Re: [SLUG] security monitor with webcam
I was racking my brain trying to remember the applications name when what should come up on lxer.com?: ZoneMinder http://www.zoneminder.com/ I'd read about this a while ago. It seemed quite good. I haven't used it though. Hope this helps. If you do use it, let me know because I'd be very interested. Regards, Patrick -- Forwarded message -- From: Morgan Storey To: Matthew Hannigan Date: Wed, 20 May 2009 18:21:43 +1000 Subject: Re: [SLUG] security monitor with webcam I used to use motion when I had a free webcam hooked up to my desktop. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Proprietary colour names (was GIMP was...)
david wrote: Excuse my ignorance, but isn't this roughly what colour management (http://www.argyllcms.com/?) is supposed to do? The main purpose of colour management is that the colour you use on one device is accurately displayed on another device. For example, if you scan an object and display that object on the screen, then when holding the object against the screen you can see no differences of colour between the object on the screen and the original object in your hand. The way we do that is to give each device a "colour profile" which describes adjustments which need to be made against a theoretical colour space for a given colour to come out "right". A problem is that there are multiple theoretical colour spaces -- as differing technologies can show a wider or narrower range of colours. So a computer screen (RGB), a three-colour plus black (CMYK) and spot printing (mixes of inks, but those mixes cannot overlap) all form differing colour spaces. And you can see from the mixed-ink case that the spaces can have internal gaps too. There are also other colour spaces not used at all in printing, but in other fields. Some colour management systems attempt to translate between the differing colour spaces. This is moderately successful, but also fails when the gamuts of the two spaces do not overlap. For example, there is no way to accurately represent a mirrored finish as opposed to a flat finish ink on CMYK or RGB. Even CMYK/RGB is problematic -- RGB colour are a light box, whereas CMYK colours are printed. So at equivalent resolutions photographs look much better on RGB screens (which goes back to the old-time serious photographer's preference for slides over paper). Going the other way, the black ink in CMYK allows much better control over dark shades than with RGB. Colour is a complicated field. I hope this gives you the flavour of it. To answer your question, there is a PANTONE colour space. In theory a CMS could convert between devices using PANTONE (actually a no-operation, since all PANTONE printers are pre-calibrated to be identical). In theory, a space-converting CMS could handle spot printing technologies such as PANTONE. In practice, the whole point of spot printing is precise control of printed colour and a designer isn't going to leave it to some subsystem to convert an RGB pixel to the exact shade they have in mind. They want to enter that exact shade into the application. With PANTONE spot printing in particular, there's perhaps some legal questions. Which Andrew mentioned in a previous post. Having written all of the above, it is well worth the hassle to get the DPI of your screen correct (so that 1inch in the application is one inch on the display) and to colour calibrate the screen, printer and scanner. Increasingly manufacturers are releasing nominal values for these calibrations for each model, and in the long run the hope is that some calibration good enough for all but the most fussy will occur out of the box. -- Glen Turner -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] /proc and /sys
>> They're entirely virtual filesystems and don't need to be backed up at >> all. In general, you should use the -x (or --one-file-system) parameter >> with rsync when you're backing up -- saves backing up (and even reading) >> useless crap like this. > > So *that's* what -x means ;-) > > > I've been doing: > > # rsync -a --exclude=/media/backupdrive / /media/backupdrive > > Without --exclude I get some "interesting" results ;-) > > Does the -x switch solve this problem too? It might sound naive, but I > understood the file system to be everything below / Each mount point exposes a filesystem, so really you have many filesystems below / ... the obviously different ones like /proc and /sys, but also the disk you mounted for backup, /home if you have that on a different disk... So yes, rsync -ax / /media/backupdrive/ will do the right thing unless you have data mounted elsewhere which you want backed up. Always match slashes with rsync source/destination by the way. - Jeff -- linux.conf.au 2010: Wellington, NZ http://www.penguinsvisiting.org.nz/ "I like your Christ, I do not like your Christians. Your Christians are so unlike your Christ." - Mahatma Gandhi -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] /proc and /sys
On Fri, 2009-05-22 at 13:05 +1000, david wrote: > To what extent are /proc and /sys recreated by the system as required, They are entirely dynamic. /proc and /sys (and, for the last several years, /dev) are virtual filesystems; the mount command that gets them there in the first place is something like # mount -t proc none /proc # mount -t sysfs none /sysfs (contrast to) # mount -t ext3 /dev/sda6 /home > and to what extent do they need to be backed-up? > Not at all. AfC Sydney -- Andrew Frederick Cowie Operational Dynamics is an operations and engineering consultancy focusing on IT strategy, organizational architecture, systems review, and effective procedures for change management: enabling successful deployment of mission critical information technology in enterprises, worldwide. http://www.operationaldynamics.com/ Sydney New York Toronto London signature.asc Description: This is a digitally signed message part -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] /proc and /sys
david wrote: > # rsync -a --exclude=/media/backupdrive / /media/backupdrive > Does the -x switch solve this problem too? If /media/backupdrive is a separate disk or partition, then yes. > It might sound naive, but I > understood the file system to be everything below / You have many filesystems. Run 'mount' in a terminal and you will get a list of your separate file systems. On my machine it looks like: /dev/sda1 on / type ext3 (rw,errors=remount-ro) proc on /proc type proc (rw,noexec,nosuid,nodev) /sys on /sys type sysfs (rw,noexec,nosuid,nodev) varrun on /var/run type tmpfs (rw,noexec,nosuid,nodev,mode=0755) varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777) udev on /dev type tmpfs (rw,mode=0755) devshm on /dev/shm type tmpfs (rw) devpts on /dev/pts type devpts (rw,gid=5,mode=620) lrm on /lib/modules/2.6.24-23-generic/volatile type tmpfs (rw) /dev/sda3 on /home type ext3 (rw) securityfs on /sys/kernel/security type securityfs (rw) binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev) tmpfs on /lib/modules/2.6.24-24-generic/volatile type tmpfs (rw,mode=0755) Most of those are virtual, with only /dev/sda1 and /dev/sda3 being real filesystems. On my machine if I did rsync -x / it would not include /home which is on /dev/sda3, but would include everything on /dev/sda1. Erik -- -- Erik de Castro Lopo http://www.mega-nerd.com/ -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] /proc and /sys
Jeff Waugh wrote: I'm doing a back up exercise, and google is not helping me. I've done a copy of the entire root drive using <# rsync -a> onto a back up drive (small because all data is on seperate drives). To what extent are /proc and /sys recreated by the system as required, and to what extent do they need to be backed-up? I hope that question makes sense. They're entirely virtual filesystems and don't need to be backed up at all. In general, you should use the -x (or --one-file-system) parameter with rsync when you're backing up -- saves backing up (and even reading) useless crap like this. So *that's* what -x means ;-) I've been doing: # rsync -a --exclude=/media/backupdrive / /media/backupdrive Without --exclude I get some "interesting" results ;-) Does the -x switch solve this problem too? It might sound naive, but I understood the file system to be everything below / -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Proprietary colour names (was GIMP was...)
Glen Turner wrote: Andrew Cowie wrote: On Mon, 2009-05-18 at 15:53 +0100, Richard Ibbotson wrote: ... much better than it was but some sort of Pantone colour integration would be good (eventually). An open source version of that would need to be implemented. Which is what the hold up is, at least as I understand it. The Pantone colour palate (specifically their name-to-ink-colour mappings) is Pantone's proprietary intellectual property and they have chosen not to let them be used in libre ways. Hi Andrew, The PANTONE CMS gamut is wider than CMYK or RGB. Since there's no way of accurately displaying PANTONE colours on a RGB screen or CMYK page PANTONE will still sell their swatch cards. I can understand that PANTONE can trademark their mixed ink names. I can understand that PANTONE may patent the inks themselves. But I don't understand how using that trademarked name to identify the ink mix product breaches trademark law. Otherwise I'd better start asking sales assistants for their "Kola nut carbonated drink" rather than "Cola-Cola(TM)". I'd be more than happy if PANTONE support consisted of a box asking for the text of the PANTONE colour, the RGB I'd like to use to display that on the screen and the CMYK I'd like to use when printing drafts. In practice, that would work by choosing a colour from the swatch, and entering it's name. Then hold the swatch to the screen until a good RGB match is found. Press a button to test print a gamut surrounding that RGB match, hold the test print to the swatch, enter the corresponding CMYK digits against the best match. Remember that only one or two spot colours are usually used. And this procedure automatically calibrates the screen and printer for the spot colour. Then the software need not carry the trademarked names, nor name-to-RGB, nor name-to-CMYK mappings. In fact, such software wouldn't be specific to the PANTONE CMS at all. Which, it seems, would serve PANTONE right. Excuse my ignorance, but isn't this roughly what colour management (http://www.argyllcms.com/?) is supposed to do? -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] Proprietary colour names (was GIMP was...)
Andrew Cowie wrote: On Mon, 2009-05-18 at 15:53 +0100, Richard Ibbotson wrote: ... much better than it was but some sort of Pantone colour integration would be good (eventually). An open source version of that would need to be implemented. Which is what the hold up is, at least as I understand it. The Pantone colour palate (specifically their name-to-ink-colour mappings) is Pantone's proprietary intellectual property and they have chosen not to let them be used in libre ways. Hi Andrew, The PANTONE CMS gamut is wider than CMYK or RGB. Since there's no way of accurately displaying PANTONE colours on a RGB screen or CMYK page PANTONE will still sell their swatch cards. I can understand that PANTONE can trademark their mixed ink names. I can understand that PANTONE may patent the inks themselves. But I don't understand how using that trademarked name to identify the ink mix product breaches trademark law. Otherwise I'd better start asking sales assistants for their "Kola nut carbonated drink" rather than "Cola-Cola(TM)". I'd be more than happy if PANTONE support consisted of a box asking for the text of the PANTONE colour, the RGB I'd like to use to display that on the screen and the CMYK I'd like to use when printing drafts. In practice, that would work by choosing a colour from the swatch, and entering it's name. Then hold the swatch to the screen until a good RGB match is found. Press a button to test print a gamut surrounding that RGB match, hold the test print to the swatch, enter the corresponding CMYK digits against the best match. Remember that only one or two spot colours are usually used. And this procedure automatically calibrates the screen and printer for the spot colour. Then the software need not carry the trademarked names, nor name-to-RGB, nor name-to-CMYK mappings. In fact, such software wouldn't be specific to the PANTONE CMS at all. Which, it seems, would serve PANTONE right. Cheers, Glen -- Glen Turner -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] /proc and /sys
> I'm doing a back up exercise, and google is not helping me. > > I've done a copy of the entire root drive using <# rsync -a> onto a back > up drive (small because all data is on seperate drives). > > To what extent are /proc and /sys recreated by the system as required, and > to what extent do they need to be backed-up? I hope that question makes > sense. They're entirely virtual filesystems and don't need to be backed up at all. In general, you should use the -x (or --one-file-system) parameter with rsync when you're backing up -- saves backing up (and even reading) useless crap like this. - Jeff -- linux.conf.au 2010: Wellington, NZ http://www.penguinsvisiting.org.nz/ "There's always a new bogeyman - every two months, there's a new axe to add to the axis of evil." - Michael Moore -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] /proc and /sys
I'm doing a back up exercise, and google is not helping me. I've done a copy of the entire root drive using <# rsync -a> onto a back up drive (small because all data is on seperate drives). To what extent are /proc and /sys recreated by the system as required, and to what extent do they need to be backed-up? I hope that question makes sense. Thanks... David. -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] webcam woes Jaunty
Ken Foskey writes: > There is a problem with Jaunty and webcams that I have: > https://bugs.launchpad.net/ubuntu/+source/libv4l/+bug/359045 > > Webcams will occasionally work. > There is also a Kernel bug that crops up because of something with > cheese: > > cheese: page allocation failure. order:5, mode:0x8004 Wow. Whatever that driver is, it asked for 2^5, or 32 physically contiguous pages from the kernel. /That/ isn't going to work well. > Googling led me to this: > http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.30-rc4 > Which I am not running: No, but that change is just to suppress the warning; apparently the uvcvideo driver /should/ retry with a smaller request, so that *probably* isn't an actual problem. Regards, Daniel -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] webcam woes Jaunty
There is a problem with Jaunty and webcams that I have: https://bugs.launchpad.net/ubuntu/+source/libv4l/+bug/359045 Webcams will occasionally work. There is also a Kernel bug that crops up because of something with cheese: cheese: page allocation failure. order:5, mode:0x8004 Googling led me to this: http://www.kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.30-rc4 Which I am not running: Ubuntu SMP Fri May 1 19:31:32 UTC 2009 (Ubuntu 2.6.28-12.43-generic) So all in all this is not very successful :-( -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
[SLUG] Skype on Mythbuntu
Hi All, I have Mythbuntu 8.04 installed on a box with two PVR-150 tuners. I'd like to use Skype as well (I use a cordless mini keyboard to control the box so can easily access the other applications). The problem is I cannot get Skype to see the webcam. When I run: ls /dev/video* I get: /dev/video0 /dev/video2 /dev/video25 /dev/video33 /dev/video1 /dev/video24 /dev/video32 Which is a bit weird given I only have two tuners. The Skype set up only sees the two tuners video0 and video1 I've tested the webcam on the same machine with Cheese - which is great fun - and which can find the webcam, but when I install effectv - which is also great fun - it gives me a the following message v4lgetmbuf:VIDIOCGMBUF: Invalid argument video_init: mmap interface is not supported by this driver. regardless of the /dev/video option I use. I've googled it but couldn't find anything particularly helpful or specific to this problem. Anyone with any ideas? Many thanks in advance. Regards, Patrick -- Registered GNU/Linux User 368634 www.youcantdothatinlinux.com -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] system restore from boot menu
On Thu, 2009-05-21 at 12:25 +1000, Jake Anderson wrote: > I can see how it can be done, but I don't imagine I'm the first person > to want to do something like this and I was wondering if anybody had > some experience with a similar solution? It can easily be done with a specially crafted initramfs and a partition to hold an image on. It's the fastest solution from a reimaging perspective, but actually building the system may take some time. Basically build a statically-compiled dd, statically-compile a simple little C program (as /init) to exec the dd, and have a minimal udev system (don't know if there's anything simpler). Basically, you use cpio to archive those couple of files and tell grub to boot the initramfs with an existing kernel. The tiny /init will exec dd with the appropriate parameters (e.g. dd if=/dev/sda3 of=/dev/sda2). Easiest way to play around with that stuff is with QEMU. QEMU can boot a kernel and initrd without even needing to set up a virtual disk with bootloaders and stuff: qemu -kernel /boot/vmlinuz -initrd=/your/initrd I've got some scripts and makefiles around for doing this exact stuff. Most important thing is to statically compile stuff. Tracking down shared libraries is a pain, even with the use of ldd. With only two or three executables, your initrd will not even grow beyond a megabyte or two. The system hinges on GRUB working, and having the kernel and initrd not die. For best results, keep them in /boot and on a separate partition, preferably sda1 (or mmcblk0p1 if it's embedded). signature.asc Description: This is a digitally signed message part -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
Re: [SLUG] system restore from boot menu
Grub is very smart but not as smart as you want believe. It has 38 commands (see below) You can easily achieve you goal *without reinstalling, swapping out disks or entering rescue mode to fix things. "DD" is nearly always available! However no matter how badly a system gets hosed, there is nearly always /sbin that stays intact. Also /etc/fstab & a few other files of paramount importance are often intact to allow a minimal system to be run. . then you have "dd" to copy partions here & there. The 3 Run levels of : emergency , 1 , S often are available when you can't boot the system to higher run levels. If ALL the above fails . appending" init=/bin/bash " to the kernel grub line will often work. (albeit in read only) you can fix that by "/sbin/mount -o remount,rw /" note the full path is probably required. Then DD will be available " /sbin/dd" If you have an exact image of a partiton elswhere just clobber the partion you have booted to. Of course you must be certain of what partition you are on. ( having an erronous entry in fstab may fool you at this point... in which case "/sbin/df" will tell you lies. The gotcha points are that /boot/grub/grub.conf entries must coincide with /etc/fstab. Three variations work with these files 1 "device" names as a naming convention 2 "label" names as a naming convention 3 "UUID" strings as a naming convention ... again grub.conf &fstab must coincide Hope this helps Roger Grub commands .. no dd or cp etc 1 blocklist FILE 2 boot 3 cat FILE 4 chainloader [--force] FILE 5 clear 6 color NORMAL [HIGHLIGHT] 7 configfile FILE 8 device DRIVE DEVICE 9 displayapm 10 displaymem 11 find FILENAME 12 geometry DRIVE [CYLINDER HEAD SECTOR [ 13 halt [--no-apm] 14 help [--all] [PATTERN ...] 15 hide PARTITION 16 initrd FILE [ARG ...] 17 kernel [--no-mem-option] [--type=TYPE] 18 makeactive 19 map TO_DRIVE FROM_DRIVE 20 md5crypt 21 module FILE [ARG ...] 22 modulenounzip FILE [ARG ...] 23 pager [FLAG] 24 partnew PART TYPE START LEN 25 parttype PART TYPE 26 quit 27 reboot 28 root [DEVICE [HDBIAS]] 29 rootnoverify [DEVICE [HDBIAS]] 30 serial [--unit=UNIT] [--port=PORT] [-- 31 setkey [TO_KEY FROM_KEY] 32 setup [--prefix=DIR] [--stage2=STAGE2_ 33 terminal [--dumb] [--no-echo] [--no-ed 34 terminfo [--name=NAME --cursor-address 35 testvbe MODE 36 unhide PARTITION 37 uppermem KBYTES 38 vbeprobe [MODE] -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
