Sky lowering their bit rate for HD channels ?
Rumor is that , after BBC , Sky is also lowering their bit rate for HD channels .
And that people would have signed letters of confidentiality in an attempt to keep it secret .
Could we ask to the WHF team to have some informations about that ?
Nothing untoward showing on linowsat.So i'd say it's just that.......Rumour!
I'm not sure about SKY lowering thier bit rates, but there was a good article in Hifi World a while backing, basically saying that the BB has decided to half the bit rate of Freesat broadcasts to the same bit rate as its FreeviewHD broadcasts.
It was saying that this decision was had no technical reason for doing so, but only to promote / increase the take up of Freeview. Whats more shocking the BBC issued a statement, something on the lines of (This may be to do with DAB radio as well) that is no proven relationship that higher bit rates results in better quality sound / picture. What a joke!
Its pathetic that the BBC has done this, just for the sake of it.
I would have thought, though that if bandwidth isnt an issue, SKY wouldnt reduce its quality of broadcasts, as it gives them an advantage / selling point over its competitors.
The BBC lowered the bit rates of satellite broadcasts not "Freesat broadcasts",it effects both Freesat and Sky! And by 40% (from 16 Mbps to 9.7 Mbps) not by half. That's not the same as Freeview HD either.sometimesuk:
I'm not sure about SKY lowering thier bit rates, but there was a good article in Hifi World a while backing, basically saying that the BBC has decided to half the bit rate of Freesat broadcasts to the same bit rate as its FreeviewHD broadcasts.
The BBC broadcast at a constant bit rate(CBR) for its satellite transmissions. Whereas channels on Freeview HD are stat-muxed,and as such means that the HD channels have a variable bit rate (VBR) of between 3 and 15 Mbps.
Err,The BBC have always maintained that the reduction in bitrateIt was saying that this decision was had no technical reason for doing so,
was because of the efficiency of their new encoders-Though something is clearly wrong since the PQ did decrease with the introduction of the new encoders,running at lower bitrates......
That is nothing more than speculation,that's been bandied about on various websites.but only to promote / increase the take up of Freeview.
Actually,technically they are correct-Depending on how demanding the content is on the encoders and the efficiency of the encoders, it's perfectly possible to run at much lower bitrates than the BBC uses and still have excellent PQ. Luxe HD is a prime example of how good HD can look at low bitrates,(around 5.4 Mbps).Whats more shocking the BBC issued a statement, something on the lines of that is no proven relationship that higher bit rates results in better quality sound / picture. What a joke!.
daveh75:Err,The BBC have always maintained that the reduction in bitrate was because of the efficiency of their new encoders-Though something is clearly wrong since the PQ did decrease with the introduction of the new encoders,running at lower bitrates......
sometimesuk:It was saying that this decision was had no technical reason for doing so,
And the reason for the Beeb doing this is cost, as they've stated themselves.
I'm confused now then.
Which optionn available at the moment gives the best picture quality. For argument sake, the one with the highest bit rate. Satalite (Sky), Virgin (Cable), FreeviewHD, or Freesat?
Daveh75, I'm no expert but I would imagine that there would be no cost saving for transmitting at a lower bit rate, as after all, the original content is "downmixed" by a computer to a lower bitrate / compression format. I cant see how selecting one format over another attracts increase costs.
IMO,without side by side comparison thats going to be hard to answer-To many variables.You cant just compare bitrates, it varies wildly from channel to channel,let alone across the various platforms.sometimesuk:I'm confused now then.
Which optionn available at the moment gives the best picture quality. For argument sake, the one with the highest bit rate. Satalite (Sky), Virgin (Cable), FreeviewHD, or Freesat?
Depends on the broadcaster. For smaller broadcasters on satellite,yes bitrates will have cost implications, because they lease capacity/bandwidth on satellite transponders, so the higher the bitrate,the more capacity they're using.Daveh75, I'm no expert but I would imagine that there would be no cost saving for transmitting at a lower bit rate, as after all, the original content is "downmixed" by a computer to a lower bitrate / compression format. I cant see how selecting one format over another attracts increase costs
This isn't the case for the BBC,because they lease entire transponders. So they're paying for the full capacity of a transponder regardless of whether they use it.So the BBC excuse of reducing costs is a poor one, they're not saving money,they're actually wasting around 8Mbps of bandwidth
daveh75:Depends on the broadcaster. For smaller broadcasters on satellite,yes bitrates will have cost implications, because they lease capacity/bandwidth on satellite transponders, so the higher the bitrate,the more capacity they're using.
sometimesuk:Daveh75, I'm no expert but I would imagine that there would be no cost saving for transmitting at a lower bit rate, as after all, the original content is "downmixed" by a computer to a lower bitrate / compression format. I cant see how selecting one format over another attracts increase costsThis isn't the case for the BBC,because they lease entire transponders. So they're paying for the full capacity of a transponder regardless of whether they use it.So the BBC excuse of reducing costs is a poor one, they're not saving money,they're actually wasting around 8Mbps of bandwidth
That was what they said, they wanted to maintain quality but it had to be kept cost effective (in one of the original threads on this subject there was a link to a blog that contained the response from the BBC person who said it). Presumably what they meant was they wanted to use the other 8Mbps for something else.
I'm not disputing they said it, i know they did,(though it's probably not on the blog now tbh, it descended into farce was edited and closed for a while).the_lhc:That was what they said, they wanted to maintain quality but it had to be kept cost effective (in one of the original threads on this subject there was a link to a blog that contained the response from the BBC person who said it). Presumably what they meant was they wanted to use the other 8Mbps for something else.
Just pointing out it's a poor excuse. It's been about 8 months since they reduced the bitrate and they haven't done anything with the capacity yet, so i dont see them doing anything with it.
daveh75:I'm not disputing they said it, i know they did,(though it's probably not on the blog now tbh, it descended into farce was edited and closed for a while).
the_lhc:That was what they said, they wanted to maintain quality but it had to be kept cost effective (in one of the original threads on this subject there was a link to a blog that contained the response from the BBC person who said it). Presumably what they meant was they wanted to use the other 8Mbps for something else.Just pointing out it's a poor excuse. It's been about 8 months since they reduced the bitrate and they haven't done anything with the capacity yet, so i dont see them doing anything with it.
I was thinking they might be using it for red button stuff, there seems to be no end to the additional channels they can get through that on Sky.
Did think that myself,when they dropped the bitrates,especially as the Olympics and the World cup were/are imminent
But the BBC have been trying to reduce the number of red button services-they cut a load from Freeview, and there has only ever had 6 Sport multi-screens available on Freesat(no News multi-screen etc). I know theres still loads of them on Sky,but for how long i wonder.
busybee330:Rumor is that , after BBC , Sky is also lowering their bit rate for HD channels .
And that people would have signed letters of confidentiality in an attempt to keep it secret .
Could we ask to the WHF team to have some informations about that ?
Can you post more details - where did the rumour come from ?
I noticed what I thought was a difference in Sky PQ tonight on Sky HD 1. I checked Linosat and couldn't believe it - they seem to have dropped the bitrate to squeeze some sports channels onto the transponder - Sky HD 4.
Most people I've come across are of the opinion that Sky HD is the best quality at the moment.
As for the BBC I should clarify that when Davey says "satellite broadcasts" he does in fact mean BBC HD broadcasts. Sky are using a higher bit rate for their content.
I can't confirm the reasons for the bit rate reductions but there are certainly rumours that it may be to do with ensuring Freesat doesn't have a better picture than Freeview, although these are pure sepculation so far as I'm aware.
I can confirm though that I have seen a massive reduction in picture quality on BBC HD since the encoder change despite BBC claims that the PQ hasn't been affected. There are still one or two programmes that look good but most are now soft especially on facial areas. Really bad recent examples are Countryfile, Waterloo Road, Ashes to Ashes and some say Jonathan Ross.
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