[yeslek]

Apologies if this has been asked earlier but I just have to know.

Why is there such a difference in the HD pic quality between BBC and ITV?

I watched "Collision" on ITV HD and recorded "Life" on BBC HD and as far as I am concerned there is a world of difference with BBC winning hands down. Even the audio is better with BBC Dolby Digital and ITV Pro Logic. Why?

[jzee]

Originally Posted by yeslek

Why?

BBC gets billions a year in guaranteed income and ITV doesn't? In the case of films the quality may be due to the fact the movie has not been remastered, even though it has been scanned in HD resolution. A modern digitally produced film will almost always look better.

[SkipTracer]

I think there are loads of post around here about PQ. I have not watched Collision yet so I can’t comment but I hope its not another naff series.

Bit rates besides I think at least 50% of HD programmes that are made for TV look like nothing more that good SD quality.

The quality can change within a series like Doc Martin for instance some of the episodes looked like up scaled SD and others where OK.

With the sound its a different story. ITV HD don’t do DD at the moment so the sound on ITV will always be inferior to the BBC.

[u006852]

AFAIK Collision was filmed in super 16.

This is a format that the BBC consider inadequate for HD and will not use it.

http://www.bbc.co.uk/blogs/bbcintern...annel_fro.html

"Moving on to programmes, one of my jobs before we had an HD service was to help production teams deliver their programmes in HD to some of our major co-producers. Very early on, we discovered that no-one would accept Super 16mm film as an HD format. I did a lot of work with post-production facilities to try to come up with a way to make it possible, but there was no compromise: Super 16 was just not HD."

BTW ITV sound is DD, but just stereo and not 5.1

[jzee]

Originally Posted by u006852

AFAIK Collision was filmed in super 16.

This is a format that the BBC consider inadequate for HD and will not use it.

Perhaps they'd like to admit a bitrate constrained at 9.7Mbps is inadequate for 1080i HD?

[yeslek]

Originally Posted by u006852

AFAIK Collision was filmed in super 16.



BTW ITV sound is DD, but just stereo and not 5.1

Not according to my Yamaha amp. It shows Dolby Digital on BBC and Pro Logic on ITV.

[tghewett]

Originally Posted by yeslek

Not according to my Yamaha amp. It shows Dolby Digital on BBC and Pro Logic on ITV.

That's right, the amp will be set to multichannel mode to decode DD 5.1 and if it only gets a stereo signal, be it analogue, PCM, or Dolby Digital 2.0, it will attempt to decode it as Dolby ProLogic. There is no way to detect if a stereo signal contains a prologic multichannel matrix, you just have to "know" and set it manually, e.g. from the sleeve information on old pre-recorded VHS films, TV listings etc..

Sometimes you'll see the BBC also show up as prologic as some programmes are stereo and so transmitted as DD 2.0 like ITV.

[u006852]

Originally Posted by tghewett

That's right, the amp will be set to multichannel mode to decode DD 5.1 and if it only gets a stereo signal, be it analogue, PCM, or Dolby Digital 2.0, it will attempt to decode it as Dolby ProLogic. There is no way to detect if a stereo signal contains a prologic multichannel matrix, you just have to "know" and set it manually, e.g. from the sleeve information on old pre-recorded VHS films, TV listings etc..

Sometimes you'll see the BBC also show up as prologic as some programmes are stereo and so transmitted as DD 2.0 like ITV.

Precisely!

I set my amp to decode stereo sources as prologic, mainly as it will move the dialogue to the centre speaker. This will "lock" the dialogue to the screen rather than the more diffuse centre image effect given by the stereo speakers 7ft apart.

[u006852]

Originally Posted by jzee

Perhaps they'd like to admit a bitrate constrained at 9.7Mbps is inadequate for 1080i HD?

Indeed.

It absolutely amazes me that they will have standards like this and only allowing 25% upscaled material, but then totally contradict themselves by pretending the bit rate is adequate.

Personally I think the management is telling technical people the cost is too high, it doesn't fit the business plan.

Technical are caught between a rock and a hard place!

[jzee]

Originally Posted by u006852

Personally I think the management is telling technical people the cost is too high, it doesn't fit the business plan.

Technical are caught between a rock and a hard place!

Actually it is nothing to do with cost as BBC are still paying for the 8.9Mbps of wasted space on the BBC HD transponder! I think the real reason is in fact incredibly stupid, that they thought they should set the level around the level of Freeview HD so it won't be seen as 'inferior' when it launches. The problem is, although the average of Freeview HD will probably be around 9.7Mbps (what the satellite fixed rate is currently), the Freeview HD BBC HD will be stat muxed, so its bitrate will be able to increase to 12-14Mbps when needed on difficult to encode scenes, i.e. shadowy/dark areas and fast/complicated movement. As a result the picture quality will be clearly superior- from a conspiratorial point of view, you could say that may help the sale of Freeview HD boxes....

[figrin_dan]

Originally Posted by yeslek

Not according to my Yamaha amp. It shows Dolby Digital on BBC and Pro Logic on ITV.

My Yamaha amp shows Pro logic in big letters but the dolby digital logo is also lit, this is on itv-HD and most BBC-HD programmes I have seen. Occasional BBC-HD programmes show dolby digital in big letters too. This is the difference between DD 5.1 and 2.0. All other channel are MPEG 2.0 so only the Pro logic logo and big letters are lit.

btw for what it's worth: 2 channel sources are not "in Pro logic" - They can be "in surround" but the centre channel is created by your Pro logic processor.

[DaveCheltenham]

Originally Posted by u006852;36583063 AFAIK Collision was filmed in super 16.

This is a format that the BBC consider inadequate for HD and will not use it.

http://www.bbc.co.uk/blogs/bbcintern...annel_fro.html

"Moving on to programmes, one of my jobs before we had an HD service was to help production teams deliver their programmes in HD to some of our major co-producers. Very early on, we discovered that no-one would accept Super 16mm film as an HD format. I did a lot of work with post-production facilities to try to come up with a way to make it possible, but there was no compromise: Super 16 was just not HD."

BTW ITV sound is DD, but just stereo and not 5.1

The Blue Ray DVD of the BBC 1995 version of Pride and Prejudice was taken from the Super 16 original negatives and is stunning and a lot better than many of the HD programmes they transmit from different sources. This is not just my opinion so perhaps the methodology has improved? Using the positives gives very poor quality and washed out colour.

Regards

[scoobiesnacks]

Originally Posted by jzee

Actually it is nothing to do with cost as BBC are still paying for the 8.9Mbps of wasted space on the BBC HD transponder:rolleyes....

jzee
Is that true - what is your source for this? I would have assumed they only pay for what they use.

[Nigel Goodwin]

Originally Posted by scoobiesnacks

jzee
Is that true - what is your source for this? I would have assumed they only pay for what they use.

It depends entirely on the contract they have, they may lease by bandwidth, but may just lease an entire transponder to do with as they wish (sub-letting any excess space to others).

In either case though, paying for something you're not using is a waste.

[Ray Cathode]

Originally Posted by jzee

I think the real reason is in fact incredibly stupid, that they thought they should set the level around the level of Freeview HD so it won't be seen as 'inferior' when it launches. The problem is, although the average of Freeview HD will probably be around 9.7Mbps (what the satellite fixed rate is currently), the Freeview HD BBC HD will be stat muxed, so its bitrate will be able to increase to 12-14Mbps when needed on difficult to encode scenes, i.e. shadowy/dark areas and fast/complicated movement. As a result the picture quality will be clearly superior- from a conspiratorial point of view, you could say that may help the sale of Freeview HD boxes....

Actually Freeview HD will launch with average channel bitrates of 12Mbps. This will go down to 9Mbps in Q3 2010 when Five HD is supposed to launch. Obviously peak bitrates will be higher.

http://www.ofcom.org.uk/radiocomms/d...nationart3.pdf

(last page)

I agree with you in so far as the BBC seem to think that a fixed bit rate of 9Mbps on satellite is equivalent to a 9Mbps statistically multiplexed terrestrial version when it obviously isn't.

[jzee]

Originally Posted by scoobiesnacks

jzee
Is that true - what is your source for this? I would have assumed they only pay for what they use.

I am pretty sure BBC lease whole transponders, as do Sky, C4 and ITV, in fact I think it is the case for all Astra transponders on 28.2 to be solely leased to one company or another. There is really no sense in the BBC HD satellite reduction other than imo to at least make Freeview HD not look inferior, and possibly to make it it superior, at least until they put 5 channels on there that is.

[RichardRees]

Originally Posted by jzee

I am pretty sure BBC lease whole transponders, as do Sky, C4 and ITV, in fact I think it is the case for all Astra transponders on 28.2 to be solely leased to one company or another. There is really no sense in the BBC HD satellite reduction other than imo to at least make Freeview HD not look inferior, and possibly to make it it superior, at least until they put 5 channels on there that is.

I think you are right re the BBC, but some transponders are leased to the likes of Arqiva who then sub-let them onwards to a multitude of broadcasters.