Aspect ratios

I’m fed up doing the same calculations every six months, so I’ll post them here in the hopes I remember where I left them. I’m also fed up with whoever decided that television pixels would be rectangular, and whoever decided not to include any conversion system in QuickTime, but there we go.

Conventional 4:3 aspect PAL transmissions are taken to be 720×576 pixels. Which the Carol Vordermans amongst you will instantly recognise as being 5:4, not 4:3 at all, so to make a full-frame PAL capture look right on a computer monitor, it should be scaled to 720×540 pixels.

Now, a 16:9 widescreen capture is still stored at 720×576 pixels, simply stretched more at the display (which is the sensible approach when you can’t change the transmission bandwidth, to be fair). So to make a widescreen frame display right on a computer, scale it to 720×405 pixels.

Some notes: I’m assuming the pixels on the target computer are square – It used to be the case that Macs would only do square pixels, but now we have more choice of monitors there’s more scope for the user to screw things up. 1280×1024, for example, isn’t the same aspect ratio as 1024×768, so it’ll look squished on (4:3) CRT monitors; 1280×960 is a ‘better’ resolution. Windows users have been able to mess things up like this since SVGA came along, of course.

Also, you may wonder why I’m only scaling the vertical resolution – why not interpolate horizontally rather than throw away vertical data? Well, because the vertical data isn’t really there in the first place; the highest-resolution capture format that’s common is (so far as I’m aware) DigiBeta, which is what most of my shows originate on. DigiBeta record decks typically handle about 500 vertical lines, maximum. When running widescreen, many cameras simply subsample the (4:3) CCDs, giving an even lower ‘true’ vertical resolution. Which sounds ghastly, but bear in mind that people happily watch VHS recordings, and VHS staggers to only about 240 lines vertically; even DV is only about 360 lines, I think. And funnily enough, all the stuff I’m playing with is DV-sourced; so scaling to 720×405 is still interpolating upwards from the true capture resolution.

There. I hope that’s clear. The magic numbers are 540 and 405; on my monitor, they look right. Thanks.

Back

Have spent the weekend thus far recovering from the rigours of TV production. Which for the most part means that I’ve been asleep.

I am starting to catch up with things, though. I have a very long ‘ToDo’ list (very long), and the number of unread entries in NetNewsWire is down below 800 for the first time in about three weeks.

Happy find so far: this entry at Typographica, leading to the fonts Gararond, Moonbeam, and Salmiak.

Home

Back in Leeds for a flying visit. Dad’s much perkier than I expected – he’s tired and short of breath, but really rather chipper. His Mac’s less sickly than feared, too, the only problem being an air gap in the mains cable. Remedy: plug it back in again. I’m posting from it now, so it seems to be working.

But I’m being rude to my mother by conversing with a PowerBook rather than her, so I’ll go now.

Chin, chin

I’m not sure if this is a general thing, or a local offer, but the Somerfield down the road is flogging half-cases of Heidsieck Monopole blue-top NV for under sixty quid. That’s way under half-price, for a wine that (if memory serves) is absolutely fantastic at the full whack.

If I knew I’d been paid for last month, I’d have picked up a case tonight. Must check bank account tomorrow…

I’m with the band.

Kevin and Mija dropped in on How2 studio filming the other day – I’m kinda busy and haven’t had much chance to eat/sleep/buy milk/blog/etc, so I’m a bit behind here. They sat around for a few hours. Maybe it was raining outside or they were bored, or something, I’m not sure. Anyway, they seemed to enjoy themselves, and professed to find the headlong careering plunge that is studio recording ‘fascinating.’

At some point Kevin asked what, exactly, I do. I had to think about that, since it’s rather hard to describe if the questioner doesn’t know how television production works. In the end, as I looked around at the scurrying figures, flurries of activity, and people loafing between being called to do something somewhere else, I realised that an adequate, if conceited, answer was, “These people are all working for me.”

At least one of us – and I couldn’t say who – said quietly ‘Woah!’

Tomorrow, of course, all but about five of them are working for somebody else. But that’s not the point.

Bowling for Columbine

I finally saw Michael Moore’s Bowling for Columbine tonight, when it went out on Channel 4. It’s fascinating, but like most of Moore’s stuff I found it strangely irritating.

The usual way it pans out is like this: the first third is a little laboured; the middle third utter genius; the final third undermines the preceding by managing to miss the point made so eloquently only a little earlier. Bowling for Columbine seemed to me to fit this pattern rather too well.

What, I wonder, was the point of skewering Charlton Heston? Hadn’t Moore already demonstrated, via comparison with Canada, that widespread gun ownership was no indicator of shooting murder rates? Hadn’t he made a convincingly strong case that basic standards of living were the key discriminator: access to healthcare, unemployment benefit, urban regeneration?

Dragging the argument back to the doorstep of the NRA seemed to me to be (pardon the metaphor) taking pot-shots at an obvious target, after identifying the far more insidious threat elsewhere. Sure, getting Wal-Mart to abandon the sale of handgun ammunition was a remarkable achievement, but it’s hard to see it as anything other than tokenism. Stunt tokenism, at that.

I found myself similarly frustrated by Moore’s book Stupid White Men, which makes a glorious point about how it’s the white guys in Washington of whom you should be scared, not the black guys down the road from you. But the book then cracks on into half a dozen other subjects, some of which simply don’t ring true and present sloppily-constructed arguments. Which rather scuppers the authority of the original essay.

I’m left with one conclusion of my own: if Moore is the best liberal media agitator America can muster, they really do have a long way to go before they can sort out their problems.