Comments
Vance says: Glad you enjoyed it
RE: hpr4627::2026-04-28 UNIX Curio #5 - Faster, Pussycat! Kill! Kill! by Vance00:14:35 Listen in ogg, opus, or mp3 format.
Antoine: Not sure if they still support it, but under some window managers you used to be able to press Ctrl-Alt-Esc and the cursor would turn into a large X or a skull and crossbones. You could then click on a window to kill the program that owned it. Similarly, Ctrl-Alt-Backspace would end the entire X session. I think this is no longer common and it might not even be possible under Wayland.
candycanearter07: Very cool, thanks! I've used 'killall' a bunch but was not aware of 'pgrep', 'pkill', and 'pidwait'. They look to have some neat capabilities - maybe you could consider doing an episode on them? (Of course, none of these are in POSIX, so you wouldn't want to use them in a script unless you knew the systems it would be used on have those utilities.)
candycanearter07 says: killer episode
RE: hpr4627::2026-04-28 UNIX Curio #5 - Faster, Pussycat! Kill! Kill! by Vance00:14:35 Listen in ogg, opus, or mp3 format.
I didn't know about kill -0, thats a cool POSIX way to check if a process is existing or not. In most of my scripts, I used the p* commands instead (pgrep, pkill, pwait) since usually getting a specific process by pid didn't matter and they all support passing a pidfile directly with -F
Antoine says: kill and killall
RE: hpr4627::2026-04-28 UNIX Curio #5 - Faster, Pussycat! Kill! Kill! by Vance00:14:35 Listen in ogg, opus, or mp3 format.
Nothing to aggregate, only to say– loved learning about Kill. In my first times of Linux, maybe a problem of mine, I had to use it almost daily (in the main purpose, not knowing until now that the command can pause or only return the running status (: ).
I found it magical, because the ctrl+alt+del of Windows was not always responsive in times of trouble, but, in Linux, accessing a terminal to uss "killall X" (or whatever program) was always possible.
Thank you, Vance, 4dshow.
Whiskeyjack says: Reply to Vance on Click Removal in HPR4618
RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack00:37:16 Listen in ogg, opus, or mp3 format.
I already have the 5 second audio sample that I need from your HPR 4637 episode from the MP3 release, but I thought it would be polite to ask you first before using it as we were already corresponding in these comments.
I have most of the script written for a new HPR episode and will begin recording the dialogue and making the audio samples used to illustrate each point. I will describe in detail what I did to the sample from your podcast in that episode and show a before and after example.
This new episode is entirely inspired by comments from listeners, and your comment describing a click problem provided a very interesting subject for discussion in it. Thank you for your feedback on this.
Vance says: To Whiskeyjack - Click Removal
RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack00:37:16 Listen in ogg, opus, or mp3 format.
Thanks for your ideas! Looking at the Ogg/Opus/MP3 files on HPR, I see that they have some additional noise during pauses that makes the click removal filter in Audacity less effective. On the original WAV file, I *was* able to remove most of the tapping noise by applying that filter to pauses with a Threshold value of 50 and a Max Spike Width of 30. Trying the same values on pauses in the MP3 file was less effective, but did improve things a little bit.
I agree that applying the click filter to the sections where I'm speaking produces undesirable distortion. It would be possible to manually highlight just the pauses and remove clicks from each one, but that would be tedious. I considered blanking out those areas, but it would be just as tedious and I thought it might sound weird for there to be total silence.
However, your suggestion of using ffmpeg's agate filter would eliminate the problem of having to manually highlight the pauses. I see that it doesn't totally zero out the waveform, just reduces it, so it shouldn't sound weird.
I would be happy to send you a WAV or FLAC file to play around with, and you are welcome to use as much of this episode as you like in your own work. E-mail me at the address on my host page.
Initial testing seems to indicate that it was likely my mobile phone that caused the problem to begin with. If that is the case, it's easy enough to get rid of the problem at its source by moving it away from the microphone (it was in my shirt pocket) or just turning it off.
Whiskeyjack says: Reply to Vance in HPR4618 - Click Removal
RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack00:37:16 Listen in ogg, opus, or mp3 format.
I had a look at your HPR 4637 episode to see what the "clicks" were like. I did some experiments to try to find a technique which could remove the clicks.
The "click removal" effect in Audacity does nothing useful to deal with this. The same was true for most of a number of other common filter techniques that I tried. The ones which did have an effect on the clicks introduced noticeable distortion in the voice which was more of a problem than the clicks.
What does work is the "noise gate" effect (which is agate in ffmpeg). You set a threshold in dB and any part of the signal which falls below that level is suppressed to zero. In other words, quiet parts of the audio are made quieter. I set a threshold of -20dB and all of the clicks were completely removed without introducing distortion in the voice signal.
In a few spots, short initial syllables on a few sentences were also cut out, but I didn't spend any time adjusting parameters to get it perfect. I suspect that another solution to this would be to not apply the effect on those few parts of the audio where this happens.
Would it be alright with you if I used a short (5 second) clip of your podcast as a noise sample in my own upcoming episode on audio filtering? This is not a noise problem that I can easily recreate and it would make for an interesting problem and solution to address.
The more I look at things the more I am convinced that there is no one size fits all solution to audio problems, only collections of tools that we can keep in our toolboxes.
Antoine says: Our State. The Invitation.
RE: hpr4616::2026-04-13 Thoughts about age control and further suggestions by Trollercoaster00:10:45 Listen in ogg, opus, or mp3 format.
Hey, Trollercoaster, I'm a member of the Legislative in Atlantis. (The underwater one.) Nevertheless, we are going to emerge soon, the making of the e-banners can begin.
(Our language is the Atlantean, we don't understand if not it — the translation, if you can read it, is in real time, by scanning of the legitimate eyes that should see the message.)
Parlament members can't roll for the Executive though. Never. You, if you can read, may come to the Palace. If so, please just let me know so I can wake both eyes of the editorial whales for the making of your Presidential Propaganda.
Ahibvederti! **–end_of_italic_atlantean_intimate_translatxxxx___**
Trollercoaster says: Looking forward at next steps
RE: hpr4616::2026-04-13 Thoughts about age control and further suggestions by Trollercoaster00:10:45 Listen in ogg, opus, or mp3 format.
Hello Antoine,
please notify me in what state you are going to submit that proposal. I will move to that state and run around with a banner "Antoine for president!"
Hey Candycanearter07,
I don't get it. Do you hate hackers?
Vance says: Click removal
RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack00:37:16 Listen in ogg, opus, or mp3 format.
Antoine, thanks for mentioning the click removal capability in Audacity! While I already knew about its noise removal filter, I wasn't aware it also had click removal.
It might have helped me for HPR4637, where some sort of electromagnetic signal was picked up by my microphone/recorder, a Zoom H2 (the tapping sound was *not* present in the room where I recorded).
While click removal does seem to distort speech when applied to it (though to my ears, it doesn't sound as weird as when noise removal is done with speech), I could have applied the filter only to the pauses, where the "tapping" is most noticeable. I will consider doing this in the event that I'm not able to eliminate the source of interference in the future, which would be the best way to go.
Archer72 says: Not fixed from أحمد المحمودي
RE: hpr4424::2025-07-17 How I use Newsboat for Podcasts and Reddit by Archer7200:05:41 Listen in ogg, opus, or mp3 format.
Hello أحمد المحمودي
This issue with Newsboat is not forgotten.
I am working on a macro to enqueue, download rename to the 'corrected' filename i.e.
hpr4580 ; The First Doctor, Part 4.ogg
P.S. How did you find HPR or get into tech or any Hacker related subject? We would definitely like to hear about it. :)
Cheers,
Archer72
Windigo says: Great usability win
RE: hpr4596::2026-03-16 Adding voice-over audio track created using text to speech on the movie subtitles by Ken Fallon00:28:09 Listen in ogg, opus, or mp3 format.
After my wife and I started enabling subtitles a couple years back, I've found it hard to watch media without them.
I love the concept you've outlined here. I know some people have difficulty reading subtitles, so being able to add an audio option is a great tool in the toolbox. :)
candycanearter07 says: electron charged opinion
RE: hpr4625::2026-04-24 Site Specific Browsers by Lee00:07:37 Listen in ogg, opus, or mp3 format.
On one hand, I don't really like webapps in general, they always feel incredibly sluggish and give me a headache. On the other hand, it DOES increase Linux support...
Ken Fallon says: Great to hear your success
RE: hpr4624::2026-04-23 Cheap Yellow Display Project Part 7: GUI Trying a Simple Hello World by Trey00:21:47 Listen in ogg, opus, or mp3 format.
I need to work on my cyd
Whiskeyjack says: Response to Antoine on de-essing in HPR 4618
RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack00:37:16 Listen in ogg, opus, or mp3 format.
I knew absolutely nothing about audio before making my first two HPR episodes.
I learned a little bit about filtering in order to try to fix audio noise problems I noticed in those ones before making the 8 part series which followed.
Most of what I know now has come about from having to address the subject more systematically while making this 4 part series.
There is still a lot I don't know, including how to use audio compression properly.
I had never even heard about de-essing until I started making this series. I found out about it while researching filters.
I am currently making a follow up episode which concentrates on filtering methods and what sorts of noise situations each method may be useful in when making a podcast. So far it looks like there are pros and cons to different methods depending on the situation rather than there being a panacea which fixes all audio problems.
So far as clicks go, the recording method that I use of making many small segments and then stitching them together rather than speaking fluidly and continuously seems to inherently need de-essing more because the clicks seem to be most common when you start speaking from a resting state. Given this situation, I have some ideas that I may try which address this specifically rather than using de-essing.
I will add compression to the list of experiments that I will do. We'll have to see if I come up with any useful results.
I am currently about to go buy a new microphone to create a new category of recording set up to collect test samples.
Thank you for your feedback. I got the idea for this project from a comment by an HPR listener on a previous episode.
candycanearter07 says: good strategy
RE: hpr4616::2026-04-13 Thoughts about age control and further suggestions by Trollercoaster00:10:45 Listen in ogg, opus, or mp3 format.
I like how you use exaggeration and parody to make your points, it makes your points both memorable and hit hard.
candycanearter07 says: intended double entendre?
RE: hpr4621::2026-04-20 Android volume control help by operat0r00:11:14 Listen in ogg, opus, or mp3 format.
I like the double meaning in the title "volume control" in both the literal issue and "control" of the "volume" of your device (like how drives are called device volumes). I also agree that the progressive locking down is annoying, and it intentionally creates a feedback loop of "well people don't understand the systems because its locked down, so we need to lock it down more so people don't break anything"
Antoine says: Applying filters - exp. with declicking - Compression?
RE: hpr4618::2026-04-15 Simple Podcasting - Episode 2 - Basic Filtering by Whiskeyjack00:37:16 Listen in ogg, opus, or mp3 format.
Worthy content! (for use and "for the fun of it"). Actually, as an Audacity user, may not use the command-line editing, but the underlying concepts are the same.
About de-esser, maybe it's better to apply it to the excerpts one need (or want) to improve. With my first uses of click removal, I liked it so much that applied to the entire recording. The result : almost no audible clicking, but a lot of lost missing "t"s in some phonemas. (Best is to don't click the tongue, but, if not, there is declicking — for specific regions.)
I don't remember using de-esser you presented, but the idea may be the same, to check the result where applied.
Aaand, I shall wait for the entire series, but one tool that I would like to listen to is compression. Let's see whether it is going to be adressed on the shows or not, anyway, thanks for sharing.
Antoine says: 'Jus'do the age verification'
RE: hpr4616::2026-04-13 Thoughts about age control and further suggestions by Trollercoaster00:10:45 Listen in ogg, opus, or mp3 format.
Just do the age verification, we can write the law.
For protection of what people of what ages shall or shall not have access to.
Yes, online.
Offline? we have not thought of that, we may have a proposal about it in a near future, thanks, Trollercoaster.
(Great show, thanks.)
Gan Ainm says: Störtebeker - again
RE: hpr4619::2026-04-16 HPR Beer Garden 12 - Baltic Porter by Keviefrom the series Beverages.00:31:47 Listen in ogg, opus, or mp3 format.
Störtebeker (the same Ö sound as Kevie's Öö!) once had a Nordik-Porter at 9.5% ABV which was an Eisbock (Ice Bock) made from their Stark-Bier (strong beer) at 7.5% ABV which is a Doppelbock (Double Bock), a strong, often dark, German lager (which might be mentioned in the upcoming episode about strong lagers).
The malty Nordik-Porter came in 0.5 l bottles and had heavy coffee and espresso notes and was really the perfect drink for a long cold winter evening.
Howerver, it's not available anymore, but they now offer Grand Marnier and Whisky cask-matured versions in 0.33 l bottles which I did not taste (yet).
0xf10e says: Preconfiguring browsers profiles? and re-replies ;)
RE: hpr4569::2026-02-05 Kiosk with guest mode on Linux by Klaatu00:23:57 Listen in ogg, opus, or mp3 format.
Great episode! A nice example of using (and adjusting!) Free Software in a public setting like, well, a library!
Btw: An example for "Public Money, Public Code" I tend to use is creating a platform for libraries to catalog and manage their books ;)
So, what about copying a preconfigured browser profiles into `~libraryguest` for some adjustments?
And clearly not over thinking: What about having swap encrypted with a new throwaway key every time? ;P I'm sure there is an option for this…
@#1 /tmp is the only other place I could think of, too, where a user's files could end up in. Maybe run `find /tmp -user libraryguest -exec rm -rf {} \+` before login/at logout.
And cleanup of ~libraryguest even on a ramdisk setup, just in case? ;)
@#3
Smb most probably can be mounted at login via pam like an encrypted homedir. In a "bigger" setup with a bunch of underpowered thinclients you could even mount ramdisks from the one box without soldered-on RAM.
@#4 Oh, RcloneView looks great! Any special permissions/group memberships a user would need?
candycanearter07 says: perpetually updated script(s)
RE: hpr4585::2026-02-27 mpv util scripts by candycanearterfrom the series Bash Scripting.00:11:55 Listen in ogg, opus, or mp3 format.
I set up a small git repository so i dont have to keep writing comments here when its changed
https://git.sr.ht/~ccaesap/dotfiles/tree/main/item/mpv/scripts
candycanearter07 says: interesting!
RE: hpr4614::2026-04-09 Dauug|18: Faster Than a ’286, but Inspectable Like a Soroban by Marc W. Abel00:37:06 Listen in ogg, opus, or mp3 format.
I find obscure hardware designs cool, and this is no exception! Deviating from the common 8-bit design is something I've rarely seen, and though I didn't understand a lot of the deeper mechanics, the way you explained it was captivating.
Kevin O'Brien says: Maybe I will
RE: hpr4600::2026-03-20 The First Doctor, Part 5 by Ahukafrom the series Science Fiction and Fantasy.00:15:26 Listen in ogg, opus, or mp3 format.
My intention was to only cover the classic stories of Doctor Who, but I suppose there is no reason I couldn't cover the renewed series as well, I've certainly seen all of them
Jim DeVore says: Is this the best approach for privacy?
RE: hpr4614::2026-04-09 Dauug|18: Faster Than a ’286, but Inspectable Like a Soroban by Marc W. Abel00:37:06 Listen in ogg, opus, or mp3 format.
I suspect this was about computer design, and a fascinating presentation of that subject.
For privacy, wouldn't it make more sense to use old hardware? Things were so much more transparent in the DOS days.
Trollercoaster says: Hopper did time traveling!
RE: hpr4603::2026-03-25 On the Erosion of Freedom in Open Source Software by HopperMCS00:17:31 Listen in ogg, opus, or mp3 format.
OMFG! Hopper went time traveling to steal my idea and actually say the opposite that he suggested when interviewing me on this topic. I'm confident that he vibe coded a time traveling machine after interviewing me... JUST TO STEAL MY THUNDER!!
Go have a look at episode HPR4616 where we sing the love song on the merits of Age Verification and how further extending it will make the world a better place! But here he's all against it?
OMFG again!
Trollercoaster
To avoid misunderstandings: OMFG means "Offering My Finest Greetings!"
Paulj says: Thanks!
RE: hpr4605::2026-03-27 Lee locks down his wifey poo by Elsbeth00:08:25 Listen in ogg, opus, or mp3 format.
Many thanks for sharing the link to the passage.
Trollercoaster says: Damn you Nerdy Nostaliga!
RE: hpr4606::2026-03-30 My Nerdy Childhood: From Floppy Disks to Dial-Up Dreams by Trollercoaster00:15:30 Listen in ogg, opus, or mp3 format.
Now you made me listen to a decade old episode of HPR! That's nostalia over nostalgia. So Nostalgia² ... for sure that can't be negative (unless it's complex nostaliga).
Ken Fallon says: Fixed
RE: hpr4611::2026-04-06 HPR Community News for March 2026 by HPR Volunteersfrom the series HPR Community News.01:00:43 Listen in ogg, opus, or mp3 format.
No problem. I renamed it. Contact the janitors for these type of issues.
candycanearter07 says: sensical date format
RE: hpr4609::2026-04-02 Proper Date Format by Ahuka00:07:19 Listen in ogg, opus, or mp3 format.
It's definitely handy to use with alphabetical sorting, especially if dealing with a cross-filesystem archive since access/modify times are rarely consistent longterm.
candycanearter07 says: misattributed comment
RE: hpr4611::2026-04-06 HPR Community News for March 2026 by HPR Volunteersfrom the series HPR Community News.01:00:43 Listen in ogg, opus, or mp3 format.
HOLY i just realized I accidentily put Windigo's name in when typing the reply for the mpv util scripts and didnt notice until just now im so sorry
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