Lair Of The Multimedia Guru

Its quite a while since ive updated my blog, and indeed ive a few things i wanted to put up but have always had something more important to do, well. Today, ive finally decided to skip doing important things and put up something really unimportant.
A while ago I was reading the manual of a toothbrush, an electric ehm “sonic” toothbrush. It said something like 40000 revolutions per second. Reading that and looking at the humble, el-cheapo toohbrush i didnt belive it, so i had to find out how fast the thing vibrates (it actually doesnt do full revolutions). Using my soundcard was out of question as that wouldnt work above 24khz. So i used a old analoge osciloscope that i got for 15 euro from a local flea market a while before.

You can see on the scope, the vibration of the toothbrush head as well as a 1khz reference square wave. The trick is that the toothbrush head is made of some kind of plastic and by rubbing it against something, it becomes electrostatically charged. Just holding the scope probe near then shows the movement of the head.
We can see on this that in about 6 cycles of the 1khz signal we have 2 cycles of the toothbrush, which would give ~1000/3 hz.
Which is 120 times off from 40000, if one considers both ends of the vibration instead of a full cycle its 60 times off. And at that point i looked at the manual again and realized it said 40000 U/min not sec :)
Which proofs my way of measuring it is quite spot on, but my way of reading the manual isnt.

Ive been using gmx since over 12 years for my email. And until recently gmx did a fine job at running a SMTP and a POP3 server. But it appears this is slowly changing. A few month ago their SMTP server stoped accepting mail with the verbose message: “550-Requested action not taken: mailbox unavailable\n550 Reject due to policy restrictions.”. It turned out that gmx refused localhost as domain to the EHLO SMTP command. They require a fully qualified domain name now right? no, not really, any random string seems to work just not localhost. My attempt to contact gmx about this, lead to no reaction.

The next thing was this: “550-Requested action not taken: mailbox unavailable\n550 invalid DNS A/AAAA resource record”, yes thats right, gmx rejected outgoing mail because the poor guy had not set up a webpage on the domain that he used to receive mail on. This one btw affected multiple people i tried to communicate with, not just one.

But hang on it was just starting, next there was “451 Requested action aborted: local error in processing’ errormsg=’recipient address nicolas george normalesup org not accepted by the server”

Also it has to mentioned that gmx at around that time (maybe 1-2 month before or so) started to randomly put “*** GMX Spamverdacht ***” in the subjects of random received mails even though i always had and have all spam filtering disabled at gmx (mainly because their filters never worked).
So yeah another try at complaining to gmx about that, and yes this time there was a reaction, i got a mail from them “GMX Sicherheit: Vorsorgliche Sicherheitssperre Ihres GMX Postfachs!” they locked my account and provided me with a few tips on how i can scan my windows system for viruses. Hello gmx, i dont use windows.

My next attempt to contact them and now find out why they locked my account lead to just a polite (probably automated) mail with a link to their payed and expensive phone support. Seriously, locking someones account and refusing to tell them why unless they pay. And locked btw means SMTP was not working, POP3 still worked and so did the web interface where one is asked to change ones password which then unlocks the account again. Maybe iam just missing the point but what sense does that have.

Was that all? no, it seems gmx also reduced the maximum size of mails as a 21mb mail i tried to send to 3 people could not be sent over gmxs smtp server and with a different smtp server it bounced from reimar who also uses gmx so it also could not be received. Iam pretty sure i did transfer bigger things years ago.
Ahh and i almost forgot: “5.7.1 : Recipient address rejected: Your MTA is listed in too many DNSBLs; check http://www.robtex.com/rbl/82.165.159.40.html”, Yes thats gmx being in the DNSBL lists at the time that happened. Now just why was i not surprised by that …

Did anyone really read this far down ? Well as gmx slowly goes from well working to something else, iam forced to find alternatives to handle email. So i got this one: michael@niedermayer.cc, iam still using the gmx addy though, feel free to use either if you want to mail or spam me. I guess if these issues with gmx continue then ill have to start updating my mail address everywhere …

2014-01-26 Update

Heres an example of the random marking of mails as spam, the 2 mails where simple git patches send to ffmpeg-devel, sent by me, at the same time from the same computer and their content should be quite similar and should not have triggered any properly trained bayesian filter.

85260 N 0126 2:11 Ronald S. Bultj (1.3K) [FFmpeg-devel] [PATCH] vp9: disable use_last_frame_mvs on resolution change (scalable).
85261 N 0126 2:30 Ronald S. Bultj (8.9K) [FFmpeg-devel] [PATCH] vp9: fix invalid ref frame w/h on size change.
85262 N F 0126 14:49 To FFmpeg devel (1.2K) [FFmpeg-devel] [PATCH 1/2] avcodec/libfdk-aacenc: change MODE_7_1_REAR_SURROUND to map to AV_CH_LAYOUT_7POINT1
85263 N F 0126 14:49 To FFmpeg devel (0.9K) ??>*** GMX Spamverdacht *** [FFmpeg-devel] [PATCH 2/2] avcodec/libfdk-aacenc: change MODE_7_1_FRONT_CENTER to map to AV_CH_LAYOUT_7POINT1_WIDE_BACK

Also ive sent gmx a link to the blogpost, no reaction from them so far

I found 2 Insects looking like this in my appartment:

Anyone knows what it is, its about 10cm large from leg tip to tip if it stretches out and capable of flight, seems not to have any inteligence to speak of. I could catch it and throw it out of my appartment but iam affraid its too cold outside?

Anyone knows what it eats? How long it lives?

My acer NB today: Critical temperature reached (101 C), shutting down.
And disablng power management of the HD produces errors after a while, not just today but always.

A little rant to keep my blog from rotting, firefox after 3.0 or so no longer works on kernels that randomize memory allocation a bit. Ones choices are either patching firefox or to disable the randomization for it. And we all know if one application needs all the security layers one can get then its the modern web browsers.
Not to mention how one can be so lame to have such bug open for ages and still not even produce an error message but rather run mmap() munmap() in an infinite loop.

As the little reverse engeneering puzzle has been solved, we need some prize …

flour, olive oil, half a teaspoon sugar, dry yeast and water. No thats not yet the price ^^; And probably not even a half correct pizza dough but i like it and am too lazy to look up what is “correct”.

After rescaling the x,y and z transformation vectors of the dough it becoms flat and roun hmm square?! (… i guess ill file a bugreport about that one later) adding tomato puree and tuna.

Adding gouda cheese and oregano, i should probably have added more cheese but transforming a block of cheese into these stripes is boring and the ready made pizza cheese from supermarket could be more accurately be described by milk+yellow color and thickening agent so that stuff was not an option.

After ~15min at ~493 kelvin

And at last, the pizza was turned into a virtual pizza, which i herein officially give to chrono! The real counterpart has for saftey reasons been quickly ea ehm i mean destroyed, to avoid paradoxes.

Random pictures from around midnight 2007-12-31 / 2008-01-01. Downscaled a little so wordpress autogenerates thumbnails and doesnt randomly refuse the uploads

Being a little bored and too lazy to do any meaningfull work. Ive looked at wikis main page and on that the Paradox of choice caught my eye, thinking its some interresting thing about math like the Axiom of choice is.

After reading the article iam puzzled why something like that is on wikipedia at all. Not to mention how things like that get linked from the front page.

Psychology has together with astrology always been a little astray from science and logic. But that article is really missing the point. Consumers dont have a problem with too many choices, they have a problem with making choices based on lack of information, wrong and irrelevant information (as presented in advertisements).
If one has a small set of products to choose from at the supermarkt one can try them all or at least a significant fraction of them and then in the future choose the best (considering quality, taste, price, …). With more products trying a significant fraction becomes impossible, one has to rely on other means of comparission. With many products thats still dead easy, for example after trying 3 differnt brands of noodles one realzes they all taste the same. So simply choosing the cheapest is the ideal choice. The same is true in a sense for green tea. None of the green teas from supermarkets i tried tastes as good as a random one from a real tea shop. It gets a lot trickier with these frozen, refrigerated, canned or dried, ready made foods there are far too many to try them all. Theres no obvious trend of taste vs. price, not even a reliable taste vs. brand trend. Only thing which has been always true is that cooked by my (grand)mother or myself tastes better :). I think supermarkets really should add some “number of packs sold per month” and “average customer rating” to their price tags.

Supperior (no frozen and dried crap), half finished, yesterday:

Finished (still yesterday)

A few days ago i came up with the idea of replacing my several years old canon digital ixus 30 with something newer and better. Maybe with a more recent canon ixus (called elph SD+somenumber outside europe), heres a summary of what ive found that has changed:

So seems like 3 years isnt enough for canon to improve their (ultra) compact cameras. What about the powershot A series? well i had the A95 for a week but it was simply way too heavy and big also its light sensitivity was not any better than the much smaller canon ixus IIRC. Though at least it had manual controls so the camera did what i wanted. And the fuji F30/F31fd? Well fuji stoped producing them and their replacment the F50fd produces vertical stripes with a nice green magenta gradient over its images, making high ISO unuseable without some cleanup. (noise is one thing but stripes even if they are fainter than the noise just isnt something i want in my images) Also the f50fd is noisier than the f31fd though still significantly less noisy then anything produced by its competitors in that size and weight range that i found.

So suggestions welcome, but it looks like i wont buy any new camera. Capitalism has once again demonstrated that it doesnt work, its not as if the consumer would know which product is best and would thus force the industry to produce better products, its rather that the industry prints irrelevant numbers (megapixels) on the cameras and the consumer buys based on that ignoring all relevant parameters. So the industry just needs to exchange the CCD with one with more megapixels and paint the camera differently instead of improving anything relevant.

Low resolution graphics modes like 320×200 are displayed with doublescan so that each logical line is drawn twice, that way 320×200 is drawn with 400 lines which looks better than 200 on a modern CRT monitor. The reason is that modern CRT monitors are designed to be able to display 1000 or more lines and if they are feeded with just 200 there would be huge black bars between these thin 200 lines, with 400 lines its better but still not good.

VGA600 is a little DOS TSR which i wrote in 1996/1997 to solve this problem, VGA600 does that by monitoring the state of various vga registers and if it detects that the current graphic or text mode can be improved then it improves it by increasing the number of lines and dot clock. So for example 320×200 would be displayed with 600 or 800 lines (which it is depends on the configuration)

Source code under GPL, README and binary are available too

Ive extensively tested VGA600 with doom and quake with a ET4000 PCI card a long time ago ;)

Patches welcome, especially ones porting this to linux and modern vga cards :)