Minimal example: transcode from MP3 to WMA:
ffmpeg -i input.mp3 output.wma
You can get the list of supported formats with:
ffmpeg -formats
You can get the list of installed codecs with:
# Convert .flac to .mp3 (lossless) | |
for f in *.flac; do ffmpeg -i "$f" -aq 1 "${f%flac}mp3"; done | |
# Convert .flac to .mp3, compress to ~ 120k | |
for f in *.flac; do ffmpeg -i "$f" -aq 5 "${f%flac}mp3"; done | |
# Convert .flac to mp3, compress to ~ 128k | |
for f in *.flac; do ffmpeg -i "$f" -b:a 128k "${f%flac}mp3"; done | |
# Convert .flac to mp3, compress to variable 190k |
Examples of getting certificates from Let's Encrypt working on Apache, NGINX and Node.js servers.
I chose to use the manual method, you have to make a file available to verify you own the domain. Follow the commands from running
git clone https://github.com/letsencrypt/letsencrypt
cd letsencrypt
$ brew install dnsmasq
...
$ cp /usr/local/opt/dnsmasq/dnsmasq.conf.example /usr/local/etc/dnsmasq.conf
/usr/local/etc/dnsmasq.conf
address=/local/127.0.0.1
State machines are everywhere in interactive systems, but they're rarely defined clearly and explicitly. Given some big blob of code including implicit state machines, which transitions are possible and under what conditions? What effects take place on what transitions?
There are existing design patterns for state machines, but all the patterns I've seen complect side effects with the structure of the state machine itself. Instances of these patterns are difficult to test without mocking, and they end up with more dependencies. Worse, the classic patterns compose poorly: hierarchical state machines are typically not straightforward extensions. The functional programming world has solutions, but they don't transpose neatly enough to be broadly usable in mainstream languages.
Here I present a composable pattern for pure state machiness with effects,
const difference = (a1, a2) => a1.filter(x => a2.indexOf(x) == -1)
Today, single page web apps are driving many websites that we use each and every day. Instead of having your browser request a new web page for each and every action you perform on a web page, single page web apps may load all in one request to smoothly and quickly transition with every action you perform.
When building single page web apps, you may decide to retrieve all of the HTML, CSS and Javascript with one single page load or dynamically load these resources as the user moves about your site. Either way, it can be a pain to bundle all of these assets together for the end user to download from your web server. This is where webpack comes into play.
webpack does all of the heavy lifting bundling all of your HTML, CSS and Javascript together. If you write your site all from scratch or depend on dependencies from npm, webpack takes care of packaging it all together for you. It has the ability to take your single page web app, cut out all of the code you don't need, then packa
Direct copy of pre-encoded file:
$ ffmpeg -i filename.mp4 -codec: copy -start_number 0 -hls_time 10 -hls_list_size 0 -f hls filename.m3u8