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UK Terrestrial High Definition TV (HDTV) trials to commence in 2006
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Tuesday 15th November 2005
On the 8th November 2005, the BBC issued a press release stating its intention to trial HDTV terrestrial broadcasts at
specific locations within the UK in 2006.
High Definition Television (HDTV) allows the viewing of TV at much higher resolutions than conventional TV.
Standard Definition broadcasts pictures at a resolution
of 720 x 576 pixels in interlaced format, but HDTV allows for progressive and interlaced pictures up to 1920 x 1080 pixels giving much higher image quality. Also, the HDTV specification
encompasses enhanced audio coding technologies such as AC3 (AAC or A52), making true 5.1 surround-sound possible.
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HDTV is already available on the Digital Terrestrial platform in other countries around the world (eg Australia), but Europe has, up to now, lagged behind in this crucial
enhancement to the television experience.
Nebula's DigiTV software application and hardware package are already capable of receiving conventional terrestrial HDTV broadcasts (MP@HL), and has been doing so now for a
number of years in Australia. However, the 2006 terrestrial trials for the UK are likely to require additional software enhancements in order to receive and decode because of the
already full TV spectrum in use in the UK. The most likely candidiate for the codec to be used is H.264 MPEG 4 AVC.
Nebula Electronics is currently talking with the relevent UK authorities with a view to having the DigiTV software ready with any enhancements necessary
to take part in the trials as and when they occur in 2006.
HDTV vs SDTV direct comparison
The following images are blown up portions of HDTV and SDTV images respectively, and nicely show three of the key differences between HD and SD formats
HDTV 1080i image
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1 - The image resolution is higher for the HD image (obviously!)
2 - The overall level of detail is much higher in the HD image. Look especially around the whiskers.
3 - There are hardly any MPEG compression artefacts visible due to the higher bitrate and/or more advanced coding methods (eg H.264).
Look at the halos around the ears in the SD image and see that they are hardly visible at all in HD.
One improvement these images can't show is there are far fewer artefacts visible during times of high image movement with HD. If you want an
example of how it is currently, closely watch the screen when the balls are going around the lottery machine on the National Lottery programme.
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SDTV image
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