Month: February 2022

Useful tools for video and audio editing

If you have your own YouTube channel or just make video or audio recordings using your mobile phone, it is good to know that there are editing tools that can help you remove undesired artifacts from recordings. For example, in an audio recording you’d probably want to remove or at least reduce a background noise. In a low resolution video you’d possibly want to have a better picture quality by making resolution higher if possible. Also, when you find a YouTube video that you think could have a better audio or video quality and this video has a Creative Commons Attribution license then you could download it, edit and upload again to YouTube. This post is exactly about such editing tools, or at least tools that I use myself and find very helpful. Most of them are free open-source tools except for video editing software.

Audio editing

Suppose, you have voice recordings that have a background noise. It would be nice to reduce it as much as possible without affecting the overall quality of the recording. There is a free tool that can do this and much more. It is called Audacity. Audacity is free and open-source professional grade digital audio editor and recording application software, available for Windows, macOS, Linux, and other Unix-like operating systems. I personally, use it to record myself playing drums. For this purpose I use two microphones and a two channel Behringer sound interface. After the recording was done I use Audacity to compress the recording and export it as mp3 file. But one of the features that is relevant to this post is the Noise Reduction functionality.

Real Life Example – Removing humming noise from Hamming’s lecture

For example, I used the Noise Reduction functionality in Audacity to remove background humming noise from the Dr. Richard Hamming’s 1990 lecture at NPS SGL. 

To do this I

Video editing – Super-resolution

Sometime videos can have a very low resolution, especially when they were recorded with old recording hardware, like old fashioned video cameras etc. But there is a solution to this problem which is called technically a super-resolution or upscaling. It allows to improve the resolution of the video by smoothing the pixels based on surrounding pixels. There are a number of implementations for an upscaling algorithms. Some of them like video2x upscaling software uses Deep Learning based upscaling implementation, for instance, NCNN implementation of waifu2x converter. Check out the GitHub repository of the video2x to learn how to use it.

Real Life Example – Upscaling Alexander Stepanov’s talk

For example, I used the video2x upscaling software based on Deep Learning model to upscale Alexander Stepanov: STL and Its Design Principles lecture from 320×200 to 640×400 resolution.

To do this I

  • Downloaded the original video (Creative Commons Attribution license (reuse allowed)
  • Used Audacity to add right mono channel to the original audio track which had only left mono channel available.
  • Used video2x software ran on a PC with Nvidia GPU to upscale the video from 320×200 to 640×400 resolution. Which took about 14 hours to process on that PC)
  • Used Movavi Video Editor to combine fixed audio track with the upscaled video
  • Uploaded upscaled video to YouTube.

You can try to play with the waifu2x Deep Learning powered upscaling website by uploading low resolution images and seeing the result by yourself.

Video editing

There are a number of free video editing tools out there, but from what I’ve seen the most useful ones that provide you with all required editing functionality are paid. And there is no workaround it. So I found this relatively inexpensive Movavi Video Editor software that I bought and use for all my video editing. Since I use mostly basic video editing, this tool suits me good. But if you are looking for more advanced capabilities, than you should check other versions of Movavi products or a different editor altogether.

How to download YouTube video for editing

If the YoutTube video has a Creative Commons Attribution license (reuse allowed) license you can use the video and edit it. There are non criminal ways to download such videos from YouTube.

Reading hundreds of books makes you a different person

This post is a summary of the hard copies of the books I read and recommend to read if you have similar interest as I do.

Exceptionally good books about Apollo Lunar Program

  1. Flight – Chris Kraft
  2. Left Brains for the Right Stuff – Hugh Blair-Smith
  3. Sunburst and Luminary – Don Eylse
  4. Apollo 8 – Jeffery Kluger
  5. Apollo 13 – Jim Lovell and Jeffery Kluger
  6. and much more here

Exceptionally good books about Deep Space Exploration

  1. Interstellar Age – Jim Bell
  2. Chasing New Horizons – Alan Stern and David Grinspoon
  3. Mars Rover Curiosity – Rob Manning
  4. The Right Kind of Crazy – Adam Steltzner
  5. and much more here

Exceptionally good books about Aviation

  1. Skunk Works – Ben R. Rich
  2. Have Blue and the F-117: Evolution of the “Stealth Fighter” – Albertt C. Piccirillo and David C. Aronstein
  3. The Power To Fly – Brian H. Rowe
  4. Herman The German – Gerhard Neumann
  5. and much more here

  1. The beginning of Infinity – David Deutsch
  2. The Music of the Primes – Marcus du Sautoy
  3. Prime Obsession – John Derbyshire
  4. Unknown Quantity – John Derbyshire
  5. Infinite Powers – Steven Strogatz
  6. The Joy of x – Steven Strogatz
  7. and much here and here and here

Exceptionally good books about Neuroscience

  1. Mind and The Cosmic Order – Charles Pinter
  2. On Intelligence – Jeff Hawkins

It’s a kind of magic. How kids can have fun with math.

source

The title of this post can seem strange to you. What mathematics has to do with magic? In my opinion, it depends on what feelings you took from math lessons at school, college or university. There are people who were frightened by math or bored by it. But there were also a lucky few who were able to spot something beautiful about math on their own or thanks to a good teacher. There’s another approach when math lessons cannot do the trick for you. Genrich Altshuller didn’t call it magic, but an encounter with a miracle. In the book How to become a genius. Life strategy of a creative person by Altshuller and Vertkin they mentioned that creative people at an early age encountered a miracle that heavily influenced their trajectory in life. If we take mathematics as an example, showing a kid that mathematics isn’t a boring, but actually interesting field to participate in can be such a decisive encounter with a miracle. And it seems to me the best way to appreciate the beauty of mathematics is by actually doing it.

To organize such an encounter for my daughter, I suggested her to create a YouTube Kids channel about mathematics for kids where she can upload videos on mathematics that kids can understand and relate too. She agreed and with a little help from me she was able to create two videos already. One about square numbers, that as their name suggest, have a shape of a square. Another one about a visual way of depicting the addition of two numbers that third graders are tasked to do at school. Let’s take for example, 111 + 37. It turns out that before kids start using column method addition it’s difficult for them to find the right answer. Using binary trees can visualize the composition of the two numbers and help a kid in summing these numbers together.

One interesting aspect of creating such short video clips is that it encourages a parent and a kid to work together to be ready to present the topic clearly in a way that a kid can understand what the video is about. Also, teaching something is one of the best ways to understand it yourself. One additional thing to mention is that the videos in the channel can cover topics that are not explained at school at all or taught only in upper grades, which provides a kid with an advantage of an early exposure to advanced and interesting mathematical topics.

This way of introducing kids to mathematics has a promise of removing boredom and rut repetition of solving similar exercises and shows kids that math has more to it than how it’s usually taught at school.