Liquidsoap – Multi-Bitrate DASH streaming configuration

This is an example of multi-bitrate DASH streaming configuration. In this example Liquidsoap will be configured to output three different MPEGTS video streams with various frame size, bitrates and one stereo audio MPEGTS stream all via  UDP.  This configuration can be used with the same setup as my previous blog post about setting up Liquidsoap MPEGTS DASH streaming. This example is using Liquidsoap v1.3.3.

Please note that this is more of a proof of concept than practical use. A hardware encoder plugin for Gstreamer would help.

Liquidsoap Configuration: MPEGTS via UDP for Multi-Bitrate DASH Streaming
set("log.stdout",true)
set("log.level",5)
set("gstreamer.debug_level",2)

set("frame.video.width",1280)
set("frame.video.height",720)
set("frame.video.samplerate",25)
set("gstreamer.add_borders", true)

input = single("/home/user/Videos/Test/test-1280x720-25fps.ogv")

#MPEGTS Output For DASH Streaming.
#You must start Shaka Packager first before starting Liquidsoap.

#Audio Channel. Port 5000
output.gstreamer.audio(
pipeline=
"audioconvert ! fdkaacenc bitrate=128000 ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5000
sync=true",
mksafe(input))

#Video Channels.
#360p Video at 600kbps. Port 5001
output.gstreamer.video(
pipeline=
"videoscale ! video/x-raw,width=480,height=360 ! videoconvert ! x264enc bitrate=600 key-int-max=72 pass=qual quantizer=20 tune
=zerolatency ! video/x-h264,profile=baseline ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5001 s
ync=true",
mksafe(input))

#480p Video at 1000kbps. Port 5002
output.gstreamer.video(
pipeline=
"videoscale ! video/x-raw,width=640,height=480 ! videoconvert ! x264enc bitrate=1000 key-int-max=72 pass=qual quantizer=20 tun
e=zerolatency ! video/x-h264,profile=main ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5002 sync
=true",
mksafe(input))

#720p Video at 3000kbps. Port 5003
output.gstreamer.video(
pipeline=
"videoscale ! video/x-raw,width=1280,height=720 ! videoconvert ! x264enc bitrate=3000 key-int-max=72 pass=qual quantizer=20 tu
ne=zerolatency ! video/x-h264,profile=main ! queue ! mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5003 syn
c=true",
mksafe(input))
Shaka Packager Command

The packager will take the UDP output from Liquidsoap and encapsulate it into the DASH format for playback via the Shaka Player or any other DASH player.

$packager \
'in=udp://127.0.0.1:5000?interface=127.0.0.1,stream=audio,init_segment=audio_init.mp4,segment_template=audio_$Number$.m4s' \
'in=udp://127.0.0.1:5001?interface=127.0.0.1,stream=video,init_segment=h264_360p_init.mp4,segment_template=h264_360p_$Number$.m4s' \
'in=udp://127.0.0.1:5002?interface=127.0.0.1,stream=video,init_segment=h264_480p_init.mp4,segment_template=h264_480p_$Number$.m4s' \
'in=udp://127.0.0.1:5003?interface=127.0.0.1,stream=video,init_segment=h264_720p_init.mp4,segment_template=h264_720p_$Number$.m4s' \
--temp_dir /home/user/tmp -mpd_output test_h264.mpd

That is pretty much all there is to it. You could add higher or lower frame size and bitrates if you wanted to. However, this configuration is pushing the limits of Liquidsoap.

Liquidsoap – Streaming DASH via UDP

So now that you have that magical UDP stream going, what to do with it? Why  not a DASH stream using the HTML5 Shaka Player? DASH is D)umb A)ss S)treaming H)ibbtyjibbty also known as the Hard Drive Killer. Cause you ain’t gunna be doing this on a mechanical drive for very long. Who thought the idea of creating millions of tiny files constantly was a good idea? We totally needed a new wheel worse than the one before it, right? I mean, who wants to install various different media players when you now can install various different browsers. Anyways, on to the show!

This is relatively straight forward with a lot of ambiguity.  The path of the stream is as follows; Liquidsoap output MPEGTS via UDP into Shaka Packager. Shaka Packager encapsulates the MPEGTS stream into a DASH stream for playback via a web server and HTML5 clients and other media players that support DASH (such as VLC).  You will want to download the Shaka Packager and Shaka Player.  This is a bit beyond the scope of this article oh how to get the Shaka Player compiled, but just trudge through it.

Liquidsoap Configuration

First part we need to configure Liquidsoap. This will be a basic configuration with the key parts being the output settings. Most notably and very important is that the Shaka Packager does not support the RTP container so it’s MPEGTS flat out.

set("log.stdout",true)
set("log.level",5)
set("gstreamer.debug_level",2)

set("frame.video.width",512)
set("frame.video.height",384)
set("frame.video.samplerate",25)
set("gstreamer.add_borders", true)

# The input file,
# any format supported by liquidsoap
input = single("/home/user/Videos/Test/video-720x576-25fps.ogv")

#MPEGTS via UDP Streaming (Shaka Packager doesn't support RTP container).
output.gstreamer.audio_video(
 video_pipeline=
 "videoconvert ! x264enc pass=qual quantizer=20 tune=zerolatency ! video/x-h264,profile=baseline ! queue ! muxer.",
 audio_pipeline=
 "audioconvert ! fdkaacenc bitrate=128000 ! queue ! muxer.",
 pipeline=
 "mpegtsmux alignment=7 name=muxer ! queue ! udpsink host=127.0.0.1 port=5000 sync=true",
 mksafe(input))

The Shaka Packager doesn’t support MPEGTS in RTP via UDP. If you encapsulate your MPEGTS stream via RTP you will get this error from packager.

[0522/093109:INFO:demuxer.cc(89)] Demuxer::Run() on file 'udp://127.0.0.1:5000?interface=127.0.0.1'.
[0522/093109:INFO:demuxer.cc(161)] Initialize Demuxer for file 'udp://127.0.0.1:5000?interface=127.0.0.1'.
[0522/093116:ERROR:demuxer.cc(207)] Not implemented reached in shaka::Status shaka::media::Demuxer::InitializeParser()
[0522/093116:ERROR:packager_main.cc(477)] Packaging Error: 4 (UNIMPLEMENTED): Container not supported.
Shaka Packager

The Shaka Packager is just a fairly simple program. I just downloaded the binaries and put them in my /home/user/bin/.

In this scenario and since we are using UDP as the transport, the Shaka Packager will need to be started first and listening for the MPEGTS stream packets BEFORE Liquidsoap starts. This is an important and key step in this.

For this example we will start the Shaka Packager program in the root web directory of our website the DASH manifest and media files will be created in this directory.

[/var/www/html/]$packager \
 'in=udp://127.0.0.1:5000interface=127.0.0.1,stream=audio,init_segment=audio_init.mp4,segment_template=audio_$Number$.m4s'  \ 'in=udp://127.0.0.1:5000interface=127.0.0.1,stream=video,init_segment=h264_384p_init.mp4,segment_template=h264_384p_$Number$.m4s' \
--mpd_output h264.mpd

The Shaka Packager is fairly straight forward. Since the Audio and Video is in a single stream we call both streams for our audio and video.  It will create all the necessary media files and the MPD manifest file in the current directory.  Once Shaka Packager is running it will just print out that it’s initialized the demuxer for input from the UDP stream.  It is now time to start Liquidsoap.

Once you start Liquidsoap, the Shaka Packager doesn’t announce anything so it is difficult to know that it is working.  With this current setup after about a minute or two the Shaka Packager will spit an error similar to this.

[0522/095415:WARNING:representation.cc(384)] Found a gap of size 343 > kRoundingErrorGrace (5). The new segment starts at 324900702 but the previous segment ends at 324900359.

If you get this error then you know it’s working. As long as the gap size doesn’t grow the stream should be good.

Shaka Player

So now that you got the stream files all going, you could point VLC to the http://localhost/h264.mpd file and VLC should be happy to play the DASH stream.  But now onto the Shaka Player. It is beyond the scope of me to tell you how to install it. But I feel you.

Following the basic guide for the Shaka Player, just copy the shaka-player.compiled.js script into the same directory as the media files. Then create a simple index.html file.

<!DOCTYPE html>
<html>
<head>
<!-- Shaka Player compiled library: -->
<script src="shaka-player.compiled.js"></script>
<!-- Your application source: -->
<script src="myapp.js"></script>
</head>
<body>
<video id="video" width="640" poster="//shaka-player-demo.appspot.com/assets/poster.jpg" controls autoplay></video>
</body>
</html>

Then you will want to create the myapp.js file which is essentially a kind of configuration and initialization file for the Shaka Player. This is the file that points to the DASH manifest (MPD) file that the Packager has created.

// myapp.js

var manifestUri = '//localhost/h264.mpd';

function initApp() {
// Install built-in polyfills to patch browser incompatibilities.
shaka.polyfill.installAll();

// Check to see if the browser supports the basic APIs Shaka needs.
if (shaka.Player.isBrowserSupported()) {
// Everything looks good!
initPlayer();
} else {
// This browser does not have the minimum set of APIs we need.
console.error('Browser not supported!');
}
}

function initPlayer() {
// Create a Player instance.
var video = document.getElementById('video');
var player = new shaka.Player(video);

// Attach player to the window to make it easy to access in the JS console.
window.player = player;

// Listen for error events.
player.addEventListener('error', onErrorEvent);

// Try to load a manifest.
// This is an asynchronous process.
player.load(manifestUri).then(function() {
// This runs if the asynchronous load is successful.
console.log('The video has now been loaded!');
}).catch(onError); // onError is executed if the asynchronous load fails.
}

function onErrorEvent(event) {
// Extract the shaka.util.Error object from the event.
onError(event.detail);
}

function onError(error) {
// Log the error.
console.error('Error code', error.code, 'object', error);
}

document.addEventListener('DOMContentLoaded', initApp);

You should now have a functioning DASH stream with Liquidsoap.  This is a basic example and can be expanded on with enough CPU resources and x264 hardware encoding via GStreamer.  The idea of DASH is to have multiple bit rates at various frame sizes so that you can cover a wide variety of client types and connectivity.  I haven’t tested this out, but you could start with a larger frame size setting in Liquidsoap then create multiple video outputs with the various frame sizes. You will only need one audio output.

Have fun!

KiwiIRC – How To Properly Start On Boot Under Linux

Ignore the ding dongs telling you to use systemd. It will work, but the pid and log files will not be touched. That’s not very helpful when using the start up script to restart, or reconfig KiwiIRC. Plus it’s handy to have log files to know what the service is doing. Crontab for the win!

Under the user that KiwiIRC is running.

$crontab -e

Then enter this line with the full path to where KiwiIRC is installed.

@reboot /home/user/bin/KiwiIRC/kiwi start

KiwiIRC will now automatically start on boot of the server and the pid and log files will be properly written to.

Notice: This version of KiwiIRC is considerably outdated and unsupported I highly recommend upgrading to the latest version.  This configuration will not work with the latest version as it is entirely different.

Sendmail – How To Deliver To IPv4 Address Per Domain

More mail servers are now accepted e-mail via IPv6.  I have had a dynamically assigned IPv6 block on my Comcast Business account for awhile and I have let Sendmail decide what to use, and about 99.9% of mail is delivered via IPv4.  Just recently it appears Comcast has assigned an IPv6 MX record for their mail server. My Sendmail picked this up and now happily attempts to deliver the mail via the IPv6 address.  Unfortunately, it is immediately rejected due to the IPv6 address does not have a PTR record.  Of course Comcast Business is far behind on assigning IPv6 blocks so there is no way to get a static IPv6 block and a PTR entry.

How do I get Sendmail to deliver to the IPv4 address instead?  It’s called the mailertable feature..  You will need this feature enabled in your sendmail.mc file. Most likely it is already enabled.

/etc/mail/sendmail.mc

FEATURE(`mailertable')

 

Now you need to make an entry into the mailertable file with the domain and IPv4 address. In order to get the IPv4 MX address for the domain you can do so by using the host command. We first look up the main domain name to get the MX records. Then lookup the IPv4 address for the MX record.  We now have the IPv4 address to where we want to deliver the mail.

[root@superstar ~]# host comcast.net
comcast.net has address 69.252.80.75
comcast.net mail is handled by 5 mx2.comcast.net.
comcast.net mail is handled by 5 mx1.comcast.net.
[root@superstar ~]# host mx1.comcast.net
mx1.comcast.net has address 96.114.157.80
mx1.comcast.net has IPv6 address 2001:558:fe16:1b::15

 

We now add these lines to our mailertable file.

/etc/mail/mailertable

.comcast.net     esmtp:[96.114.157.80]
comcast.net     esmtp:[96.114.157.80]

 

Don’t forget to issue make to update the db files for Sendmail to see the changes to the mailertable file. And then restart Sendmail.  It will now deliver to the specific IPv4 address.

[root@superstar mail]# make
[root@superstar mail]# service sendmail restart
Redirecting to /bin/systemctl restart  sendmail.service
You bet there is a catch! If the IPv4 address changes, you will need to manually make the change.
That’s it all there is to this. Sendmail is now delivering to the IPv4 address.