Digital TV video bitrates – September 2011

The other day Prime TV started broadcasting a new channel in its 6/60 bundle here in Canberra, and presumably elsewhere. This is called ‘Television 4’ and is numbered channel 64. It carries primarily advertorial stuff (exercise programs, Foreman grills and whatnot), plus some educational promotional stuff, apparently largely in consort with the University of New South Wales.

So, time to update the video and audio bitrates for digital TV again. (The last update was in January this year.)

To gather this data, on 19 and 20 September I  recorded six hours, in three separate chunks, from each station onto a Topfield PVR. Then I whacked the minutes and megabytes into a spreadsheet, did the division and subtracted the audio bitrate. These figures probably overstate things a little, depending how much extra the Topfield adds into its recording stream (not much, I imagine, because they are standard MPEG files), and the presence of subtitles. So, really, only the first two significant figures of the video bitstream should be considered.

Also, remember, this is in Canberra. The figures may well be quite different elsewhere. Our commercial stations still broadcast their HD as 1,440 x 1,080, for example.

If anyone would like to repeat the process in a major capital city, I’d be happy to email through the spreadsheet on condition that you provide the information back for publication here in due course.

ABC has reduced the bitrate on News 24 by over 1Mbps and fed that back into the three SD channels. The new channel seems to have come at the expense of Channel 6 and Channel 60. Even so, it has a very low average video bitrate, and the picture quality suffers accordingly. In particular, there is quite a bit of macro blocking.