By Andy Quested
As chair of the EBU 3DTV Group I thought it was about time I gave an update on our thoughts and our work and maybe make a comment or two about the third dimension.
The Group was formed about 6 months ago and much has happened in that comparatively short period.
Figure 1 illustrates the state of 3D broadcasting in July 2010 just after our first meeting. Figure 2 has the position at the beginning of 2011 and shows just how fast 3D is growing. The number of 3D channels is still growing but is there enough content and how good is that content and more importantly, how good is the 3D’ness of the content?
If you look at the maps again, the really sad thing is the lack (or even complete absence) of the Public Service Broadcaster (PSB).
As part of the process of setting up the 3D Group we sent out a survey asking about the relevance, concerns and plans of each Member. We also asked if the Members wanted the EBU to do something, such as provide information, recommendations, tech notes, etc.
There was an overwhelming response. The survey was sent out on a Friday and by the following Monday morning there were over 90 responses! There is obviously a demand for information but I don’t believe there is a desire to do anything but observe.
The survey did allow us to set some simple but clear objectives for the Group:
• Provide objective information on the different 3DTV technologies;
• Inform general managers about the anticipated 3DTV developments over the next 2-4 years and the implications;
• Provide an overview of the worldwide standardisation activities and the areas where EBU Members’ input is required;
• Collect EBU Members’ requirements (technical, psycho-visual, business related) and ensure their adoption.
We are gathering information about the current issues and techniques for 3D programme making at the moment, but we have already delivered the second objective, which is available at tech.ebu.ch/3dtv.
The Group wanted to provide the answer to any PSB who asks, “If I had to start from scratch what do I need to know to make a good 3D programme?”.
The answer is – take some advice, then take some more and keep taking advice through the whole process. But where and what advice? Here are some early thoughts.
Advice 1. Will it work in 3D? – What really makes a programme work in 3D is not the technology but just like 2D, it’s the story and the context. So you could ask – “Can the story use or benefit from 3D?”. Can it play to the medium to tell the story or is 3D just a “box office” effect? You should be able to watch a 3D programme and almost not notice it’s there, but at the same time, miss it if it was not there. That doesn’t mean that it’s too subtle to see, but that it’s a natural part of the story.
Advice 2. Can you capture it in 3D? – There is a very high probability that traditional 2D camera positions, especially at large arena venues, will not be good for 3D. This is where there’s no substitute for experience and expertise, or if you are doing it on your own be prepared to accept the fact that you will make a lot of mistakes early on that will never see the light of transmission. Just because you may need new camera positions for good 3D, it doesn’t mean you need to keep all the old 2D positions. The 2D coverage may well be different but not necessarily unsatisfactory.
Advice 3. Planning – Call in the experts early and make sure there’s someone leading the project whose role is to maintain an overview of the whole process from beginning to end. There are new jobs to consider but right at the top is the stereographer. Phil Streather, the stereographer involved in the EBU’s 3D training cannot emphasise enough the importance of planning and preparation. Chris Johns who is leading BSkyB’s 3D efforts cannot get through a presentation without using the words on every slide of his presentations.
Advice 4. Communication – Keeping everyone fully informed and up to date with the inevitable changes is vital, especially for live programmes where there is not usually the chance to correct issues during the event. Even what you think is obvious should be communicated; does everyone know you are doing 3D? Does everyone know the left from the right? Does everyone know there are two video streams? A good programme plan with contact details is just as important as the cameras.
Advice 5. Cameras and Rigs – It is tempting to save money here because rigs can be incredibly expensive. Conversely it is easy to over specify. Setting a top end rig to capture a shot a simple side-by-side rig could deliver just as well is a waste of money. Then again trying to do a “money shot” with inadequate equipment will produce poor results and bad 3D. You will end up wasting money trying to correct the 3D in post or if it’s live, you will just upset the audience. The moral here is to take advice.
Advice 6. Contribution Circuits & Signal Processing – This is where advice has to be backed up by tests and experience. How will the signal from a live event be sent back to base? What compression will be used and will it handle the two vision streams in the same way? How do you standards convert two image streams identically? Is the infrastructure capable of handling two streams – dual link SDI? 3G-DS? Or is it 3-DL? There are too many options to discuss in this short article. Remember, no matter how good the 3D is on site, if you can’t get it back to base and on-air, all the work is for nothing.
Advice 7. Recording & Post Production Compression – How will NLE compression handle 3D? What about 3D EVS or must you use 880Mbs HDCamSR? Long term storage formats for the archive are really important but often overlooked. The best advice for the archive is to store two image streams (Left eye and Right eye) clean. That means, do not squeeze to Side by Side or Top & Bottom. This is essential to maintain quality as the 3D distribution technology evolves. Plan your post production short term storage and contribution to deliver both Left and Right eye images at the highest possible quality.
Advice 8. Editing & Audio – Speaking as an ex editor, once you are into post production you can only work with what you’re given, the tools you have and your imagination and skill. Seriously though, on a TV budget for post, you can only do so much. This is where any lack of planning or communication will catch you out. However, if you have planned and communicated, the post will be smooth, but just in case, the 3D tools now available from the main NLE manufactures can at least help in tricky situations.
Advice 9. Subtitles, Graphics and Captions – Where to put them? – Titles have to be carefully placed so they don’t become divorced from the image they are associated with. Too far forward and the audience feel their eyes crossing tying to read them. Too far back and they appear on top of the objects or performers they are supposed to be behind.
The advice could go on for a lot longer but we need more knowledge to help.
So, is this what the EBU 3D Group can do? Talk to the manufactures, the experts and the audience so that the EBU can provide the guidance, recommendations and expertise its Members expect.
Coming so soon after the pressure to go HD, many PSBs are asking if 3D is a dimension too far. But the results of the survey sent out by the 3D Group demonstrated there is a real concern about the impact 3D subscription channels will have on the PSBs’ position and reputation for innovation in each territory.
At the EBU Technology Seminar the last session was on 3D with three very good presentations. I took the opportunity to ask Members to support the work of the Group with practical help. Please take some time to look at the presentation on the EBU Technical website and come and join us.
The Group’s next, and most important task, is to disseminate all the information on the processing, technology and techniques required to make good 3D high definition programmes for a public service audience with the quality (editorial and technical) our audiences expect.
As part of this process, I have taken on the role of joint ITU special rapporteur looking at the issues surrounding 3D production. I am looking forward to the next few months. It’s going to be an interesting, exciting and worrying journey and I hope some of you will join me.
Andy Quested is Head of Technology, BBC HD & 3D, BBC Future Media & Technology and the Chairman of the EBU Project Group on 3DTV.
Copyright Tech-i 2011. Published with kind permission of EBU Technical.