Project Zebra: And thus, the Cyclopean nightmares ►

◄ Project Zebra: Signal the final curtain call in all its atomic pageantry...

2023-07-02 📌 Project Zebra: Hippocrates himself expounded on the virtues of salt

Tags 🏷 All 🏷 Linux 🏷 Tech 🏷 Personal

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

Title reference: Smith and Jones, the first David Tennant episode with Martha which I've been using as a test disc for the networked DVD playback stuff I'm writing about further down.

Haven't switched my main PC on much, so this'll just be a few topics.

fdupes is a lightweight command line tool to find duplicate files based on md5 hashes, and is in the Ubuntu repositories. Optionally it can delete the dupes or replace them with space-saving hard links.

It appears that Plasma 5.27 added new, undesirable tiling behaviour that breaks previous expected behaviour. If you snap two windows to halves of the screen, then move the border between them the tiling area is changed. Which wouldn't be a big problem except the ratio is remembered and not reset when the windows are closed or untiled.
https://forum.manjaro.org/t/undesired-snapped-window-behaviour-change/138220/6
https://www.reddit.com/r/kde/comments/118axuk/disable_auto_resize_plasma_527/
https://bugs.kde.org/show_bug.cgi?id=465937
"A bit of experimenting has shown that if you open the tiling interface (Meta+T) and delete all the tiles, all of the quick-snapping features behave like they used to in pre-5.27" This worked in 5.27.4 but someone's commented it doesn't in 5.27.5 so hopefully will get sorted out before anything updates.

Then who knows when the Plasma 6.x branch will be coming to stable distros? Hopefully there'll be another LTS using 5.x, to be honest. In the Linux world everyone remembers the gulfs between KDE 3 and 4, and Gnome 2 and 3. In the Windows world people remember Vista, 8, 8.1 and it looks like 11 will be another steaming pile. Reassurances that Plasma 6 will be evolution from 5 rather than revolution are welcome, but people are acutely aware that projects can be subverted by egos because they've seen it happen so often.

Android VLC can play DVD ISOs but apparently still not, at the time of writing, from a VIDEO_TS folder. I tried doing this almost ten years ago under Windows using a Nexus 7 and the tablet wasn't really powerful enough. Looking at the problem again now using a mid-range Samsung tablet and average router and wifi adapter (without rummaging behind the monitor I think mine's still an old Belkin one that could possibly do with replacing) it's much better and a matter of one terminal command. I already had some Samba shares set up. Note that which USB port and what cables you use can also make a big difference to the stability of network speeds if using an external adapter.

Just do "ln -s /dev/sr0 dvd.iso" wherever you want the symbolic file to be created. VLC can then play the "ISO" from a share directly including the DVD menus. You can possibly do similar on Windows; https://www.howtogeek.com/16226/complete-guide-to-symbolic-links-symlinks-on-windows-or-linux/

Of course you can easily rip a load of DVDs to ISOs on a drive or NAS if preferred without it taking too long these days, using standard tools such as K3b or Handbrake. But this is nice and immediate if you just want to pick out a disc and watch it around the house.

(History note: network attached optical drives were briefly a thing, Samsung had something called a "Samsung Wireless SmartHub WiFi DVD Writer" which I had many moons ago and if memory serves worked with early Android and relied on setting up its own wireless network).

And then I thought... can a drive be hooked up to a Raspberry Pi (or other minimal hardware) and effectively be a network-attached device for a tablet? A headless Pi booting to the command line, a Samba share, a symbolic link to a block device and thee. Well, trying to run any kind of GUI on the Zero W 2 I've got taxes it to the point the pointer is jumpy. A small laptop doesn't fit in the gap on the end of the shelf. A netbook? Better. I'd got the parts to refurb a Dell Mini 1018 and it should run Xfce or an even more basic DE. The 10" screen size is decent enough for a music library interface.

And for CDs? It's apparently more complex to share directly to Android because CDs aren't mounted in same sense that filesystems are. But they are exposed as files in modern Linux, so maybe it's just a case of finding the right approach. "ln -s /run/user/1000/gvfs/cdda:host=sr0 cd" is enough for terminal software such as mpv to use the fake .wav files in it. Conversely, Android apps aren't showing the symlinked folder, whilst other symlinks in the same SMB share location work fine.

Maybe an FTP server would work better? Adapting the instructions in a few how-to guides I started with "sudo apt-get install vsftpd" and editing the config:

sudo nano /etc/vsftpd.conf

# Allow anonymous FTP? (Disabled by default).
anonymous_enable=YES
# Uncomment this to allow local users to log in.
local_enable=YES
# bits I added
local_root=/home/admech/VSFTP
anon_root=/home/admech/VSFTP
pasv_enable=YES

sudo systemctl restart vsftpd

But reading around further it doesn't appear that vsftpd follows symlinks at all, so a different FTP server would be necessary. The "mount --bind" trick doesn't work with the gvfs path. So I've disabled vsftpd, although it's good to know how simple it is to set up for sharing media on a local network, if Samba doesn't suit.

It's a mostly theoretical problem anyway. I don't acquire CDs often and have the thousand or so I've got ripped to Lame alt preset standard MP3s mirrored to a micro SD card I can put into the netbook or a tablet.

The easier and better solution is to run VLC on the laptop and then make use of VLC Mobile Remote on Android (which I did pay for, as it seems great for browsing and selecting media). To better facilitate this, I added a couple of auto-run options to Xfce to start VLC at boot (vlc --qt-start-minimized) and automatically mount the SD card with the same command Thunar uses (udisksctl mount -b /dev/sdb1).

For the record, I can confirm that a Dell Mini 1018 (running Xubuntu minimal) plus a reliable wireless card can stream DVDs to a tablet. The USB2 port gets the wireless adapter and the USB3 port gets the DVD drive. The seller was fairly upfront about the hardware, which seems to be in good nick apart from the keyboard having a dodgy connection and one 'always-down' key and a worn out left mouse button on the track pad, but I had a spare keyboard as well as a power adapter and SSD. Putting 2GB of RAM in it rather than 1GB cost less than three quid, and a track pad to cannibalise the buttons off was similarly inexpensive. They're a bit of a pain to work inside but being an intentionally fanless design are generally okay with light load tasks without melting completely. I'll call it a win, as well as a bit of welcome nostalgia for previously-owned Dell Mini 10 netbooks.

The built-in Bluetooth adapter couldn't find the audio receiver. The built-in wi-fi doesn't seem to work, but then again neither does another small WiFi adapter I tried. One with a huge aerial branded LB-LINK does. I disabled both of the built-in options in the bios so they couldn't overlap things I'd plugged in, and got a more recent adapter, thinking it might be possible to use one for both BT and Wi-Fi. This didn't quite work.

The Bluetooth adapter I got is a TP-Link AC600 Archer T2UB Nano with a Realtek chipset that's supposedly supported by the 6.2 kernel. The BT works, and connects to the speakers, and drivers on https://github.com/aircrack-ng/aircrack-ng didn't seem to work with it but those on https://github.com/morrownr/8821cu-20210916 did. There's no point getting into which device ID lsusb shows because apparently TP-Link have a habit of changing the exact hardware in their devices without changing the model number, so it's likely to be luck of the draw what you get. I think due to being a nano-sized adapter (and possibly due to the Bluetooth signal interfering as well) the transfer wasn't reliable enough to stream a DVD, so I went back to the aerial style adapter plus the T2UB plugged into a mini hub.

Oh well, we've learnt something else. And if you're not being masochistic and use newer hardware, it should all involve less trial and error.

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