Insights

OMG! I’ve got pwnd. By the interwebz.

Wednesday, November 16th, 2016 | Gadgets, Insights, Misc | 1 Comment

I saw this random add on Facebook, some 5 piece Star Wars canvas depicting Lord Vader. Loved it. Honestly, I love personalized ads, as they show me stuff I really like.

Lord Vader Canvas

This time I fell for a fraud. It seemed legit, I guess, there was PayPal to pay, free worldwide shipping (this should have rung a bell already) and 32.99 USD seemed a good deal.

Bought and paid October 1st.

PayPal

Contacted seller November 6th.

Hi there, I am still waiting for my “STARWARS 5 PIECE CANVAS LIMITED EDITION”. Purchased at first of October.

Is there anything wrong?

Cheers
Nick

Never got a reply.

Double checked the website November 16th.

bildschirmfoto-von-2016-11-16-09-11-34

Offline.

Okay, seems I was to naive to trust in this bargain. Contacted PayPal, hope I will get my money back.

So, please, if the offer looks the least dodgy think twice. It can happen, even to old online veterans. When in doubt use a service like PayPal who might give you another layer of buyer protection.

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Transparency and Torture. In Data Compression. Solved.

Friday, October 28th, 2016 | Insights, Music, Tech-savvy | 1 Comment

First, let me introduce what transparency in data compression means, excerpts from Wikipedia:

In data compresion and psychoacoustics, transparency is the result of losy data compresion acurate enough that the compresed result is perceptualy indistinguishable from the uncompresed input. In other words, transparent compresion has no or imperceptible compresion artifacts.

Transparency, like sound or video quality, is subjective. It depends most on the listener’s familiarity with digital artifacts, their awarenes that artifacts may in fact be present, and to a leser extent, the compresion method, bit-rate used, input characteristics, and the listening/viewing conditions and equipment. Despite this, sometimes general consensus is formed for what compresion options “should” provide transparent results for most people on most equipment. Due to the subjectivity and the changing nature of compresion, recording, and playback technology, such opinions should be considered only as rough estimates rather than established fact.

Judging transparency can be dificult, due to observer bias, in which subjective like/dislike of a certain compresion methodology emotionaly influences his or her judgment. This bias is comonly refered to as placebo, although this use is slightly diferent from the medical use of the term.

To scientificaly prove that a compresion method is not transparent, double-blind tests may be useful. The ABX method is normaly used, with a nul hypothesis that the samples tested are the same and with an alternative hypothesis that the samples are in fact diferent.

In case you managed to read the above paragraph and are still here: congratulations! How do you feel? Slightly nauseous? Even annoyed? Maybe. The above text has been slightly altered. I “compressed” it by removing all double consonants. You can still read it, sometimes you might even not realize the change from the original text. Most probably you found a few (annoying) errors. Keep in mind how reading that text made you feel.

The Story

I was talking to a friend of mine the other day, and he explained to me why he dislikes audio compression with an easy analogy. Listening to compressed sound can be compared to reading text that is missing characters, that you might not even notice. Your brain will fix the issues and you will be perfectly capable of reading the text. Still, your brain has to work more than it would reading the unaltered text. Same goes for audio compression (read psychoacoustics). Lossy audio compression still tries to sound like the original (i.e. retaining the perceived quality) by removing things you are not meant to hear anyway. Easy example: just after a loud sound, like a hi-hat hit, other frequencies, that you cannot hear anyway due to this high impact noise, will get removed (masking effect). Sounds legit. So throw it away. Still, compression will make your brain, your perception work harder to fill these gaps of information. Maybe. Most probably. Like reading the above text made your brain work harder. Reading the foobared text was less enjoyable. So why should you listen to music that will subconsciously decrease the “enjoyability” of listening instead of feeding your ears the real deal?

Conclusion

Finally, I have an easy explanation why you should not listen to (badly) compressed music but stick to lossless compression like flac or the original. It simply will be more enjoyable for your ears and brains, even though you might argue the super-duper encoded files your were listening to before were “transparent”. Maybe they are more likely entities of unwitting torture 😉

The Future

For me the days of lossy compression are not over. That would be naive. Still, I will try to listen more and more to the best possible source at hand (as hard drive space is not really and issue any more). I already encoded my mp3s 1 or 2 steps “higher” than the “transparent” setting is for me (e.g. in case you hear no difference in -V 3 compared to -V 4 go for -V 2). I enabled high quality streaming in Spotify (i.e. ogg Vorbis q9 according to Spotify). Right now I plan to build an audiophile music player (Raspberry Pi, Volumio, DAC, Reclocker) and re-encode my favorite CDs using flac. Even though I might not actually hear any differences if will just make me feel better listening to it. A placebo? Maybe. It’s one I will take. Happy listening!

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PS4 fan noise – solved. Banished, to be more precise.

Thursday, September 29th, 2016 | Gadgets, Insights, Tech-savvy | No Comments

I cannot write about this topic any more, so I let my HDMI cable tell the story.

dav

dav

dav

🙂

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Deleting symlinks aka “Don’t drink and sudo”.

Tuesday, September 13th, 2016 | Insights, Linux, Tech-savvy | No Comments

failcatWell, I did neither, yet still fucked up my installation the other day. Here is how I managed it – and yes, there is some knowledge sharing / advice in here, so read on.

I guess everybody who ever came across a *nix prompt knows the infamous “rm -rf” command and only uses it when it’s really save. Well, pretty much save and then whoopsy … files gone. So here goes my latest foobar.

I wanted to create a symlink from my small home partition to a big data portion for my gnome-boxes, as disk images tend to get big. So I created and “cd”ed into the destination folder:

cd /bfd/gnome-boxes/

and checked whether the dir is empty thus suitable. It was.

So now I symlinked the current directory to ~/.local/share/gnome-boxes

ln -s . /home/nick/.local/share-gnome-boxes/

So far so good. I “cd”ed into the original folder to check whether the link was created okay, but it only showed something like

gnome-boxes -> .

instead of

gnome-boxes -> /bfd/gnome-boxes/

WTF? The . is a reference to the current directory which was /bfd/gnome-boxes at the time I used it. Hmm, the ln took that dot pretty literally (which is obviously my fault).

So, I wanted to get rid of that wrong symlink. First, as the “directory” gnome-boxes was a symlink, i.e. a file, I tried to simply delete it with rm. That was when the real fun began.

You can test this behavior, create a test directory, that holds a file (touch file) and a directory (mkdir dir). Then go create that bogus symlink (ln -s . ./test)

drwxrwxr-x. 2 nick nick 4096 13. Sep 12:50 dir
-rw-rw-r--. 1 nick nick    0 13. Sep 12:53 file
lrwxrwxrwx. 1 nick nick    1 13. Sep 12:53 test -> .
[nick@localhost 1]$ rm test/
rm: das Entfernen von 'test/' ist nicht möglich: Is a directory
[nick@localhost 1]$ rmdir test/
rmdir: konnte 'test/' nicht entfernen: Not a directory
[nick@localhost 1]$ rm -rf test/
[nick@localhost 1]$ ll
insgesamt 0

All gone 🙂

Not only the dir was gone but basically my whole ~/.local/share/ directory was empty. I symlinked gnome-boxes to ., so the current dir, thus rm -rf gnome-boxes deleted the current dir. Eff.

How to prevent this.

* Use unlink. It’s saver as it only calls the unlink function and cannot delete regular files.
* Don’t “tab” complete your commands. A simple “rm gnome-boxes” without the trailing slash would have done the job and saved me the re-installation. Luckily this is done in less than half an our with modern distros, still, I felt like an idiot. Lesson learned.

This was done with a super smart ASF member behind me, whom I showed the funny “Is a directory / Not a directory” error messages. We had a good laugh after deleting my share folder. Facepalm deluxe!

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Relapse. Rinse. Repeat.

Friday, March 20th, 2015 | Insights | 4 Comments

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PS4 fan noise – pretty much solved.

Wednesday, December 24th, 2014 | Gadgets, Insights, Tech-savvy | 3 Comments

So Sony did not manage to solve the PS4 sounding like a hair dryer issue. I had to take it into my own hands and it became sort of like a personal crusade.

TL;DR

Break your warranty. Replace the thermal paste. Hate Sony.

Kill the noise – €10

01-foam My first idea was to simply buy some acoustic foam and kill the noise. As this foam works best with high frequencies I thought it might work. I put some foam in my TV stand, made sure enough air would be supplied and fired up the machine. It took maybe 20 minutes for the jet engine to set off. Even though the stand is permanently open in the back and has air vents on top it heated up and got noisier than ever. I took out piece by piece of the foam to no avail.

More air – €2

02-elevation Next thing I tried was elevating the thing, so that there is no heat buildup on the bottom of the case. Looks funky, but is completely useless yet cat approved.

More cooling – €30

03-heatsink Next thing I got was a giant heatsink. I figured putting it on top of the device might help to keep the overall heat at bay. Again, no notable results.

The last frontier – breaking the warranty and replacing thermal paste. – €20

04-thermal-paste Sony, I hated you so much already that I dared to open the box and break my warranty. You were not able to fix this multiple times, so I didn’t give a rat’s ass about the warranty anymore. I bought myself Arctic Silver 5 with some paste remover and surface polisher. I also got some new cooling pads. It turned out to be a good idea.

As you can see the thermal paste looks completely wasted. Not evenly spread, bubbles of locked-in air, dry. I am not a hardware pro but this looks pretty bad to me. Also, the cooling pads were rather small, also dry and put in place in a very inaccurate way. I fixed that as well.

Recap

After replacing the thermal paste and cooling pads the machine was running almost without any noticeable noise. It takes maybe 20 minutes for the fan to speed up to a level where I can hear it, but it is much more silent now. Tried to put the machine back into my TV stand, but that did not work, it still overheats in there. So now the PS4 is sitting below my TV stand, elevated with felt pads, cooled by a giant heatsink and its warranty broken for the final fix, good thermal paste.

I spent over €50 and quite some time to get to this point. Again, I cannot emphasis how disappointed I am with Sony and its customer care. Case closed.

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Cannot umount busy file system – who’s to blame?

Tuesday, February 4th, 2014 | Insights, Linux, Tech-savvy | No Comments

Use fuser and ps to identify what process/es is/are occupying the file system.

ps -lf -p $(fuser -c /mount/point 2>/dev/null)

This is an example that is in no way related to anything that has ever happened in the real world:

[user@host somefolder]$ sudo umount /media/somefolder
umount: /media/somefolder: target is busy
        (In some cases useful info about processes that
         use the device is found by lsof(8) or fuser(1).)
[user@host somefolder]$ ps -lf -p $(fuser -c /media/somefolder/ 2>/dev/null)
F S UID        PID  PPID  C PRI  NI ADDR SZ WCHAN  STIME TTY        TIME CMD
0 S user      5058  5054  0  80   0 - 29109 wait   09:22 pts/0      0:00 bash
[user@host somefolder]$ cd ..

lol 🙂 pebcak!

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HDMI colour space – a crooked bastard!

Thursday, November 7th, 2013 | Gadgets, Insights, Misc, Tech-savvy | No Comments

One would think that hooking up a device to a TV using a HDMI cable would automagically result in a perfect picture. Digital, 1080p full HD, state of the art, out-of-the-box. That’s not true. I recently encountered shitty display quality problems that originated from a faulty HDMI setup.

First, the problem: sometimes black was more like a gray matter, sometimes dark details simply vanished into sludge. I did hate my telly so much for its shitty display quality that I sold it for a few dimes and got myself a new one. But guess what, the problem persisted…

After more investigation on the matter I came across the fact, that there are different colour ranges in different HDMI standards and one handles the range from e.g. black to white from 0 to 255, the other from 16 to 235. This made me think. In case I had a mismatch of these standards, and let’s say my media player sends a lot of dark gray values that range from 0 to 16 and the receiver simply omits all these information and starts with pure black at 16, it’s natural my dark details got lost. Or, the other way around, my media player starts at 16 with pure black while my telly thinks that 16 already is a dark gray, as it starts with black being 0.

So, sending full range and displaying limited range will result in dark areas that are to light and light areas that are to dark.

Sending limited range and displaying full range will underexpose blacks and overexpose whites.

Here is an example (I simply altered the source and target colour ranges with Gimp):

Nature LimitedFull Nature Original Nature FullLimited

The differences may seem subtle (or YOUR display isn’t properly calibrated), but believe me, I love to crawl in dark dungeons on my PS3 or watch horror flicks that make heavy use of the darker parts of the colour palette. My telly looked like the picture to the right all the time and it drove me to sell it for “bad black levels” (just compare the tree’s trunk in the pictures and you will see the difference). Silly me. A perfect gradient illustrates the problem even more:

Gradient LimitedFull Gradient Original Gradient FullLimited

Now, that I have my systems set up right I enjoy using it so much more than before. So, give setting up your expensive home cinema a try, it doesn’t make sense to spend thousands of bucks on the equip and not setting it up properly.

As far as I understand the problem, as long as you have the sending and the receiving device configured the same you are good to go.

One last thought: I hate all the fancy tech shit becoming more and more “easy” to set up yet the problems that come along constantly increase. I never experienced problems with an old VCR or a Super Nintendo – that’s what I call “plug’n’play” 🙂 To set up a modern home entertainment system you need to really dig into it to do it right. Maybe I should look at it from a Dark Souls perspective. It’s a pain in the arse, but as soon as you’re done it’s very very rewarding.

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Three letter words taken from “Game of Thrones”

Wednesday, July 17th, 2013 | Books, Insights, Language, Quirks, Reviews, Vocabulary | No Comments

Reading “Game of Thrones” I realized I couldn’t translate a lot of three letter words. Most long words are phonetic or somehow make sense of their own, but three letters without a hint … try it yourself, how many of the following words can you translate? (click on a word to see the translation)

maw
to cog
pus
sap
sod
pup
to jet
ire
to err
fib

Now that you know the hard three letter words go and get yourself a copy of the brilliant Song of Ice and Fire series.

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Everyday Life’s Insights II – Keep Keepsakes

Friday, October 19th, 2012 | Activities, Insights, Photography, Tech-savvy | No Comments

I love to keep things. Not in a messy kind of way, rather hanging on to the past. Which is worse is up to you to decide. Anyway, people tend to tell you to get rid of old unused stuff, get rid of all the clutter. So last time I “optimized” my cellar I threw away my somewhat broken Ixus 70 which turned out to be a pretty bad idea.

Someone that is very closely related to me dropped the old camera to the floor. The flash did not fire any more after that stunt. So we bought a new Ixus 500 HS – a decent device but by far not as convincing as the 70 in terms of features, handling and (subjective) image quality.

Anyway, the old one went straight to the storage to RIP. Same goes for my first “New Zealand” Ixus, a 330 from 2002 – what a beauty! 🙂

So I decided to throw away the beloved Ixus 70 because of a broken flash. A few weeks later I felt the need for a camera that I could take on bike trips – and what do you not need for landscape photography? Correct. A flash. The old Ixus would have been the perfect companion for the purpose. What a bummer.

Bottom line: Keep your stuff unless you are absolutely sure you don’t need it any more. Full stop.

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