Picalo open source data analysis software ►

◄ TFNation 2017

2017-08-01 📌 Project Zebra: and you're rushing headlong

Tags 🏷 All 🏷 Linux 🏷 Tech 🏷 Personal

This entry is part of my Project Zebra series covering migration to Linux for personal computing use.

This month's entry is queued early and going to be about half "doing stuff" (get_iplayer, software shortcuts, screen tearing, rotating MP4 files with VLC) and half nostalgia about Linux and other platforms with a quick foray into emulation of Archimedes and Spectrum machines.

1/ Because I tend to forget, a very quick start guide for get_iplayer, after you've followed instructions at https://github.com/get-iplayer/get_iplayer/wiki/unixpkg paying careful attention to the note it's a good idea to get a fresh copy.

  1. Invoke from a terminal with: get_iplayer_web_pvr
  2. Point your browser to:
  3. Paste in URLs from the BBC iPlayer site and click on Record

To change the default download folder, use syntax similar to

get_iplayer --prefs-add --output "/home/admech/Data/Fugacious/Videos/get_iplayer"

2/ As a fix with TrueCrypt and other software that assumes it's in Gnome and tries to launch Nautilus by name, create a file called the name of what would be the executable (so 'nautilus' in this case) in /usr/bin with the following:

exec nemo $3
exit 0

Don't forget to mark the script executable. You may also want to turn off "Browse removable media when inserted" in the Xfce settings if you haven't already as auto-open will launch Thunar.

Source: https://ubuntuforums.org/showthread.php?t=1871021

3/ Screen "tearing" is an annoying issue with certain hardware, driver, etc combinations, and you'll know how affected you are if you don't already if you play something like the intros to Have I Got News For You or QI or hit up https://www.youtube.com/results?search_query=tearing+test

In Xfce you could first try toggling Settings > Window Manager Tweaks > Focus > Synchronize drawing to the vertical blank but there is a rendering setting that can be tried with Intel graphics chipsets, so if you don't know what you're using try running inxi -G at the terminal.

Then, as suggested by https://wiki.archlinux.org/index.php/Intel_graphics#Tear-free_video

Create /etc/X11/xorg.conf.d/20-intel.conf containing

Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "TearFree" "true"

And reboot to apply the setting. It definitely seems to make a difference.

After making the tearfree settings when resuming from hibernation or locking and then unlocking the screen both monitors came on mirrored. Changing 'active-monitor' in /etc/lightdm/lightdm-gtk-greeter.conf from 1 to 0 sorted the smaller monitor getting the login window, and then per https://wiki.archlinux.org/index.php/multihead I used xrandr again to check the IDs and created /etc/X11/xorg.conf.d/10-monitor.conf so that there's a default config:

Section "Monitor"
Identifier "HDMI3"
Option "Primary" "true"

Section "Monitor"
Identifier "VGA1"
Option "below" "HDMI3"

Also, it may be worth noting that according to https://wiki.debian.org/Hibernation you can specify scripts to run on resume from hibernation or other events.

4/ VLC is able to rotate any video whilst you're watching it, but current versions will also respect transform metadata that's tagged to a file – eg if you recorded a video in portrait on a phone you might want to always view it rotated by 90 degrees.

I've only tried this with standard MP4 files but other container formats may work as well and if necessary ffmpeg can "convert" losslessly by copying the audio and video streams:


ffmpeg -i input.mkv -vcodec copy -acodec copy output.mp4

The syntax to add a rotation is almost as simple, per

ffmpeg -i input.mp4 -c copy -metadata:s:v:0 rotate=180 output.mp4

As a side point you can use this command that's part of the ffmpeg package to check if a file already has transform information:

ffprobe <inputfile>

Doing this in metadata, of course, means you can avoid re-encoding and losing quality.

5/ Okay, having left myself those notes, I'm going to turn to some retro computing with Tux, a digital magazine that ran for twenty issues starting a bit over ten years ago and which is still available as lovingly crafted PDFs from http://www.tuxmagazine.com/

It's well worth a skim to be reminded of things that used to be issues back then whatever platform you were on, like storage space or MP3 encoders or being part of Generation X. And it's the Linux world I remember, where KDE and Gnome had less alienated their user bases by trying to reinvent the desktop paradigm badly as a workflow tool rather than a way for people to manage things themselves. See issue 11 for lots of old KDE and Gnome pics.

In most issues everything looks like someone went a bit mad with Windows9x and a copy of WindowBlinds (or thought that Windows XP looked good) because bright eye candy was the in thing. And the screenshots all feel very homely because that's the next step on from the kind of era I gravitate to with skins and themes, desktops circa 2000 having clean colourful icons but lots of grey, 3D borders and corners.

Something I'd forgotten is that ten years ago there were quite a lot of commercial Linux distributions. In some cases large software releases still came on multiple CDs, although DVDs were emerging as a replacement. Oh, and Google hadn't somewhat rescued the web browser market from Microsoft with Chrome and Chromium, starting on the path to edging out Firefox even on Linux.

Also mentioned by Tux magazine was Neverball http://neverball.org/index.php which at first I thought was a Fervour like game, where you steer a ball over a course and try to avoid falling off, but in Neverball you basically tilt the board and it's mouse control rather than keyboard, which I always find annoying.

This got me wondering how easy it would be to get the platforms I've been known to occasionally dip into emulation of (Acorn Archimedes and Sinclair Spectrum) running on Linux. Pretty easy, it turns out. For starters the discontinued VirtualA5000 can allegedly be made to run under Wine, but ArcEm (which I never got to work under Windows) was easy to compile and works like a charm. The only downside is relatively high CPU usage on my ThinkCentre M92p whilst supposedly idle.

If you want a hard drive you don't need an image, create two folders called 'hostfs' and 'extnrom' and copy the files hostfs,ffa, hostfsfiler,ffa and support,ffa from subfolders of the ArcEm folder into the latter. You can then use this HostFS filer to copy the contents of mounted floppy images to from within RISC OS.

As it happens I already have similar "drives" from playing around with emulation ten years or so ago. Having reinstalled furiusisomount for ease of mounting my UDF format ISO backups (use the loop setting with UDF images) I dug these out and they were usable, although I did end up using XnView to batch rename some key extensions. Apparently in VA, fff is txt, feb is oby and ffd is dat, which is very odd as it uses the RISC OS ones for the rest: https://en.wikipedia.org/wiki/List_of_RISC_OS_filetypes

For a Spectrum emulator, it's a bit easier, search for 'fuse emulator' in the Ubuntu repositories via Synaptic before snagging a 48.rom or plus2-0.rom (both should have good compatibility) from http://www.shadowmagic.org.uk/spectrum/roms.html and then

fuse --tape 48.rom

See the World of Spectrum site for some classic games, such as Chaos: http://www.worldofspectrum.org/infoseekid.cgi?id=0000894

JSW2: http://www.worldofspectrum.org/infoseekid.cgi?id=0002595

💬 Comments are off, but you can use the mail form to contact or see the about page for social media links.