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Listed below are comments made by Squegg between Thursday, 19th November 2009 and Thursday, 10th December 2009 (15 Hours Ago) .

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The Hitchhiker's Guide to Encoding: And Another Test...(Or PSNR and all that...) 12:03pm on 10 Dec 2009 Quote: "..on the train just looking at the country side passing by when he was convinced he saw compression blocking in the leaves of trees..."

I really did laugh out loud! A great story.

BTW, Has anyone compared the GOP contents from each encoder?
The Hitchhiker's Guide to Encoding: Mostly Testing (Or how to set up an encoder test) 5:53pm on 09 Dec 2009
"..but you know many BBC HD programmes are 1080p25 - actually 1080psf25 ie progressive "wrapped" inside an interlace carrier!.."

We know only too well Andy...
The Hitchhiker's Guide to Encoding: Mostly Testing (Or how to set up an encoder test) 5:47pm on 09 Dec 2009 Dear Andy,

Thanks for the encoding info.

I notice that early NHK tests with picture size found audiences were happiest between 3H and 4H. More motion and a preference towards 4H was more comfortable.

(I. Yuyama, Fundamental Requirements for High Definition Television Systems, NHK Technical Monograph No 32, pp14-20.)

Cinema Audiences apparently cluster around 3.3H
{We shouldn't be surprised for low motion 24fps.}

(D. Fink, Color television Vs Color Motion Pictures, SMPTE Journal, vol 64 No 6, June 1955.)

Regards,

'S'
The Hitchhiker's Guide to Encoding: So Many Tests, and Thanks for All the Recommendations (Or the BBC and the EBU) 8:57pm on 08 Dec 2009 #61 Paul, I havered over Mondeo for a while...

#63 Vism, That presupposes an mean rate of 8Mb/s per channel which is less than the previous half-MPEG2 rate. I agree that stat-muxing will help, but only as far as it goes within mux-ing limits. The clue is from recent references from Andy and Danielle over the introduction of 'more challenging' material. i.e. material with more movement in it.

Also, let's not forget that there is already a massive amount of compression going on. The raw data rate is around 39Gb/s (1440x1080x25) {so much for the vaunted return to square pixels!}.
It would be interesting to know the average number of I frames per second. Anyone?

Encoder advancements will, I'm sure be inevitable, but attention should, as I've said before, focus on improving QUALITY rather than the diminishing return of shaving the odd 0.5Mb/s off the bit rate.

It seems that just "it'll do" is the new gold standard. Typical British thinking.
The Hitchhiker's Guide to Encoding: So Many Tests, and Thanks for All the Recommendations (Or the BBC and the EBU) 6:45pm on 08 Dec 2009 ...so long and thanks for the BITS.
The Hitchhiker's Guide to Encoding: So Many Tests, and Thanks for All the Recommendations (Or the BBC and the EBU) 6:32pm on 08 Dec 2009 Dear Andy,

Thanks for your references on standards.

It seems to me that there is an unspoken problem. The elephant in the room: External political pressures to solve political problems. Some mandarin at OFCOM wants to maximise revenue in return for his/her knighthood.

Therefore there is pressure to shoehorn 4-5 HD channels into a multiplex. In order for those channels to squeeze in, something has to give. The excellent work on DVB-T2 has enabled just over 40Mb/s space to be available (so far). MPEG4 as you indicated should improve bitrate by 2:1. However, that is a theoretical figure on a like for like basis. MPEG2 is probably within its theoretical maximum in terms of technology, whereas MPEG4 is in it's infancy, as you indicated; V1 of the firmware. Given that 19.5Mb/s in a mature MPEG2 environment, it seems on the surface that an immediate 2:1 improvement to an immature MPEG4 environment does not seem likely somehow. Please convince me.

Furthermore, the aforementioned pressure on shoehorning suggests that external pressure has been brought to bear to find 'ingenous' solutions to reduce the bitrate; e.g. a reduction from 1920 to 1440 pels/line, disguised in spin as "efficiency".

It may well be one of a range of 'suitable' formats to broadcast, but does it fulfill the public service remit of 'world class' technical quality expected of a premier broadcaster? In this regard, the BBC is running a 'Bentley' whilst Sky is running the 'Rolls Royce'.

Lastly, there seems to be a race for the minimum possible bitrate for a given source, but there seems to be no room for QUALITY. Tanberg promote their latest MPEG2 coder as able to produce 10% better pictures or to reduce the bitrate by a similar amount to increase channel capacity on a multiplex. How many broadcasters are going to take the 10% extra quality route? I suggest none.

Efficiency is a tension between Quantity and QUALITY and I suggest that in the current circumstances, it is tipped too far towards quantity concerns rather than quality requirements.
Points of View and HD Picture Quality: a response 11:07am on 05 Dec 2009 Unfortunately I could only watch Live at the Apollo in SD at a friend's place last night (Yes, I have real friends so I can't be that geeky, eh Emma?).

Well, what a surprise!

Yes, it was recorded in glorious JudderVision/NechriColor.

What do comedians do when they talk?

Move about the stage and wave their hands around. What does the camera do? Pan.

Judder-Judder-Judder.

The 'APOLLO' in the background particularly showed large areas of Judder.

It didn't look 'live' either. The 3/4 body shots didn't seem in focus either. VERY disassociating.

I'm sorry, how can large area judder be good TELEVISION?

25Hz motion for this kind of material sucks big time.
The Hitchhiker's Guide to Encoding: Before we start 3:40pm on 04 Dec 2009 Dear Andy,

I look forward to your travails with interest. It's easy to forget the complexities of the new sometimes.

I think we all appreciate your engagement on something in which we all have an interest or stake.

'S'.
BBC HD on Freeview: rollout dates 6:48pm on 21 Nov 2009 I concur with HD1080 (again)

50Hz Motion is NECESSARY for accurate motion portrayal.

25P is only required for film transfer. EVERYTHING else should be either 50 fields or frames.

Otherwise 720p50 ought to be reconsidered.

Judder is an unacceptable picture artifact for a modern television system.
Top Gear on BBC HD from November 15th 12:40pm on 19 Nov 2009 Well, It was good to see Top Gear in HD. Praise where praise is due.

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