Let’s Talk: Learning by Speaking

I did a talk “Hacking with Git” at BSides Glasgow. This was the first time I put myself out there to do a talk at a grown up event. Stop holding yourselves back! Learn, share and enjoy folks. You don’t have to become a public speaker. Blog, make youtube videos, stick a tool out there. Even if you only solve a problem that you have, you solved one of your problems.

This blog is about the things I learned along the way some of which might help you if you decide to go for something similar.

Here is a list of things that I learned or improved my abilities in during the process:

  • Using PowerPoint – I am god mode in the office suite (not a cool brag, but a brag there). I do not count PowerPoint when I say that. It is by far (for me) the worst bit of office. Bits of it are just plain inconsistent with how word and excel do things.
  • Recording videos of my desktop screen – I had tried this before. I definitely got better.
  • Video editing – I have never done this before.
  • New Python modules: CMD2, GIN, tqdm – I am so average at python. But I try and have made a few scripts in my time. These modules helped me and I am totally in love with CMD2. I plan to cover these things when I release the tools later. I have an ode to CMD2 at the end of the work blog here.
  • Preparing a talk for a limited time slot – I am pretty sloppy in my timing of tasks in general. I frequently talk to people so long that they are knackered and I am knackered. I am working on it 😀

Doing something beyond your current skill set is great. Not before it happens. Not during the moments of doubt. But now. Looking back at it I have nothing but positive feelings about it.

Hopefully the thoughts below help someone else add their voice to whatever event.

The Journey

After submitting the talk I went through a cycle of doubt. I avoided it. I procrastinated hard. Rather than making the slides for “Hacking with Git” I literally made a talk about procrastinating and delivered it at the local Defcon meetup DC44141.

Sorry to anyone who turned up for a real talk who saw “Professional Procrastinator”. I literally decided to do the talk about 8am on the day. Doing that was catharsis. It earned me confidence that I could just go talk rubbish for a while and the sky didn’t fall.

That talk ended with me nervously standing while this played:

A friend had asked me to put words to the Quincy theme in the days before Defcon. Instead of recording the demo videos for “hacking with git” I made this ^^^. While I was clearly procrastinating, I did learn some serious skills:

  • VLC
    • Can strip an audio track.
    • You can then replace that audio track.

Other things you can do with VLC that I learned recently is that you can convert video files from one format to another. It is really the “Swiss army knife” of video and audio conversion and there was me thinking it just played videos.

Appease the “Demo Gods”

If you have made a tool or you have a technique to talk about then you are going to need to demonstrate it. PoC or piss off right? A technical talk needs a demo. Ask the organisers if they have a reliable network for your needs.

Live hacking something takes some guts and you need more if it needs the Internet.

Even if you can demo something live consider what happens if it all goes to shit on the day. I suggest you record a video where it worked fine. You then only have to worry about this: does the venue have speakers?

Having offset the fear of the demo gods by deciding early that I had to make videos, I relocated my fear onto the venue not having a sound system. Turns out they did, turns out it was all fine.

Desktop Recording Software

I have dabbled with recording my desktop a few times. I had used “Screen Recorder” in the past on Windows. While it works, your options for free are minimal and you are limited to 5 minutes. This is literally why most videos I made before are < 5 minutes long.

Once before I have recorded a demo within Kali using “recordMyDesktop“. Which is fine if you are doing something only within Kali. The problem I had with that personally was my voice sounded like it was coming in from another universe in that video. To solve that I ended up purchasing a USB microphone (see below) which I could send straight into the VM which was dedicated. Absolutely solved the problem.

In the end I discovered a free screen recorder baked into Windows 10. Part of the XBOX app you can record anything. This worked well and had no time limits and meant I could record anything on a screen. If you find this Microsoft. Just cut the code out from the XBOX app and provide it as a dedicated app please kthnxbye.

Buying a Microphone

I looked around for a microphone which would improve over the gaming headset I have.


After reading numerous reviews I ended up choosing a “Snowball Blue“. This has a few settings and I have been able to use it for: Skype, Recording Guitar, Singing, and making videos.

It is pretty versatile for the ~£50 price tag. I am very happy with this piece of kit. It is the only item that cost money during the process and personally it has been money well spent.

Recordings for “Hacking with Git” had to happen late at night when my kids were asleep. Sadly in a small room which makes the audio worse than it should have been. Don’t judge the mic on the audio in the videos. It has performed much better when I get the chance to use it in my living room.

Video Editing

The tools that I needed to demonstrate take a few minutes to run. I could describe what they were doing much quicker than showing them completely. I figured it would be really boring for a crowd to watch a progress bar. So I needed to learn how to edit videos.

I found OpenShot which is free and *awesome*. It is available on Windows and Linux. I tried both platforms and they worked for me. The process was intuitive and there are plenty of tutorials on YouTube.

Preparing your talk for a limited time slot

While I have done a few talks before this was the first time I practised effectively. I recorded my efforts and did a bunch of dress rehearsals. I listened back to them and found the parts where I was waffling.

An initial run of the talk was a flabby 55 minutes. On the day it was a taught 38 minutes, AND I had added a bunch of slides since the ludicrously long one to boot. I said more in LESS time! Practising is apparently good; who has knew this?

PowerPoint has “presenter” view which comes when you have two monitors (laptop and external). The external will show the slides “to the audience” and the laptop screen will show presenter view as below:


The highlighted bit shows the time since the presentation started. This was a vital part of the practice sessions for me.

PowerPoint Presenter Mode Not Working

In the days before BSides I was getting stressed because my “presenter” mode was not launching. I could not find the solution until literally the day before BSides I discovered Nvidia are messing with me.

The option shown below is buried within “nView Desktop Manager” -> “Applications” and “Enhancements” menu:


Telling that option to do one made presenter view work perfectly. Just in time for me to get my practices done. I hope that little Nvidia trick saves someone the mad panic I had.

In conclusion;
I don’t know how to end blog posts.

C’est fin.


Leave a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.