Monday, January 31, 2005

Flying the Flag

I am not exactly an avid flyer of my national flag, although I believe that those who wish to do so should certainly be permitted, even encouraged, to do so. I also think that built-environment planning has some value and even support some amount of heritage protection. Nevertheless, facing a $50,000 fine for flying the flag without permission seems absurd to me.

This situation has the feeling of "because people will do bad things even given total freedom to act, they should be given no freedom to act". Can "erecting 3m flag poles" be added to a list of things that people can do in a heritage area without formal consent? Is non-visibility of the flag an important element of our heritage?

Friday, January 28, 2005

XML-binary Optimized Packaging

At last, XML has a formal, standard means of dealing cleanly and efficiently with arbitrary binary data. To date the approach has been to base-64 encode which:
  • Enlarges the data.
  • Spreads each group of three bytes across four bytes, marginally worsening the performance of efficient update algorithms like rsync when synchronising changes.
  • Renders in-place use (e.g. mmap()ing a video stream) impossible.
The adopted approch utilises a MIME multipart/related container to move the binary streams out of the XML document itself and the Content-ID: header plus cid: scheme to tie the pieces back together, substantially the same approach as a scheme that I've contemplated in the past to solve much the same problem.

What they've done that I had not considered is to define a mapping between this efficient form and a simple XML document with the binary stream base-64-encoded in place which means that efficient representation and canonical form (e.g. for signing) need no longer be in conflict.

Monday, January 24, 2005

A Rotary-Dial Cell/Mobile Phone

Oh the humanity... A working cell/mobile phone embedded in an old rotary dial phone; both retro and absurdist at the same time.

Thursday, January 20, 2005

From Norway to Norway via The UK, France, Belgium, The Netherlands, Germany, Denmark and Sweden

When mapping software goes bad. Scenic perhaps, but bad.

Tuesday, January 18, 2005

This product moves when used

I'm thrilled to learn (via Seth Godin) that an organisation exists which monitors lawsuit abuse and, as an aside, grants awards (pictures) for absurd, presumably lawsuit-inspired, "safety" labels on consumer products. This year's first- and third- place getters are painful to contemplate (a toilet brush labelled "DO NOT USE FOR PERSONAL HYGIENE" and a thermometer whose packaging is marked "Once used rectally, the thermometer should not be used orally, for sanitary reasons."), however to my mind, the second place getter has an understated but rather more compelling absurdity to it: a child's scooter marked "THIS PRODUCT MOVES WHEN USED".

Warnings about obvious risks are a long familiar irritation, but a warning that a product actually does what its name says it does is getting beyond the pale.

Monday, January 17, 2005

Better Use of the RF Spectrum?

Business Week is carrying an article by Greg Blonder entitled America Needs Unchained Spectrum. His argument appears to me to contain a couple of minor errors (e.g. that the "good" CB service delayed the introduction of the "great" mobile service - I am not convinced that these two sets of products were ever in competition; although the trunking of dispatch systems (taxis, couriers, ...) to the public phone system may have delayed the availability of what would otherwise have been a ready early market, so maybe his conclusion holds for reasons different to those that he suggests) and completely overlooks the cost of replacing the current deployed inventory of end-user devices (TVs, cordless phones, baby monitors, cell/mobile phones, radios, WiFi infrastructure, ...), but broadly his claim appears to have some merit.

That TV broadcasters are able to have exclusive use of enormous chunks of spectrum for a single use (if we have no interesting content for a given timeslot, fill it with infomercials) and that they have this dominion even in areas where their signal is not wanted (Blonder implies that 20% of the population is a huge audience for any given broadcast) or not even available (behind obstructions or in unserviced rural areas) probably made sense when there were only two or three channels in existence and when those two or three were a matter of great interest for an entire population, but does seem a little out of place in the current environment.

Sunday, January 16, 2005

Glow-in-the-Dark Gold Fish

Well, Taikong's TK-1 Flourescent Ricefish, to be precise (video).

I don't know quite what to make of this; is it a cool technology demonstration, an abominable manipulation of the genes of a species to satisfy mere asthetic concerns, or a better place to start developing GM expertise than, say, experimentally manipulating the genes of food intended for human consumption?

Centi-inches

Slowly but surely, the world crawls towards metric. In many places, imperial mesaures are of course still in wide use but even in, say, the US it is often neccessary to use both in the same transaction. e.g. If you ship a package out of the US, you ordinarily have to provide package dimensions not only in imperial measures for your courier, but additionally in metric measures for US customs.

One of the really cool things about metric, aside from the serious attempt that was made to establish a rational and interconnected basis for the metre, kilogram and second (which means that there are less arbitrary constants to memorise when converting from, say, joules to amp-metres), is that larger and smaller units of measure for the same quantity are always multiples of powers of ten so you can convert from 2.7Km to 2,700m to 270,000cm or 2,700,000mm just by moving the decimal point around. Try that with miles, yards, inches or thirty-seconds of an inch. No doubt you already knew this.

What you perhaps did not know, and that I've just noticed, is that users of imperial measures are discovering the joys of metric scaling, but are perhaps a little shy about acknowledging metric origins. At present, google lists just 24 pages which contain "centi-inches", but 152,000 which contain hundredths-inches.

Perhaps inches could be renamed "freedom-centimeters" :-)

Thursday, January 13, 2005

Tool-use in crows

No, really.

I have long thought of tool use as one of the more obvious identifying traits of human beings, although quite clearly, other primates are capable of it. What I did not know is that some crows are capable of tool use, and are capable of doing it inately (Reuters), that is, without instruction from parents (or from human researchers).

There's more reading to do though; my attempts to find Kacelnick's (or, more likely, Kacelnik's) actual work have come up dry, in particular:

- His recent publication lists do not appear to be terribly current.

- Searching Nature doesn't help, it only lists one 1989 book review by Kacelnik, has 45 hits for Kacelnick, none of which have anything to do with crows and in fact no recent articles at all on tool-using crows by any author.

- What I have found so far is a 2002 article in Science which documents the ability of a crow to manufacture a tool with an astonishing video of a crow actually doing so.

UPDATE 15-Jan-2005: The article has now appeared; it would appear that Nature sends out its press-releases before putting articles onto its website...

Sunday, January 02, 2005

Motorola A768i video encoding

I wanted to be able to watch videos while commuting via public transport. So, as previously, gaining access to the filesystem via SMB over TCP/IP over USB:
sudo insmod usblan.o vendor_id=0x22b8 product_id=0x600c
sudo ifconfig usb0 192.168.1.2
mkdir /tmp/a768i
sudo smbmount //192.168.1.1/home /tmp/a768i -o uid=$USER,gid=$USER

Then to re-encode and transfer:

ffmpeg -i infile -s qcif -r 12 -ac 1 -ar 8000 -b 30 -ab 12 outfile.3gp
cp outfile.3gp /tmp/a768i/myMedia/


(ffmpeg's output could be sent directly to the filesystem mounted from the phone, but it appeared to me that this made the entire operation very slow. Perhaps ffmpeg is performing small, unbuffered writes and smbfs isn't coping.)

I use the ffmpeg options suggested by James Bowman, note in particular that the ffmpeg build needs the amr/3gp support built in. Follow the instructions in amr.c in the source tree.

When playing the result on the phone, using the media player directly (add 3gp streams to the playlist) provides one compelling feature over opening a single stream from the file manager: when the media player is playing videos from a playlist, tapping the video image makes the video fullscreen, doing so with a video opened from the file manager does not.

Note that the player's startup time lengthens as the stream gets longer, to the point where a stream with a length beyond some threshold (20 minutes?) won't open at all. Chopping longer streams up with mpgtx (into, say, five minute chunks) appears to work, but some amount of damage is done to the resulting streams.


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