tag:blogger.com,1999:blog-27988188.post3008089709684082318..comments2023-08-16T09:40:15.272+01:00Comments on Irascible Ian's Personal Blog: The BBC Just Don't Get Hi-Def!Anonymoushttp://www.blogger.com/profile/13442419547110456696noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-27988188.post-61055917984321499302008-05-16T20:06:00.000+01:002008-05-16T20:06:00.000+01:00Nigel (loopy films)Thanks for the explanation.Nigel (loopy films)<BR/><BR/>Thanks for the explanation.Anonymoushttps://www.blogger.com/profile/13442419547110456696noreply@blogger.comtag:blogger.com,1999:blog-27988188.post-84122447062395255442008-05-16T19:57:00.000+01:002008-05-16T19:57:00.000+01:00Ed,Thanks Ed. That sounds more promising, although...Ed,<BR/><BR/>Thanks Ed. That sounds more promising, although the quotes from Russel T Davies about not wanting to waste the budget on hi-def were from an article published earlier this week (wish I could find the wretched thing again to find out when the interview actually took place).Anonymoushttps://www.blogger.com/profile/13442419547110456696noreply@blogger.comtag:blogger.com,1999:blog-27988188.post-19524928481639821902008-05-16T19:42:00.000+01:002008-05-16T19:42:00.000+01:00I think the point Mr Benjamin is making is that ma...I think the point Mr Benjamin is making is that material originated with interframe compression at 35Mbps may look good on a digital projector in a cinema when it has been edited and mastered at higher bitrates with intraframe compression eg HDCAM. However, if it is shown with another round of interframe compression and a much smaller bitrate - ie HD broadcast chanels - it looks crap!<BR/><BR/>"The transmission bit rate for all HD output (BBC and non BBC) was decided upon by extensive audience testing on a huge range of material, and is of course a compromise between quailty and available channel space."<BR/><BR/>This bit makes me laugh however. It seems more like greed and stupidity on the part of the broadcasters [not only BBC] that agreed to such a low bitrate of around 6Mbps. We all get lousy pictures, so they can run E4 AND E4+1 etc, despite the fact that everybody has Tivo or Sky+ or Virgin+ or Freeview+. Also pointless, as they don't increase their advertising revenue as planned, merely fragment their audiences and share the same revenue across more channels.<BR/><BR/>And you know what's worse?<BR/>The bit rate per channel is variable, so if you notice the picture quality getting worse in the middle of a programme, it is probably because the broadcaster has stolen bandwidth for the commercials on one of their other channels!<BR/><BR/>Of course Mr Benjamin is concerned more with camera usability and recommendations for their producers, rather than the technical broadcast specs that I emailed you. But they are clearly being absurd over S16mm film. When telecined at HD resolution, grain is not a problem when the film is shot and exposed correctly, even using 500ASA stock. You will get far worse noise [like grain, only worse] from many of the highe-end HD cameras when usin ggain or "pushing the ASA" in post. But they don't have a rule about that!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-27988188.post-4556213312098807482008-05-16T19:35:00.000+01:002008-05-16T19:35:00.000+01:00Hi Ian,FYI I am reliably informed by some crew on ...Hi Ian,<BR/><BR/>FYI I am reliably informed by some crew on Doctor Who that they've been shooting HD since season 3. I believe the first two seasons were shot on DigiBeta due to a very cheap deal struck with a local supplier, and at that point no-one involved knew if it was going to be the big hit it turned into.<BR/><BR/>Incidentally I'm totally with you when it comes to Torchwood. Makes me all sad inside..Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-27988188.post-82421181307146656582008-05-16T18:30:00.000+01:002008-05-16T18:30:00.000+01:00I'm afraid I'm still confused. On the one hand you...I'm afraid I'm still confused. On the one hand you seem to be saying that EX footage is "high bitrate" (when shown in a cinema) but too low for hi-def TV?Anonymoushttps://www.blogger.com/profile/13442419547110456696noreply@blogger.comtag:blogger.com,1999:blog-27988188.post-80687257693013536282008-05-16T14:11:00.000+01:002008-05-16T14:11:00.000+01:00Hi there Ian - it seems my appearance on the 'Reel...Hi there Ian - it seems my appearance on the 'Reel Show' has stirred you up somewhat! I'd like to comment on a few of your responses. In a limited time, I had to get over some of the camera issues that I felt were important and unique. We have a team here at the BBC whose job is to assess any suitable new cameras coming onto the market, and we tend to home in on any unique features, good or bad. Just one really bad feature could mean the camera is rejected, even if the rest are exemplary. <BR/><BR/>We scored the EX1 14% higher than the Z1 (which I suppose is actually 11 of 10 roundabouts), whereas other cameras had previously only been around the same or a couple of percentage points higher. This scoring takes into account all camera features not just picture quality, but operational aspects, weight, button placement, sound features, and much more. Each feature is scored, weighted for importance, then added up to give a total. <BR/>This scoring is only looking at the camera section, and as such does rate the EX1 highly. <BR/><BR/>However, the recording section compresses the image more than our lowest acceptable quality at 50MB/s. We have done extensive tests, considering the whole production chain from origination through a variable post production route, playout and transmission, and decided on this figure. Comparable trials at Sky have also confirmed this. <BR/><BR/>A cinema screening of EX1 material could of course look great, with controlled post production and a high bit rate playback. <BR/><BR/>The transmission bit rate for all HD output (BBC and non BBC) was decided upon by extensive audience testing on a huge range of material, and is of course a compromise between quailty and available channel space. <BR/><BR/>I think the main confusion was that I do rate the EX1 camera section very highly, wheras the recording section falls below our quality threshold.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-27988188.post-6890648639922488752008-05-12T16:34:00.000+01:002008-05-12T16:34:00.000+01:00The BBC are not excluding use of "non HD quality f...The BBC are not excluding use of "non HD quality footage", merely limiting it to a maximum 25% of a programme's content, much as they do with DV on SD. I have their new spec as a PDF, so will have to email it to you. <BR/>Apparently S16mm film is not of high enough quality, even when telecined to HDCAM! <BR/>As you suspect, this has a lot to do with the extreme compression that achieves a broadcast HD data rate of around 6.5 Mbps, and fears of what that might do to film grain.<BR/><BR/>They kind of have a point with HDV and even XDCAM though - it is not only the low data rate but also the interframe compression that causes problems. <BR/>The current "required delivery format" - HDCAM - has a data rate of 135 Mbps which makes even 35 Mbps appear very poor by comparison. And from September the mastering format will be HDCAM SR at 440 - 880Mbps, so you can see where they are going with this.<BR/><BR/>I know that data rates are not the only factor, it is also about the type of compression used, but they serve as a good general guide.<BR/>The latest technology - wavelet compression - is a big improvement on DCT, but "visually lossless" makes about as much sense as "fresh frozen" to me ;)Anonymousnoreply@blogger.com