Live multicast streaming using OSMF

In this article you will create a basic MediaFactory-driven Open Source Media Framework (OSMF) 1.5 player and use the updated F4M file format specification to play back a live multicast P2P stream with the help of the Adobe Flash Media Live Encoder, Adobe Flash Media Server 4, and the Multicast Configuration tool that comes with it. When used together, these tools provide a powerful, easy-to-implement solution for delivering video with enhanced reach and capabilities.

The new Multicast Configuration tool makes it easy to create an OSMF-ready F4M manifest file to use with any RTMP based video publishing tool, including the free Flash Media Live Encoder, and to work with the new RTMFP multicast application that ships with Adobe Flash Media Server.

Note: The version of this tool that ships with Flash Media Server 4 is outdated and will not work with the OSMF implementation of multicast. The Multicast Configuration tool included in the sample file for this article is the latest version and should be used in place of the one that ships with Flash Media Server 4.

This article covers the following topics:

• Using the Adobe Flash Media Server 4 Multicast Configuration tool
• Using an F4M external XML based file to define and load the appropriate content
• Implementing a multicast P2P stream via an F4M file

You can use Adobe Flash Builder 4 or Adobe Flash Professional CS5 to complete the steps in this article. After downloading the sample files for this article, follow the steps below to get started.

If you're using Flash Builder:

1. Choose File > Import > Flash Builder Project, select the sample ZIP file, and click Finish.
2. Open the file OSMF_MulticastF4MSample.as in the {SAMPLES_PROJECT}/src directory.
3. To set the class file as the application file to compile, right-click the OSMF_MulticastF4MSample.as file in the Package explorer and select Set As Default Application. This will add the project to the list of compilable applications. A blue dot on the file icon indicates that the file is the default application file.

If you're using Flash Professional:

1. Unzip the sample ZIP file.
2. In the OSMF_MulticastSample folder, open the src/OSMF_SampleTemplate.fla and save it as OSMF_MulticastF4MSample.fla.
3. Change the document class for the file (in the Property inspector) to OSMF_MulticastF4MSample.

Follow these steps to create the manifest file:

1. Open the {SAMPLES_PROJECT}/multicast_configurator/configurator.html file in a browser.

Note: The version of this tool that ships with Flash Media Server 4 is outdated and will not work with the OSMF implementation of multicast. The Multicast Configuration tool included in the sample file for this article is the latest version and should be used in place of the one that ships with Flash Media Server 4.

2. Once the Multicast Configuration tool is open, select Fusion for the multicast type.
3. For the RTMFP URI, enter rtmfp://localhost/multicast.
4. For the Stream Name, enter livestream.
5. For the Publish Password, enter realeyes.
6. Leave the Group Name at its default value: fms.multicast.example.
7. Leave the IP Multicast Address and Port at its default value, 224.0.0.254:30000 (see Figure 1).

8. Click Generate. This will create your Publisher Stream Name and allow you to save the manifest.f4m file.
9. Click Save Manifest File, and save the file as manifest.f4m in the {SAMPLES_PROJECT}/src/assets directory.
10. Click Copy to copy the Publisher Stream Name to the clipboard.

Now that you have a manifest file and the stream name, follow these steps to run the sample application:

1. Start Flash Media Live Encoder, and paste the Clipboard contents in the Stream setting.
2. Make sure the FMS URL is set to rtmp://[YOUR SERVER ADDRESS]/multicast (see Figure 2). You can click Connect to see that it works, although it's not necessary.

3. Return to Flash Professional or Flash Builder and open the {SAMPLES_PROJECT}/src/OSMF_MulticastF4MSample.as file.
4. In the initPlayer() method, change the parameter that is passed to the URLResource() constructor from DYNAMIC_STREAMING to MULTICAST_F4M:

5. Save the file and run the application.
6. Start Flash Media Live Encoder. After a few seconds, you should see the stream in your application (see Figure 3).

For more information on multicast and OSMF, see the Open Source Media Framework Developer's Guide (PDF, 1 MB) or visit the Open Source Media Framework website. You may also want to explore the sample projects and templates in the Video Technology Center and the Flash Media Server Developer Center.

To learn how to make a multicast video player without using the MediaFactory class and an F4M manifest file, read the companion article, Creating a simple multicast video player using OSMF.