Freeview HD

Freeview HD offers high definition TV from the BBC, ITV, Channel 4 and Channel 5 without subscription via a TV aerial. You will need a Freeview HD receiver or Freeview HD TV (DVB-T2).
Freeview HD was the first operational TV service in the world using the DVB-T2 standard, which will require the purchase of new compatible reception equipment. 
The signal is encoded with MPEG-4 AVC High Profile Level 4, which supports up to 1080i30/1080p30, so 1080p50 cannot be used.

The system has been designed from the start to allow regional variations in the broadcast schedule. Services will be statistically multiplexed, which means bandwidth is dynamically allocated between channels, depending on the complexity of the images – with the aim of maintaining a consistent quality, rather than a specific bit rate.

The video for each channel can range between 3Mb/s and 17Mb/s. Dolby Digital audio will be transmitted at 320Kb/s for 5.1 surround, with stereo audio at 128Kb/s; audio description takes up 64Kb/s, subtitles 200Kb/s and the data stream, for interactive applications, just 50Kb/s.

 
Technical Information

The Digital TV Group publishes and maintains the UK technical specification for high-definition services on digital terrestrial television (Freeview) based on the new DVB-T2 standard. The specification is known as the D-book.
Freeview HD is the first operational TV service in the world using the DVB-T2 standard.
This standard is incompatible with DVB-T, and can only be received using compatible reception equipment.
To qualify for the Freeview HD logo, receivers need to be IPTV-capable and display Freeview branding, including the logo, on the electronic programme guide screen.
The Freeview HD trademark requirements state that any manufacturer applying for the Freeview HD logo should submit their product to the Digital TV Group’s test centre (DTG Testing) for conformance testing.

To ensure the provision of audio description, broadcasters typically use the AAC codec.
Hardware restrictions allow only a single type of audio decoder to operate at any one time, so the main audio and the audio description must use the same encoding family for them to be successfully combined at the receiver.

In the case of BBC HD channels, the main audio is coded as AAC-LC and only the audio description is encoded as HE-AAC.
Neither AAC nor Dolby Digital Plus codecs are supported by most home AV equipment, which typically accepts Dolby Digital or DTS, providing stereo, rather than surround sound output.
Transcoding from AAC to Dolby Digital or DTS and multi-channel output via HDMI was not originally necessary for Freeview HD certification.

As of June 2010, the DTG D-Book includes the requirement for mandatory transcoding when sending audio via S/PDIF, and for either transcoding or multi-channel PCM audio when sending it via HDMI in order for manufacturers to gain Freeview HD certification from April 2011.

Thus equipment sold as Freeview HD before April 2011 may not deliver surround sound to audio equipment; later equipment must be capable of surround sound compatible with most suitable audio equipment.

Channels

Freeview HD offers high definition TV from the BBC, ITV and Channel 4 without subscription via a TV aerial. You will need a Freeview HD receiver or Freeview HD TV.
Freeview HD was the first operational TV service in the world using the DVB-T2 standard.
Viewers not able to view ITV HD, have the option to view for free via Freesat on satellite.