Monday, June 13, 2011

Chroma Kee

I’ve always found that I learn far more about a piece of software through playing rather than working and that’s certainly been the case with the offline video editing program Kdenlive. I’ve also found that when you have a definite goal in mind then “the software doesn’t do that” no longer becomes an option and you use the software far more inventively in order to achieve it.

And so it proved when I decided, using Flash 8 and Kdenlive, I’d try and recreate the title sequence for ITN’s News At One. I first saw this title sequence back when the programme was called First Report – that was before the soporific Aussie soap The Sullivans pushed the programme to its more familiar one o’clock slot.

Here are the original News At One titles that someone culled from TV Ark:


As you can see, it’s quite a complicated title sequence and people who know far more about this sort of thing than me have noted how hard it would have been to achieve in the 70s. They’ve always been very, very good technically at ITN.

Although I haven’t got a clue how ITN did it, I decided on the basic approach of having two layers of video in Kdenlive for my version.

The bottom layer would be the typing hands (or paws in my case – thanks Lionel!). These were shot on my little Canon Ixus camera and then put through the Kdenlive “Threshold” filter and coloured with, of all things, the MSU Old Cinema filter.

Lionel touch-typing

The top layer of video would consist of the zoom out of the Houses of Parliament’s clock tower (replaced by the block of flats where I live) which fades out, and the photo montage of odd people and drab places (replaced by pictures of my daughters, their toys and things in the square outside).

Creating the montage for the top layer was straight forward. I loved the fact that, on the original, the outlines around the images were all different widths, and some of them were even bent out of true. Even the top of the News at One logo was at an angle!

Creating the montage in Flash

The problem I faced was how to merge these two layers. My first thought was to use a Chroma key, but this gave me all sorts of problems and some rather nasty digital fringing that looked like anything but 70s television.

Click to enlarge

What I really needed was to be able to export transparency from Flash into Kdenlive – and it turned out that I could. The first step was to export the sequence out of Flash 8 as a PNG sequence at 24 bits per pixel with alpha channel, like this:

Getting transparency from Flash to Kdenlive

Then I could import the PNG sequence into Kdenlive, and use a Composition transition to knit the two layers together.

Click to enlarge

PNG sequences are the best thing ever invented for my work – everything can use them perfectly and they mean that I can transfer work between packages without losing quality or suffering odd effects.

So, here’s the finished sequence:


Now I understand keying properly I can do loads of things I thought I simply couldn’t do before. And all because I thought I’d do a little sequence to make my daughters laugh.

Saturday, June 11, 2011

Test Card F Prototype

One of my favourite websites is Mikey Bennett’s Vintage Technology page. I love looking at all the vintage television sets Mikey has lovingly restored back to full working order. If your old Bush has lost its colour or your horizontal hold is ruining your enjoyment of your Rank then Mikey’s your man.

Mikey on an experimental 1969 3-D television

A few years back Rory Clark created a very entertaining DVD to demonstrate all the sets in the South West England Vintage Television Museum collection that Mikey curates. The DVD featured a range of test cards and tuning signals from the very old up to the present day accompanied by a selection of tones and music. Although it has given sterling service since then, Rory wanted to create an updated and expanded DVD for Mikey.

One of the cards Rory wanted to include this time was a prototype Test Card F featuring a rather different picture in place of Carol Hersee. Here’s the original:

String vests have never photographed better

Unfortunately the surviving scan of the card wouldn’t really show off Mikey's television sets to best effect as it has faded quite considerably – the grey linearity squares had a distinctly reddish cast and the green castellations in the reference generator area had almost gone black. Therefore Rory asked me if I could recreate the card.

To do this, I used Inkscape as I only draw items in Flash now if it’s completely unavoidable. This is what I came up with in Inkscape:

She’s gone. Was it something I said?

The hardest job when recreating the card was doing the hand lettering on the caption. I did experiment to see if I could get away with using Benguiat Condensed, but it simply didn’t look close enough. In the end, the lettering took as long as the whole of the rest of the card.

It’s interesting to see the differences between this card and Test Card F. A good place to go to find out what's missing is Alan Pemberton’s Pembers’ Ponderings website. He has two clickable Test Card Fs which will tell you exactly what each part of the card does.

I can't wait to see how Rory “distresses” the my Inkscape drawing to make it look like a real transparency on the finished DVD.