An update.

I took a raw video as an experiment, and used ffmpeg to crop to a sub-frame and change the output resolution. I can "top and tail" by taking opening and closing sequence videos and gluing them together.

So I think ffmpeg does what I need for now.

Is anyone interested in seeing it?

@christianp Here:

I'll probably re-record this, it was literally an unrehearsed, unscripted hack to check the process.

All comments, criticisms, thoughts, and suggestions welcome.

@ColinTheMathmo cool!
A technical note: the camera seems to keep adjusting focus. There's an app called Open Camera ( that lets you lock the focus while recording


@ColinTheMathmo it would make a good entry in the lock-down math-off 😉

@christianp I still don't really know what it is I'm supposed to do about that. I don't know what you mean by a pitch, why you're selecting two, why you're getting people to vote, ...

I just don't understand people.

But we knew that.

@ColinTheMathmo did you follow the math-offs in 2019 and 2018?
A "pitch" is just an essay or a video or a paragraph about some interesting maths. Like a Big MathsJam talk in a blog post.
The competition element is just to provoke interest - doesn't mean anything, really. Readers will be asked to vote for the pitch that made them go "Aha!" the loudest.

@ColinTheMathmo The root of it was "how can I get my friends to show me cool bits of maths?"

@christianp Hmm. You are using the word "pitch" in a manner almost completely different from how it is used in business, and that confuses me. And I've never liked the idea of getting people to vote between this and that in this context.

Having said which, I completely understand that it generates engagement, and that's where the "I really don't understand people" bit comes.

I find it hard to do things like this "as a bit of fun." People have often told me to lighten up, but <fx: shrug />

Sign in to participate in the conversation

The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!