WatchPeopleCode

I recently got interested in streaming video on the web watching WatchPeopleCode and it’s been a fun experience screencasting, even if it did not work as I expected.

I did already subscribe to a youtube channel that screencasted some programming but watchpeoplecode is more entertaining and interactive, plus you can see interesting projects while being coded!

What I don’t really like is the ubiquity of Flash to stream those screencast, Youtube, Twich and the WatchPeopleCode mediaserver are Flash-only compatible. Basically if you want to stream something live on the web you use Flash.

Live streaming with HTML5

Running a search for live streaming with HTML5 returns some interesting results, like stackoverflow, github projects or wowza forum.

But the most important link is this: the Icecast project.

Icecast is a streaming media server which currently supports Ogg (Vorbis and Theora), Opus, WebM and MP3 audio streams.

Wait!? Theora? Webm? Icecast can do video?

Icecast

Turns out that Icecast can do Webm streaming from 2012 and this is very important because as you can see from theese tables with a single codec we can target the whopping 64.87% of device (both mobile and desktop). It’s a shame that another codec like Theora can do only 48.54% and is not available on Chrome for Android.

So with just one stream we can target a good share of our target, that’s good but we still know nothing about Webm streaming.

Digging in the Icecast docs reveal that is a piece of cake,

<mount>
        <mount-name>/arewestreamingyet.webm</mount-name>
        <username>yourusername</username>
        <password>yourpassword</password>        
</mount>

and we can do listener authentication and source authentication with another service.

The drawback is: a mount is a user streaming to Icecast, what if you want to add another mount? You must edit the config file, like every time you want to have multiple sources transmitting at the same time.

That sucks.

Maybe you can schedule streamers and just have one source or spin another icecast server when a streamer want to stream. Seems like Icecast is a no go.

Icecast-kh

Icecast is a stable project and it’s moving slow and steady but there is an experimental branch called kh that offer interesting features like wildcard mounts. This would be the end of our problem and we could just configure the serve to use authentication on wildcard mount.

This would change the config to something more like

<mount>
        <mount-name>/*/live.webm</mount-name>
        <authentication type="url">
                <option name="stream_auth" value="http://auth.example.org/source.php"/>
        </authentication>
</mount>

Ok good, we are ready. Let’s install the kh branch on our machine.

No packages, just source release, mmmmmm this is not what I expected.

Debian packaging system

After installing from source and configuring and trying the configuration and the streaming part and seeing everything work as expected I had a bad feeling about doing the same work every time I wanted to spin a new Icecast server (like a relay node to serve more user).

Maybe today I can learn something new, like how to make a Debian package.

The best resource I found is this set of slides, it contains most of the information that you need to get started and keep going.

Let’s go!

Prerequisites

Add a deb-src entry to your /etc/apt/sources.list file and run

apt-get update
apt-get build-dep icecast

Luckily for us the kh branch has the same requirements as the master branch.

Get the sources

The kh branch is published as a source package on Github, download it

wget https://github.com/karlheyes/icecast-kh/archive/icecast-2.4.0-kh3.tar.gz

and extract it

tar xzfv icecast-2.4.0-kh3.tar.gz

rename the directory to icecast-kh-2.4.0 and the source release to icecast-kh_2.4.0.orig.tar.gz

Scaffold the debian direcetory

Create a directory called debian, there will be placed the files describing the release info and packaging instructions. This is difficult and a time consuming process.

There are a lot of [tools][debian_tools] available to do this work, just use them

cd icecast-kh-2.4.0
dh_make

Edit the package metadata

In the previous step the command dh_make generated a bunch of files for us and placed them in the debian directory inside the icecast-kh-2.4.0, those files are the metadata attached to the package.

  • control: the real metadata about the package; deps, name, mantainer, project page
  • rules: how to build the package
  • copyright: info about the license and copyright
  • changelog: what changed from one release to another

you should edit them and place some useful info in there.

Just build it

But what we really care is the package itself, a tool like ansible can take care of installing the packages needed by our icecast-kh package. (the post is getting long so I decided to skip the previous part)

debuild -us -uc

If everything has gone as it should now there is a .deb file sitting in the parent directory and you can use that instead of building from sources relaying on a custom shell script.

Conclusion

This was the rigth time to learn something like packaging for Debian and the icecast project was what I needed to get started.

The docs on the Debian wiki are not that exhaustive and the most tedious part was getting the right info and trying what could work.

[debian_tools]: