toastedsandwi.ch -- not often about toasted sandwiches

DVD ripping part 2 — ddrescue, “dvdbackup —mirror” and “dvdbackup —feature”

So I’ve got things working a bit better now. There have still been one or two that haven’t ripped using one of these three methods, but this covers 99% of my DVDs that I want to play with MythTV:

• Method 1 : ddrescue

  ddrescue -n -b 2048 /dev/sr0 dvdtitle.iso dvdtitle.log
  

  When this works you might get one or two error sectors, but most of the disc will rip without error. These errors are intentionally added as part of the copy-protection. This gives a DVD iso image which mythvideo is happy to play.

• Method 2 : dvdbackup —mirror

  This produces a VIDEO_TS folder which, again, mythvideo is happy to play. Sometimes this doesn’t work, or produces a damaged rip which is several times the size of the real DVD. If it’s bigger than about 10GB then this probably won’t play, so try method 3:

• Method 3 : dvdbackup —feature

  This produces a VIDEO_TS folder, but often mythvideo won’t play it. mplayer is generally happy to play this.

All in all, still a bit of a pain but at least I can play most of the DVDs I own now!

Moved from Posterous to Tumblr…

Blog moved since Posterous is closing soon to “concentrate on Twitter”… Hopefully the RSS feed will continue working (need to check on this!)

http://Justmigrate.com was a big help to move the posts across but the (very few) comments can’t be migrated on this way, so apologies to both commenters when on the previous host!

The main features I was using were post-by- email and Markdown for formatting, both of which are available on Tumblr. Phew :D

MythTV playing of copy-protected DVDs

After a fair amount of pain trying to find ways of getting copy-protected DVDs to play under MythTV:

• Seeing if MythTV can play these DVDs directly from the disc (no)
• Trying to find Linux tools which can rip the DVDs (none)
• Running various windows DVD-ripping tools under WINE (just gives disc read errors and fails)
• Running various windows DVD-ripping tools in a VirtualBox VM (just gives disc read errors and fails)
• Realising that one of the DVD drives I was trying this on is still region-locked (Linux kernel messages like “Add. Sense: Read of scrambled sector without authentication”)
• etc

..I’ve made the sad realisation that I’m just going to have to keep a Windows machine around to be able to use something like DVDFab HD Decrypter to rip to an iso or AUDIO_TS/VIDEO_TS directory structure, which MythVideo can then play fine (either locally on the frontend, perhaps via a USB stick, or via a network filesystem mount like NFS or samba).

Ah well, at least I have a way of playing these DVDs now, so it’s better than nothing, but it would be nice to get this all working without having to resort to a Windows box and some proprietary software. (I got rid of my DVD player yonks ago, after switching to MythTV for all my TV-related shenanigans)

Encrypted USB stick goodness on Linux as a non-root user (LUKS + cryptsetup + pmount)

(Distilled from the instructions at http://www.mattmckimmy.com/blog/2009/09/21/setting-up-luks-encryption-on-usb-… and with added pmount and not so many screenshots :)

This uses LUKS and cryptsetup, as well as pmount to allow non-root users to mount the device.

Steps required are

• apt-get install pmount cryptsetup (or equivalent on non-Debian distros)
• add user to required group (plugdev, on Debian) to allow pmount to be used by a normal user to mount removable devices
• dmesg | tail => check for device name, such as sdb
• fdisk /dev/sdb (or whichever disk dmesg said) => create sdb1 as type Linux and to fill usb stick
• cryptsetup --verify-passphrase luksFormat /dev/sdb1 and set passphrase
• cryptsetup luksOpen /dev/sdb1 secureUSB
• mkfs.vfat /dev/mapper/secureUSB
  • If you use vfat then there is max file size of 4Gb
  • If you use ext4 or a similar filesystem then you’ll need to ensure that the UIDs/GIDs match with the machine(s) you’re going to plug the usb stick into, as the filesystem will store the file and dir owners, permissions etc.
• cryptsetup luksClose secureUSB and you’re done with the setup of the stick
• Now as a normal user you should be able to do pmount /dev/sdb1 and it will ask you for your passphrase.
• pumount /dev/sdb1 will unmount this
• Rejoice! :D

xmodmap for hacking keymaps is old hat; setxkbmap is the new hotness

I used to have a bunch of calls to xmodmap to do funky things like swapping the “alt” and “Windows” keys, setting caps lock to be another control key, and to set the right alt key (“Alt Gr”) as a Compose key ( see http://en.wikipedia.org/wiki/Compose_key ).

Instead now you can totally do all this with “setxkbmap” in one go, and no horrible .Xmodmap files to maintain (which are fiddly with the modifier keys such as control, and to remove the lockiness of caps lock) :D

The things I like to change on standard keyboards are all in the following command:

setxkbmap -model pc104 -layout us -option 'compose:ralt,ctrl:nocaps,altwin:swap_lalt_lwin'

..this set right alt as compose, sets caps to be an extra control key, and swap left alt and the left windows key.

Much nicer!

Google Plus photo uploads

Turns out that trying to upload > 4000 photos to Google+ makes Chrome (21.0.1180.89 on Linux) very angry. Using > 5.6Gb of memory is part of that anger.

Not recommended  :)

Android 4.1.1 on Motorola Milestone 2 (via CyanogenMod 10 and xda-developers.com)

I thought I was going to be stuck with Gingerbread (2.3.4) on my Milestone 2 (which I got as one of the few options of an Android phone in the UK with a hardware QWERTY keyboard) since Motorola have decided to not allow unlocking of the bootloader on most of their phones (see https://developer.motorola.com/products/bootloader/faq/ ) and don’t do updates for this phone anymore. Thanks Motorola Mobility.. now owned by Google, so this seems even more insane :(

However, those clever chaps (and chapesses) at xda-developers.com have managed to come up with versions of CyanogenMod which work on the Milestone 2, allowing me to install Ice Cream Sandwich (4.0.x) or Jellybean (4.1.x) :D ( The forum thread for this with the instructions is at http://forum.xda-developers.com/showthread.php?t=1827801 )

But wait! First it needs rooting before you can install a custom ROM, and SuperOneClick didn’t appear to work for me using the GUI app.

So I found some instructions at ; http://www.cypherpunk.at/2011/10/08/manual-rooting-android-on-linux-2/ which worked except that I needed to use the “zergRush” exploit instead of the “psneuter” one.

Having used CM10 (4.1.1) for a bit I have to say that it’s a great deal better than I expected on this moderately old and low-spec (for now!) phone. It seems to kill background tasks off so that the amount of memory available for the front task is kept as high as possible, but this doesn’t have any terrible side-effects that I’ve noticed so far :D

In summary, CM10 on the Milestone 2 : Heartily recommended!

e4rat — defrag and preload for faster boot

For people who don’t have an SSD, e4rat ( available from http://e4rat.sourceforge.net/ ) is totally worth it. Whilst I have no scientific facts to throw at you, it’s definitely made my machine boot faster. And not just the boot to the login screen, as the preload runs for 120 seconds (by default, or until you kill it), so I just quickly logged in to X, ran chrome, a terminal, ssh and a few other things on top of the window manager etc.

So if you use a chunk of spinning metal for your boot/OS disk then head over to their site and download either the source or if you’re on Debian then install the provided deb (it’s not available via apt-get in the default repos yet).

Doooo iiiiitttt! :)

(If you’re using ext3, then you’ll need to convert to ext4 by following the instructions on https://ext4.wiki.kernel.org/index.php/Ext4_Howto#Converting_an_ext3_filesyst… to convert it to ext4 before you can use e4rat)

Winbind + AD + different distros and samba versions == madness

As an attempt to integrate Linux machines into a mostly-AD environment, Winbind looks like it might be a great solution.

However, using the same config on different Linux distros which contain samba packages of various vintages, including Debian testing (wheezy), Ubuntu 12.04 LTS and Scientific Linux 6.2) I get:

• Sometimes getent passwd and getent group enumerate and sometimes they don’t get any users/groups from AD (obviously winbind enum users = yes and likewise for groups are set as appropriate). This seems to be pretty arbitrary even during one session on one distro.
• Some versions show more groups than others with group or id.
• Not all of our AD groups have gidNumber values set, so the GIDs for these groups vary between machines. Ugh.

I might be missing required config, but I’ve spent enough time on this for now, and I’d much rather use distro-supplied packages so sorry winbind, but you’re not for me right now.