Currently I’m involved in a friend’s project to develop his own Internet TV (webcast). At first I tried Darwin Streaming Server (free one) then we finally decide on using Wowza as streaming server (finally the paid one eh). DSS is open source project from Apple, which using source code similar to its paid version, Quick Time Streaming Server (QTSS). Just that QTSS is only available for Mac OS Server.
DSS
DSS is using protocol RTSP (Real Time Streaming Protocol). It’s installation on Linux Centos 5.5 is quite easy.
- I followed step by step procedure as in howtoforge.com site, it’s detailed already
- Then proceed to live streaming configuration, i found useful guidance in soundscreen.com site. First need to put file qtaccess (can be found in config folder /etc/dss/conf) inside movies main folder
- Edit qtaccess file and give write access to user group broadcaster as the following code:
<Limit WRITE>
AuthGroupFile /etc/dss/qtgroups
AuthUserFile /etc/dss/qtusers
require group broadcaster
</Limit>
- Run command qtpasswd as root then add new user in broadcaster group
- Configure encoder to broadcast to DSS. I’m using wirecast trial version
Go to menu broadcast, set:- encoder: DSL/Cable-MPEG4
- destination: Announce to Quicktime Streaming Server
- hostname: xx.xx.xx.xx
- file location: live.sdp
- username: xxxxx (created in step 4 above)
- passwd: xxxxx
This is automatic unicast where file sdp (session description protocol) is created automatically in the server. That’s why we need to give write access for broadcaster.
- Open quicktime to see streaming result. Go to file –> Open URL. Put yourserver address which will be similar like this: rtsp://yoursite.com/live.sdp
When we tried the live streaming via DSS, we faced issue with the picture. Especially when viewed in low bandwith, we got lag and the picture was no good. I thought it has something to do with the config especially related to buffering, but changing some value in file streamingserver.xml is no use.
Another thought is connection issue between encoder and DSS since both are not in the same network. We were trying to lower encoder bitrate, lower the quality but still the same problem. Is it just the nature of RTSP protocol ? When test using RTMP, we get lag in low bandwith but the picture is still good, not disturbed.

I tried to look for some clue in mailing list, found that many users are left DSS and use other application, like Wowza. Perhaps because there’s no further update since 2008 and also Apple seems to focus more on its HTTP Live Streaming, rather than its QTSS. I started to feel will be lack of support for DSS.
With the problem is still unsolved for DSS and time is running out, we decided to try Wowza trial version.
Wowza
First I download the rpm from the official site, and obtained trial license for 30 days via email.
Installation is much easier. Just follow the quick start guide.
In order to do live streaming:
1. install the live application examples or you can manually configure the application.xml.
2. set the encoder, for wirecast just follow this article.
First attempt, live streaming was run well. As expected, the quality of the picture is good. For test the streaming, I was using flash player from the examples for the playback.

To protect server from unauthorized access to broadcast, I use media security module. First download the files, and put the jar files in folder lib. Add authorized user in file conf/publish.password, then configure the same credential in the encoder as well. You’re good to go
Next step, we decided to try Jwplayer for playback. How do I do it ? See you in the next post

