@SiemusS recently asked me to review the draft documentation for FQ_CoDel for OPNsense.
The document turned into a fairly nice description of the FQ_CoDel algorithm. See https://github.com/opnsense/docs/blob/master/source/manual/how-tos/shaper_bufferbloat.rst
I do a lot of work with spreadsheets. Some are pretty simple, and I can inspect them by hand. Some are enormously complicated – hundreds of rows, dozens of columns, etc. It’s not practical to inspect/test them manually.
Enter ExceLint. It’s an add-in to Microsoft Excel that “lints” a spreadsheet. (A “linter” is a program that picks off ‘bits of fluff’.) The ExceLint team reports they regularly find errors, some material, in spreadsheets they test. (I was pretty lucky – there were a couple minor errors, but I was OK.)
ExceLint requires you to “side-load” a manifest.xml file that points to the resource files the add-in uses. The ExceLint home page describes the side-load process. It stopped working a while ago, so I just started to hope my good spreadsheet-fu continued. But then I decided to do a bit of troubleshooting, and found that ExceLint retrieved its code from a defunct server running on azure.com. I fixed it a couple ways:
You can now use ExceLint again, using publicly served resources from Github. You can even test at https://excelint.github.io/ExceLint-addin. The result isn’t terribly interesting – it displays the ExceLint logo, with a spinner that runs forever.
The PRQL project provides a simple, powerful, pipelined SQL replacement. To make it easier to share the development environment, there is a Dev Container that bundles the dozens of components into a single container. This makes it easier for new person to start using the project: they don’t have to collect the proper (sometimes conflicting) versions of the tools on their computer.
The Dev Container had been working fine for over a year. I recently noticed that there was a new version of Docker Desktop (old: 4.29.0; new: 4.30.0). After the upgrade, some of the services – the Playground and the “Book” (the documentation) – were not available from the Dev Container.
The fix was to force those services to bind to the address 0.0.0.0 (not “localhost”, not 127.0.0.1) in the task file that configures them. See the PRQL repo for details.
As we take a shot at opening people’s eyes to bufferbloat, we should know some of the “objections” we’ll run up against. Even though there’s terrific technical data to back up our research, people seem especially resistant to thinking that bufferbloat might affect their network, even when they’re seeing problems that sound exactly like bufferbloat symptoms. But first, some history:
The very idea of bufferbloat is simply unbelievable. Jim Gettys in 2011 [1] couldn’t believe it, and he’s a smart networking guy,. At the time, it seemed incredible (that is “not credible” == impossible) that something could induce 1.2 seconds of latency into his home network connection. He called in favors from technical contacts at his ISP and at Bell Labs who went over everything with a fine-toothed comb. It was all exactly as spec’d. But he still had the latency.
This led Jim and Dave Täht to start the investigation into the phenomenon known today as “bufferbloat” – the undesirable latency that comes from a router or other network equipment buffering too much data. Over several years, a group of smart people made huge improvements: fq_codel was released 14 May 2012 [3]; it was incorporated into the Linux kernel shortly afterward. CAKE came in 2015, and the Wi-Fi fixes that minimize bufferbloat the drivers arrived in 2018. In 2021 cake-autorate [4] arrived to handle varying capacity ISP links. All these techniques work great: in 2014, my 7mbps DSL link was quite usable. And when the pandemic hit, fq_codel on my OpenWrt router allowed me to use that same 7mbps DSL line for two simultaneous zoom calls.
As one of the authors of [2], I am part of the team that has tried over the years to explain bufferbloat and how to fix it. We’ve spoken with vendors. We’ve spent untold hours responding to posts on assorted boards and forums with the the bufferbloat story.
With these technical fixes in hand, we cockily set about to tell the world about how to fix bufferbloat. We assumed it would be an easy task. Our efforts have been met with skepticism at best, or stony silence. What are the objections?
So… All these hurdles make it hard to convince people that bufferbloat could be the problem, or that they can fix for themselves.
A couple of us have reached out to Consumer Reports, wondering if they would like a story about how vendors would prefer to sell you a shiny new router (or new bigger ISP plan) than fix your bufferbloat. This kind of story seemed to be straight up their alley, but we never heard back after an initial contact. Maybe they deserve another call…
The recent latency results from Starlink give me a modicum of hope. They’re a major player. They (and their customers) can point to an order of magnitude reduction in latency over other solutions. It still requires enough “regular customers” to tell their current ISP that they are switching to Starlink (and spend $600 to purchase a Dishy plus $100/month) to provide a market incentive.
Despite all this doom and gloom, I remain hopeful that things will get better. We know the technology exists for people to take control of their network and solve the problem for themselves. We can continue to respond on forums where people express their dismay at the crummy performance and suggest a solution. We can hope that a major vendor will twig to this effect and bring out a mass-market solution.
I think your suggestion of speaking to eSports people is intriguing. They’re highly motivated to make their personal networks better. And actually solving the problem would have a network effect of bringing in others with the same problem.
Good luck, and thanks for thinking about this.
This is a slightly edited version of a post first published on the bloat and starlink lists.
Rich Brown
[1] https://courses.cs.washington.edu/courses/cse550/21au/papers/bufferbloat.pdf
[2] https://www.bufferbloat.net/projects/bloat/wiki/What_can_I_do_about_Bufferbloat/
[3] https://lists.bufferbloat.net/pipermail/cerowrt-devel/2012-May/000233.html
I regularly record public meetings in my town and post them on Youtube. This allows residents who could not attend the meeting in person to see what occurred. It also supports creation of accurate minutes.
I like to add a label (showing the committee name and date) and a timecode (a running clock showing the current time in the meeting). I found a free program Shutter Encoder that does this. It works well, but has a detailed (very fussy) user interface that requires a long set of steps for every new video.
Since I only deal with a couple variations of the recordings, I decided to write scripts that use the ffmpeg program directly to accomplish these repeated, well-defined tasks.
I now move the video/audio files into this directory and issue a command like the one below, and wait a few minutes. The resulting video is ready for uploading to Youtube.
sh ./AddTimecode.sh "Lyme Committee Meeting-6Feb2024" 09:58:00 Here are the notes I use to remind myself how to make the videos using my Mac. This information and the resulting scripts are also available on my github repo.
NB: You may need to install the ffmpeg program. Download a pre-built binary from ffmpeg.org, or read more on that site for getting a version for your computer.
To convert an audio-only recording into a video suitable for uploading to Youtube, this script combines a static JPEG photo with an audio track. The repo contains a photo of the Lyme Town Offices which is used by default. To use the script:
hh:mm:ss is the actual start time of the recording:sh AddTimestamp.sh "Meeting Name and Date" hh:mm:ss
The script looks for a .mp4 file (and the image of Town Offices) to produce an output file named Meeting Name and Date-timecoded.mov
3. Cleanup: Move the original audio file and the resulting …-timecoded.mov file to the CompletedFiles folder so they won’t interfere with subsequent runs. Discard after they have been uploaded
A Panasonic HDC-TM80 video camera produces a AVCHD meta-file that contains the video from a recording session. The files in an AVCHD file are within the AVCHD/BDMV/STREAM directory with filenames 00000.MTS, 00001.MTS, etc.
Drag the AVCHD file into this folder and run this script:
sh ./TimecodeAVCHD.sh "Meeting Name and Date" hh:mm:ss
The script looks for a file named AVCHD and outputs file named MeetingName-timecoded.mov
Sometimes, a meeting is recorded by an Owl Camera. This results in a good video with good audio, but it’s still helpful to display the meeting name and timecode at the bottom.
Drag the Zoom file (a .mp4 file) into this folder and run this script:
sh ./TimecodeZoom.sh "Meeting Name and Date" hh:mm:ss
The script looks for any file with a .mp4 extension and outputs file named MeetingName-timecoded.mov
Background Information
StackOverflow/SuperUser and similar sites are your friends.
So is ChatGPT. I gave it this initial prompt, “give me a ffmpeg command to read a .mts file and add a label and a timecode and output a .mov file. Be sure the audio of the .mts file is preserved.” and iterated to get the final commands.
Experiments with ffmpeg From: https://superuser.com/questions/1041816/combine-one-image-one-audio-file-to-make-one-video-using-ffmpeg
ffmpeg -loop 1 -i image.jpg -i audio.wav -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest out.mp4ffmpeg -loop 1 -i Lyme-Town-Hall-Offices-cropped-1024.jpeg -i SB-20231130.mp4 -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest 11Nov2023-first.mp4
Takes a while to encode
ffmpeg -r 1 -loop 1 -y -i 1.jpg -i 1.m4a -c:a copy -r 1 -vcodec libx264 -shortest 1.avitime ffmpeg -r 1 -loop 1 -y -i Lyme-Town-Hall-Offices-cropped-1024.jpeg -i SB-20231130.mp4 -c:a copy -r 1 -vcodec libx264 -shortest 11Nov2023-second.mp4
~5 seconds; result 18.6mbytes. Creates file that cannot be opened by QuickTime Player
ffmpeg -r 1 -loop 1 -y -i Lyme-Town-Hall-Offices-cropped-1024-1.jpeg -i SB-20231130.mp4 -c:a copy -r 1 -vcodec libx264 -shortest 11Nov2023-three.mp4
Blows big chunks with “odd dimensions” error
-pix_fmt yuv444p right before name of output file.time ffmpeg -r 1 -loop 1 -y -i Lyme-Town-Hall-Offices-cropped-1024-1.jpeg -i SB-20231130.mp4 -c:a copy -r 1 -vcodec libx264 -shortest -pix_fmt yuv444p 11Nov2023-four.mp4
Fast (takes 5-10seconds). Creates file that cannot be opened by QuickTime Player
We promise not to fix it if we don’t know it’s broke. My mentor at Dartmouth College, Stan Dunten, said this all the time.
That’s why I always send in short reports to webmaster@…. mentioning something that didn’t look right. Most of the time it’s something silly. And sometimes I get a heartfelt “Thanks!” because I pointed out a real problem.
I was playing with ChatGPT and Klavier.ai the other day. It purports to import documentation so that you can ask questions about it. I let it read in the PRQL Language Book, and you can see the rest of my experimentation at the PRQL site.
I often hear people saying they have bad responsiveness / high latency on their high-speed internet connection. Even though they have a contract for 500 mbps+ service from their ISP, a speedtest shows high ping times when the link is loaded.
The answer is well-known – install a router with SQM that knows how to control latency (“bufferbloat”). But… they counter, a router to handle my high-speed network is expensive! And that blows out my budget!
I posted a contrarian viewpoint in a post on the OpenWrt forum:
Save money and purchase a 250mbps to 350mbps connection and use good SQM (for example, the IQrouter v3, or any reasonable performance OpenWrt compatible router.)
Unless you’re unusual, and the transfer speeds of your bulk up/downloads are unacceptable, it’s likely that a lower speed to your ISP with a modestly-priced router that controls latency will make you just as happy.
Not only will you save money with a less-expensive router, you save every month with a lower ISP bill.
Many people are surprised to hear that their web browsing doesn’t have to be crowded out by intrusive ads. There is an entire industry of “ad blockers” and “content blockers” that claim to fix this.
uBlock Origin is the one I use. Its author, “gorhill” states that it’s Free. Open-source. For users by users. No donations sought.
Accept no substitutes! The other products carry names that combine the words “ad”, “block”, “guard”, “plus” and a whole host of synonyms. And I wouldn’t trust any of them – they all come with with strings (or fees) that make them less than perfect.
For Chrome or Firefox:
For Safari:
For Other Browsers:
I can no longer bring myself to write bare SQL – PRQL makes building queries so easy.
I have become enamored with PRQL – Pipelined Relational Query Language, pronounced “Prequel”. It’s a simple, powerful, pipelined SQL replacement.
From the PRQL Github page: Like SQL, it’s readable, explicit and declarative. Unlike SQL, it forms a logical pipeline of transformations, and supports abstractions such as variables and functions. It can be used with any database that uses SQL, since it compiles to SQL.
I wrote a blog post over on the prql-lang.org site that tells how to make SQL queries “look good” using PRQL. See more »