Digital TV - the bits they don't tell you

We are currently being rushed headlong into a new age of digital TV. After years of black and white 405 line VHF TV, followed another long period of 625 line colour UHF TV we are in the middle of the changeover to digital, with High Definition hot on its heels. I have no problem with digital TV, especially as I am in a technology industry and have a background in electronics. In principle it's a good idea, but the way it is being 'sold' to the public is very one-sided.

Initially Richard Wilson told us that it will be free from interference - well Richard, 'I don't believe it!'. Watch a digital terrestrial channel for a while and see - and hear - what happens. An analogue signal with interference will cause a buzz or crackle on the sound and a flash of visual disturbance usually in a thin horizontal strip across the picture, but in most cases doesn't stop you seeing or hearing the programme. What happens with digital? The picture degrades into blocks, freezes and skips. The sound channels click loudly in a manner that is likely to cause damage to your speakers over a sustained period of time. Cable is less prone to this type of interference, and I can't vouch for satellite as I don't subscribe to the Murdoch coffers. I do remember the analogue satellite systems being affected by rain though - white speckles all over the picture!

Another problem that you may notice with cable is that there is a delay, due to the processing that has to go on to convert the signal for transmission and then back again in your STB - switch from an analogue channel straight to the same channel on digital and hear the last few seconds again! They may not be true of satellite, although I think it will be, and it also happens of Freeview. So when you see New Year in on digital, you are almost certainly a few seconds behind everyone on analogue. It is also possible to have unsynchronised sound and picture due to delays in processing causing the lips to move at a different time to the words coming out - I have experienced this several times on cable.

Picture quality is also an area of concern. To fit in all the extra channels the signals are compressed and multiplexed together before transmission, to be converted back at the set-top box (STB). This compression is done in the same way as MP3 encoding or JPEG compression - the image is degraded into stepped bands of colour instead of being a smooth transition from one area to another - the loss of detail allows the picture to be compressed better to take up less bandwidth. The effect shows up well in dark areas that have bright lights shining out of them, like football floodlights or stage lighting at concerts, etc. Faces sometimes show digital artifacts as well - sometimes you see lips or eyes appear to move as if they are floating within the face, not attached to it. Expensive large screen plasma TVs show these symptoms up much more. So although the image looks better - especially if you connect the components together with RGB SCART connections, it's no longer what I would call 'broadcast quality'. I can only hope it improves once the analogue transmitters are turned off and the bandwidth is freed up. It needs to be sorted out by the time we get High Definition whatever happens.

We also have to take out subscriptions or at the very least extra STBs for all of the places around the house where we want to view or record TV. If you want to watch BBC1 in the lounge whilst taping one of the Discovery channels and the kids are watching MTV and Disney in their bedrooms the extra cost adds up - that's four boxes/subscriptions. To do this with a current analogue system costs no extra (although the choice of channels is more limited, obviously). So all of a sudden we have to fork out a lot more to do what we can do for just the cost of the TV license now.

Talking of channels - when are we going to sold the channels we want, not a package? Whilst I like to watch VH1 & 2, MTV, Kerrang and Magic, I'll never watch hip-hop or dance channels, so why should I have to have them included. I would much prefer to pay per view of any channel that isn't one of the base pack 'free to air' channels. Anything over 5 minutes watching a channel and you start to pay per minute. It would cut my costs significantly as 90% of my viewing is on one of the many BBC channels. After all, I can only be watching one channel at any time, so why do I need to pay for the ones that I'm not currently watching - and how about the bulk of the time when the TV is switched off?

I also wish that we weren't sold a package as containing X number of channels, when many of them are in-house sales and support channels, shopping channels, rip-off premium rate call 'competition' channels and 'plus 1' channels. None of these should count towards the number of channels. I'd also be inclined to remove those channels that continually repeat the same programming - many show the same programmes two or three times a day, and then repeat again a few weeks later. Having all of these channels is pretty pointless most of the time - yes, we have a greater 'choice' of what to watch, but if only there was stuff on all of these channels that was worth watching more of the time. I reckon that 99% of my viewing is actually spent on less than 10 channels anyway! Just how many forensic science, home makeover or history of WW2 (and how the Americans won it) can you really watch?

Whose idea was it to show programme trailers during the advert breaks within other programmes? The advert breaks are intrusive enough on their own and far too long in many cases. They break the flow of what you are watching, although they can be a useful toilet break. Having clips from another programme within the one you are watching is worse still. They are even more disruptive.

Whilst on the subject of adverts, when are we going to get a set sound level throughout? You watch a drama and turn up the sound to hear the conversation at a comfortable level, only to have an advert break where the levels are many dBs higher, waking up the rest of the house. The same goes for background music - the BBC's Spooks is one specific example of this. I have no problem with dramatic or atmospheric music or clips of good backing music in a programme - but why must it involve such a large change in volume level? If there's one benefit I'd like to see from digital TV it would be the ability to set peak levels for sound in adverts, backing music and speech independently of each other - that way the people who don't like drum beats during the news, or backing music to nature programmes can set in to 0, or at least a comfortable level - and my wife wouldn't keep telling me to turn the TV down all the time - I have to keep adjusting the volume up and down all the time to get to hear the programme properly without upsetting her!

Ideally the best way to watch any commercial channel is by recording it and fast forwarding through the breaks, but the lack of flagging of the break start and end is making that more hit and miss now - and it's done intentionally to make it more difficult to do just that. The excellent ER on E4 currently is a good example of most of these problems - excessive adverting with trailers, loud advert breaks and those bloody pointless 118 sponsorship adverts and no warning as you switch in and out of the breaks - one minute there's blood and guts then the scene cuts to a pair of morons crawling across the floor that do not make me want to find out someone's phone number at all. It does have a good level for background music though - far better than a lot of programming.