“Over Specifying” an Excel Range Selection…

Whilst attempting to wrestle some data into submission and line ’em up like good little datum on an Excel chart, I ran into an issue attempting to utilise a dynamically defined range of data as the chart’s data source.

I had followed the sages’ advice found over the Internet, first finding out you cannot use an INDIRECT() function directly while specifying chart series source data, then attempting to replicate the advice on using named ranges (as an additional level of indirection).

Unfortunately, try as I might, I still kept getting the dreaded “Excel found  a problem with one or more formula references in this worksheet” error, for which the description and suggestion was to “Check that the cell references, range names, defined names, and links to other workbooks in your formulas are all correct.”, whenever I tried to save or even tab away/take focus away from the data input field:

If you are sharp-eyed and am an Excel expert, laugh at my folly and move on… If you are still clueless on what the cause is, please do continue reading…

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Logitech G933 Microphone Borked by Own Logitech Software…

OK, so I love headsets that have their own microphone toggle switch that is not tied to some software switch requiring a mouse click or even a keyboard shortcut or press. The switch can be a physical in-line flick or push button switch for wired headsets, or, in my current case, a flick up/down microphone on my wireless Logitech G933 headset I purchased quite a while back…

Recently, with the pandemic raging all around and Work-From-Home (WFH) being the norm, a good headset with microphone control was a must.

Unfortunately, for some odd reason, my Logitech G933 headset microphone started to “crap out” – once muted (i.e. flipped up) the microphone would never re-activate, even with repeated power cycling of the headset. Only a reboot would work…

Frustrated, I was finally ready to throw the headset away when I tried it with another laptop… It worked without issues… I suddenly remembered about the Logitech G Hub software that was running (and not running very well at that – it hangs on the loading screen, which I previously tried troubleshooting but never got anywhere).

I killed the G Hub process and suddenly, my headset was working just fine again!

My Background…

Skeletons In My Closet

(or in my case, Diners In The Background, aka the Case of the Faceless Man)…

With the recent global pandemic, working from home means parking myself at my (messy) workbench, work laptop tucked under my triple monitor set-up… that, due to my small apartment, is actually in my dining area (with the dining table at my back). This means I (usually) do not enable my video/webcam feed during virtual meetings/teleconferences, mainly to

  • retain some modicum of privacy for the rest of my household
  • avoid the extremely distracting situation of having people walking past behind me (and given that my webcam is perched on top of my monitor that has been raised to eye height and therefore is pointing downwards, means headless torsos traversing stage left to right or vice versa)
  • avoid having some person/s sitting down at the dining table behind me, eating or whatever

Unfortunately, forced to show my ugly mug via video/webcam feed during work calls, due to guilt for not doing so while everyone else was, or because of conducting customer training, I had to scramble to find a solution to “hide” my background.

You Feel Sense Me?

I immediately thought of depth-sensing cameras, hopeful that the days of the Xbox Kinect have been left behind in the name of maturity… A full day of researching depth-sensing capable cameras came up with disappointing results, however.

The Intel D435 is the only widely available retail webcam considered “current”, with everything else, like the Intel SR305 and similar third-party Intel SR300-based products (like the Creative BlasterX Senz3D and the Razer Stargazer) currently relegated as “discontinued”/”unsupported” (due to the latest Intel SDK dropping support for SR300) or “limited support” (i.e. using only the normal, 2D RGB sensor, like any other normal HD/FHD webcam)

Countless other pages I forgot to bookmark/note down simply distilled into the single fact that dabbling with depth sensing cameras was a hit-or-miss affair, with actual software support not universal, despite Intel’s SDK having being already been provided… Maybe if someone can write a “tween” application (here or here) that would create a fake green screen that (most) other “normal” software with native support for green screens (like OBS and Zoom) could use, this may be the ideal (compared to what follows below)…

If you have to ask why: some of the solutions proffered still pick up persons moving behind me, and often incorrectly, resulting in some disembodied torso crossing behind me; the use of depth sensing would result in picking up only me, assuming some ability to control/select the distance/depth…

Since I did not want to spend money on something that may work (but most likely not), that brought me back to the “standard” webcam + “human shape/form sensing” and “‘smart‘ background removal”…

I tested several options I could find, namely:

One key point for me, which may not be applicable to you, is that I needed the software to work with BlueJeans, the “video conferencing application of choice” for work.

2021/07/01 Update: With my work moving over from BlueJeans to Zoom (citing the latter is more commonly found everywhere, probably due to their offering of a “free” tier), this is no longer a requirement. Zoom itself had introduced non-green screen background replacement shortly after this article was written also, and to date, it’s outline detection appears to equal or surpass Snap Chat’s.

2020/07/13 Update: BlueJeans surprised me today with an updated version, with a new “background” feature ala Zoom’s virtual background feature (i.e. not requiring chroma-keying/green screen)…

The good: less CPU intensive, less lag than routing through Snap Camera (as expected).

The bad: Shape/person object detection is still wanting, in comparison with Snap Camera (better) or even PerfectCam’s (best) shape detection – persons walking in my background still “appear” in BlueJeans as compared to the other two, despite the rather large distance separation.

Jump past the break to see what I eventually use now…

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Crouching Tiger, Hidden User-SID-in-Registry…

I was poking around my Windows 10 registry and stumbled across an “account unknown” SID – which immediately triggered my “hack alert” (not to mention my OCD)…

I traced this inherited permission up to registry root – which got me really worried

I was about to just “try and clean it up” (e.g. search the entire registry for the same SID and delete it if no such value, i.e. reference, was found), but decided to quickly search the ‘net while waiting for regedit to complete the full tree search when I stumbled upon this.

TLDR: Don’t blindly delete any unknown SIDs…

<RANT> Trust Microsoft to do something stupid like this, all in the name of attempting to “hide” or obfuscate their spying (in the case of this specific SID “S-1-15-3-1024-1065365936-1281604716-3511738428-1654721687-432734479-3232135806-4053264122-3456934681” in question); I mean, why would Edge, one piece of software requiring outbound network connectivity, need to have read permissions of the entire freakin’ registry?!?). This looks like one massive data leak/breach (via an Edge exploit) waiting to happen.</RANT>

Fixing Adobe’s Constipation…

So I ran into an issue where Adobe Acrobat refused to output any prints, citing two errors in succession: “document could not be printed” and “there were no pages selected to print“. A quick Google search found this (extremely old*) Adobe Community post.

Specifically, step #3 fixed it for me (i.e. deleting the entire %LOCALAPPDATA%\Adobe\Acrobat\DC folder). Just remember to quit Acrobat first

*Hey Adobe, it will be great if you can get your shit together and fix issues as old as this.

Clamping Down HARD on DHCPd MACs…

There is an eight year old issue (at the point of writing this) with pfSense DHCPd that somehow did not restrict DHCPd IP “handouts” despite the chosen setting to “Deny unknown clients”… Which, after some digging, turns out more to be of a misunderstanding than what the “common people” would think.

Despite the “Deny unknown clients” setting, certain clients requesting an IP from a pool/interface that does not explicitly list its MAC address will still get an IP address. It turns out that said client is considered “known” if the MAC is listed anywhere else (i.e. in some other MAC address list)…

Anyway, I got fed up with this seemingly insecure behaviour and managed to hack a fix… some 8+ months ago… Just that I never got around to posting the details for people willing to hack their own pfSense fix (unlike my other SSHd configuration fix which was documented in full)…

Well, to cut the long story short, the pull request (merged with another upstream fix) has now been accepted and merged (actual changes)… You will see this fix some-time-soon-now in some upcoming pfSense release… Enjoy!

2021/02/28 Update: A year later and only now is the DHCPd fixes released with a new stable release (2.5.0), instead of the expected 2.4.x! Well, it’s “finally out there”…

2021/06/01 Update: As of time of writing, it appears that 2.5.0 and 2.5.1 are, unfortunately, bugged and I do not recommend upgrading to 2.5.0/2.5.1…

2021/07/07 Update: pfSense 2.5.2 is now released… YMMV…

Exporting Clips Off A Dahua NVR Part Deux…

So, another day, another kid, another requirement to pull video off the DVR…

I totally forgot about my previous post and attempted to use the in-built NVR software (which requires ye ‘old Internet Explorer because it’s an ActiveX plugin) and, to my amazement, discovered that the video extraction actually works (although you still need to manually convert .dav video to something else that’s, you know, a known standard that is universally playable)… I am not sure how I missed this the last time, but oh well…

Anyway, as per usual, the quick instructions are here for posterity and future reference…

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Playing and Converting Dahua NVR’s .dav H264 Videos…

Well, as if fighting the NVR in attempting to export video clips ain’t enough. There’s a need to convert stuff just to play ’em back…

I tried a solution using VideoLAN’s VLC Media Player, but that was a hit-or-miss affair (i.e. sometimes it worked, other times, not).

Enter FFMPEG

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Exporting Clips Off A Dahua NVR…

I recently had an unfortunate episode requiring the exporting of a clip off a Dahua NVR, but I needed someone else to do it… (and no, I was not in jail, trying to instruct someone else to pull exonerating evidence off some CCTV, if that was what you were thinking)…

My original method of using the in-built web UI off the NVR, manual streaming conversion via VLC Player (after fiddling with it for a temporal configuration change to “enable” playback of .dav files) was just not going to “cut it”…

So, once I had the time, I waded into the battle of the forever-changing, forever-beta nature of Dahua firmware, software and hodge-podge end-user solutions…

SmartPSS

There happened to be a “new” version of the SmartPSS software (v2.002.0000008.0.T.190801); which was supposedly released a month ago (2019/08/01, as of writing this). This software was “supposed” to have had some (old) “enforced 1 hour video export” bug fixed. However, I was pulling my hair out as to why I could not seem to limit the video clip I chose to export. I finally found my clue and therefore am posting this here for posterity (actually, to enable other people to follow the same instructions to do this).

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Forcing dhcpd On pfSense To Forget…

So I was playing around with 2 new TP-Link HS110 units I bought from Amazon, and I was attempting to swap the two with two other existing units (which had older firmware), having the two new units take the identity (name/ID and pfSense dhcpd statically defined IP addresses) of the “older” units… Review of that device aside, I was pulling my hair out because the old units kept getting their old IPs, as did the new units!

Funnily enough, the units appear to “take turns” “phoning home” – such that in the Kasa control application, there were duplicates of the old unit name/IDs shown, and it “flip-flopped” on showing the availability (and also the recorded energy consumption).

I figured it must be the DHCP service/daemon, since I kept seeing the DHCPDISCOVER and DHCPOFFER in the dhcpd logs.

Time to roll up my sleeves and fix this…

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