Digital TV video bitrates – January 2011

Time to update the video and audio bitrates for digital TV again in the light of the introduction of the new channel ‘Eleven’. (The last update was in October last year.)

To gather this data, on 18 through 20 January I  recorded at least 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.

Station Ch Audio
video bitrate (Mbps)
ABC1 2 MPEG 2.0 256 720 x 576i 4.95
ABC2 22 MPEG 2.0 256 720 x 576i 4.04
ABC3 23 MPEG 2.0 256 720 x 576i 3.97
ABC News 24 24 DD 2.0 256 1280 x 720p 9.12
SBS ONE 3 MPEG 2.0 192 720 x 576i 4.12
SBS TWO 32 MPEG 2.0 192 720 x 576 4.15
SBS HD 30 MPEG 2.0 192 1280 x 720p 9.37
SC10 Canberra 5 MPEG 2.0 256 720 x 576i 5.14
ELEVEN 55 MPEG 2.0 256 720 x 576i 4.17
One HD Canberra 50 DD 2.0 448 1440 x 1080i 11.47
PRIME Canberra 6 MPEG 2.0 256 720 x 576i 5.06
7TWO Canberra 62 MPEG 2.0 256 720 x 576i 4.64
7mate Canberra 63 DD 2.0 256 1440 x 1080i 9.99
WIN Canberra 8 MPEG 2.0 384 720 x 576i 4.94
Canberra GO 88 MPEG 2.0 384 720 x 576i 4.58
GEM Canberra 80 DD 2.0 448 1440 x 1080i 9.72

ELEVEN has come at the expense of about 1Mbps from SC10 Canberra, and about 2.5Mbps from One HD Canberra. TEN and PRIME had rock steady bitrates across the three different recordings (max variance: 0.02Mbps), while WIN’s varied a little (max: 0.14Mbps), SBS a bit more (max: 0.34Mbps) and ABC quite a bit (max 0.86Mbps). I suspect that ABC at least actively manages its bitrate allocation according to programming requirements.

Update (11:13 am): fixed the audio bitrates and, consequently, the video bitrates on ABC News 24 and GEM Canberra. The former has reduced its bitrate, while the latter has reverted to a largely unnecessary 448kbps.

This entry was posted in Codecs, DTV, HDTV. Bookmark the permalink.

4 Responses to Digital TV video bitrates – January 2011

Leave a Reply

Your email address will not be published. Required fields are marked *