I have just released my first MicroISV application SAM Contacts.

It’s a simple and easy to use contact manager application with some unique features like tag clouds and Google maps.

I’ve been using Asterisk for years and never really wanted to use Skype, but since many of my friends do, I decided to have a go. It was quite unthinkable to use Skype separately from Asterisk, I mean I have all of my communication unified through Asterisk box, and now this thing called Skype had to be exempted from the rest. No way. So I was looking for a way to connect them. Skype uses proprietary protocol for communication, and the company DOES NOT ALLOW reverse engineering. Therefore, there was no “clean” way of making a Skype channel for Asterisk, like it was done with Cisco’s Skinny protocol. Well, how do we connect then?

There are two possible approaches: hardware and software one. Hardware approach would require some “Skype to phone” adapter “thingy” that connects to Windows PC via USB, and has FXO and FXS, through which it then connects to Asterisk via Sipura 3000, or what have you. I excluded the “enterprise level multi-channel skype gateways” because they are too expensive. I mentioned Windows PC because I had one up and running 24/7, as described in the previous post.

Available software

I decided upon software approach, since I did have available Windows PC, and didn’t want additional “Skype thingy” and addional Sipura. Here are my choices:

• ChanSkype, Asterisk channel driver for Skype. It sounds great but has one major flaw: it requires X server and I want my Asterisk box to run clean without any additional burdening services.
• PSGx, Personal Skype to H.323/SIP gateway. I have been using it for a while, and it turned out to be buggy and unreliable.
• Uplink Skype to SIP adapter is what I am using right now.

Windows installation

You can download Uplink Skype to SIP here.

When you run the setup program you get a dialog like this:

Then you just let Windows install the unsigned drivers. These audio drivers are the heart of the program. The program sets up these drivers to work as Skype’s headset, and then translates the sound coming from them into SIP packets:

As shown in the figure  (Skype audio settings), the sound coming from you, through the microphone, is getting into SIP packets via Uplink’s sound driver, and vice versa for the sound of the speaker. There are similar hacks with the actual microphone and speakers, that is hardware ones, to find out more check out Grynx’s blog.

Uplink settings

Account settings:

• SIP number and password : your Skype number/nickname and password that are the same as in sip.conf.

• Server: Asterisk IP address.

Network settings:

• Listening local port: default for these settings is not the same as Asterisk’s default SIP and RTP settings, so pay attention.
• Public IP address of your Asterisk box..
• External SIP and external RTP also differ from Asterisk’s default settings.

Asterisk Skype2SIP configuration

here’s my configuration:

sip.conf

[tokenskype]
type=friend
host=dynamic
nat=yes
username=tokenskype
secret=tokenskype
canreinvite=no
insecure=very
dtmfmode=inband
disallow=all
allow=alaw
context=incoming_skype
callgroup=2
pickupgroup=2
canreinvite=yes
qualify=yes

extensions.conf

exten => 711,1,SetCallerID(${MY_ID})
exten => 711,n,Dial(SIP/echo123@tokenskype,40,rwW)
exten => 711,n,Hangup()

Here you see extension for Skype’s echo test. Buddies should be added the same way.

Putting it all to work

After everything is installed and upon starting Skype2SIP you should see something like this:

And if you do “sip show peers” in Asterisk’s prompt:

Calling test echo extension:

and Uplink’s screen shows (talking for 52 sec, then hanging up, from 9:41 to 10:33):

Now just add a few buddies, give them extension numbers, and you’re set to talk…

Just a few final words:

• I made a context for incoming Skype calls “incoming_skype”, as you see in sip.conf excerpt . There you can customize it to dial a specific phone, softphone, send e-mail or whatever…
• Skype video calls can not be routed through Asterisk, but Asterisk is capable of conducting video calls, which is an entirely new topic…

So you gathered a lot of movies and music on your hard drives and want to “consume” them from something more convenient than monitor screen and desktop speakers, (or God forbid, laptop ones). Your new plasma/LCD TV and 5.1/7.1 sound system are just waiting for all that digital content to flow their way. Burning CDs and DVDs to watch the movies and listen to the music is just such a tedious task. And what about podcasts, YouTube, recording live TV, playing games, or just plain surfing the web on your new screen, wouldn’t that be nice?

Well there are some consumer electronic devices that do some of the mentioned, but I haven’t heard of a single device that is capable of all that. So I built one. From a PC, of course.

What are the main tasks this system is supposed to perform:

• Have all music in one place - iTunes
• Listen to the music - iTunes
• Share music library among computers in the house - iTunes
• Watch podcasts on TV - iTunes.
• Carry music around - iPod and iTunes
• Watch the movies :
  • rent movies
  • copy them onto HDD - DVD Decrypter
  • watch whenever I want to - PowerDVD and K-Lite Codec Pack
  • delete from HDD
• Record live TV - Beyond TV
• Surf the web - Firefox
• Manage photos on TV - card reader and any photo application
• Trasfer movies onto iPod - Videora
• Play games on TV - this is a PC, so no problem
• e-mail - Outlook, Thunderbird…
• watch presentations, touch up a document while lying on the sofa - MS Office, OpenOffice
• serve all of the above to other PCs in the house - just get additional UPS and keep the system running

Software infrastructure

I instantly dismissed “Windows Media Centre” PC when I realized that:

Media centre uses a new file format called DVR-MS. DVR-MS creates an MPEG-2 file that includes metadata about the recorded program to be stored. ((source http://www.microsoft.com/windowsxp/mediacenter/evaluation/faq.mspx))

Do we really need another proprietary format?

MythTV is great but it runs on Linux, and iTunes (my choice of audio library software) doesn’t, so that is out..

I finally decided upon plain Windows XP with some additional software, as follows:

• iTunes for music and podcasts (I own multiple iPods so that was a quick decision).
• PowerDVD (with additional codecs for DivX and such) for watching movies.
• Beyond TV for recording live TV. This was necessary because the software that came with Hauppage TV card was buggy and used up too many resources. Beyond TV is great, runs in background, and has sleek interface with good “from a couch” visibility.
• Dvd Decrypter for transferring DVD movies to hard drive to watch at my convenience.
• Videora for converting movies to iPod H.264 format. It has a nice feature that anything copied to a designated folder gets converted to ipod format and inserted into iTunes library automatically.
• K-Lite Codec Pack, a set of filters needed for encoding and decoding (playing) audio and video formats.

Hardware infrastructure

We need three basic parts : audio, video and TV.

Video part

Unless playing games is your top priority, video card does not have to be a top-notch. I have GeForce 8600, NVIDIA’s mid-range card, enough for home theater requirements and occasional CivIV session. Since my LCD TV (Sony KLV-S40) has only VGA input, I needed DVI to VGA adapter, as shown in the figure above.

TV also has a HDMI ((High-Definition Multimedia Interface transmits uncompressed video and audio streams to designated interface)) . This one, unfortunately, as it is the case with almost all new HDMI interfaces, comes coupled with HDCP technology:

High-bandwidth Digital Content Protection (HDCP) is a form of digital copy protection developed by Intel Corporation to protect digital audio and video content as it travels across DisplayPort, Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI), Gigabit Video Interface (GVIF), or Unified Display Interface (UDI) connections. The specification is proprietary, and implementing HDCP requires a license.
Pre-2005 HDMI and DVI formats already displayed HD resolutions that HDCP provides but without any digital protection. As HDCP is being introduced as mainstream, plasma, LCD TVs, monitors and projectors with HDMI and DVI displays (all models pre 2005) will not be able to display HDCP material. ((source: http://en.wikipedia.org/wiki/HDCP))

Digital content protection in your own home, as integral part of devices you paid good money for, that seems like “Big Brother” to me, and I will try to avoid buying any more such devices. I just don’t like paying for something I didn’t want in the first place…

Audio part

For audio card I choose M-Audio Revolution 5.1. It provides channel-accurate surround reproduction and high-definition audio up to 192kHz at 24-bit resolution. I use card’s digital output making it work in Direct mode, where no other settings may be adjusted.

That’s not a problem, since the card is then connected, via S/PDIF, to Panasonic SAXR30 digital receiver, which does all the sound processing for it, whether it be DTS, Dolby Digital, Dolbly PrologicII, or whatever.

So setting different sound profiles or adjusting volume is done via receiver.

TV part

I receive only analogue TV so this part was easy: Hauppage WinTV-PVR-350 TV recording card with built-in both hardware MPEG decoder and encoder for watching and recording TV, respectively.

Connectivity

I have wired and wireless Ethernet all through the house, so plugging this Home Theatre PC to the switch made all the content available.

Peripherals

Ergonomics and ease of use is what drove this “project”. If my husband and kids had to choose between eighteen remote controls, and their respective dialects, to achieve a simple task…well…enough said. I wanted ONE device to rule them all, and ended up with three:

Logitech Harmony 895, advanced remote control that incorporates both IR (infra red) and RF (radio frequency) to take full control of all devices, even when they are out of sight. It replaced all of my remote controls by either learning their IR codes or downloading specifications from the internet. Nice thing is that it can combine several operations to accomplish a single action, like when I press the action “Watch movie” it changes TV’s source from TV to PC, sets receiver’s source to PC and changes settings to Dolby II surround , all with one click.

Logitech diNovo Edge bluetooth rechargeable keyboard with integrated laptop-like mouse pad. Comes in handy for surfing the net or searching through music library.

Logitech MX Revolution Cordless Laser Mouse is the most used amongst them, to be exact 80% of the time .

Thus, is my task accomplished? I think so. I have a device that serves and plays digital content, records live TV, does podcasts, is a gaming console and does everything else that a full blown PC does, unlike all those crippled proprietary Media Center devices.

I rest my case.