5 replies to this topic

[pheggie]

http://3dcinecast.bl...v-standard.html

"The DVB Project Considers New 3DTV Standard

The DVB project finalised the first 3DTV broadcasting specification at the beginning of 2011. It’s now an ETSI standard - the world’s first 3DTV broadcasting standard. This is a ‘Frame Compatible’ format that can work with existing HDTV set top boxes – though they may need a download upgrade to take advantage of the capability to position subtitles at different scene depths, to match the positions of different characters in the scene.

Some terrestrial broadcasters argued that, if they were to use a 'Frame Compatible' system, they needed a way to serve 2D viewers at the same time, without taking up another delivery channel. One way, though not always possible, depending on nationally sold set top boxes, is to use MPEG signalling to instruct the set top box to stretch and display the left image as a 2D image. Another, is to use an interactive application (such as MHEG-5) to pull out, stretch, and display the left image as a 2D image as part of an interactive ‘red button’ service. Each approach has pluses and minuses.

Thousands of hours of 3DTV programming have been made; and, across the world, programme makers understand the supreme care that is needed to make 3DTV programmes to minimise eye discomfort. We understand more about what window violations are tolerable, how to handle scene cuts, converged and parallel shooting, and about maximum positive and negative disparities for home size screens. 3DTV production grammar is being tamed.

There is always a horizon. For 3DTV, in the longer term, this may be a multiview broadcast system, where autostereoscopic displays provide more than two images. Beyond that it may be an ‘object wave’ system, of which the hologram is a simple form. But these are probably not for the near future – more research and development is needed before we see large screen consumer autostereoscopic displays which are not head-position sensitive.

The issue now for DVB is whether an ‘improved’ plano-stereoscopic system will be needed in the next five years. The DVB Project has been discussing this and hopes to reach a conclusion in the autumn of 2011. This would be 3DTV ‘Phase 2’. True, it would need a new set top box (or equivalent), but the pay off would be extra quality or features.

One of the open issues is picture quality. The current 'Frame Compatible' (or Phase 1) delivery system is obliged to share the resolution capability available from an HDTV delivery channel between the left and right images. Would there be a seriously perceptible improvement in quality if the Phase 2 system delivered all the resolution capability of an HDTV channel in each image?

Would it be enough to justify a new delivery system? Blu-ray delivers full HD quality to each eye (well, at 24Hz anyway). Will broadcasters need to match this to be competitive? There is a terrestrial HD 3DTV system on air in Korea that transmits the left and right eye separately that is setting the world an example here.

A second issue is compatibility. Under what circumstances does it need to work? Will the new system need to be compatible with ‘Frame Compatible’ (FC) reception ( i.e. a Phase 1 signal with top-up)? Will the new system need to provide an HD 2D image for viewers with 2D only displays, together with something extra that can add up to two HDTV L and R images? This is called ‘2D Service Compatibility’. It could be nice if broadcasters had the option of providing either Service or FC compatible signals.

A third issue is viewer ‘depth range adjustment’. It is easy to move the whole 3D image - lock, stock, and barrel - backwards or forwards by shifting the left and right images together or apart. It is difficult to actually change the depth range in the scene. This needs sophisticated processing in the display and helper signals (L and R depth maps) with the broadcast. Will it be a sufficiently attractive new feature to justify the extra things needed? If we could adjust the ‘depth range’ of the 3D picture to suit our taste, our age (oldies prefer less depth), and our viewing distance from the screen, it would certainly be a ‘plus’. But, how much of one?

Furthermore, my simple mind is wondering if we could include in our DVB Phase 2, the Service Compatible system of separate L image and R images used in Korea today, as an option, would that be welcomed? Would we have the world covered in this case?

There are also thoughts about whether, beyond Phase 2, there could be a ‘Phase 3’, when the full majesty of the MPEG HE-AVC compression technology is ready for the market. This might save as much as 50% bit rate compared to MPEG-4 AVC. If so, we could work on the requirements for this Phase 3 in a few years’ time.

But the 64,000-dollar-question of what Phase 2 will be remains open as this is written. Listen to some of the debates at IBC this year, and you should find some clues.

By David Wood, TVB Europe

Wednesday, September 07, 2011

Labels: 3D, Codecs and Formats "

[alanh]

pheggie,
I always try and go back to the source to findout what was originally said
DVB3D fact sheet. is the closes I can find to your link of the DVB.org website

I suggest you read 10 things you need to know about 3-D TV which I posted in the 3-D strand.

I also suggest you read 10 things you need to know about 1080p @ 50 frame/s

There are a few ponts which do not apply in Australia and other countries
MHEG-5 was standardised in 1998. It is only used in UK and Hong Kong and has recently been added to the TV standards for Australia, NZ and South Africa. No one else is using it.
So the suggestion to use an MHEG-5 command to expand one of the two images to fill the screen. Australians would have to either replace their new DTV or buy a new STB.

The MVC-MPEG-4 is quite capable of being used for only a pair of images. If this is used then a single signal can be displayed on all MPEG-4 capable receivers. The depth signal is ignored by MPEG-4 part 10 decompressors. The depth signal is also 1920 x 1080p at the same frame rate as the same 2-D image. The bit rate is halved because each pixel is labelled with a 4 bit word which is accurate enough for the human perception system.

Remember like us Europe is selling excess terrestrial TV channels to the Wifi industry so there is no channels available for a separate channel for 3-D signals.

So a compatible Multiple View/2D signal is required for all terrestrial TV, and whilst more channels are available from satellite, this is at considerable. cost.

Some receivers in Australia are not MPEG-4 capable for 2-D TV, however DVB-T2 is really required for extra data whether it is used for 3-D oar to provide extra programs.

MHEG-5 was added to the Australian receiver recommended standard late last year.

AlanH

[MLXXX]

pheggie, on Sep 8 2011, 02:20 AM, said:

http://3dcinecast.bl...v-standard.html

"The DVB Project Considers New 3DTV Standard

Thanks Pheggie, an interesting article.

Quote

A third issue is viewer ‘depth range adjustment’. It is easy to move the whole 3D image - lock, stock, and barrel - backwards or forwards by shifting the left and right images together or apart. It is difficult to actually change the depth range in the scene. This needs sophisticated processing in the display and helper signals (L and R depth maps) with the broadcast. Will it be a sufficiently attractive new feature to justify the extra things needed? If we could adjust the ‘depth range’ of the 3D picture to suit our taste, our age (oldies prefer less depth), and our viewing distance from the screen, it would certainly be a ‘plus’. But, how much of one?

This is indeed an issue to consider. The Full HD 3D format introduced for Blu-ray players last year is for the encoding and subsequent decoding of discrete Left and Right images (albeit that there will normally be a large extent of correlation between Left and Right content).  There is no depth signal encoded for these Blu-ray discs.

Similarly, and more obviously, a frame compatible side by side broadcast using existing protocols supplies discrete Left and Right. There is no creation of 3D using 2D plus a depth map.

Whether consumers really need to be able to 'dial up' the 3D to be stronger or weaker than that inherent in the discrete Left and Right camera images in today's source material, is open for debate.  However given the proclivity of TV manufacturers to offer video enhancements, no doubt manufacturers will be interested in high speed software solutions that can make a coarse analysis of the more obvious apparent stereoscopic differences between Left and Right and attempt to either exaggerate or reduce such differences under consumer control.  How successful such techniques would be remains to be seen. At this stage it would be safe to assume that such manipulation would sometimes result in obvious visible artifacts.

As the quote indicates, a better solution, if this type of consumer optimisation is planned, is for the source material to include a depth map in addition to discrete L and R images; rather than the consumer device electronics trying to infer a depth map in real time, from the discrete L and R source images.  [I note there are further issues if depth maps are to be employed, related to transparency and occlusion.]

Edited by MLXXX, 10 September 2011 - 12:03 AM.

[alanh]

MLXXX,
You are contracting your other post which says that Blu-ray is using MVC-MHEG-4. To adjust the depth is to amplify or attenuate the depth signals.

Note HDMI Version 1.4 includes single 1920 x 1080p signal with a depth signal. So its up to the Blu-ray player as to whether the output is in the image and depth signal or it decodes the image and depth signal back to a pair of side by side images.

So as you said in your other post, MVC-MPEG-4 is actually recorded on the disk and not the frame compatible signal.

AlanH

[MLXXX]

alanh, on Sep 10 2011, 08:11 PM, said:

MLXXX,
You are contracting your other post which says that Blu-ray is using MVC-MHEG-4. To adjust the depth is to amplify or attenuate the depth signals.

"Contracting" I presume is a typographical error, and what was intended was "contradicting".

No, to adjust the depth is not as simple as amplifying or attenuating the depth signal unless a depth signal actually exists in the first place, e.g. has already been encoded, or can be approximately inferred. The primitive protocol of 2D + depth is not in popular use for movies. Can you cite any current titles encoded that way?

Quote

Note HDMI Version 1.4 includes single 1920 x 1080p signal with a depth signal. So its up to the Blu-ray player as to whether the output is in the image and depth signal or it decodes the image and depth signal back to a pair of side by side images.

The fact that an HDMI standard includes the primitive 2D + depth protocol doesn't mean that Full HD -3D Blu-rays are encoded with that protocol. On the contrary they are encoded with MVC as two separate video streams. That requires a higher bitrate but provides correct stereoscopy.

Also I am not aware of any Blu-ray player that outputs the primitive 2D + depth protocol when it has two accurate Left and Right video streams available to output from a Full HD 3D Blu-ray (in over/under format).  How odd that would be. Where is your evidence?  Certainly my own Panasonic 3D Blu-ray player includes no such option.

Quote

So as you said in your other post, MVC-MPEG-4 is actually recorded on the disk and not the frame compatible signal.

Was this ever in dispute?

Challenge

Kindly provide your evidence (if any) of a Blu-ray player that can be set to output 2D + depth when playing a Full HD 3D Blu-ray encoded with MVC.  It should be easy for you to find a user manual where such a setting is referred to, if indeed "its up to the Blu-ray player as to whether the output is in the image and depth signal or it decodes the image and depth signal back to a pair of side by side images".

It seems to me alanh that this is another example of your imagination running riot. I have come across nothing to give credence to what you are suggesting here of a particular feature that 3D Blu-ray players routinely offer.  It would not be impossible to incorporate such a feature in a specialised 3D player, but it certainly isn't the norm, to my knowledge.

Edited by MLXXX, 11 September 2011 - 09:11 PM.

[pheggie]

UK get new 3d standard in 2012

http://3dradar.techr...2012-19-09-2011