Archive for Operating Systems

Changing the Android Default Alarm on Zenfone 2

I don’t like the default alarm sound on my phone much and apparently changing it to something a little bit gentler can only be done on a per-alarm basis. Luckily I found this:

Today I was looking for a way to change the sound that is applied by default to new alarms you create in the Alarms app. After quite a bit of effort I came upon the following procedure:

  1. Install ES File Explorer
  2. Open it and select / from the Favorites
  3. Browse to /system/media/audio/alarms
  4. Click on the file you want and in the "Open with" prompt select "ES Media Player"
  5. Click on the bell beside the file name, pick "Set alarm" and click OK

Should you choose to change again the default, you may notice that the defaults you pick will appear in the music library. Also, they will be listed twice in the tone selection list which appears when you manually change the tone of an individual alarm.

You can fix that with the following steps:

  1. Open Settings
  2. Go to Applications > Manage Applications > All
  3. Click on Media Storage and then Clear data
  4. Reboot your phone
  5. You will now have to set your new default sound

(I've noticed that sometimes, when you view a music album which doesn't have a cover art image and add an album.jpg file to it later, Music Player will not use that file for the cover art. The above steps, as a side effect, will make Music Player look for images for all albums, thus having the cover art of all your albums updated.)

Hope this helps 🙂

Comments

You Can Just Concatenate MPEG-2

To deal with the inferior FAT file system, it would seem that consumer-level Sony video cameras write video files of a maximum of about 2.1 GB. A sensible approach, but annoying to work with. Luckily they can be concatenated without any concerns or side effects for easier viewing and editing.

cat 00006.MTS 00007.MTS 00008.MTS > output.mts

For other video formats, see the ffmpeg FAQ.

CommentsTags:

Steam Error: “invalid depot configuration”

I just had to share this mysterious error message.

A screenshot of a Steam error dialog that says invalid depot configuration.

Simply retrying made it go away.

Comments

Launcher with parameters in Xfce

Back in November I decided to try Aard 2 on my laptop. I followed the instructions and it worked. Then I created a launcher with the following command and suddenly it did not.

java -Dslobber.browse=true -jar ~/programs/aard2/aard2-web-0.7.jar ~/programs/aard2/slobs/*.slob

A different strategy, passing a command to Bash, did the trick.

bash -c "java -Dslobber.browse=true -jar ~/programs/aard2/aard2-web-0.7.jar ~/programs/aard2/slobs/*.slob"

Enjoy your fully functional launcher! 😉

CommentsTags: ,

Qalculate!, My New Favorite Calculator

Over the past few years I acquired a bad habit of using search engines for basic calculations and conversions. I’m not talking about the stuff you should just do in your head — not quite that bad, but about the fact that several Linux distros, including my favorite of Debian Xfce, don’t seem to ship with a calculator by default. So I finally got around to testing some programs and Qalculate! does all I want. You can install it on Debian using sudo apt install qalculate-gtk. There’s a list of features on the website. Enjoy a few screenshots.

qalculate-conversion-celsius-fs8
Celsius to Fahrenheit.
qalculate-conversion-km-fs8
Kilometer to mile.
qalculate-conversion-money-fs8
Euro to Dollar.

I hope you’ll like it too!

CommentsTags: , ,

Image Optimization Guide

On the forum I administer, I am forced to run a tight attachment policy. Disk space doesn’t grow on trees. Occasionally this leads to questions about the small attachment size limit of 50 KiB. This guide is intended to clarify that this is not nearly as tiny as you might think. Note that although I’ll mention commands without much explanation for the sake of brevity, you’re always recommended to further explore the possibilities offered by those commands with the --help flag as well as by running man the-command-here.

First you need to ask yourself what kind of file type is appropriate, if you have the choice. On screenshots, the main purpose of attachments on my forum, you’ll often encounter large areas of uniform background colors. PNG is therefore almost invariably the right choice. Crop out everything but what’s relevant. JPEG is appropriate for more dynamic pictures such as photographs. If you want to do a lot with photographs, you might want to consider an external hosting service. My wife likes SmugMug. Still, for thumbnails you might be able to do a fair bit more within a few hundred KiB than you might think. Finally, the vector graphics in SVG result in pictures that always look sharp. You’ll typically have drawn these in a program like Inkscape or Adobe Illustrator.

Table of Contents

  1. 1. Optimizing JPEG
  2. 2. Optimizing PNG
  3. 3. Optimizing SVG
  4. Addendum A: Scanned Documents
  5. Addendum B: Video

1. Optimizing JPEG

Often you’ll want to crop your file. Do not edit your JPEG followed by resaving it because this will result in reduced quality! You can crop losslessly with cropgui. On Windows you can use IrfanView.

If you don’t want to crop, and also potentially for some post-cropgui optimization, use jpegtran -copy none -progressive -optimize file.jpg > file-opt.jpg. Note that this will get rid of all metadata, which may be undesirable. If so, use jpegtran -copy all -progressive -optimize file.jpg > file-opt.jpg.

Of course if you want to scale down your JPEG there’s no point in mucking about with lossless cropping first. After scaling down, check how long your quality can go (also see a little helper script I wrote). In any case, you should avoid introducing any unnecessary compression steps with associated quality loss. Here are some results:

  • The original 11.jpg at 2.19 MB.
  • Losslessly cropped 11-crop.jpg at 1.11 MB.
  • Optimized with -copy all -progressive -optimize 11-crop-opt.jpg at 1.04 MB. -copy none would’ve saved an extra whopping 40-some KiB, which on this kind of filesize has little benefit, and besides, I quite like the metadata. For thumbnail-sized files the balance is likely to be different. For example, the 52.2 KiB SmugMug auto-generated thumbnail below can be insignificantly reduced to 51.1 KiB with --copy all, but to 48.2 KiB with --copy none. I think an 8% reduction is not too shabby, plus it brings the file size down to under the arbitrary 50 KiB limit on my forum.

2. Optimizing PNG

As I wrote in the introduction, for screenshots PNG is typically the right choice. If you want to use lossless PNG, use optipng -o7. In my experience it’s ever so slightly smaller than other solutions like pngcrush. But as long as you use a PNG optimizer it shouldn’t much matter which one you fancy. Also see this comparison.

If you don’t care about potentially losing some color accuracy, use pngquant instead. To top it off, if you really want to squeeze out your PNG, you can pass quality settings with --quality min-max, meaning you can pass --quality 30-50 or just --quality 10. Here are some quick results for the screenshot in the SVG section below, but be sure to check out the pngquant website for some impressive examples.


$ du -h --apparent-size inkscape-plain-svg.png
27K	inkscape-plain-svg.png

$ du -h --apparent-size inkscape-plain-svg-fs8\ default.png 
7.6K	inkscape-plain-svg-fs8 default.png

$ du -h --apparent-size inkscape-plain-svg-fs8\ quality\ 10.png 
4.3K	inkscape-plain-svg-fs8 quality 10.png

In this case there is no visual distinction between the original PNG and the default pngquant settings. The quality 10 result is almost imperceptibly worse unless you look closely, so I didn’t bother to include a sample.

3. Optimizing SVG

For using SVG on the web, I imagine I don’t have to tell you that in Inkscape, you should save your file as Plain SVG.

Save as Plain SVG in Inkscape.

What you may not know is that just like there are lossy PNGs, you can also create what amounts to lossy SVGs. There are some command-line tools to optimize SVGs, including (partially thanks to this SO answer):

  • Scour is probably the best command line tool for some quick optimization. You can just use the defaults like scour < in.svg > out.svg or scour -i in.svg -o out.svg. But I recommend you go further.
  • SVGO (SVG Optimizer)
  • SVG-optimiser (by Peter Collingridge)
  • SVG-editor (by Peter Collingridge)

My personal preference for squeezing out every last byte goes toward the web-based version of the SVG-editor by Peter Collingridge. By running it in a browser with inferior SVG support such as Firefox, you’ll be sure that your optimized SVG still works properly afterward. The command line tools can only safely be used for basic optimizations, whereas the effects of going lossy (such as lowering precision) can only be fully appreciated graphically.

Addendum A: Scanned Documents

Scanned documents are a different item altogether. The best format for private use is DjVu, but for public sharing PDF is probably preferable. To achieve the best results, you should scan your documents in TIFF or PNG, followed by processing with unpaper or ScanTailor. If you’ve already got a PDF you’d like to improve, you can use pdfsandwich or my own readablepdf.

Addendum B: Video

I’m not aware of any lossless optimization for video compression such as offered by jpegtran, but you can often losslessly cut video. In the general purpose editor Avidemux, simply make sure both video and audio are set to copy. There is also a dedicated cross-platform app for lossless trimming of videos called, unsurprisingly, LosslessCut. If you do want to introduce loss for a smaller file size you can use the very same Avidemux with a different setting, ffmpeg, mpv, VLC, and so forth. You can get reasonable quality that’ll play many places with something like:

ffmpeg -i input-file.ext -c:v libx264 -crf 19 -preset slow -c:a libfaac -b:a 192k -ac 2 output-file.mp4

For the open WebM format, you can use something along these lines:

ffmpeg -i input.mp4 -c:v libvpx -b:v 1M -c:a libvorbis output.webm

More examples on the ffmpeg wiki. Note that in many cases you should just copy the audio using -acodec copy, but of course that’s not always an option. Extra compression artifacts in audio detract significantly more from the experience than low-quality video.

CommentsTags:

SSD Performance in Modern Laptops

After acquiring a new laptop in October ’16, I was surprised to find how fast the old Intel Core 2 laptop still felt. To dig a little deeper, I decided to shoddily compare the performance of the first (SATA) SSD I ever bought back in 2010 to the (M2) SSD in my new 2016 ASUS UX305C. The old laptop did not feel faster than the new one as such, but between an ’09 AMD Phenom II and an Intel i7 there was a really noticeable speed increase on the same SSD. But this new laptop actually seemed to be slower at installing programs.

  • screenshot_2016-11-03_15-02-37-benchmark-ssd-120gb-2010-fs8
  • screenshot_2016-11-03_15-06-56-ssd-64gb-2015-zenbook-ux305c-fs8

Obviously in 2016 and beyond I’d strongly consider upgrading to a larger model, but that it could also be worthwhile to upgrade for performance reasons saddens me. The write rate is particularly bad, and this can be felt in software installation taking longer than on the old laptop. NB The old laptop originally came with a significantly slower HDD, so I suppose I shouldn’t be surprised that my old desktop SSD performed better… Still, I was expecting more. As long as it’s better than your average HDD I suppose I can’t complain.

CommentsTags:

libGL error in Steam and Broken Age in Debian Stretch

After some update or other, Broken Age refused to start.

$ ./start.sh 
Running Broken Age
libGL error: unable to load driver: radeonsi_dri.so
libGL error: driver pointer missing
libGL error: failed to load driver: radeonsi
libGL error: unable to load driver: swrast_dri.so
libGL error: failed to load driver: swrast
X Error of failed request:  BadValue (integer parameter out of range for operation)
  Major opcode of failed request:  155 (GLX)
  Minor opcode of failed request:  3 (X_GLXCreateContext)
  Value in failed request:  0x0
  Serial number of failed request:  91
  Current serial number in output stream:  92

Oh well, let’s give it a little hand, shall we?

LD_PRELOAD='/usr/lib/i386-linux-gnu/libstdc++.so.6 /lib/i386-linux-gnu/libgpg-error.so.0' ./start.sh

This loads the included libraries before any others, in order to override the incompatible libraries shipped with the program in question. The same trick also works for Steam. If gaming is your goal, you should probably stick to whatever version of Ubuntu is supported best. I’m just pleased that I can play the occasional game like Oxenfree (no preloading required, mind you) or Broken Age on my workhorse without having to install any stability-reducing binary blobs.

Comments (1)Tags: ,

Fix No gksu(do) Permissions Prompt on Gparted, Synaptic, Mounting Drives, Etc. in Debian

I run Debian Stretch (testing) as my daily driver, and at some point I stopped being able to start programs like start Synaptic, Gparted, Synaptic etc. without manually typing gksu(do). The solution is as simple as it is seemingly unnecessary and stupid:

sudo apt install policykit-1-gnome

The problem is apparent upon reading the description:

This implementation was originally designed for GNOME 2, but most
GNOME-based desktop environments, including GNOME 3, GNOME Flashback,
MATE and Cinnamon, have their own built-in PolicyKit agents and no
longer use this one. The remaining users of this implementation
are XFCE and Unity.

Reported as Debian bug #843224. My first?


D’oh, I wrote this on November 5, 2016. I’ll still publish it anyway in case it’ll still help someone searching for a solution.

CommentsTags: ,

UNetbootin Custom Drive Selection

UNetbootin has been broken for many, many years, but just today (a few years after the fact) I discovered that the previous GUI option to show all drives was readded as a command line option. So if the program doesn’t want to detect your drive, just use the targetdrive argument:

unetbootin targetdrive=/dev/sdf1

And voila, it’s working. I have no idea why it should have to be so difficult. The program categorically refuses to detect any of my USB flashdrives or harddrives, so since the removal of show all drives it’s been utterly useless.

PS This is basically only for Windows ISOs. For everything else you can just use, e.g., dd. Much easier.

Comments

Older Entries »