The Jumppa
Posted 126 days ago by ajv
iPhoto 11 hangs at start
Posted 133 days ago by ajv
What a nice Sunday fighting with iPhoto ’11. This is how it went:
- Tried to import some 300 photos (wanted to do some spherical panorama cooking) from a SD card, but iPhoto hanged at “Preparing to import”, and would not continue. Nothing would stop import or quit iPhoto gracefully so had to force it quit. After force quitting, iPhoto would hang on startup, just showing the rolling beach ball along with the main window.
- Did quite a few photo library restorations from Time Machine backup – taking about 40 minutes each (70 Gb library), but did not help at all. Glad they exist, anyway.
- Found out that iPhoto hangs when starting with an empty library (start with holding down the alt key)
- Tried deleting everything iPhoto-related from home directory (Caches, saved application states and so forth), still hangs. Tip: get a list of iPhoto related files in terminal by issuing:
find . | grep -i iphoto
- Learned that Time Machine canʼt do a full iPhoto Library backup when iPhoto is open.
- Uninstalled iPhoto and re-installed it from App store – still hangs at startup with empty library
- After all this rebooted the whole thing and got it working. Even with the latest Time Machine backup that was carried out with iPhoto running – some photo descriptions were lost and some photos belonging in the trash were still in the normal places in iPhoto events.
It is now 11:45PM and I think I spent at least 4 hours of my Sabbath with this crap – where can I send the bill? Anyway, remember to back up, kids!
Theoretical living room acoustics - New Formula
Posted 147 days ago by ajv
Just came across a paper where different ad hoc formulae for predicting rectangular room reverberation time are compared with actual measurements: R. Neubauer et al: Prediction of the Reverberation Time in Rectangular Rooms with Non-Uniformly Distributed Sound Absorption
In the paper, Neubauer et al also derive a “New Formula” with improved accuracy, given in equations 20-21. It seems though that the equation 21b has a typ’o negative sign prefix that seems a bit off. Anyway, I wrote a Matlab code to test it:
Haven’t tested it yet, but seems to give a figure in the same ballpark with my measurements by just picking the absorption coefficients with the Stetson-Harrison method. Now if I get to test this more with actual absorption data (available here for some basic materials and here for Ecophon Master SQ) and one could see the differences not unlike my high fidelity measurements, that’d be something. But it’s getting late already…
Update 26.12.2011 14:30. And the same in your favorite browser, caveat emptor still applies:
Practical living room acoustics - phase 1 preliminary results
Posted 151 days ago by ajv
Finally got the Ecophon Master SQ elements (600 × 1200 × 40 mm, 23 in total) installed on the living room walls. Here is some preliminary reverberation time (RT60) measurements using high fidelity N900 microphone and Matlab software
This is how it sounded like:
Impulse response in living room before acoustic conditioning 20.12.2011
Moved the couch to the center of the room before installing the acoustic elements. This increases RT since the hardwood floor along with the room corner are exposed adding to the reflections. Results:
Analyzed 13 sounds, mean RT60 = 1.471586 +/- 0.118441, median RT60 = 1.461902
Installed the elements, couch still in the center of the room. This is how it sounded like:
Impulse response in living room after phase 1 acoustic conditioning 21.12.2011
Rt60 Results:
Analyzed 15 sounds, mean RT60 = 0.989894 +/- 0.049873, median RT60 = 0.985948
The difference is very audible, even by the better half. Hooray.
To be continued…
More practical living room acoustics
Posted 165 days ago by ajv
Making the living room more cozy acoustic wise is getting closer. I ended up deciding to put Paroc Royal or Ecophon Master SQ up on the walls near the ceiling.
I did some planning using Google Sketchup, just to see how 1200×600 elements would fit in there.
Here the smaller gap between the elements is 10 mm (in the groups of four) and 90 mm between the groups.
Also found out how to display Google Sketchup models in iPad:
- Get a STL-exporting plugin
- Figure out how to install plugins (hint: place the Ruby scripts inside the directory given by Sketchup.find_support_file(“plugins”) in the Ruby console (Tools menu -> Ruby Code Editor -> Show Ruby Console (monkey wrench icon, just as you would guess)
- Get a Dropbox account
- Place the STL-model in Dropbox
- Get MeshPad app for iPad
- Get Dropbox app for iPad
- In the Dropbox app, open the STL model
- Dropbox app does not know what to do with it, push the arrow icon (the one that looks not unlike the share/tweet icon)
- Victory
Easy as 1 2 3 4 5 6 7 8 9
How to convert videos to webm-format
Posted 170 days ago by ajv
It took some time to figure out, how to convert videos to webm format using a bit old Ubuntu Linux, where none of the available encoders (ffmpeg, mencoder) support webm encoding.
The most straightforward way is to compile WebM encoder from source. Just clone the git-repository
git clone http://git.chromium.org/webm/libvpx.git
install yasm assembler
sudo apt-get install yasm
and do the standard
./configure && make
and copy the vpxenc to /usr/local/bin. Then have your video converted first to yuv format
ffmpeg -i myvideo.avi myvideo.yuv
and use either the fast 1-pass encoding
vpxenc myvideo.yuv -o myvideo.webm \ —i420 -w 1280 -h 720 -p 1 -t 4 \ —good —cpu-used=3 —target-bitrate=2000 —end-usage=vbr \ —fps=30000/1001 -v \ —kf-min-dist=0 —kf-max-dist=360 \ —token-parts=2 —static-thresh=1000 \ —min-q=0 —max-q=63
or the nicer quality 2-pass encoding
vpxenc myvideo.yuv -o myvideo.webm \ —i420 -w 1280 -h 720 -p 2 -t 4 \ —best —target-bitrate=2000 —end-usage=vbr \ —auto-alt-ref=1 —fps=30000/1001 -v \ —minsection-pct=5 —maxsection-pct=800 \ —lag-in-frames=16 —kf-min-dist=0 —kf-max-dist=360 \ —token-parts=2 —static-thresh=0 —drop-frame=0 \ —min-q=0 —max-q=60
helistin.fi terve24.fi, huoltamo.com etc password analysis
Posted 174 days ago by ajv
Now that the passwords and user names have been compromised for the above mentioned sites, we get a look into passwords differences in health-related and pre owned car sales sites .
This time around the username and passwords match in around 1600 cases (approx 2%). Salasana is the most popular one, but qwerty is left out of the top 20. Surprisingly enough, anneli is again the top 20.
| # | password | number of occurrences |
|---|---|---|
| 1 | salasana | 190 |
| 2 | aurinko | 145 |
| 3 | johanna | 123 |
| 4 | vauva | 91 |
| 5 | nallepuh | 78 |
| 6 | 123456 | 76 |
| 7 | susanna | 74 |
| 8 | mansikka | 72 |
| 9 | rakkaus | 67 |
| 10 | katariina | 61 |
| 11 | pauliina | 59 |
| 12 | mussukka | 59 |
| 13 | emilia | 58 |
| 14 | terveys | 57 |
| 15 | tiikeri | 56 |
| 16 | hannele | 51 |
| 17 | kukkanen | 50 |
| 18 | enkeli | 50 |
| 19 | helistin | 49 |
| 20 | anneli | 49 |
netcar.fi password analysis
Posted 186 days ago by ajv
As the netcar.fi username and password database with around 12000 records was compromised earlier today, I thought it’d be fun to run a simple analysis to see how many usernames and passwords match and on the other hand get the list of most used passwords. The results:
611 (about 5%) usernames and passwords match, and the most common passwords are:
| # | Password | Number of occurrences |
|---|---|---|
| 1. | 123456 | 35 |
| 2. | salasana | 28 |
| 3. | bemari | 15 |
| 4. | perkele | 14 |
| 5. | auto | 14 |
| 6. | 1234 | 14 |
| 7. | mattisili | 11 |
| 8. | netcar | 10 |
| 9. | juhani | 10 |
| 10. | antero | 10 |
| 11. | yamaha | 9 |
| 12. | rasmus | 9 |
| 13. | johannes | 9 |
| 14. | ilmari | 9 |
| 15. | anneli | 9 |
| 16. | sierra | 8 |
| 17. | oskari | 8 |
| 18. | kissa | 8 |
| 19. | toyota | 7 |
| 20. | qwerty | 7 |
OP's interest funds perform poorly
Posted 245 days ago by ajv
Especially the 3 mo euribor one which absolutely should not lose value. For comparison, see e.g. Seligson Rahamarkkinarahasto AAA .
Now OP is in trouble with government bonds, having quite surprisingly relatively high stakes in Greece according to Morningstar . I still recall OP Euro A having Bear Stearns bonds in top 5 in 2007 Fall.
Used motorbikes cheaper in fall - a case study
Posted 248 days ago by ajv
View larger.
iMac day 400+
Posted 327 days ago by ajv
Hard disk failure. The system began to lag / stall and finally did not even boot. When booted in verbose mode (press cmd + v at startup), it was evident that at least the book keeping of the disk had gone corrupt.
The standard OS X Disk utility, which displays SMART. status would say the disk is “verified” and reported no errors with it. After starting the thing from OS X DVD and restoring from an old backup (a 2 days old back up could not be restored), the disk structure seemed also ok. However, comparing Disk Utility’s results with SMART utility revealed that the SMART status is in the eye of the beholder
I called the local Apple hotline, who told it’s better to send the thing to authorized service partner, who would charge 150-200€ for disk replacement. I also went to a PC shop where, when asked if they could replace a iMac HDD, they told me “Oh sure, is it a laptop, we’ll charge 25-75€”. Based on these, and especially the friendly guy at Apple hotline who specifically told me not to try replacing HDD myself, I decided to buy a Samsung 103SJ 1 TB disk and dig my torx drivers to broad day light.
Replacing the disk was a lot easier I thought it would. There is a very good tutorial available at ifixit . I even cut it a bit short and did not detach other cables between the motherboard and display than the vertical sync ribbon.
However, after replacing the old Hitachi 1TB HDE721010 SLA330 disk with the Samsung the HDD fan would start to make noise not unlike a normal PC. Apparently the factory installed hard disks in iMacs (late 2009 models and newer) have Apple’s proprietary firmware and read the HDD temperature not through SMART but through a separate thermal sensor connector.
I could not get that to work with the Samsung HDD (actually the connector would not fit like ifixit documentation advises). The noise issue was resolved by installing a piece of software, HDD Fan Control, which allows for manual tweaking of fan speed as a function of HDD temperature. And this thing gets the temperature through SMART and not by some proprietary means. The only downside was the price tag, about 30 € for such a small piece… But worked like a charm.
It still beats me, why I could not use my latest Time Machine backup to restore the system. I managed to get the disk to the state it was on 2nd of January 2011 and right now I’m restoring the home directory from the latest backup, which seems to run fine so far 55 GB / 171 GB.
Zotac Zbox HDMI audio out on Ubuntu 10.10
Posted 403 days ago by ajv
Got a Zotac HD-40 for replacing PS3 for browsing and playing movies on TV. Everything except audio over HDMI worked out of the box with Ubuntu 10.10. For audio, a) unmute sp/dif of nvidia card b) test it works with “speaker-test -D plughw:1,7 -c2” c) if it does, put the following in /etc/asound.conf (have to create a new file):
pcm.!default {
type hw
card 1
device 7
}
I browsed through hundreds of web pages telling to work with drivers and compiling kernel, but the above should do it. Worked for me anyway.
Edit: goddamit, spotify does not work… we’ll see.
Edit 2: audio stopped working again. Once I got rid of pulseaudio (sudo apt-get purge pulseaudio), audio was back up and Spotify works too. Nice. Oh, and I put explicitly hw:1,7 for audio device on xbmc.
Also, had to tune some vblank options in xbmc to get rid of video tearing. Could say this thing didn’t work out of the box.
Google Home View has no respect for privacy
Posted 407 days ago by ajv
See this .
Requires a recent and decent browser with WebGL support ie. not IE.
Comment [3]
Strobist action
Posted 452 days ago by ajv
Nikon SB-600 camera left with shoot through umbrella.
Nikon SB-600 camera right with shoot through umbrella.
ATLAS BLAS SSE2 randomly segfaulting
Posted 541 days ago by ajv
Last night I wrote some code using world famous BLAS dgemv to perform matrix-vector multiplication. The first thing this morning was to check out the modifications from code repository and continue hacking at work.
Turned out I’d be hunting for a bug causing segmentation fault the whole day. The code would crash at random times when dgemv was called, and I knew that it was going to be a fun day chasing the memory corrupting lines from the code. Because RAII, I had no calls to “new” or “malloc()” and pals in the code so it would be easy.
First, wrote a simple piece of code performing the same dgemv to reproduce the bug. Could not get it to corrupt memory.
Next, checking what’s going on using valgrind (gotta love it). It reported “Use of uninitialised value of size 4” on every call to dgemv. Double checked the parameters and matrices & vectors. Quadro-checked. Used —track-origins=yes. Valgrind told something wrong inside blas’ stack. Damn.
Tried the same code on a different machine on different blas (2pm). Everything works. Double checked with valgrind. No complaints altogether. Tried to change blas implementation on the development machine, using update-alternatives. Would not work but always link to the SSE2 version. Removed atlas sse2 libraries altogether and tried 3dnow optimized version (4pm). Everything works. Can go home now. Not a very productive day.
Old news
Posted 594 days ago by ajv
Suomen Kuvalehti writes on 4th of October 2010 :
… finanssiriisin juuret esiin 1970-luvun Yhdysvaltain asuntomarkkinoilta. Siihen aikaan kongressi halusi tukea huonoja kaupunginosia pakottamalla pankit myöntämään niihin asuntolainoja.
While traakki.net wrote on 5th of January 2009 :
Some people might still remember that the ongoing recession was triggered by subprime mortgages across the pond. It’s origin were on the typical “the road to hell is paved with good intentions” Community Reinvestment Act
N8 versus Canon IXUS 130
Posted 597 days ago by ajv
Nokia’s N8 camera versus Canon IXUS 130
Matlab clone on your browser
Posted 602 days ago by ajv
Now if someone came up with implementation that supports plot() through Google Visualization API or something.
Comment [1]
ADHD-instituutin aivosähköposti
Posted 609 days ago by ajv
Sekos ADHD-instituutin aivosähköposti,
kun Pekka Erik Auvinen kakskakkosensa osti.
Hura-huh-hah-hei!
Holmlundi haulikoille,
lahtas Kauhajoen Matti toistakymmentä.
N8 turns any screen to touch screen
Posted 609 days ago by ajv
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