BBC HD Picture Quality Campaign *** NEEDS YOUR SUPPORT ***

[Saner]

Originally Posted by TonyA

Downloading it now.... that site for the download is "interesting"!

Was just a link I had from someone who wanted a copy of a sql backup I had.

Now you have made me aware of it, I am going to have to investigate some more :D

[TonyA]

Originally Posted by grahamlthompson

Sorry Tony I should have done the conversion at my end before uploading the files. Not sure if the two support files will work with the original (if renamed to match). If it's a big hassle post and I will check

Graham

Hi Graham, I've downloaded it, and ran it through AV2HDR and played it via the USB stick. Looks really good. HD as it should be seen!

[awesometeeth]

cant get the download to work, it stops after a few secs. only 50kbs anyway tsk

[Volante]

I support the picture quality campaign. Not because of bitrates, encoders, PSNR, capture tests, or any other technical justification.

I am just a viewer, a supporter of the BBC, but a fussy customer and one with a keen eye.

Whatever the differing opinions on forums, which is healthy debate, most of the time, it is my opinion on which I make my stance. As valid as the next.

BBC HD was always very good. Now a lot of the material suffers.

I ADMIT, some is still very good. Pirates of the Carib..Dead Mans...was an example of a very good PQ. I ALSO admit that Gavin and Stacey, in my opinion, is smeary in SD also, so I think this is a production problem rather than HD. Top Gear Polar. I have pre and post August recordings. Not a lot of difference but there is a difference.

So, yes, sometimes it can produce the goods under the new set up. But not consistently.

But I noticed the PQ change BEFORE even knowing anything about bitrates and encoders. My dear lady, who doesn't give a monkeys about all this debate, has also said 'can't see the difference'.

We don't even get 1080x1920 for God's sake!

My point....I believe the PQ has suffered in the most part. And that is all that matters.And if this dumbing down is allowed, then we here in the UK, will have mediocre HD.

The British 'that will do' attitude strikes again. Good job we don't make TV's in this country..but in there, lies the problem. A lot of the panels are just too good for what we get transmitted.

[awesometeeth]

One thing I really would like to make crystal, the encoders have moved on so much from a few years back.

I have personally seen H.264 encoders evolved over the years, it could make up for the drop in bitrate.

maybe surprising, but its the truth.

edit: and if we hadn't noticed, we have already lost any quality battle. just load up any SD channel and see what they are happy pushing onto us

[Mike02]

If everything else stays the same then reducing the bitrate usually reduces the picture quality.
However in this case as with SKY a year or so ago an investment in the latest mpeg4 encoder has allowed HD broadcasters to realise the promise of the H.264 codec.

This codec was advertised with a 40% saving in bandwidth over mpeg2 and that was back in 2005/06 hence the choice to use the more expensive solution by SKY etc.
Three years later the H.264 hardware and software are finally capable of delivering on the performance the customers were promised although tweaking and fine tuning will probably be high on the agenda for the next few weeks to maximise performance from footy (very demanding) downwards.

In essence broadcast HD using H.264 was always meant to be around the 10-12mbps region and SKY+HD was set up the way as seen in the predictive usage level of around 5gig an hour.


Mike

[mwardy]

Mike02: ok, so where does that leave the BBC with its 9.7 mbps CBR? And the EBU recommendation of 12.1 mbps minimum bitrate for its current encoder at its current resolution?

I don't think any sensible person is saying there can't be significant bitrate reductions that maintain or, gasp, improve the PQ, perhaps back to the trial levels. (Hat ready on the grill.) It's just that the BBC has gone too far and underestimated its audience IMHO. I believe the high level decisions are being taken by the guy who gave us DAB...God help us.

Why should tweaking be especially high on the agenda for the next few weeks? Was that an insider hint about current events?

[Mike02]

Its only a laugh mate. It was a quick copy and paste job from DS.

You got me before Graham did




Mike

[mwardy]

Mike02: bloody hell, that was obscure

edit: but it brought up something interesting. That quote is from here: Digital Spy Forums - View Single Post - BBC HD has new encoders. Slashes bandwidth by 40% too. but from post 16 onwards there is an exchange with the BBC about Luxe HD that makes me think Luxe is not pre-encoded but uses the software based x.264 encoder. Fancy that!

[Mike02]

yep I thought it was good

[loz]

Originally Posted by Volante

But I noticed the PQ change BEFORE even knowing anything about bitrates and encoders. My dear lady, who doesn't give a monkeys about all this debate, has also said 'can't see the difference'.

This was the point I raised in my blog explaining why I ended up starting the no 10 petition, that I too had no idea about any encoder or bitrate changes by the BBC when I first noticed the decline in PQ on BBC HD.

I and others are being accused of assuming because the numbers are smaller they must be worse and hence imagining the decline, but it is evident many people beside myself had noticed the decline without knowing the numbers had changed.

[TonyA]

Originally Posted by loz

This was the point I raised in my blog explaining why I ended up starting the no 10 petition, that I too had no idea about any encoder or bitrate changes by the BBC when I first noticed the decline in PQ on BBC HD.

I and others are being accused of assuming because the numbers are smaller they must be worse and hence imagining the decline, but it is evident many people beside myself had noticed the decline without knowing the numbers had changed.

That goes for me too! I had no idea, until I kept watching the channel and thinking that the PQ wasn't as good as it had been, and only when I started to dig around on the internet, I discovered Paul Eaton's campaign, and discovered that the Beeb had changed things in the background!

Don't give a toss if its bitrate, bobrate, nitrate, encoders, decoders, scotch and soda's.... (I think I've seen too many "Two Ronnies"!) - I just want them to admit that there is a problem, and sort it out, so we get the picture quality that we used to have and marvel at, rather than this!

[TonyA]

Did anyone see Wallander on BBC HD last night?

I think that pretty much summed up what's wrong with BBC HD right now.

Last year the program displayed some of the best HD PQ that the channel had showed mainly due to it being shot on the RED HD cameras (the 1st BBC drama to use RED). The opening scene of the first episode where Wallander walked through the yellow rapeseed field to reach a girl, who was pouring petrol over herself, was totally stunning.

Then we come to this year, and last night's episode... what a mess. At times it was like the picture was grey and fuzzy, with no depth, no detail, unless everything in the picture was still, but as soon as there was movement, all detail was lost again. As for the dark scenes, the digital blocking was terrible.

Perhaps the Beeb are using this as a ploy for us to all rush out and buy Blu-Ray box sets of these series, so we can actually see them in real HD, and therefore also bolster the BBC coffers!

[Eltee]

Originally Posted by TonyA

Did anyone see Wallander on BBC HD last night?
I think that pretty much summed up what's wrong with BBC HD right now.

I didn't see last night's Ep but would be interested to know if this is yet another BBC programme broadcast in ProLogic and not DD 5.1. They seem to be growing by the month. I know everyone is fixated with picture quality but sound is just as important.

[grahamlthompson]

Originally Posted by Eltee

I didn't see last night's Ep but would be interested to know if this is yet another BBC programme broadcast in ProLogic and not DD 5.1. They seem to be growing by the month. I know everyone is fixated with picture quality but sound is just as important.

The audio is DD2.0

[Eltee]

So, a questionable picture and non-surround sound. Nice one, BBC

[ayh20]

The one that got me over the Xmas break was the New years Eve Joules Holland ... it was staggeringly bad.
The way the dark parts were broadcast was appalling ... artists appeared to have halo's where the encoder couldn't simply deal with light reflecting of artists hair. Simply staggering ....

(I do have to say the SD version was just as bad)

What we need is lossless encoding or maybe some standard for what percentage of detail is lost in the encode/decode process.

Andy

[grahamlthompson]

Originally Posted by ayh20

The one that got me over the Xmas break was the New years Eve Joules Holland ... it was staggeringly bad.
The way the dark parts were broadcast was appalling ... artists appeared to have halo's where the encoder couldn't simply deal with light reflecting of artists hair. Simply staggering ....

(I do have to say the SD version was just as bad)

What we need is lossless encoding or maybe some standard for what percentage of detail is lost in the encode/decode process.

Andy

Lossless encoding is impossible there's too much data to transmit. It's more a question of loss of detail in rapidly moving objects which is where bitrate comes in.

[awesometeeth]

the one thing i want to know, those who have seen awful progs recently, have you seen anything that you thought looked good?

i know the jools holland thing looked truly awful on SD, but i didnt expect much else

edit: and nother question while im here :D do you still find HD has the same impact on other media? Do you still find blu ray gives you the "wow" factor to use the excruciating word

personally i don't. nothing make me go ooh any more

[ayh20]

Originally Posted by awesometeeth

the one thing i want to know, those who have seen awful progs recently, have you seen anything that you thought looked good?

i have seen things on other channels that i thought were good .... and somethings that are ok..

Originally Posted by awesometeeth

edit: and nother question while im here :D do you still find HD has the same impact on other media? Do you still find blu ray gives you the "wow" factor to use the excruciating word

Well i've only recently bought into BluRay and yes i think it has the wow factor.

The biggest wow is for DVD's played on the BR ... I'm stunned how good it makes them

[ayh20]

Originally Posted by grahamlthompson

Lossless encoding is impossible there's too much data to transmit. It's more a question of loss of detail in rapidly moving objects which is where bitrate comes in.

It's certainly not "impossible", impractical almost certainly ... I'd be intrigued on what sort of bit rate that would be required. 30mb ? 40mb ?

But what about 3D TV ? Isn't that going to require very high bit rates ? (Personally i don't get the point of 3D TV ....)

You mention rapid movement .... a good example of what's wrong with BBC HD was a recent music show ... the background was static and crystal clear, the artist was bouncing in time with music and blurred out of recognition.. for pete's sake they only have to transmit the bit that's moving ! And it can't even cope with that ... duh

[TonyA]

Originally Posted by ayh20

i have seen things on other channels that i thought were good .... and somethings that are ok..

Well i've only recently bought into BluRay and yes i think it has the wow factor.

The biggest wow is for DVD's played on the BR ... I'm stunned how good it makes them

I think that's where things have gone wrong. Some other HD channels broadcast very good HD: Eurosport and Rush for example, but we're being dished up "ok" or at worst "bad" HD from BBC HD now, whereas they used to broadcast an excellent picture.

I've seen many BD's that have that "wow" factor. But I think I understand where you're coming from awesometeeth, that basically we're getting more used to that level of PQ, so that something has to be pretty exceptional for us to notice it. Although the same could be said, that when something is bad, we're now noticing that more too!

I bought the 1st season of Big Bang Theory recently on DVD (I know its filmed in HD), and when played back via the PS3's Blu-Ray drive the picture is exceptional! Don't see the point in spending extra to get the BD if that's how good it comes out on DVD!

[wack]

I watched Nurse Jackie last night and the picture was awful, the worst i've ever seen, really grainy, I do hope this isn't going to be the standard transmitted when freeview HD launches this year

[grahamlthompson]

Originally Posted by ayh20

It's certainly not "impossible", impractical almost certainly ... I'd be intrigued on what sort of bit rate that would be required. 30mb ? 40mb ?

But what about 3D TV ? Isn't that going to require very high bit rates ? (Personally i don't get the point of 3D TV ....)

You mention rapid movement .... a good example of what's wrong with BBC HD was a recent music show ... the background was static and crystal clear, the artist was bouncing in time with music and blurred out of recognition.. for pete's sake they only have to transmit the bit that's moving ! And it can't even cope with that ... duh

It's impossible to exactly represent an analogue waveform by digitising it. Digitising works by splitting up an analogue waveform into little chunks of square waves the higher the sample rate the smaller the square wave chunks the closer the waveform get's to the original signal but it can't by definition be 100% accurate. Once digitised to transmit it has to be compressed using mpeg compression which creates a full frame of data and sub frames of data containing difference info which allows the decoder to rebuild the original frames. The faster the motion the higher the bitrate required to follow the motion. This process is also inherently lossy so again it's not possible to create a 100% accurate representation of the original source.

A lossless system does exist it uses a single uhf carrier to carry a single TV channel fm modulating the carrier signal using the original waveform. At the receiving end (given a good interference free signal) the uhf carrier is generated locally subtracted from the transmitted carrier leaving only the original waveform. It's known as analogue TV and it's currently being shut down so that dozens of inferior quality transmissions can be shoehorned onto the same uhf carriers using digital multiplexing. Result less uhf band required for TV so the government can flog of the spare capacity.

[ayh20]

Originally Posted by grahamlthompson

It's impossible to exactly represent an analogue waveform by digitising it. Digitising works by splitting up an analogue waveform into little chunks of square waves the higher the sample rate the smaller the square wave chunks the closer the waveform get's to the original signal but it can't by definition be 100% accurate. Once digitised to transmit it has to be compressed using mpeg compression which creates a full frame of data and sub frames of data containing difference info which allows the decoder to rebuild the original frames. The faster the motion the higher the bitrate required to follow the motion. This process is also inherently lossy so again it's not possible to create a 100% accurate representation of the original source.

A lossless system does exist it uses a single uhf carrier to carry a single TV channel fm modulating the carrier signal using the original waveform. At the receiving end (given a good interference free signal) the uhf carrier is generated locally subtracted from the transmitted carrier leaving only the original waveform. It's known as analogue TV and it's currently being shut down so that dozens of inferior quality transmissions can be shoehorned onto the same uhf carriers using digital multiplexing. Result less uhf band required for TV so the government can flog of the spare capacity.

Umm .... not quite what i meant Graham...

My assumption was that the images were captured on a high quality HD cameras (@HD resolution or higher) or cinema film formats (35mm ?), then edited/post production at native resolution. Therefore the limitations are in the capture/production end .... the transmission chain should then be completely transparent.

At the mpeg compression level, as you say, there are compromises that have to be made. It is perfectly possible to be lossless at this stage, but this requires silly bitrates. Compromises have to be made i know, but how can Sky get it right (the Gaza docu the other night was impressive) and the BBC quite so bad.

I want to see what the production team produced not the rubbish that the broadcaster transmitted. (any more than willing to pay extra for it .. )

[grahamlthompson]

Originally Posted by ayh20

Umm .... not quite what i meant Graham...

My assumption was that the images were captured on a high quality HD cameras (@HD resolution or higher) or cinema film formats (35mm ?), then edited/post production at native resolution. Therefore the limitations are in the capture/production end .... the transmission chain should then be completely transparent.

At the mpeg compression level, as you say, there are compromises that have to be made. It is perfectly possible to be lossless at this stage, but this requires silly bitrates. Compromises have to be made i know, but how can Sky get it right (the Gaza docu the other night was impressive) and the BBC quite so bad.

I want to see what the production team produced not the rubbish that the broadcaster transmitted. (any more than willing to pay extra for it .. )

Ignoring audio 1920 x 1080 25fps source using 8 bits for red green and blue requires 1920 x 1080 x 24 x 25/1000 = 1244160 kbpps which is 155,520 kbytes/sec or about 150 Mb/sec. (thats the data transfer speed the TV has to shift data to a full HD display)

ie for truly lossless transmission without any compression about 130 times the current bitrate used by BBC HD

[awesometeeth]

if ITV HD can produce fantastic results, should the shift not move away from the bitrate argument (its only .8 MBit higher)?

although saying that bbc hd is currently 10MBit, maybe your fight has worked

[grahamlthompson]

Originally Posted by awesometeeth

if ITV HD can produce fantastic results, should the shift not move away from the bitrate argument (its only .8 MBit higher)?

although saying that bbc hd is currently 10MBit, maybe your fight has worked

The source material makes a big difference. Anything with any degree of rapid movement decays into a motion artefact mess with insufficient bitrate. Look at the Luxe HD pictures with only 5480kbps, slow pans over tropical beaches and exotic swimming pools don't tax the h264 encoders very much.

[Geoff_W]

Originally Posted by grahamlthompson

A lossless system does exist it uses a single uhf carrier to carry a single TV channel fm modulating the carrier signal using the original waveform. At the receiving end (given a good interference free signal) the uhf carrier is generated locally subtracted from the transmitted carrier leaving only the original waveform. It's known as analogue TV and it's currently being shut down so that dozens of inferior quality transmissions can be shoehorned onto the same uhf carriers using digital multiplexing. Result less uhf band required for TV so the government can flog of the spare capacity.

Totally agree!

We start off with superb performance and then the dead hand of the accountant reduces it to rubbish. Happened with LP > CD > MP3, then FM > DAB (High Bitrate) > DAB (Low Bitrate), now HD Hi-PQ > HD? Poor PQ. The problem is, the discerning listener/viewer is outnumbered by the uninformed majority who happily accept 2nd- and 3rd-rate quality.

Just like most things in this world, progress doesn't necessarily mean better!

Geoff

[awesometeeth]

Originally Posted by grahamlthompson

The source material makes a big difference. Anything with any degree of rapid movement decays into a motion artefact mess with insufficient bitrate. Look at the Luxe HD pictures with only 5480kbps, slow pans over tropical beaches and exotic swimming pools don't tax the h264 encoders very much.

ITV HD is bad as well is it?