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Freeview Picture Quality

Getting Worse? (November 2005)

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NG
noggin Founding member
Ah...

The DigiTV software is reporting the bitrate quoted in the MPEG transport stream headers, or elsewhere in the stream, that indicate the MAXIMUM possible bit rate that could be expected, not the actual bitrate being used. The max figure is used by some MPEG2 decoders to allocate memory for the buffers required to decode MPEG2.

You'd do a LOT better looking at the bitrates reported by TSReader Lite, which actually measures the bitrates for each audio and video stream in a mux.

The ITV/C4 Mux contains a total of 24Mbs - and within that carries a LOT of channels. (ITV1,2,3,NC, C4, E4, E4+1, Quiz Call, though I think More 4 is carried on a Freeview mux?, as well as teletext) That means that if the bandwith is shared equally - they all get an average of 3Mbs...

BBC One on Freeview in England is permanently 4.8Mbs (or was last time I checked)
LO
Londoner
noggin posted:
The ITV/C4 Mux contains a total of 24Mbs - and within that carries a LOT of channels. (ITV1,2,3,NC, C4, E4, E4+1, Quiz Call, though I think More 4 is carried on a Freeview mux?, as well as teletext

More4 is on Mux 2 - it's E4+1 that's on a different mux
BC
broadband cowboy
http://forum.digitalspy.co.uk/board/showthread.php?s=d104c06691c0c7e28f00b8a7f2e24573&t=293019&page=1&pp=25

Just dug up a thread which will tell you a bit more about it - have a read - some of the channels are operating down around 2Mb/s - what S4C were using for their rugby at one time - don't know what they're using now......
BC
broadband cowboy
http://www.cs.ucl.ac.uk/staff/r.akester/icomiv3.pdf

Some more proof. 15Mb/s ? Laughing Laughing Laughing Laughing Laughing Laughing Laughing Laughing
CO
ChrisO
noggin posted:
The DigiTV software is reporting the bitrate quoted in the MPEG transport stream headers, or elsewhere in the stream, that indicate the MAXIMUM possible bit rate that could be expected, not the actual bitrate being used. The max figure is used by some MPEG2 decoders to allocate memory for the buffers required to decode MPEG2.


That makes absolute sense. I did some Googling and it produces similar figures to what you guys have been quoting, in the region of 3 to 4 Mbps for BBC One on various sites. 15, bless.
BC
broadband cowboy
If you'd watched soccer on ITV digital that went bust , you'd know the bitrate was of a lower order ( very low ). They're only in it for the money ! so don't expect your piccies to get any better- just your "choice" of more channels.
That forum I posted has some very interesting reading , by the way.

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