TJC’s gists

TJC / darken.sh

Created May 13, 2024 02:27

Darken an image with ImageMagick command line

	#!/bin/bash
	# Assumes .jpg files, fix that if you need to
	input="$1"
	output=$(basename -s .jpg "$input")
	output="${output}-darker.jpg"
	convert "$input" -fill black -colorize 35 -quality 90 "$output"

TJC / BenchTime.scala

Last active August 29, 2022 08:10

Benchmark ways of getting the time as seconds (Scala/Java)

	import java.time.Clock
	import java.time.Instant

	object BenchTime {
	val clock = Clock.systemUTC

	def bench(fn: () => Unit, iterations: Int = 1000000) = {
	val start = System.nanoTime
	Range(0,iterations).foreach( _ => fn() )
	val end = System.nanoTime

TJC / mysql-formatter.scala

Last active March 18, 2022 04:53

Mysql 5.7 compatible Scala/Java DateTimeFormatter expression

	import java.time._
	import java.time.format.{DateTimeFormatter, DateTimeFormatterBuilder}
	import java.time.temporal.ChronoField._

	// This one doesn't work, because Mysql can return five-digits of precision, if the sixth digit was 0
	val badFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSSSSS")


	val mysqlFormatter = new DateTimeFormatterBuilder().appendValue(YEAR, 4)
	.appendLiteral('-')

TJC / soulaflare.ino

Created March 2, 2021 13:04

Soulaflare twinkling LEDs code

	#include "Arduino.h"
	#include <stdlib.h>
	#include <FastLED.h>
	// Was built against version 3.1

	#define LEDPIN 0
	#define LEDPIN2 1
	#define LEDCOUNT 420
	// Unused unless I go for non-mirroring:
	#define LEDS_PER_STRIP 210

TJC / encode_x264_screen

Last active January 27, 2021 07:19

Re-encode OSX screen recording mov files to a tenth of their size

	#!/bin/bash
	# Requires ffmpeg - brew install ffmpeg
	if [[ -z "$1" ]]; then
	echo "Usage: $0 Screen\\ Recording\\ at\\ 2021-01-21.mov"
	exit 1
	fi
	basefilename=$(basename "$1" .mov)
	outputname="$basefilename.mp4"

	nice ffmpeg \

TJC / encode_x264

Created August 20, 2020 07:44

Encode a Quicktime file to MPEG4-x264

	#!/bin/bash
	docker container run -u 1000 --rm -v "$PWD:/mnt" \
	-v "$SRC:/input.mov:ro" \
	alfg/ffmpeg \
	nice ffmpeg -hide_banner \
	-loglevel warning \
	-i "/input.mov" \
	-c:v libx264 -preset medium -profile:v high -level 4.2 -crf 21 \
	"/mnt/output.mp4"

TJC / ButterflyActor.sc

Created July 10, 2020 04:45

How to test Akka Actor has stopped, when using scheduler?

	import java.util.concurrent.TimeUnit

	import akka.actor.typed.Behavior
	import akka.actor.typed.scaladsl.{Behaviors, TimerScheduler}
	import scala.concurrent.duration._

	class ButterflyActor(
	timers: TimerScheduler[TriggerMessage],
	) {

TJC / Basic auth.md

Last active October 3, 2022 21:39

(Simplified) HTTP Basic auth vs MAC signed auth

Client:

username = "alice"
secretKey = "12345"
method = GET
url = "https://example.com/private"

Client sends what it essentially this HTTP request:
method = GET
URL = "https://example.com/private"

TJC / RubyRunner.scala

Created June 20, 2019 04:43

Run a Ruby function from Scala and get the result.

	import org.jruby.embed.ScriptingContainer

	object RubyRunner {
	def rubyScript = io.Source.fromFile("demo.rb").mkString

	def main(args: Array[String]): Unit = {
	val result = runScript(rubyScript, "hello world")
	println(s"Ruby returned: $result")
	}

TJC / apparent_temp.scala

Last active February 8, 2019 06:15

apparent temperature equation

	// rh = relative humidity, in range from 0.0 to 1.0
	// t = temperature (celcius), typically in range from -10 to 50
	// v = wind speed (m/s)
	def vp(rh: Double, t: Double) = rh * 6.105 * Math.exp( (17.27 * t) / (237.7 + t))
	def at(t: Double, rh: Double, v: Double) = t + (0.33 * vp(rh, t)) - (0.7 * v) - 4.00

Toby Corkindale TJC