David Simpson

Sometimes I need to concatenate several mp4 files together. ffmpeg is a good tool for this job.

On OSX, it’s easy to install using Homebrew:

brew install ffmpeg

If you have MP4 files, these could be losslessly concatenated by first transcoding them to mpeg transport streams.
Source – https://trac.ffmpeg.org/wiki/Concatenate

Say we have 2 mp4 files to concatenate or join together, first we transcode each of these into an intermediate format:

ffmpeg -i input1.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate1.ts
ffmpeg -i input2.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts intermediate2.ts

After that we can concatenate these together using the following:

ffmpeg -i "concat:intermediate1.ts|intermediate2.ts" -c copy -bsf:a aac_adtstoasc output.mp4

For more file, just piple separate the additional files here: "concat:intermediate1.ts|intermediate2.ts"

I recently read Use Raspberry Pi to Measure Broadband Speeds to Hold Your ISP Accountable on Make and realised that this was an excellent candidate for monitoring my somewhat unstable Virgin Media connection.

I use an OpenWRT router (running a VPN to add a little bit of privacy), so I could adapt the article to run on the router rather than an attached Raspberry Pi.

Here are the steps adapted for OpenWRT…
Continue reading…

I’ve tried to add styles to the Confluence editor. It wouldn’t take them. Perhaps one of Atlassian’s values is “Don’t f@@k the editor”.

<web-resource name="editor-scripts" key="editor-scripts">
  <resource name="editor-templates.js" type="download" 
    location="assets/js/editor-templates.js" />
  <!-- // TODO: Check whether I need a context here -->
</web-resource>

<web-resource name="editor-styles" key="editor-styles">
  <resource name="css/confluence-editor.css" type="download" 
    location="assets/css/confluence-editor.css"/>
  
  <dependency>com.atlassian.confluence.plugins:confluence-editor-plugins</dependency>
  <dependency>${project.groupId}.${project.artifactId}:editor-scripts</dependency>
  <dependency>com.atlassian.auiplugin:ajs</dependency>
  <context>editor</context>
  <!-- // TODO: Check whether I need all the dependencies here -->
</web-resource>

My confluence-editor.css styles just wouldn’t be accepted. Javascript injection worked just fine though. Perhaps I could use JS to inject my styles?

Yup. Adding this to my editor-templates.js file worked a treat:

var editorCss = AJS.params.staticResourceUrlPrefix 
  + '/download/resources/me.davidsimpson.confluence.addon.awesome-addon'
  + ':editor-styles/css/confluence-editor.css';

if (AJS.params.isDevMode) {
  editorCss = editorCss + '?_=' + Date.now();
}

$('#wysiwygTextarea_ifr').contents().find('head').append(
  '<link type="text/css" rel="stylesheet" href="' + editorCss + '" media="all">'
);

Note the cache busting timestamp for local development.

I’ve been looking at the network traffic and noticed a lot of calls from one machine to an address I’d never heard of: all-systems.mcast.net

Information on this seemed somewhat sketchy until I spotted this page on Multicast Addresses

ALL-SYSTEMS.MCAST.NET
224.0.0.1 All systems on the local subnet.

What? All the machines on my local network? Really?

Pinging it confirmed this:

$ ping all-systems.mcast.net
PING all-systems.mcast.net (224.0.0.1): 56 data bytes
64 bytes from 192.168.1.136: icmp_seq=0 ttl=64 time=0.103 ms
64 bytes from 192.168.1.153: icmp_seq=0 ttl=64 time=14.788 ms
64 bytes from 192.168.1.120: icmp_seq=0 ttl=64 time=239.376 ms
64 bytes from 192.168.1.162: icmp_seq=0 ttl=64 time=256.191 ms
...
64 bytes from 192.168.1.119: icmp_seq=1 ttl=64 time=50.762 ms

The machine accessing all-systems.mcast.net is running a DLNA server, so it appears to be broadcasting its presence to all the machines on the local network. Panic over.

Today I had the need for a macro to embed a JSFiddle in Atlassian Confluence. I checked, none exist.

No matter. I forked Gister: GitHub Gist Macro for Confluence, changed some code and few minutes later got this:

It seems to work nicely.

• If you want it, get it here
• If it doesn’t work, post an issue
• If you like it, leave a comment & say so. Or buy me a pot of tea: