Posts in the «Varia» Category

I bought kinect last weekend (right after releasing the official api) and I’m really amazed by its possibilities. New ideas keeps popping up each day, so stay tuned for more vids :)

From the Equation OCR front line…

Problem:

Splitting up handwritten calculations into single lines.

Algorithm description:

First map all the strokes on the y-axis. Then travel along the axis and record the the ink density (number of strokes underneath). Remember local maximums. If the density falls below a certain percentage (tolerance) of a last local maximum – insert a break line.

C# code:

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A TED talk presenting 4 ways sound affects people. Really interesting and much in the spirit of the post I wrote some time ago.

…you can look but you better not touch

Recently I’ve started working on a new project with my friend, so development of Falasol will be slower for a while. But fear not – I’m not going to give up on that. Falasol is my long term plan and what you can see so far is just a little part of it. I expect to get back to it next year. Meanwhile I’ll be occasionally posting stories from EqOCR development. You probably guessed that it will have something to do with equations & math – that is correct.

It was back at school when I discovered the charm of equations

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Winter wake up plan

Morning time-bomb

This setup was on my mind since I was a kid. But it was recently when I found the missing device to make it happen. Couldn’t believe when I saw it on the shelf at my usual shopping market: THE POWER STRIP TIMER.

So here it is: my geek’s dream wake-up scenario!

1. Evening

   • Set-up the turntable with an LP to be played in the morning
     Can be classical Vivaldi’s Four seasons, jazzy Amy Winehouse, Sabaton‘s battle-metal, chilled out Air, Fink Flooyd‘s psychedelia, dark vibes of Black Sabbath or what have you…
   .­
   • Start a quiet playlist from the laptop for good night via surrounding 5.1 speaker system
     Before falling asleep I usually have some wine & read a book in bed for a while. It’s nice to have something playing in the background. Happened few times that a song was able to ‘incept’ a cool dream :)

2. When sleeping

   The scheduled task on the laptop stops the lullaby music around 1.30 – 2 o’clock. REM sleep phase is better with as little outside stimulus as possible.

3. Morning

   7.30 – power cord timer kicks in

   • Sun-imitating lamp gently warms up
   • Vinyl gets a spin – for an extra kick the turntable is connected directly to amplifier =:]
   • After soaking up the music for a couple of minutes ain’t nothing gonna break my stride!

The LP usually finish about the time I leave. Automatic timer turns-off the lamp & turntable few minutes after.

How cool is that! :D

As promised last week I’m going to compare three methods of optimizing 2 ^ x calculation:

• Cache table – described in my previous post
• Polynomial approximation – suggested by Gregory, implemented here celt_exp2(…) and described here
• Compact IEEE-754 – 3 lines of code(!) described here and here

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Signal processing often requires moving between logarithmic & linear domains. In audio area we can talk about Octaves (logarithmic representation) and Frequencies (linear representation). Octave -> Frequency conversion corresponds to transformation x = 2 ^ x.

Most programming languages provide support for such calculation, for example Pow(a, b) in C#.
Those functions however tend to be time consuming. We can take advantage of the fact that in our case a = const = 2 and optimize the calculation.
Let’s start with equation:

a ^ ( b + c ) = a ^ b * a ^ c

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Yes, it has been 1 year since first release of Falasol. Time to stop for a second and take a look around: where it all has begun, how far has it gone by now and – what’s most exciting – where it’s heading.

Audio Engineering – research & innovate

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Recently I came upon two amazing documentaries. Both rock-related, but quite in a different manner ;) …read more >>