Thursday, October 29, 2015

UHD-TV test material; how I'm going to demo monitors

After all the monkeying around with the Canon monitors last week I decided I need a decent variety of clips to show off UHD displays to the best of their ability. For some reason customers are not satisfied with just seeing test signals?!
So - although I have the TG-100 for uncompressed 4k test signals (the Visualiser really shows all you need to know!) and I can show:
  • Resolution
  • Colour Space
  • Temporal performance
  • Dynamic Range
So, I went looking for some well shot UHD footage at the TV 4k raster of 3840x2160 (I know, all you DCI-snobs, "true" (sic) 4k is 4096x2160). The Harmonics site has some nice short uncompressed YUV-planar format videos; - But don't expect your laptop to be able to play these guys! At 12GBits-1 they are monsters and so for ease of use you may want to compress them down to a more manageable 500MBits-1 (or so) using GLYUVPlay which can be found at Henryk Richter's site. In video coding research, standalone implementation and testing of video codecs often involves the use of raw YUV streams. Since these streams can be parsed and generated by very simple means, raw YUV files are very common in video codec standardization and development. 

I have made the H.264 variants and you can find them on my Google Drive folder.

Friday, October 23, 2015

So it's time to change ISP (again!)

So it looks like TalkTalk have had their customers' database exfiltrated and it seems they have done everything wrong! It's a shame as I've found them to be a fine ISP (MUCH better than Virgin) with good speeds and impressive uptime. They haven't bugged me endlessly with the TV and mobile up-sell and the bill has remains consistently ~£15 month-1 less than Virgin ever was.

So, having watched with a mixture of annoyance and amusement here are a few thoughts; 
  1. Don't claim that "we take customer account security extremely seriously" after a breach; behave like you believed it before the hack,
  2. Don't hide behind the claim that "...we have been suffering a sustained attack" - all ISPs (or any big internet-property) is under constant DDoS and other assault; it's no excuse today.
  3. Don't tell customers to go and update their user passwords and then have a broken website for twelve (and counting!) hours afterwards,
  4. Hash your customer database with a reliable method (even MD5!) and salt the hash - in 2015 this is now considered standard practice for people who "take security extremely seriously" (sic),
  5. Don't tell customers to "keep an eye on their bank accounts and credit card statements" - this is your fault, don't load the responsibility for the mess onto customers,
  6. Put data security and best practice ahead of sponsoring TV talent shows,
  7. Have a chief executive (who had the nerve to go on Newsnight) who actually knows how your customer database works - they're the CEO of an ISP for goodness sake!
So that's it; perhaps now ISPs will use results of proper pen-testing as marketing rather than the guff that passes for customer information currently in service provider adverts. If one company includes the word "bcrypt" on their website they'll get my business.

Thursday, October 22, 2015

Canon's 4k Native IPS television monitors

I had an excellent half day with Canon's UK imaging display guys to look at their DP-V series 4k native displays. To my shame I had assumed that they would be like the HP Dreamcolor or Eizo ColorEdge series monitors which are advertised as being suitable for film and TV work but as I've often said; " SDi BNC and a preset called Rec.709 does not a broadcast monitor make"!
In the case of those two manufacturers they assume that taking their print-prep graphics display and making it SDi capable is all that's needed; forget proper RGB linearity and a controlled white-point. In the case of the HP they still advertise it at 250Cd/m2 for white (four times what it should be - you can't grade with that) and every time I've had an Eizo to play with I've found the same. Even employing a LUT to tame something like that is a bad idea as having to take 250Cd/m2 down to a more sensible 80Cd/m2 means you've lost two stops (12dBs, two significant bits) of dynamic range; not what anyone wants.
So - native 4k displays using LED-backlit IPS-LCD and not OLED. Every display technology suffers issues and although I think the poor inherent RGB tracking of OLEDs is entirely addressable in a LUT (which is why I love the Boland BVB25 for colour-accurate TV work) OLEDs are noisy once you get very close to black thus limiting their dynamic range (fine for 10-bit TV work; but for 16-bit HDR film imagery, not so much - yet!). Canon has consequently chosen IPS-style LCDs (with a level-modulated LED backlight). The LED backlight is the same technology as that used in the Dolby PRM-4220 grading monitor which is how they achieve the high dynamic range with a possibility of >1000Cd/m2 for specular highlights in HDR 16-bit video. I got to see the originators of this technology, Brightside, back in 2005
So, proof of the pudding etc - I profiled the 24" edit suite variant and it was very close to the Rec.709 spec (the fact that I left LightSpace set for a 2.2 gamma whilst the monitor has a true BT.1886 gamma for HD rasters may be to blame). With 4k source material the results look great.

 I started at 2k to see how it did

 At 4k I can only manage 25 FPS at best!

Zooming in on the frequency grating shows aliasing, but only on the camera pics, I couldn't photograph it with my 10Mpix camera without catching aliases in the camera's OTF.

Getting closer gets a bit better, but to the eye the resolution is astounding
The Sarnoff ladies at true-4K

I profiled the display at 17-points so 5,000 measurements take around two hours with the Klein
Looks pretty good for greyscale performance, and I suspect if I set LightSpace's gamma correctly it would be better

The coloured dots are rec.709 and the big cube is the gamut of the display; it covers the colour space nicely.



Friday, October 02, 2015

The £50 Amazon Kindle Fire 7" tablet

I spanked £50 of birthday vouchers on one of the new cheapie Amazon Kindle Fire tablets - just the little 7" one - very similar spec to the current Google Nexus 7 tablet. 
It's very clear that they're selling it as a loss-leader on Amazon Prime and the Kindle Store etc. There is no way they can build a 7" Android tablet for around 10% of the cost of an iPad!

I've forced myself to put the 10" iPad aside for a couple of days and use this and for the most part I've been really impressed. Part of the exercise was also to get a bit more familiar with Android and although Amazon describe this as "Fire OS5 Bellini" but it's really Android 5 Lollipop with Amazon's skin. This is fine for the most part except for the fact that Amazon and Google don't get on and so you don't get the Google Play Store. There have been a couple of apps which aren't yet on the Amazon Store and so they aren't available on the Amazon tablets. Most significantly Dropbox - hmm, bit of a problem.
However - as a tablet OS it is nippy; apps launch quickly, the screen swipes and scrolls nicely and makes for a very nice experience. It's a lot lighter than the iPad at 300g and so is much nicer for reading in bed. The fit and finish is much like the Google tablets and considerably better than other sub-£100 "one-hung-lo" brand cheap Android tablets. It only comes with 8 gigs of memory, but they throw in a 32gig SD card (or they were for pre-orders) and since Android manages all of that it's really not an issue.

So far it works well with all the Bluetooth gadgets I've tried (a couple of speakers and a keyboard) and it hasn't dropped off any of the wireless networks I've attached it to (and I can't say that about the iPad). It has a much lower resolution screen than the iPad but I've only noticed that on the Facebook app.
In terms of resolution the camera is not great - I took a bunch of photos on a nice sunny day in London and they all look a bit like 'phone camera pictures from ten years ago!

Another area where it scores over iOS is that you can see the file system - USB cable (standard micro-B connector; you probably have several of them already - especially if you have a normal book-reading Kindle). It makes extracting photos or dropping MP3s, documents etc onto the device a doddle (can't do that on an iPad!). Another very cool (and non-Apple feature) is the profile selection from the lock-screen. On the subject of the lock-screen you get adverts (I've only seen books so far) but clearly this is where some of the economy comes from. 
So; top-right on the lock-screen you see icons with names. If you've added additional profiles multiple people can unlock the gadget and it gives you all your stuff; your Amazon accounts (Kindle books, Amazon music etc) as well as a new profile for email (POP3, MS Exchange, IMAP, Google etc). Again, not something Apple has ever been able to do.

So, Pros
  • Profiles
  • File System
  • Standard Connectors
  • PRICE!
  • No Google App Store
  • Screen resolution (only in some cases)
  • Camera resolution
BUT, 10% the price of an iPad! I'll probably root it and stick regular Android 5 Lollipop on it when I can an afternoon to spare. It's not quite an iPad but I could have ten of these things for the same price!