CERN Centos Dojo 2017, Event report (1 of 4): Thursday meeting

Over the last few days I’ve been in Geneva for the CERN CentOS Dojo, 2017 edition.

(This is part 1 of a series of four posts. They are gathered here.)

On Thursday, prior to the main event, a smaller group of CentOS core community got together for some deep-dive discussions around the coming challenges that the project is facing, and constructive ways to address them.

This meeting was very potentially productive. I say potentially because some great decisions were made, with universal approval, but everything depends on the execution. Some of these decisions will take a great deal of work over the coming months. Of course, nobody is averse to hard work, but we all also have other things to do. So we need to keep the long-term health of the project firmly in mind, and find time for these tasks.


The full notes from that meeting have been posted to the Centos-devel mailing list for further discussion.

The attendees were from many different organizations, countries, and cultures. While the various organizations represented have rather different goals and motivations, there was great unity of purpose – ensuring the long-term health of the CentOS project.

Topics covered were focused on removing roadblocks to forward movement on the project, and removing obstacles to new contributors to the project coming on board and getting things done. This was very encouraging.

We were disappointed that a number of prominent community members were unable to attend. Notably, Karanbir was absent due to a broken toe:


Continuing discussion of the topics will happen on the centos-devel mailing list, and, as always, people who want to step up to assist in any of the identified tasks are encouraged to speak up and volunteer.

CentOS is a community of project communities, and works best when those projects identify the things that will make them more productive, and then step up to make those things happen.


CERN Centos Dojo 2017, Event report (0 of 4)

For the last few days I’ve been in Geneva for the CentOS dojo at CERN.

What’s CERN? –

What’s a dojo? –

What’s CentOS? –

A lot has happened that I want to write about, so I’ll be breaking this into several posts:

(As usual, if you’re attempting to follow along on Facebook, you’ll be missing all of the photos and videos, so you’ll really want to go directly to my blog, at



For the second time this year, I’m sitting in a place that I have read about for decades. I’m in a conference room at CERN, attending a CentOS meeting. CERN is the home of the Superconducting Super Collider, as well as being the birth place of the World Wide Web.

This afternoon I’ll tour the data center where a lot of the computing for the SSC happens, as well as seeing some of the actual experiments. Photos to come later this evening.

The earlier visit referenced above was Oak Ridge National Labs. I actually visited ORNL when I was in college, but on my most recent visit I got to visit Titan – one of the world’s largest supercomputers – and actually walk through it. It was very loud.


The day that started awful ended pretty well.

I woke up this morning, to make a long story short, with pain in my chest and left arm. We called 911 and the ambulance came. The EMTs checked me out and recommended that I go to the hospital. 5 hours later, I was discharged. They couldn’t find anything wrong. We figure that I just have a pulled muscle in my neck and shoulder.

Anyways, we had planned to go hiking today, so we decided to go ahead and do it anyway. We climbed chimney tops. Isaiah and I made it to the top, you can see my pictures on Flickr.

I’m not certain, but I think the last time I climbed chimney tops was at least 20 years ago. Perhaps a little bit more. It was a lot harder hike this time than it was then. I remember jogging up to the peak with Tim and Tony and Eddie.

But we made it to the top and back with no ill effects. My neck and chest and shoulder feel the same now as they did this morning. So I guess there’s nothing to worry about.

Event report: OpenStack PTG

Last week I attended the second OpenStack PTG, in Denver. The first one was held in Atlanta back in February.

This is not an event for everyone, and isn’t your standard conference. It’s a working meeting – a developers’ summit at which the next release of the OpenStack software is planned. The website is pretty blunt about who should, and should not, attend. So don’t sign up without knowing what your purpose is there, or you’ll spend a lot of time wondering why you’re there.

I went to do the second installment of my video series, interviewing the various project teams about what they did in the just-released version, and what they anticipate coming in the next release.

The first of these, at the PTG in Atlanta, featured only Red Hat engineers. (Those videos are HERE.) However, after reflection, I decided that it would be best to not limit it, but to expand it to the entire community, focusing on cross-company collaboration, and trying to get as many projects represented as I could.

So, in Denver I asked the various project PTL (project technical leads) to do an interview, or to assemble a group of people from the project to do interviews. I did 22 interviews, and I’m publishing those on the RDO YouTube channel – – just as fast as I can get them edited.

I also hosted an RDO get-together to celebrate the Pike release, and we had just over 60 people show up for that. Thank you all so much for attending! (Photos and video from that coming soon to a blog near you!)

So, watch my YouTube channel, and hopefully by the end of next week I’ll have all of those posted.

I love working with the OpenStack community because they remind me of Open Source in the old days, when developers cared about the project and the community at least as much, and often more, than about the company that happens to pay their paycheck. It’s very inspiring to listen to these brilliant men and women talking about their projects.

Video noise reduction using kdenlive and audacity

I’ve been doing interviews at the OpenStack PTG this week, and the space I started in was very noisy. I’ve been trying to figure out how to reduce background noise, and I think I finally figured it out.

(I’m sure that the same process works with other tools, but these are the ones that I use.)

In short, the process is this:

  1. Extract audio from original recording
  2. Noise reduction in Audacity
  3. Add video and noise-reduced track to kdenlive.
  4. Mute video track, and “group” the audio and video tracks
  5. Edit as usual

In more detail, here’s how you do that:

  1. Extract audio from original recording:

At the command line, convert the video directly to an mp3. ffmpeg takes care of the details:

ffmpeg -i original_video.mp4 original_audio.mp3

2. Open the audio track in Audacity, and noise-reduce

Select a section of the audio where nobody’s talking. This gives you the typical background noise that you want to remove. The longer this section is, the better your overall noise reduction will be.

Click “Effect” -> “Noise Reduction”, and then press the “Get Noise Profile” button.

Now, unselect the section (ie, by clicking anywhere in the track) then remove that noise from the entire track by clicking “Effect” -> “Noise Reduction” and clicking “OK”.

DO NOT make any edits that change the length of the track, as it must be exactly the same length as the video clip.

Now export the track again as an mp3.

3. In kdenlive, add the original video, and the new audio.

Add the two clips – the original video and the new audio to the timeline and make sure that they line up exactly.

4. Mute the video track by clicking the speaker icon next to the track.

Click the video track, then control-click the audio track. Press control-G (or right-click and select the “Group clips” option) to group the tracks into a single unit.

5. Edit as usual

In particular, when you cut or drag one clip, it will also happen to the other, so cutting out sections will affect both tracks, and they’ll stay in sync.

The Things They Carried

Every time I go to a conference, I pack pretty much the same things. Each item has its place in my bag.

Here they all are. Click on the picture for the full size. Image annotations were made in Inkscape, with assistance by Ruth.

Missing from this photo is my laptop, which of course I also always take. Except for that one time I forgot it, and Maria had to rush it to the airport for me. Oops. The laptop is a Lenovo T450s ThinkPad running Fedora 26. It has roughly 78,000 stickers on it.

The numbered items in the picture are as follows:


  1. This is a lovely leather satchel which Maria ordered for me, from China. People ask about it all the time. No, I don’t know what site it came from. It is awesome. It has all the pockets. So many pockets.
  2. This is a “travel charm” that Daniel got for me in a shinto shrine downtown Tokyo. The next time I was in Tokyo I got one for each of the coworkers I travel with the most. No, I’m not superstitious. It’s just a nice reminder of going to Tokyo, and a lovely gift from a friend.
  3. Tablet. This one is a Samsung Galaxy Tab A. It has numerous downloaded movies from Netflix on it, as well as a dozen books. It keeps me entertained on the plane.
  4. Phone. Google Nexus 6P
  5. Plastic bag of micro SD cards, which I use in the various audio and video recording devices I carry with me.
  6. Power supply for my laptop.
  7. This little guy is named Zipper Pull Man, and was made for me by my daughter, Rhiannon, probably 15 years ago. Possibly longer. It is made of plastic beads strung on plastic cords, and has traveled with me to 5 continents. In October it’ll go to the 6th. It has been repaired and restrung many many times.
  8. Leather cable wrap. Maria made this out of scrap leather. It holds various USB cables and chargers.
  9. Another leather cable wrap. This one usually carries AV stuff, like video adapters and audio cables. It’s got USB cables in it right now. You can never have too many cables.
  10. Wallet
  11. 22,000mAh phone charger battery. Can charge my phone about 5 times, or my tablet twice, from dead.
  12. Collapsible tripod for my video camera
  13. Zoom H2n microphone/recorder.
  14. Extension audio cable for that microphone
  15. Canon Vixia HF R72 video camera.
  16. Universal international power plug adapter.
  17. Phone charger battery. Can usually get one charge out of this one.
  18. Keys
  19. Micro SD card reader. Plugs into a USB port.
  20. Headache pills
  21. Mini power strip. 3 outlets.
  22. Passport
  23. Yet another cable wrap. I might slim it down to just two. I might have too many USB cables.
  24. Reading glasses. Yes, I’m that old.
  25. Sunglasses.
  26. Spare batteries for #15
  27. Gorillapod flexible tripod for #13
  28. Hearing aid batteries.
  29. Flashlight and bottle opener
  30. Another USB SD card reader. Handles micro SD cards and regular SD cards.
  31. Power supply for #15
  32. Remote slide clicker thingy
  33. Dart sharpener
  34. Handle for man-on-the-street interviews using #13
  35. Remote bluetooth microphone for my hearing aid
  36. Monocular. That’s like binoculars, but just one.
  37. Various business cards.
  38. Fancy USB-C charger for #4
  39. These items usually end up in my suitcase rather than my carry-on, since they are pointy. The black case holds my darts. The weird monkey thing is a PocketMonkey tool. And the knife is my current favorite pocket knife.
  40. Moleskine cahier notebook and fountain pens. The pens are in a Quiver pen holder.

By the way, “The Things They Carried” is an excellent book by Tim O’Brien. You should read it.

Addendum: There’s one tiny un-numbered box right in the middle. That is a 20 cent Euro coin that was in the bottom of my bag.


Obligatory eclipse post

Three videos from the eclipse. (As usual, if you’re reading this on Facebook, you’ll miss all the good stuff. Follow the link above for the actual post.)

First, the making of the tinfoil hats:

Then, there’s the eclipse itself:


It is incredibly hard to hold the camera still, and also follow the sun’s motion, with a tiny hand-held camera, while also holding eclipse glasses over the lens.

Here’s the same video sped up x 6, for the timelapse effect, but it ended up being far too jumpy.


I’m going to see if I can figure out how to stabilize it.


Video production and open source communities

In this mornings community managers meeting at work, I presented on using video as part of our community promotion. As I said at the beginning, this is a hobby which I enjoy – although I’m far from being an expert. And I’m trying to figure out if it’s actually useful as part of promoting our projects.

Here’s a summary of what I talked about, and some of the questions that were asked.


I use a Vixia HF R72 camera. You can get it from a number of online vendors. Here’s one of them:

This camera is available in a number of different models. I got the one that had the largest on-board storage, so that I didn’t have to mess with SD cards. However, you can get it a lot more cheaply with less on-board storage, and get as large an SD card as you think you’re going to need. For reference, a minute of raw video at default settings on my camera takes roughly 150MB. Plan accordingly.

When I’m doing planned video (as opposed to roaming about, on-site videos) I use an external mic, plugged into the camera. I have a Zoom H2n (see one at for example). I have a GorillaPod – which is a flexible tripod (see here: ) so that it can set on any surface securely. It also provides a slight noise dampening effect to isolate it from the surface it’s sitting on.

However, the on-board mic on the camera is pretty good.

Remember that you have a better video camera in your pocket than most movie makers have had in the history of film. Full feature films are being made with iPhones these days.

Meanwhile, I’ve been trying to justify the expense of a GoPro for some time. I really want one, but I realize this is mostly geek appeal, and I probably wouldn’t get enough use out of it to justify the cost. The main reason I didn’t buy one as my original camera is that it doesn’t have an audio input jack, making it less than ideal for the kind of interview situations that I started with.


I edit video with kdenlive – – which is free and available for most modern operating systems. It took me perhaps 5 hours to get comfortable with it, and another 10 to feel like I’m really good at it.

Now, if you’re going to be a professional, you’ll probably end up using some expensive software from Adobe, or from Apple. And that’s great. I’m sure they are objectively better, in ways that professional videographers can appreciate. But for us amateurs, kdenlive has everything that we’re likely to need. And it’s free.

Several years ago I tried to teach myself to use iMovie – back when I was a Mac user – and found it incredibly intimidating. I’m curious how I would feel about it now that I know more.


There is a huge selection of free music available at Free Music Archive – – in a wide variety of genres. I have always found something that seemed to fit the video.

Here’s one of my favorite videos featuring music from there:

(Note: If you’re reading this on Facebook, you won’t see the video. Follow the link at the top to my website.)

What’s unclear to me about FMA is what their business model is, and how all of these talented artists are making a living. Sometimes I feel bad about that.

Reasons for making videos:

There’s lots of reasons for making videos. What your reasons are will greatly affect how much time and effort you put into it, what kind of video you make, how you promote it, and so on.

Some reasons include:

  • Because making videos is fun
  • To show off a project/hobby/interest/yourself/something cool
  • To educate
  • To draw people in, so that they go to another site
  • To advertise a product/project
  • To put a human face on some project/product/concept

For my personal channel, it’s primarily the first two reasons. This morning I posted a video of a caterpillar, because I wanted to. There’s really no other reason.

For work, though, I have to justify the time that I spend, in terms of what the measurable benefits are. Mostyly, in that case, it’s the other four reasons.

Which leads to …

Measuring whether it’s effective:

Measuring whether what we do at work advances the goals of the company/project/whatever is tricky. If I enjoy doing something (like making videos) then I’m likely to think that it’s a useful thing to do, and look for reasons that support that.

But it’s important that it is actually effective, for some definition of effective. Does it bring traffic to the site? Does it educate people in performing some particular task. In fact, is anybody at all watching the videos, or are they just sitting there sad and lonely?

What to make videos of:

In short, everything. However, this can be extremely time consuming if you want to do postproduction, so you might want to be selective.

For the purposes of work, I recommend:

Events/Presentations. If you’re at an event, capture video of the sessions you attend. The people that weren’t there sometimes appreciate this. Make sure you ask the speaker if it’s ok. Make sure you have a mic, and that the speaker users it.

Meetings. Maybe. If you use some kind of video conferencing meeting service, and if the content of the meeting might be useful to someone else that couldn’t make it, press record. Why not? I wish I’d recorded the meeting this morning, for example, since I’m sure I’m forgetting something that was discussed.

People. People like to talk. Most of them, anyways. If you ask them to write a blog post or article, they’ll all say yes, but almost none of them will actually do it. But get them in front of a camera and start asking questions, and most people will have something useful to say. Everyone is an expert on something, and they like to talk about it.

YouTube has been kind enough to provide us with infinite storage for anything we want to create. Granted, they have their own reasons for this. But you might as well take advantage of it.


Other topics and questions that came up:

Q: Do you ask people to sign any kind of waver when you take video, saying that it’s ok to put it online for the whole world to see?

A: I never thought of that. I probably should. Seems that it’s also company policy for me to do so, so I should start right away. However, I always clearly set the expectation – “This will be on YouTube, ok?” – and get verbal assent, and this hasn’t, so far, resulted in any problems.

Q: How much time does it take?

A: It depends. If you’re getting a video of a presentation or a meetup, just post the raw video and be done with it. Total time: Length of event plus upload time. If you’re doing a more formal interview, it can take around 5-10 minutes per minute of final product. And if you’re doing something more elaborate like piecing together several clips and trying to tell a coherent story, it can take hours to make a 5 minute product.

And I’m sure that people that do this for a living are both better than I am at it (so they can do it faster) and more careful (so they do more work in that time, for a better finished product).

One thing I didn’t mention is that rendering the video (the process which produces the final uploadable file) takes a really long time. Around 5-10 minutes per minute of video, depending on your computer.

So, really, you need to experiment, and figure this out.

Q: How do you have people prepare for an interview?

A: I always provide a list of questions ahead of time. Usually a day or two before, so that they can think about what they’re going to say. Giving them a sample video of someone else answering similar questions is a great way to get them prepared. Then at the end, I always ask “was there something that I didn’t ask?” so that they can put in what they actually wanted to say. I then edit that bit into a relevant place in the conversation.

Q: Who are some YouTube’ers that you like to watch.

A: I like Casey Neistat – – because he’s really good at this, and his videos are, mostly, a lot of fun. And some of them aren’t. But he just post stuff because it interests him, and this seems to work out for him. (Warning: He’s not careful about his salty language. Sometimes.) My kids watch hours and hours of Good Mythical Morning. These guys are insane.

Related, I hate technical videos that take information that could be adequately stated in 2 lines of text, and make a 15 minute rambling video about it. There’s thousands of “how to install Whatever on CentOS” videos out there that, tell you to type “sudo yum install kdenlive” but take 15 minutes of boring voiceover to do it. Thanks. I’ll do without.

Q: What’s the hardest thing about starting making videos?

A: Feeling that you don’t have anything that anybody will want to watch, and it’ll just be stupid. Solve this by just looking at Youtube. 300 hours of video are uploaded to YouTube every minute. That’s almost 50 YEARS of video every day. And, sure, most of it, nobody ever watches. But I guarantee you have something more valuable to say than about 45 of those 50 years of content.


Finally, some links.

My personal YouTube channel:

The RDO Community channel:

kdenlive –

And I’ll probably eventually make a video to accompany this blog post. Because that would make sense. But I’ll try not to make it boring. Which could take a little longer.


Home automation, and youtube videos

(Note: If you’re reading this on Facebook, you’re missing half of the story. Please follow the link to my website to see the rest of the post.)

I’ve been tinkering with making videos for a while, and have been learning a lot over the last year or so. Last week I decided to make a video about something not work related, and picked home automation. As it turns out, what I have to say about home automation fits naturally into 4 (or possibly more) episodes.

Here’s the first one.

What I learned from doing this video:

  1. Lighting is important. This is way too dark
  2. Need to actually show more of what you’re talking about, than just talking about it.

And here’s my second one:

I’m very pleased with this second video, but I still learned a few things from it. I learned a lot about the tool I’m using (kdenlive) and what you can do to paste various tracks together. Also, watching it again, I’m sure I can do better on sound levels. There’s just too much difference between the tracks where I’m sitting at my desk, and when I’m doing to “on site” clips. The former, I’m using my desk mic, and the latter is using the onboard mic on my camera. My desk mic is a better mic, but I just have it turned down lower. I can probably also adjust this when I’m editing the video.

In my next episode, I’ll be talking about the Phillips Hue products, and in the fourth, the Osram/Sylvania Lightify product.


The Margin Is Too Narrow