Standard definition, high definition, 576i, 1080i, MPEG2, MPEG4, what does it all mean. Here’s a simple explanation of what you need to know.
To be able to view all the multi-channels available on Digital TV in Australia your TV or other device needs to support the standards and formats in use.
Typically TVs, Set Top Boxes and Recorders on the market in 2016 will support all the standards and formats in use. The Freeview logo ensures that the device is fully supported, but devices without the Freeview logo may still be suitable.
All Digital TV capable devices such as Digital TVs, will support standard definition. The standard definition format used in Australia is 576i.
This the standard for all “Standard Definition” Digital TV broadcasts in Australia. It uses a resolution of 720×576 in an interlaced format. In Australia it runs at 50 fields per second, which means 50 times per second every second row of pixels is refreshed.
This is one of the two “High Definition” Digital TV broadcasting standards in Australia. It uses a resolution of 1280×720 in a progressive scan format. In Australia it runs at 50 frames per second, which means every row of pixels is refreshed 50 times per second. Being a progressive scan format, there can be less flicker and motion blur. Image artefacts may be reduced in movies too.
This is the highest resolution standard in use for Digital TV broadcasting in Australia. It can use a resolution of 1920×1080 or 1440×1080 in an interlaced format. In Australia it runs at 50 fields per second, which means 50 times per second every second row of pixels is refreshed.
Analogue TV was transmitted in Australia using the PAL-B/G format. Video was transmitted 576 lines or rows of pixels in an interlaced format at 50 fields per second. Audio was transmitted using FM.
Some early LCD and Plasma TVs only included analogue tuners. While some of these TVs supported high definition, up to 1080i, they needed Digital Set Top Boxes to use Digital TV.
MPEG2 was the first format used to transmit Digital TV in Australia and as such will be supported by all TVs, Set Top Boxes and Recorders that include digital tuners.
MPEG4 has been used for some channels since 2015. It uses a higher compression ratio to allow more content to be broadcast by a station in a broadcast channel. However some older Digital TVs, Set Top boxes and Recorders may not support this format. On devices that don’t support MPEG4, selecting one of these channels will give a “Scrambled” or other error message.
You can check whether your TV or other device supports MPEG4 by checking the specification section of your manual. Also all devices that carry the Freeview logo and branding will support MPEG4 as this is a requirement for certification.