Rick's b.log - entry 2008/11/20

Nice work if you can get it...

You might think I'm mad to be sorry to be going, and in a way I am. Read that either way, I'm sorry and I'm mad. ☺ You see, the shift pattern sucked beyond the telling of it. My last b.log entry before this is the 9th, like two weeks ago. I have on my little media player device Heroes #3.04 which I am sort-of watching at break times. On the device are episodes 5 and 6. On my harddisc and converting as I type this are episodes 7, 8, and 9. There's a long list of films that I have recorded, transcoded to XviD, dumped onto DVD-R. I think when I finish my contract I can spend a week solid watching all the stuff I missed while working. And then... then there's the little matter of all those emails I owe people. Poor American Andy has heard barely a sentence from me in three months. I've not been much better with the rest. I mean, I get home from work, read the (sometimes long) emails, and after reading and thinking about it, it is time for bed. I'm on earlies this week. Tuesday, went for a quick kip (still dressed!) at 5pm. Woke up at 3am when my alarm went off. About the only time ever I have been bright in the morning!

...but you cannot deny the obvious attraction of €1000(ish) in the bank account. Last months pay will go to getting broadband hooked up. I am deferring this until early December so I know fairly well that I will be able to be available for them should I need be. This, the final pay, will go towards a new harddisc (approx 200Gb), perhaps a better media player - I hope to find one under €80-100 which can play DivX/XviD directly. Oh, and some to attempt to save so I'm not always "running on empty", and so when unexpected things happen like the car's starter motor fails, we can drop it off with a local mechanic we trust and say "fix this".

But, I guess that is not to be. My ANPE advisor thinks I am much better suited to working in a "cabinet informatique", a little computer place. Sure, I bet poking around sick computers, fitting networks and crap... that'd probably keep my happy, but hands up if you can name such a place within twenty miles of here (excepting local nerds working out of their bedrooms). Oh, I'm sorry, I forgot to tell you where I live. Well, never mind, don't put your hands up, there are only two, one in each of the two local towns. And they don't look the sort of places that can take on a full-time employee, even one fluent in the language of broken-Windows (French XP, when it bluescreens at boot, whinges in English!). So I guess it'll be the dopey sending-of-CVs-to-hear-no-reply-justify-my-very-existence-to-half-a-dozen-people parade of beaurocracy. Tant pis, hein?

Why is a pie so hard to make?

TightVNC extras (and VirtualDub!)

Another one, very useful, is when using VirtualDub to transcode. I set up a list of jobs, then let the job list run. Leave it to get on with things. Lurking in the job control window is the menu option to shut down the computer when done. So I can leave it running into the night, and know it'll turn itself off when it has finished. It's just a shame it won't "hibernate" instead of "shutdown", but never mind...

Problems recording video into a computer?

Note, however, that my video capture is 352×288 (the processor isn't powerful enough to do full-screen), so in essence when I record it is dropping every other line anyway. I think it works better in single field mode for video as video recorders don't tend to have a very stable timebase. A few quarter-microseconds here or there is probably no big deal to a TV, but could be a problem for a computer capture device! Maybe the ability to grab a field and skip the next gives my hardware time to sync to a jittery signal?

One field? Two field? What!?!?
The impression that TV wants to give you is of a picture 'updated' fifty times a second. However the 'bandwidth' (the amount of space required to broadcast a signal) to do that is unacceptably large, so analogue television is broadcast as twenty five frames per second, and these frames are split into two fields. Your television works by tracing lines on the screen, down the screen, 576 of them (well, that are visible, don't worry about the others). A complete frame will make your television show 576 lines. The two fields? Think of them as "all the odd lines" and "all the even lines". This is a method called interlacing where every other line is displayed, and then we go back to the beginning and do every other alternate; like 1,3,5,7....2,4,6,8...
Good capture software will offer you three ways to capture:

1. Two-field deinterlaced
   This will capture both fields and attempt to merge them together. The side effect of this is that motion may look a little bit blurry as things will have altered slightly from one field to the next (which represents one 50th of a second in time).
   There are different styles of deinterlacing with names like "Bob" and "Weave". If your software offers a choice (some don't, it depends on whether the software does this, or the video capture hardware itself), you'll need to play around to see which you feel works best for you.
2. Two-field interlaced
   This will capture both fields and merge them together with no further work. The side effect of this is moving things will contain jaggy lines (known as "combing") where there are differences between one field and the next. Some people live with it, some feel it is the most annoying thing ever.
3. One-field
   This will capture only one of the fields, usually doubling up the lines to make up the gaps, and discard the other field. This will offer effectively half the desired resolution, but as a trade-off it should eliminate interlacing artefacts - either the combing or the blurring. For what it is worth, while my own 352×288 captures look really crap when played back on WMP(9), they look okay when played on a DVD player that is connected to a TV using RF. You only notice the lack of resolution in captions and credits, or very harsh contrast (like the film "Renaissance!).

Can't we get a decent TV picture?
With traditional methods? No.
There may be a hope with digital broadcasting either recording the MPEG stream directly, or recording the picture in "progressive" mode (that draws each frame as a complete entity, not split fields). This will require special hardware, either DTT receivers that can push through the data stream intact, or capture devices that work using inputs other than RF/composite/S-video/etc.

How come when I ripped a DVD, it didn't do this?
DVDs are encoded as frames, either 25fps (for PAL) or 30fps (for NTSC). The splitting of the frames into fields is done by the player; which is why European DVD players can usually make some attempt at playback of NTSC material - just rearrange/diddle the frames to fit the desired output (often simply by playing five at 25fps and dropping the sixth frame!). Ironically it is said that American hardware is less broadminded and DVD players/VCRs don't know what to do with PAL (25fps) source material. Bizarre!

Sound drift when recording from a stable source
The most stable source you are likely to get is a direct connection to a digital satellite receiver (or DTT box). The box itself builds the picture, and does so to exactly 720×576 resolution (unless HD, obviously) at the exact timebase required. However, you may still encounter drift.
If the drift is small, maybe a few seconds per hour, this is normal. You will need to transcode using software such as VirtualDub which permits you to alter the frame rate. Try 24.999fps - it's only a hiccup away from exactly 25fps and it ought to clear up the problem.
If the drift is large, in the order of a minute per hour or worse, there is something wrong with your software and/or hardware. Try alternative software.

The drift occurs because of timing mismatch. If you think about it, a modern PC often runs the video capture and audio capture in separate processes. This means, effectively, one "program" is looking after the sound, and one is looking after the picture. The audio is a constant 44100Hz, 16 bit, stereo input. The video is 720×572 (full screen) or 352×288 (reduced), 25 times per second. Both making use of the same (PCI) interface. Both probably making further use as while the audio and video are fighting to get in, the assembled composite video stream is also fighting to get back out to your harddisc, often via an IDE controller combi-chip that is wired to be 'a PCI device'.
If you are clever, do the maths. Tell me the relationship between each sample of audio and each sample of video. If you are not clever, trust me, there isn't one. Each bit of hardware uses a different clocking rate, so it only works by virtue of "adding up" to be the same length.

So what about interleaving in AVI files?
There is no direct relationship between the audio and video in an AVI (or MPEG) file. It isn't as if "this bit of sound goes with this bit of picture". The sound is a stream that begins at the beginning and ends at the end, and the video is likewise.
Consider:

In order to prove there is no real relationship between the two streams other than starting time, make a DivX using VBR audio (variable bitrate). Fast-forward to about halfway into the film, back up a bit, then see how far out of sync the audio and video are. This is less of an issue with CBR (constant bitrate) audio as the relationship between bits/time is the same, however it varies in VBR mode so the only way to get it exactly correct is to whizz to the current playback position right from the beginning... which would be unacceptably slow.

aMaizeing!

As I write this, the field has been roughly ploughed, tilled, turned, and is being sowed with a new crop. Something perhaps more suited to the wet warm winter we are supposed to have... like rice, maybe? ☺

It appears as if the current "farming practice" handed down from on high (ie the EU someplace), is to "screw the set-asides and screw nature". Now, the set-asides were always going to be controversial because of greedy little oiks and the idea of being paid to not grow something; however they did serve a useful purpose in encouraging pollinating insects and a variety of bugs to have a place to live, and now - perhaps because of the cock-up in biofuel plantations and fears of world wheat shortages, the result has been a rampant destruction of such meadowy areas.
Well, I have a solution. It is as follows:

• Every farm must dedicate at least 5% of its land space to meadowland. This can be any convenient area; at least half of which must be consistant from one year to the next, the other half can 'move'. Such land is to remain untouched during the life-cycle of the wildlife inhabiting this area, and it is to be a complete no-go zone for hunters.
• Meadowland must be such, therefore field edges (unless at least 15-20m+), mown 'grass' around the occupied buildings, and grazing land do not count.
• They are not paid for this meadowland, however farms which provide more than 5% will receive bonuses. Those with the basic 5% will receive nothing, and those with less will be fined.
• There has always been controversy on whether to pay by yield or on land area; for either method will promote the unscrupulous destruction of hedgerows in order to make field sizes (and yields) larger. Therefore existant hedgerows should be recorded and planning permission required for their removal, with the requirement of a reason better than "to make my field larger" or "to allow me to plough this field and that field in half the time".
• Grants should be offered for reinstating hedgerows and forested areas, but not if such areas have only recently been destroyed/removed.
• Farmers should have the right, without threat of penalty, to refuse instructions on what crops to grow in at least 20% of their land. Chances are they will know their land and the suit that says "grow X here" probably doesn't. Or doesn't give a...
  Obviously, if the farmer is paid upon yield and crop, it is in their interests to make their land productive rather than bugger around in politics.
• Any given field must be rested for a year (with some sort of fixant crop) at least once every six years.
• If payments are to be based upon field size, France offers a complete set of land registry documents (the "plan cadastral"), I am sure other countries offer similar. These documents, drawn up by a highly trained professional (the "experte geometaire", I think?) are the ones used to calculate field size. Not the field itself. From these plans, deductions should be made for watercourses and margins etc; and any payments offered are to be based upon this. Furthermore, if the plans show a hedgerow that is not there, any payment should reflect a deduction of margins on both sides of this hedgerow. This, obviously, to discourage wholesale ripping out hedgerows in order to make fields larger.

I completely understand farmers wanting to look after their best interests. There is a certain amount of greed in all of us. Would I be really happy to work on extra at my job, or was it only for the money in my bank account? The thing is, every farmer has at his command environment-changing machinery, and while one farmer might laugh at the idea of him ruining the ecology, it is quite a different matter when you have a hundred farmers laughing at that idea, and 100 farmers probably accounts for a mere ten mile radius... it is like trying to make a difference in the world. Individually we cannot achieve much. Together? Anything is possible. The principle works in any direction, for good and for bad. A big march of togetherness brought Nazi atrocities throughout WW2, and a big march of togetherness brought LiveAid into being, broke records for Children In Need, and elected the first black president into a country that still hasn't fully come to terms with "people of colour". Amazing things are possible. Amazing with a smile, or amazing with mouth open in disbelief. It's about time we opened our eyes and realised that maybe a can of beans for 8p a tin and bread for 20p a loaf isn't necessarily a good thing.

The housing crisis

The housing crisis - alternate

[...] In one signed document the government has negated all the efforts with respect to householders changing their light bulbs to energy efficient ones. In fact the creation and later disposal of these mini-fluorescent lamps are possibly even worse for the environment than standard bulbs - not least because fluorescent bulbs have some nasty stuff inside, such as mercury, which has been removed from batteries in recent years only to turn up in supposedly "Eco" lightbulbs. If we can pull a conspiracy from this factoid (in other words, look beyond the 'green' packaging and figure out what's going down), I would be somewhat inclined to question if this has anything at all to do with the environment, or has the continued availability of "cool gadgets" over the last decade or so has placed quite a toll on the electrical distribution systems, what with all these "digital" receivers, telly/satellite/radio, cheap'n'cheerful computers, Wee, no... Pee, no... Wii devices and those mind-blowing billion-inch don't-sit-too-close-or-you’ll-see-every-pixel HD Ready televisions. There isn't enough cash to pay the company directors and implement a radical overhaul of the distribution network. So the quick fix is to blag everybody into believing that low power light bulbs are friendly to the world. Presently, twenty million 60W bulbs (=1 200MW) will become twenty million 17W bulbs (=340MW). Quite a difference. [...]

Graphics tablet - under pressure

Things aren't so good regarding the AAAA battery. Farnell nominally lists two, only one has no price with the order code, I guess this is either an error or an indication that the item is no longer carried. Pearl carries none... Could be difficult to get replacements, but the search continues.

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