Category: Javascript

Firefox has limited ability to handle H.264

The Firefox browser’s WebRTC and MediaRecorder functionality can handle H.264 (Advanced Video Codec) coding and decoding, but only with H.264’s constrained baseline profile. Other, higher, profiles just don’t work. And in Firefox’s WebRTC implementation (v87) attempts to use higher profiles fail more-or-less silently. Firefox works around all the patent issues with H.264 by using an automatically downloaded plugin called “OpenH264… Read more →

Web Beacon API

There’s a sweet little function in web browsers called the Web Beacon API.  It’s a simplified version of the XHR or Fetch API that does a fire-and-forget POST operation to a server. It’s nice for a few reasons.  First, browser Javascript (front-end Javascript) can use it without any need to process results coming back. Just call navigator.sendBeacon().  If your page… Read more →

Choropleths: color-coded maps showing data by state or other geography

A Choropleth is a colored map, typically showing information gathered by some kind of census. A well-known example is the New York Times’s COVID-19 map. Let’s say you have some data that’s coded by geographic area. For example, you might have a table showing the number of COVID cases per 100,000 people county by county in Massachusetts. It might look like… Read more →

Safari web extensions compatible with the rest of the world

About time! Apple announced in Safari 14, Web Extensions will be compatible with those used by Chromium and Firefox. They’ve bravely added a tool to XCode to help people convert their old Safari extensions to the what they call the new format. Most people probably won’t find that useful, having converted their Chromium extensions to work on Safari in the… Read more →

getDisplayMedia vs. getUserMedia

I’ve been messing around with the browser API navigator.mediaDevices.getDisplayMedia(). The question I hoped to answer: can I capture the content in some computer display surface and push it through the same sorts of process that I use with .getUserMedia()? I tested on Google Chrome 84. Answer: yes. It has some quirks. It doesn’t need, and indeed rejects, elaborate constraints.  {… Read more →

New Microsoft Edge rolls out to everybody this month

About time! the new Chromium-based Edge browser will show up on Windows 10 machines in this month’s update. For the cancelled Internet Explorer and Legacy Edge project people, I would have more sympathy if their work products hadn’t baffled software developers for a quarter-century. IE and old Edge were in the uncanny valley of compatibility. They worked well enough that… Read more →

JSDoc configured

JSDoc is a way to put programmer documentation in Javascript code. It’s in the tradition of Doxygen , Javadoc, and C#’s documentation comments. And what a sorry tradition that is. Tools for extracting that kind of documentation and making, well, documents from it are just atrocious. (Set me straight in a comment if I’m wrong.)  Sure, the various IDEs use… Read more →