TV Technology Update

What’s going on in the jungle of new screens, formats, high definition, 3D, Internet TV

HDTV - present and immediate future

• iPlayer and other Catch-Up services • Display devices • PVRs and recording devices• HD Tuners (satellite and Freeview)• Some practical pointers to choosing a TV.

From www.avforums.com• Sky digibox to freeview • This site looks like the kind of place where I get the answer!

I have a Sky digibox (Sony) which I am trying to transform into a freeview box (I now have a Sky+ box so this one is no longer of use). So I am plugging it into the TV aerial, but it says 'no sattelite signal being received'.Is this a problem with my aeial not being a digital aerial? Or is it no possible to transform a Sky digibox into a freeview box?I should also point out that I do not have a viewing card into my box (i.e. it is now in the Sky+ box) - do I need to purchase a Freeview card??

If this is not possible - was told it was - I will simply go out to purchase a new Freeview box. I just wanted to make use of my Sky digibox.Thanks

DSO schedule

• 1st Border 20082nd West Country 20083rd HTV Wales 20084th Granada 20095th HTV West 20096th Grampian 20097th Scottish TV 20098th Central 20109th Yorkshire 201010th Anglia 2010

•11th Meridian 201112th Carlton/LWT 201113th Tyne Tees 201114th Ulster 201115th Channel 2012

PVR / DV(D)R ?• There are no Twin Tuner PVRs that also have DVD

burners.• Panasonic DMR-BW780, DMR-BW880 now do this but with

Blueray burners in DR (direct recording) mode (£600) = BDR

You can buy:An HDD-DVD machine with a single Freeview tunerAn HDD only machine (PVR) with two tuners.

If you get the latter, you can connect via RGB (preferably) to your existing DVD recorder and create a disc for something you want to keep.

• You can also use the internal HDD for recording/timeshifting.

• Editing features on PVRs are usually very limited/basic.

• Can also use USB stick with some TVs and STBsHiDef will only play back via original display (DRM)

Modulation and encoding

• MPEG4, especially H264/AVC, much more efficient vs MPEG2 (but needs more processing power).

• DVB-S2 (usually combined with 8PSK instead of qpsk) enables more “channel efficiency”.

• DVB-T2 encoding used for Freeview HiDefn. About half of currently available 32 inch+ TVs have the necessary tuner ( timeline - Feb 2011)

• Backwards compatible with standard DVB-T

Resolution• 720P – 1280 x 720 pixels , progressive

• 1080i – 1920 x 1080 pixels , interlaced i.e. sequential fields(input)

• 1080p – 1920 x 1080 pixels, pixels updated twice as often.

• 1080p available but… only sources are Blueray discs and some games• 1080P needs lots of bandwidth (expensive to transmit)

• Would need 50 or 60 inch screen viewed from less than 8 feet to notice any difference !

• It is now affordable / mainstream

• The term "Full HD" has never been used by EICTA (now Digital Europe) who set the standard. They used (and still use) "HD Ready 1080p“, but retailers seemed to think that would cause confusion among consumers, so the term "Full HD" was used, and is now generally accepted to mean a set that will accept a 1080p signal and has a native resolution of at least 1920x1080.

High Definition Recording

• A shambles when first appeared (mid 2010)

• Humax, Philips (=Pace), 3View, Digital Stream, Sagemcom, Toshiba, Sharp, Tvonics, Triax

• with Blueray (and twin tuner) : Panasonic DMR BW880 (about £500).

Freesat and Freeview variants

• Big teething problems (many software updates) for early models (Humax-Foxsat Tesco/Fetch-TV, Digital stream. (prices from approx £150-£300)

• Can only improve and HDD sizes now from 300 GB to 2 TB.

Distance from screenYou don’t want to see the pixel structure

Screen size Viewing distance range 26" 3.25 - 5.5 feet =Screen size x 1.5 to 2.5

32" 4.0 - 6.66 feet

37" 4.63 - 7.71 feet

40" 5.0 - 8.33 feet

42" 5.25 - 8.75 feet

46" 5.75 - 9.5 feet

50" 6.25 - 10.5 feet 58" 7.25 - 12 feet

65" 8.13 - 13.5 feet

70" 8.75 - 14.75 feetNB: for immersive 3D experience multiply by 0.78 ( or 75%) or try 1.4 x

screen size

Internet TV, iPlayer , Lovefilm etc.

• BBC iPlayer isn’t just available on my PC and Blackberry.

• I can get it via Virgin Media cable box and via internet connection to my TV.

• Many TVs now have an ethernet port (RJ-45 network cable socket); connect this to your router

• Wireless connection not recommended – cost and bandwidth issues for streaming video.

• I can now search Youtube, subscribe to Lovefilm etc. all via the TV and its remote.

• Can also play downloaded or ripped films or shows via USB stick. (format memory stick as FAT32 on PC first)

Internet TV etc. continued

• Virgin cable modem -> router WAN port.

• Router LAN port 1 to TV

• Router LAN port 2 now goes to former router site upstairs where a basic $10 5-port ethernet switch has all the connections that previously went to the router (Son’s PC, wife’s PC, X-box etc.)

• Same will work with standard ADSL-router, connect 1 port to TV, add a switch if you have run out of LAN ports.

• Wireless connection is a last resort – even Homeplugs (using mains wiring) may be preferable !

Internet TV continued again

• Blueray players (now available for < £100) often have ethernet too, so can be used with TV that doesn’t have this.

• Some have USB ports too, can be used in same way as TV USB port.

• The converged household is happening (was promised 15 years ago)

• Note that web functionality is not as complete as on a PC and that TV manufacturers’ implementation of it (GUI, middleware etc.) varies and will expand or improve.

• It also creates some licensing headaches or issues

Display types

• CRT (not many are HD), Ebay / Freecycle/Freegle

• Plasma – on 6th-8th generation• LCD – improving fast• SED – seems dead 1080p for 50 inch+ screens

• RPTV (DLP, LDC, LCoS). Good value, large ‘n dark

• HT projectors – prices dropping needs large room

• OLED – but when in living room size screens with longevity and affordablilty

CRT – Cathode Ray Tube

• So-called “direct view” technology.• Few HD models (Samsung, Sony , LG making slimmer, Philips ?)

• Geometry issues but best contrast etc.

LCD• Progressive scan by default• Response times improving (<10 mSecs) – but

almost impossible to compare like with like as no standard method of specifying this ! This is 1 cause of “motion tracking” errors.

• Backlight technology improving• Some have audible hum/Buzz (PSU compromises in

design)

• Insects can get trapped between layers !• Not childproof – unless extra glass front like Loewe models

• Half power of plasmas• Contrast / greyscale issues – poor blacks / greys. Easy

to “cook” the specs to get high numbers on the glossy !

• Watch for dead pixels – manufacturer policies vary

Dead Pixel policies and examples (CTL)

– 12" - 17" LCD Screens: 2 lit, 2 unlit, or 4 colored non-performing pixels

• 19" & 20" LCD Screens: 4 lit, 4 unlit, or 7 colored non-performing pixels

Plasma screens

• Power hogs

• Good brightness / contrast• Possible image “burn in” issues (logos if static)

• Regassing myth !• Many are not HD – how good is internal scaling ?

RPTV (Rear Projection)

• Great value if you have the space• Full 1080p available – needs 60 inch+ to distinguish advantage

• Poor brightness in daylight conditions

• Lots of space for connectivity• Cheap way to get “attention grabber” – tends to

dominate a living room !

Home Theatre Projector

• Great if you have dedicated room / space

• UXGA / HD types < £1000 by mid 2006

• Same technology base as RPTV

Next : some future happenings….

OLED – Organic LED Emiting Display

• Promises to eventually oust LCD / TFT with better contrast, lower power (but they said that about SED and “SED is ded”)

• LG 15” model is £1500• 31” exhibited, guess at £6000 (with 3D) • LG target 2013 for real OLED marketing.• Samsung rumoured to be trying to catch up.

Defunct Sony XEL-1 (11” screen) sold for £2000, RRP £3,500

LCD improvement• Choice of White LED, RGB LED, OLED,

CCFL & hot cathode backlighting

• LED has aging problems unless compensated for

• RGB LEDs if switched fast (needs more complex control / driver ICs)

• Dramatic improvements possible as well as purer whites

• Luxeon hi-brightness LED market leaders

Color Gamut

Attainable Colors with CCFL & LED Backlight Systems

130%70%100%

Colors that Human can See

The “LED TV” marketing scam

• Currently available LCD TVs sold as LED are in fact LED-backlit, LED replacing CCFL tube behind screen.

• This is no big deal except that Joe Public often (mistakenly) believes these are true LED-emissive or LED matrix screens !

• 'LED' and LCD TVs are the same

Edge vs “Full LED”

• Edgelit LED backlit screens are thinner and cheaper to produce and hit the WAF* button often needed for a sale.

• Full LED backlighting needs many more LEDS e.g. 2000 vs 100 but, with the right electronic control can result in a better picture, e.g. black-to-white transitions or black next to white (but doubles cost and a lot thicker)

• * wife acceptance factor

Connections – digitalall use TMDS signalling similar to LVDS interfaces on ICs

• HDMI High Definition Multimedia Interface. Supports 165 MPixels/second

(almost 5 Gbps). 19 pins, supports audio packets, TMDS signal identical to DVI, 19 pin connector. Latest version = 1.4a with ARC (audio return channel) and HEC

HDMI switches are newish and costly ; TVs now often have 3 or 4 HDMI ports.

HDMI includes content protection (HDCP).

For DVI it is a manufacturer’s option !

• DVI Digital Video Interface. No audio,-I has VGA (RGB) output (like Graphics

cards).• Other : Displayport (more for PCs), Firewire (camcorder) AKA 1394, iLink

•DVI-I DVI-D

Connections - Analogue

• VGA = analogue RGBHV or RGB + Csync

• YPrPb or “component” = luminance + colour difference signals , normally using phono sockets AKA “RCA jacks”.

• SCART – has RGB or S-video , Cvbs (composite) and audio, fast blanking for RGB, pin 8 I/O switching. 21 pins.

• S-Video Y/C , luminance and chrominance widely used in camcorders

Motion & Processing artifacts

• Blurring may be due to : • internal picture processing assistants (Pixel Plus, Crystal Vision etc.) • or poor screen response (especially LCD with >25 mSecs response • or poor colourspace conversion or scaling (picture size / format conversion)• 100 Hz interpolation & processing done badly (on CRTs)

Other artifacts can be due to :Any of the above

Or Poor MPEG decoding

Or Over compression of the signal ( usually the broadcaster’s fault) – stat-muxing

Broadcasters may have used transcoding or transrating in the signal chain

Look for display that allows turning off enhancement features – not all do.

MotionBlur (extreme example)

• The same effect as “frame blending” (simulated motion in some games).

• Here’s the correct image

Motion Blur

• Look for this by watching a soccer ball

• There may be other motion artifacts and jerkiness also, especially if the video transmission is over compressed.

• Javelin may jerk in flight as well as not appearing to be a straight line shape (aliasing jaggies)

• 100 (or 200) Hz option may help this but needs to be able to be disabled (can cause its own unlikeable effects).

How do you test / preview

• Take good DVD with you & ask shop to play it through your chosen display device via decent connection (not composite or RF input)

• Go to A/V specialist shop ; you may pay a little more but you’re paying for some decent advice and service.

• John Lewis 5 year g’tee is often worth paying a little extra for (try a price-match attempt 1st)

Testing / Previews (contd.)• Don’t be fooled by DVD demos showing

Toy Story, Monsters Inc and similar “3D cartoons”

• These always look good even on a poor display

• Make allowances for poor signal distribution in DSG / Comet etc. when you compare

• Confirm that viewing angle will be ok for your room (especially with LCD displays)

Other points• Cables do vary in quality – but £30-£50+

for a SCART cable is only a placebo (but it is

worth paying £5 rather than £1 in order to get individually screened cores).

• Digital connections should be less critical*

(as long as they are built such that they don’t fall apart after a few insertion/extraction cycles)

• Surge/spike protectors are worth having, especially if they also have RFI filters

• Forget the guarantee on the above

• None will protect against a direct (or very near)

lightning strike.

• *HDMI cables ok from £1-£10, £30 for long one (7.5 metres or more)

Brands to look at• Genuine Japanese household names (Sony,

Hitachi, Panasonic,Sharp,Toshiba,JVC , Sanyo, Mitsubishi ? etc. )

• LG & Samsung (improving)

• Loewe

• (possibly/arguably) B & O

• Dell – but newish and unproven for displays• Philips and Thomson – very variable

Debatable Brands – low end of market)

• Tevion / Medion (Aldi, ToysRus)

• Video Seven, Crown , Acer, AOC

• Benq (good name in USA)• Bush, Goodmans , Alba , Wharfedale,

Pye, Grundig – all are marketing names trying to live off reputation they had when they were real manufacturing companies

• H & B – French marketing company• Beko ,Vestel, Fusion – Turkish (make low end

sets for Toshiba, Philips and others as “branding exercise)

• Orion, Naiko, Akura, Watson, Mikomi

Some setup hints 1• LOOKS LIKE NORMAL TV

• TV channels look same as before HD was installed :

• Have you connected your HD box using the HDMI lead ?

• You could still be actually watching SDTV ! Ensure your box is set to HDMI output

• Confirm you are tuned to an HD channel

The new HD channels sit alongside the old SD ones, and you may inadvertently have tuned in to the lower-quality digital signal.

Some setup hints 2• POOR SD PICTURE • Common complaint about new HDTV set-ups is that

the picture quality of SD material is poor, with huge gaps in detail :

• Standard definition programmes have only 480 lines of information rather than the 720 or 1,080 of HD.

• So when you buy a large new flat screen the picture quality on SD programmes is woeful.

• Unfortunately, there's no real affordable solution, with upscalers capable of changing 480 into 720 costing up to GBP1,250 (Lumagen, Iscan etc.)

• But current generation of TVs do have better upscaling software built-in as standard.

Gaudy bright cloours• Not a problem with high-definition, rather the way

manufacturers set up their TVs before shipping them : • To make them stand out on the shop floor, colours

are always set too bright and vibrant. • Go into your TV's menu, choose the picture-settings

option and adjust all the elements until you get a more natural image.

• If you need help with this, look out for THX-certified DVD movies e.g. Star Wars titles & many Disney, which often come with THX Optimizer in the special features list on DVD. This walks you through the process.

• Otherwise purchase Avia or Video Essentials DVD

Heavy Contrast• If the protagonists in your HD drama stand out a little

too far from the crowd, with what appears to be a halo of white around them, it could well be that your TV's contrast setting is too high.

• This is often a problem if you had your flatscreen TV before you got HD, and the contrast was boosted to improve the picture on SD broadcasts :

• Similar solution to Overly Bright Colours.

• Enter your TV's picture-settings menu and adjust the contrast until the lines disappear and normal service is resumed. If necessary, use a THX Optimizer to help you calibrate the settings.

Films blurred, out of focus• Are movies a disappointment ? Perhaps your TV is

outputting at too low a resolution. • There are 2 HD formats: 720p and 1,080i. • While sport looks great in 720p - faster image updates

to follow the action more easily – this is non optimum sharpness for films at this resolution.

• If your HD box's settings menu allows it, set it to output to your screen in its 'native' resolution - ie, how it's broadcast - rather than default to 720p or 1,080i.

• This allows the processing software in your TV to deal with the image and (hopefully) make it look its best.

Artifacts in dark areas• When you look at the dark areas of an HD image,

there are annoying amounts of movement in the picture, as if the black is 'crawling' across the screen.

• This irritating problem, known as 'dynamic false contouring', is the result of poor signal processing :

• The answer ? • New TV ! • Be warned, when looking for a new screen -

particularly from one of the less well known brands - ensure you test it with some dark images before parting with your money.

Powerline Adaptors (AKA Homeplugs)

• http://www.southgatearc.org/news/october2008/comtrend_powerline_adaptors.htm

• This video demos QRM via a Sony SW RX and a scanner & also includes a brief look at the Comtrend Homeplug innards.