nickkraakman

FFmpeg Cheat Sheet for 360º video

Brought to you by Headjack

 
FFmpeg is one of the most powerful tools for video transcoding and manipulation, but it's fairly complex and confusing to use. That's why I decided to create this cheat sheet which shows some of the most often used commands.

 
Let's start with some basics:

• ffmpeg calls the FFmpeg application in the command line window, could also be the full path to the FFmpeg binary or .exe file

tlasica

mkdir enhanced
for sp in *.jpg; do 
  echo "Converting Image: $sp"
  convert -auto-gamma -auto-level -normalize $sp "enhanced/$sp"
done

# from http://superuser.com/questions/370920/auto-image-enhance-for-ubuntu

zentetsukenz

Docker

Files and Folders.

|
|\_ app
|...
|\_ docker
| |

cecilemuller

How to setup Let's Encrypt for Nginx on Ubuntu 18.04 (including IPv6, HTTP/2 and A+ SLL rating)

---

Virtual hosts

Let's say you want to host domains first.com and second.com.

Create folders for their files:

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

ozydingo

module ActiveRecordExtension
  extend ActiveSupport::Concern

  module ClassMethods
    # Simple left join taking advantage of existing Rails & Arel code
    def left_joins(*args)
      inner_joins = self.joins(*args).arel.join_sources
      left_joins = inner_joins.map do |join|
        Arel::Nodes::OuterJoin.new(join.left, join.right)
      end

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

jhilden

When using react-rails for an internationalized app it makes a lot of sense to use i18n-js for translations, so that you can reuse the the strings from your rails app's .yml files (and all the tooling & services that exist around that).

When you use the prerender feature of react-rails you face 2 problems:

• The first is that translation.js & i18n.js from i18n-js need to be loaded inside the server-side JS prerendering processes, which is achieved by loading them inside the components.js.
• The second problem is the server processes need to be aware of the current locale of each HTTP request. This is done by adding a custom renderer and using the before_render hook to configure i18n-js accordingly for each render call.

joepie91

Don't use VPN services.

No, seriously, don't. You're probably reading this because you've asked what VPN service to use, and this is the answer.

Note: The content in this post does not apply to using VPN for their intended purpose; that is, as a virtual private (internal) network. It only applies to using it as a glorified proxy, which is what every third-party "VPN provider" does.

• A Russian translation of this article can be found here, contributed by Timur Demin.
• A Turkish translation can be found here, contributed by agyild.
• There's also this article about VPN services, which is honestly better written (and has more cat pictures!) than my article.

wvengen

Finding a Ruby memory leak using a time analysis

When developing a program in Ruby, you may sometimes encounter a memory leak. For a while now, Ruby has a facility to gather information about what objects are laying around: ObjectSpace.

There are several approaches one can take to debug a leak. This discusses a time-based approach, where a full memory dump is generated every, say, 5 minutes, during a time that the memory leak is showing up. Afterwards, one can look at all the objects, and find out which ones are staying around, causing the