: some don’t…)

INTERVIEW So how reliable is PDC?
Richard Eagle
Richard Eagle
Manager Technical Operations, C4

It is in fact fairly reliable. There are the occasional failures, which are very irritating to the viewer who really wanted to record that particular programme. The problems tend to come with schedule complexities and especially late changes. But we can accommodate these in our control room by use of a special button, which reverts the system to TIMER mode and allows most of the programme to be recorded under normal circumstances.

At the moment, Channel 4 and Channel 5 have a full PDC system. But many of the ITV companies don’t.

BBC2 has an experimental system. But BBC1 has nothing.

  Until this week, that is, when they suddenly announced some good news…

"There is currently an experimental service
operating on BBC2 and an experimental
service is planned to start early next month
on BBC1, with a full service following
shortly after."
  So PDC is coming to a TV station near you, even if it’s not there yet. But will this new technology make it harder to program your video? Well apparently not, because most work with VideoPlus, so it should be just as simple.

Hugh Peltor

Hugh Peltor CBE

My advice to anyone going out to buy a video cassette recorder tomorrow is to make sure that it has two features: VideoPlus and Programme Delivery Control. That way you have the best of both worlds.

Andrew On my web site I’ve heard from people who’ve had problems with PDC videos.
Hugh Peltor Yes, I think there have, particularly with the early models and in the early years of Channel 4, being the only broadcaster using programme delivery control. But clearly we’ve taken a lot of effort, by we I mean the manufacturers and the broadcasters, to iron out these problems.
Andrew Unfortunately there’s one problem that all the technology in the world won’t solve. If you want to record two consecutive programmes on two different channels, you still won’t get both programmes in full if they overlap because they didn’t begin and end on time.
Roger Bolton Which is all viewers wanted in the first place.

Other Right to Reply pages at this site...

Full Contents Channel 5 Preview Channel 5 Reception PDC Widescreen DOGs Branding Future TV

625 TV Logos Programme Delivery Control Explained Public Information Films Channel 5 Invasion of the Web Snatchers Digital TV - Beyond the Hype
TV Room TV Logos PDC
PIFs Channel 5 Web
Digital TV


625: Andrew Wiseman's Television Room (2K)