The BBC Trust is now involved in the complaints about the declining quality of the BBC�s HDTV signal. Hundreds of viewers have complained, either direct to the BBC or via TV Internet forums, arguing that the BBC�s images are failing in their core remit to �adhering to, or seeking to exceed, industry standards for picture resolution�.

In December Andy Quested, the BBC�s HD Principle Technologist, went on line in a formal BBC blog about HDTV with a series of answers to viewer complaints, and which failed to address many of the grumbles. The blog has since been discontinued.

The BBC�s head of HD, Danielle Nagler, has admitted that the BBC�s HD output is now only 9.7 Mb/s, significantly down on its initial 19 Mb/s broadcasts, and this � say the BBC�s critics � is at least part of the reason why images are softer and lack the �Wow� factor of true HD. BSkyB uses up to 19 Mb/s per multiplex for its top quality HD coverage (and generally operates its sports HD within a range of 15-17 Mb/s).

This lower BBC HD channel quality was noticed late in 2009 when the BBC changed their HD encrption software.

Mr Eaton, in his formal complaint to the BBC Trust, says that BBC high-def transmissions are some 20% below those recommended as the HD minimum by the European Broadcasting Union, and as such should not be described as HD.

Eaton includes in his submission contributions from many informed viewers who question the reasons and excuses given by the BBC for their output. Additionally he points out that the BBC�s pixel output � at least one method of calculating quality � is 25% below �Full HD� (at 1.55m pixels per screen, compared with more than 2.07m pixels on �full 1920 x 1080� HD.

In fact, says Eaton, the BBC�s British HD bitrate output is the lowest in Europe, lower even than the much-criticised Channel 4 HD, and lower even than the BBC�s own BBC HD Europe feed (at 16 Mb/s in full HD at 1920 x 1080). Eurosport HD comes out best in Eaton�s submission.

According to reports and forum posters even though Channel 4 HD is showing upscaled SD it still looks as good and sometimes better than BBC HD does.