Archive for May, 2009


The Future of visual and auditive media

Some terminology

High-Definition Television, or HDTV, is a broadcasting system with higher definition than standard-definition television, or SDTV.

What used to be

As I understand it, the North Americas use the NTSC standard of television screens with progressive screens of 525 scan lines (lines of pixels) and a frame rate of 29.97 frames per second. Progressive in this context means that the entire raster, or image, is updated in one scan (progressively?).

Here in Europe, however, the PAL standard is more common, with 625 lines, but with an interlaced signal, which means that half of the raster — every other line, starting with the even numbers first and from the top – is updated in one pass, then the other lines in a second pass, with a frame rate of 50 Hz, or 50 passes per second, resulting in a full raster update every 25th second and ultimately a frame rate of 25 FPS.


A couple of new standard formats are here, the most common of which are called 720p and 1080p, standing for 720 and 1080 vertical lines respectively. The standard aspect ratio is 16:9, so the digital resolutions would be 1280×720 for 720p and 1920×1080 for 1080p. As a side note, 720p is perfect for my current computer screen as it has a resolution of 1280×1024, perfectly matching the pixel width of 720p to the pixel. But most new computer screens nowadays are 1920 pixels wide.

Typically, 1080p is referred to as Full HD, and you will most likely see more “Full HD” stickers on screens that support it rather than “1080p” ones, probably because people don’t know what 720p and 1080p means. Everybody hates numbers, right?! Screens that support 720p and other, more non-standard, resolutions are referred to as “HD-Ready” (personally, I think this is ridiculous), which is pretty much just a sugar coating to mask the real message, which is “Less than 1080p.” Or worse yet, “Less than Full.”

Always make sure you find out the real resolution of a television or computer screen before you make the purchase, and do weigh in the factor of pixel density. If you go and buy a 40-inch screen, but it only has about 20 by 10 pixels, the picture is obviously going to look like crap, because the pixels will be more like regular light bulbs than little dots. So if you go for a really large television, you would probably prefer a 1080p television, whereas a smaller one would do fine with 720p (and indeed the smaller ones are mostly 720p).

The Future

I stumbled upon a article called Super Hi-Vision, and was blown away. Apparently it is an experimental format and proposed standard of High-Definition audiovisual media with a video resolution of not double, not quadruple (as in 2160p, referred to as Quad High Definition), not eight times, but sixteen times the resolution of Full HD: 4320p, with a resolution of 7680×4320 — four times the height and four times the width of 1080p.

Ultra High-Definition Video

Ultra High-Definition Video

A nice comparison, stolen from the Wikipedia article, is shown above (click for true resolution). Notice the light-blue surface as HTDV/Full HD/1080p, and compare that to Super Hi-Vision in darker blue. Astonishing.

Some Numbers

My screen resolution is 1280×1024 on a 17-inch screen. This translates to about 96 Dots-Per-Inch (DPI).

If you would take a Super Hi-Vision resolution of 7680×4320 at a DPI of 96, as with my screen, you would have to make the screen almost 92 inches across the diagonal, or over seven and a half (7.65) feet. Or 2 and one third (2.33) of a meter, I should say.

My screen resolution makes for 1280×1024 = 1 310 720 pixels, or a little over 1.3 megapixels. 1080p makes for 1920×1080 = 2 073 600 pixels, or about 2 megapixels. 4320p gives you 33 megapixels (33 177 600).

Enough said, I think, about Super Hi-Vision. Let’s talk about the sound system that is being developed to go with this super-high-resolution video — the 22.2 surround sound system. 24 speakers total, 2 of which are subwoofers: one left and one right. 9 speakers will be on a top layer, above the heads of the listeners, another middle layer with more speakers, and a bottom layer with a few more speakers along with the left and right subwoofers. I think I need say no more.

I guess the next obvious step in video would be a resolution with the same amount of pixels as the amount of light receptors that are in the average human retina, and in sound would be the walls, ceiling and floor of the room being one single speaker — with some type of dynamically targeting membrane — including the surface behind the huge screen.

Enjoy the future!


Unnecessary database updating

I have a really old laptop that I put Ubuntu on. It used to have Xubuntu on it but even though Xfce is faster than GNOME, I like GNOME better.

There is a problem with a fresh install of Ubuntu however (and all other editions I assume), where there’s heavy unnecessary HDD activity, and the top utility reveals mlocate to be the perpetrator.

To disable mlocate running automatically, I just changed the permissions of /etc/cron.daily/mlocate to 644, by running:

$ sudo chmod -x /etc/cron.daily/mlocate

Problem solved, and no more seemingly random slowdowns by heavy activity on the HDD, which is slow as it is!

Also, turning off automatic checking of updates helps a lot too. It’s a great relief not to be interrupted in your… “work”, let’s call it, by heavy HDD activity, so it’s better to perform updates and package listing updates manually when it suits me.