[opendtv] UK HDTV results
- From: Dermot Nolan <dermot@xxxxxxxxxxxxxxxxxxxxxxxxx>
- To: opendtv@xxxxxxxxxxxxx
- Date: Tue, 28 Nov 2006 17:27:05 +0100 (CET)
Hi,
I thought you might be interested in this URL:
http://www.bbc.co.uk/info/policies/pdf/dtt_hdtrial.pdf , detailing the results
of the current MPEG4 DVB-T HD trials in London.
I have recently been watching the tests on a Sony VAIO laptop with very
interesting new software from Nebula electronics (www.nebula-electronics.com)
which supports the H264 DVB-T transmissions and can be used with any Microsoft
BDA TV driver. I am using it with a Hauppauge WinTV HVR 900 DVB-T stick (the
Nebula software works with any DVB-T stick using BDA such as Hauppauge. Having
adjusted the video display options using the sophisticated Nebula software I am
able to receive flawless HD pictures on a widescreen VAIO laptop. I think the
software cost me about £70. The software provides a wealth of information: the
SNR at my location is 28dB about 12 miles away using a rooftop antenna (ERPs
are 5kW for the BBC HDTV stations and 1.5kW for the commercial HDTV channels
sharing a multiplex: the range of the service is quite big although it doesn't
match the Freeview stations at 20kW. Naturally the Nebula switches seamlessly
between the HD transmissions and the Freeview MPEG2 stations. It also has a
full 7 day EPG, built-in PVR and capability to burn recorded transport streams
to DVD. Neat. The HD streams appear to be running at 20Mb/s for widescreen
1080i, there is some disappointment with the current efficencies of MPEG4
encoding which doesn't deliver on its promises, and a full commercial service
probably depends on analogue TV shutdown, spectrum availability and a DVB-T2
which is currently being defined. More efficient coding schemes are being
considered by the BBC et al: watch this space. The transmission parameters
appear to be 8k 64QAM, ie around 24 Mb/s in an 8Mhz channel.
This little purchase enabling MPEG4 HDTV on a laptop with a conventional DVB-T
stick shows how far the industrialisation of the DVB-T system has come compared
to its rivals. It did not surprise me that the Phillipines chose DVB-T in
preference to ATSC: the commercial flexibility and pace of product development
says it all. I haven't seen any reception problems in the HDTV services
although, of course, there are encoder errors from time to time: inevitable
with an experimental service.
In the evenings the BBC is showing a lot of dramas made in HDTV, some
simulcasts eg 'Strictly Come Dancing' and 'Robin Hood', live in HDTV, ITV
appears to be showing films, and the others are showing US HD imports such as
Desperate Housewives and Lost.
Kind Regards,
Dermot Nolan
Other related posts:
- » [opendtv] UK HDTV results
