By Dan Barrett

Nine this week wowed sports fans with the news that the network will begin simulcasting its primary channel in HD, but not all viewers with a high definition television will be able to watch it.

The network has announced a radical shake-up of its current broadcasting channels. Its current HD channel Gem will shift to standard definition, Nine will introduce its new free-to-air broadcast lifestyle channel 9Life, and Nine will begin broadcasting its primary channel as a pair of standard definition and high definition channels.

To accommodate the extra channels that will broadcast, Nine has had to embrace a different compression type. From the commencement of digital TV broadcasting in Australia, networks have broadcast their signal with the MPEG2 compression type. To broadcast 9HD, Nine will employ MPEG4. This means that older TV sets and receivers may be able to receive a high definition MPEG2 signal, but are not equipped to receive MPEG4.

For most viewers, this shouldn’t pose a problem. It is believed that the average life cycle of a television set in Australia is about five years, with older sets that don’t support MPEG4 no longer being used as a households primary set. Of course, some viewers may still be using older TV sets.

When asked how many viewers may be negatively effected, Nine’s director of broadcast operations Geoff Sparke advised Mediaweek that it’s “hard to say. We believe that MP4 decoders have been inbuilt since about 2007, and on average about one million panels are sold per year. So I would suggest the main screen in about 90% of homes are MP4 capable”.

Viewers who cannot receive the HD signal will be able to continue to watch Nine as a standard definition channel.

The shift to adopt MPEG4 compression broadcast does bring with it a significant video quality upgrade. Currently the Australian HD signal offers a 1440 x 1080 resolution, but MPEG4 will provide greater clarity, with Sparke confirming they will broadcast in full HD 1920 x 1080.

Nine will re-stack their channels on 26 November 2015. Some viewers may need to re-scan their television sets to receive the new channel lineup.

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