Openworld FlashPresenter - Using HTTP Streaming technology for video/audio delivery

When HTTP Straming should be used.

For sure, the most reliable Flash video/audio stream delivery technology is based on RTMP protocol. This technology lets user to navigate across the stream with very short delays, required only for stream buffering at the client side. Using RTMP technology client side receives the video/audio stream in the real time, i.e. with the speed, defined by the video bitrate. Thus, the Internet traffic is as low as possible in this case.

The main RTMP technology disadvantage is the special server-side software need, as well as the price of this software. Vast majority of web hostings around the world offer only HTTP (web) server with PHP/MySQL or similar server-side add-ons. Hostings, offering RTMP server, usually have ten to thirty times higher hosting fee. Such situation makes it dificult to host Flash content for individuals and non-commercial organizations, as well as for small business companies.

Here is where HTTP Streaming technology can help. It uses any HTTP (web) server with PHP/MySQL or other similar server-side scripting language and database engine. In brief, the technology works as follows. The server-side script accepts a time value from the client-side Flash application, finds offset value in the video file (using the database, storing these values) and sends a video file portion, starting from this offset, back to the client application. In this way client-side Flash application receives the video/audio stream starting from the required time value, but not from the zero time offset. In addition such script can limit the delivery speed (a number of bytes, coming from server to client per second) down to a value, enough for reliable playback, but not creating a big extra (useless) Internet traffic.

How to enable the HTTP Straming delivery in your presentation.

1. Export your presentation with HTTP Streaming option selected in the Video Delivery Method section. Also you must specify a URL for video delivery in a special format like this:

http://your.website.com/somepath/stream.php?br=nnn&file=yourfile

where:
• your.website.com - is the domain name of your website;
• somepath - is a subdirectory (if any) where the script is located;
• stream.php - is the script name;
• br=nnn - is the bitrate value (nnn is the number of kilobits/s);
• file=yourfile - is the video/audio file name without FLV extention.

2. During the video export a dialog appears, asking for indexing SQL file creation. You need to choose the file name, the table name and the indexing interval. Then a text file will be created near of your output video file, containing the SQL script for your database engine. This script creates a new database table with your FLV file index. You need to import this file into your database using your database Administration Board. Please refer to your database engine documentation or a help file for more information about SQL files import.

3. Upload your presentation to a web hosting server: just copy all the directories, which you have got within an export directory, assigned at Openworld FlashPresenter Export page, to your web hosting server into any web-accessible directory, as you need. Video delivery path (URL) may differ from other presentation parts location.

4. At the web hosting server side:

• create a subdirectories structure at your web hosting server, like which you can see within the Docs\HTTPStream\ subdirectory of the Openworld FlashPresenter installation directory; The "root" of this structure must be accessible by HTTP, as the URL http://yourwebsite.com/somepath/ (see above);

• upload the stream.php script, which you can find in the Docs\HTTPStream\ subdirectory of the Openworld FlashPresenter installation directory, to the "root" of created directories structure;

• update the Docs\HTTPStream\inc\config.php script, assigning your web hosting data for the server-side database engine and the default streaming parameters;

• upload the config.php script, pointed above, into the inc subdirectory of the directories structure created;

• upload your video files into the streams subdirectory of the directories structure created; each file must have .flv extention;

Of course, it is possible to modify the stream.php script, adding some extra features, like the client identification and/or authorization, access control, etc.