EX3 for UK Broadcast

[Eric A Robinson]

Hi All you EX3 UK based film makers. We are currently working on a doc. here in Scotland and are looking at the possibility of having it broadcast. Have any EX3 users had any experience of delivery of footage for broadcast here in the Uk. Could anyone advise on a the most effective work flow. To date we have shot all our stuff in 1080p 35Mb/s. Any advice anyone could could give would be great.

[Alister Chapman]

To date all the EX footage that I have been providing for broadcast has been edited in FCP, rendered to ProRes HQ and output over HDSDi to HDCAM or HDCAM SR. I shoot everything I do at 25P as stock footage is a big part of my business and it's easier to standards convert progressive material than interlace.

I provided an hours worth of footage to Summer Films for an SD show. The footage was dubbed to HDV (YUK!) so they could edit in with Avid I believe.

[Eric A Robinson]

Hi Alister.

Thanks for that, I will take your and advice and adopt that particular workflow as you suggest. What quality do you shoot in?

[Steve Phillipps]

At present XDCam EX falls below the BBC requirements in that the minimum codec requirement is 50 mb/sec. But it definitely tends to be decided on a case by case basis, and you'd have to speak to your producer/commissioner to find out what's acceptable. The same goes for workflow, you'll need to ask what your client requires.

Steve

[Eric A Robinson]

Hi Steve

Thanks for that. I did look at using the convergent flash XDR recorder which I was informed if hooked up to the EX3 via the HD SDI it will give 50mb/s and above mpeg2 HD. The cost at the moment is beyond our budget, though it is the way we intend to go once we have heard other peoples experiences of using the unit. At 3.5K it is quite an expensive bit of kit for a small outfit like us. The 50 mb/s does appear to be plucked out the air as Discovery appear to be happy with screening content shot on the EX3, or so I am told.

[David Heath]

Originally Posted by Eric A Robinson

The 50 mb/s does appear to be plucked out the air as Discovery appear to be happy with screening content shot on the EX3, or so I am told.

There is inevitably a "where do you draw the line?" side to all this, and I'm glad I don't have to do the drawing! The 50Mbs isn't quite as arbitrary as you may think - the clue being in the codecs full name - XDCAM HD422. The use of a 50Mbs datarate allows 4:2:2 sampling, and whilst at first sight it may seem that doubling the number of chroma samples sucks up all the extra bitrate, in practice it's easier to compress a lot of samples than fewer, so it does have a general compression advantage over 35Mbs, colour space aside.

It's not just the BBC, incidentally. The EBU recently did extensive next generation codec testing, and XDCAM HD422 at 50Mbs was recommended by them as the minimum recomendation for a long GOP codec for general broadcast use.

[Steve Phillipps]

And the Flash XDR will also do 100 mb/sec, plus upto 160 mb/sec I frame - that's the one I'd really like to see.
Not sure if this was fully resolved, but I posed the question as to whether the overcranking (SQ motio mode) would work via HD SDI out. I get the feeling it won't, so to do slomo you need to use the 720/60P mode.
Nano Flash is on the way soon, cheaper, smaller, looks really good.

Steve

[Eric A Robinson]

Hi Steve


I thought these little drives were only good for data transfer applications as opposed to data capture due to the low read write speeds?

[Steve Phillipps]

The new Nano Flash AFAIK is exactly like the XDR except it's smaller, has less audio capapbilities and only 2 CF slots instead of 4.
Steve

[Dan Keaton]

Originally Posted by Eric A Robinson

Hi Steve


I thought these little drives were only good for data transfer applications as opposed to data capture due to the low read write speeds?

Dear Eric,

The Flash XDR records 4:2:2 video, from any HD-SDI source, such as an EX1/EX3.

The files are compressed using a high-quality Sony MPEG2 module at 50 or 100 Mbps.

In the future, we will offer I-Frame only, at 100 Mbps and 160 Mbps, as a menu option.
However, while 160 Mbps sounds better than 100 Mbps, it is not.

Our "Master Quality" option is 100 Mbps Long-GOP option. This is the "Sweet Spot", since I-Frame only is not as efficient as Long-GOP.

By recording the HD-SDI output, you instantly upgrade from 4:2:0 to 4:2:2, as the recordings done in-camera are 4:2:0.

Steve, your statement is correct.

[Eric A Robinson]

Hi Dan


When you say 'we' are you saying your company are producing such drives? If so where might I point my browser to get some information. ta.

[Steve Phillipps]

Eric, here's the link Convergent Design, experts in HDMI, SD, HD, and HDV
There's also a dedicated forum for Flash XDR on this site.
Steve

[Alister Chapman]

While the BBC and others may well stand on a high spot and shout out loud that they will only take 50Mbps 4:2:2 the reality is somewhat different. While I am sure that given the choice of the same footage at 35Mbps or 50Mbps they would choose the 50Mbps. But if the only way the can get the material they want (either through technical or budget issues) is to use a below spec format they will take it.

When DVCAM was first released the BBC were very vocal about never using it as it was too highly compressed and not "broadcast quality", the same with HDV yet a massive amount of the BBC's output is shot with DVCAM and even some of the BBC's flagship HD shows make extensive use of HDV, in particular "Strictly come dancing". Most of the rehearsal and behind the scene footage is shot on HDV. These sequences make up half of the show. My guess is that budget constraints mean that they cannot pay for a dozen crews up and down the country with HDCAM or DVCPRO-HD kits so instead they use PA's with Z1's. The BBC's own not less than 50Mbps rules are clearly being broken by the BBC themselves on prime time, big audience HD shows, not for technical reasons but purely on cost grounds.

The difference between a PDW-700 and an EX in progressive is tiny. The compression ratios are just about the same. I don't see how encoding more data at a given bit rate gives you a compression advantage, that's lost on me I'm afraid. I accept that obviously the 700 has a bit more chroma information. Certainly in the Luma channel there should be no more artifacts from an EX than a PDW-700. Both the EX and PDW 700 compression ratios are around 20-1. It's arguable that because the EX is VBR the EX should be producing less artifacts than the constrained CBR of the 700. If artifacts and generation loss was really the big deal that everyone is so afraid of then XDCAM HD which is 16:1 would outperform XDCAM HD 4:2:2. We also need to consider that when Discovery tested the EX it was at 30fps. It was found to be perfectly acceptable by them at 30fps, but here in Europe we are only using 25fps which gives us a lower compression ratio.

My point is that the decision to draw the line at 50Mbps 4:2:2 is not IMHO entirely based on quality, artifacts or generation loss. By drawing the line there the engineers are able to exclude all us "sub-standard" producers. The Engineers don't like the idea that someone with a a good story, a good eye for composition and a "cheap" camera can produce programmes that can rival programme made using the mega bucks formats that are the engineers bread and butter.

At the end of the day with almost all broadcasters it is not the engineers or producers that run the company. It is the accountants that (sadly) run these organisations. Budgets are getting smaller if not cut altogether, especially in the current financial downturn. At the end of the day broadcasters must have new programmes to survive and if it becomes a case of getting it made by company A for half the price of company B with just a teeny, tiny, virtually impossible to see difference in quality the accountants will steer towards company A. Put it another way. The comissioning editors are given a budget by the accountants to fill their time slots. If they can get 3 programmes for the price of 2 there will be significant pressure on them to take the 3.

These are my views, they may be wrong, perhaps the BBC will clamp down and stop their own productions from using HDV. Certainly if you have a 700 or Flash XDR you should find it easier to sell your material but that doesn't necessarily mean that you will automatically be more profitable, especially if you do anything that involves lots of travel as lugging a full size kit around the world can be very expensive. The BBC have broadcast a lot of my XDCAM HD and EX footage as have ITV, Channel 4, Channel 5, Virgin One, Discovery, Nat Geo to name just a few. Admittedly much of my material is fairly unique and not readily available here in Europe but the fact that it is "only" 35Mbps hasn't lost me any business.

Rant Over... sorry.

[Dan Keaton]

Originally Posted by Eric A Robinson

Hi Dan


When you say 'we' are you saying your company are producing such drives? If so where might I point my browser to get some information. ta.

Dear Eric,

By "we", I mean our company Convergent Design, www.Convergent-Design.com.

I became the Director of Sales and Marketing for Convergent Design in December of 2008.

Prior to that, I helped by contributing on a volunteer basis by making recommendations to the design and development team since late 2007.



Yes, we make the Flash XDR which is currently in stock and available for sale.

If you want to find out more about the Flash XDR, I recommend that you start at this link, there are links after the main text to more information.

Flash XDR.

We have a separate forum on DVInfo for dicussion of the Flash XDR and the nanoFlash:

Convergent Design Flash XDR - The Digital Video Information Network

The nanoFlash is not ready for sale at this time, but is a more compact model of the Flash XDR minus professional analog audio inputs and outputs. It still records audio, if it is present on the HD-SDI or HDMI inputs.

Here is a brochure for the upcoming nanoFlash. We are more than 60 days away from delivering our first nanoFlash.

http://www.convergent-design.com/dow...20Brochure.pdf

[Gary Nattrass]

Originally Posted by Alister Chapman

While the BBC and others may well stand on a high spot and shout out loud that they will only take 50Mbps 4:2:2 the reality is somewhat different. While I am sure that given the choice of the same footage at 35Mbps or 50Mbps they would choose the 50Mbps. But if the only way the can get the material they want (either through technical or budget issues) is to use a below spec format they will take it.

When DVCAM was first released the BBC were very vocal about never using it as it was too highly compressed and not "broadcast quality", the same with HDV yet a massive amount of the BBC's output is shot with DVCAM and even some of the BBC's flagship HD shows make extensive use of HDV, in particular "Strictly come dancing". Most of the rehearsal and behind the scene footage is shot on HDV. These sequences make up half of the show. My guess is that budget constraints mean that they cannot pay for a dozen crews up and down the country with HDCAM or DVCPRO-HD kits so instead they use PA's with Z1's. The BBC's own not less than 50Mbps rules are clearly being broken by the BBC themselves on prime time, big audience HD shows, not for technical reasons but purely on cost grounds.

The difference between a PDW-700 and an EX in progressive is tiny. The compression ratios are just about the same. I don't see how encoding more data at a given bit rate gives you a compression advantage, that's lost on me I'm afraid. I accept that obviously the 700 has a bit more chroma information. Certainly in the Luma channel there should be no more artifacts from an EX than a PDW-700. Both the EX and PDW 700 compression ratios are around 20-1. It's arguable that because the EX is VBR the EX should be producing less artifacts than the constrained CBR of the 700. If artifacts and generation loss was really the big deal that everyone is so afraid of then XDCAM HD which is 16:1 would outperform XDCAM HD 4:2:2. We also need to consider that when Discovery tested the EX it was at 30fps. It was found to be perfectly acceptable by them at 30fps, but here in Europe we are only using 25fps which gives us a lower compression ratio.

My point is that the decision to draw the line at 50Mbps 4:2:2 is not IMHO entirely based on quality, artifacts or generation loss. By drawing the line there the engineers are able to exclude all us "sub-standard" producers. The Engineers don't like the idea that someone with a a good story, a good eye for composition and a "cheap" camera can produce programmes that can rival programme made using the mega bucks formats that are the engineers bread and butter.

At the end of the day with almost all broadcasters it is not the engineers or producers that run the company. It is the accountants that (sadly) run these organisations. Budgets are getting smaller if not cut altogether, especially in the current financial downturn. At the end of the day broadcasters must have new programmes to survive and if it becomes a case of getting it made by company A for half the price of company B with just a teeny, tiny, virtually impossible to see difference in quality the accountants will steer towards company A. Put it another way. The comissioning editors are given a budget by the accountants to fill their time slots. If they can get 3 programmes for the price of 2 there will be significant pressure on them to take the 3.

These are my views, they may be wrong, perhaps the BBC will clamp down and stop their own productions from using HDV. Certainly if you have a 700 or Flash XDR you should find it easier to sell your material but that doesn't necessarily mean that you will automatically be more profitable, especially if you do anything that involves lots of travel as lugging a full size kit around the world can be very expensive. The BBC have broadcast a lot of my XDCAM HD and EX footage as have ITV, Channel 4, Channel 5, Virgin One, Discovery, Nat Geo to name just a few. Admittedly much of my material is fairly unique and not readily available here in Europe but the fact that it is "only" 35Mbps hasn't lost me any business.

Rant Over... sorry.

Thank you Alister this is exactly what I have being going on about for the past two years, the current broadcast climate can not sustain everything being shot at full HD.