## A Greasemonkey/Tampermonkey script to down-mix YouTube videos to mono

You may have had the annoyance of trying to watch a YouTube video with only one ear because the audio was recorded as mono but exported to YouTube in stereo. I too was frustrated with this issue tonight so I wrote a quick script to remedy it. It can be used by Tampermonkey (Chrome) and Greasemonkey (Firefox).

Continue reading → Fix YouTube Mono (One Ear) Audio

## Generate List of Integers Differing From Input By 1 bit

To make a hypercube graph it is necessary to connect vertices that have ID’s that differ by 1 bit. I did not readily find any algorithms to do this, so here is my own written in JavaScript.

```let pad = (str, max) => {
return str.length < max ? pad("0" + str, max) : str;
};

let generateDifferByOne = (input, numBits) => {
let inputBits = pad((input).toString(2), numBits).split("").reverse();
let allDiffer = [];

for(let b = 0; b < numBits; b++){
if(inputBits[b] === "0"){
let newNum = inputBits.slice();
newNum[b] = "1";
allDiffer.push(parseInt(newNum.reverse().join(""), 2));
}
}

return allDiffer;
};
```

The method above does not generate any values lower than the input, but that can be fixed by adding an “else” inside the loop to switch 1’s to 0’s and push it into allDiffer.

## Dynamically Set Deep Dictionary Values

If you have ever needed to set some values of a dictionary in JavaScript or PHP, then you know that you have to do something like `myArray[a][b][c] = 0`. But what if we don’t know that the subkeys will be “a->b->c” until runtime? You would need a way to index into the dictionary dynamically and return the resulting modified dictionary. Below are code snippets in JavaScript and PHP that do exactly that.

Continue reading → Dynamically Set Deep Dictionary Values

## Regex to Make Text Links HTML Links

### Regex used to select and replace URLs in plain text with clickable links

`(https?://([-\w\.]+)+(:\d+)?(/([\w/_\.%-=#~\@!]*(\?\S+)?)?)?)`

### PHP

```\$regex = '(https?://([-\w\.]+)+(:\d+)?(/([\w/_\.%-=#~\@!]*(\?\S+)?)?)?)';
\$text = mb_ereg_replace(\$regex, '<a href="\\1">\\1</a>', \$text);```

## PHP PDO Verify DB

If you have ever needed to verify, create, or update database schema then you will probably like this snippet (ok, it is a little long to call a snippet). This code assumes that you have a class with a shared PDO.

Continue reading → PHP PDO Verify DB

## Python Multiprocessing

The following code will enable you to implement multiprocessing in any Python project that contains a for loop. Take your for loop that has a long-running function in it and replace “for i in iterable” with your for loop conditions. Change “function_name” to the name of the function that will be executed. Change the list of function arguments to what you need.

```import multiprocessing
number_cores = multiprocessing.cpu_count()
pool = multiprocessing.Pool(processes=number_cores)
r = [pool.apply_async(function_name, args=(function_arg1, function_arg2)) for i in iterable]
output = [p.get() for p in r]
pool.terminate()```

The above code would be the multiprocessing implementation of the following.

```output = []
for i in iterable:
output += function_name(function_arg1, function_arg2)```