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QuickTime 4 introduced support for receiving real–time streamed data. That is to say, QuickTime–savvy applications can receive video, audio, and other kinds of data streamed across the Internet. Real–time streaming, unlike the progressive downloading of movie files that has been available since QuickTime 3, can handle live data and does not require downloading potentially huge files onto the user’s computer; this permits QuickTime playback applications to support uses such as video–on–demand and rebroadcast streaming.

The real–time streaming provided by QuickTime 4 was a client–side technology only; it did not provide any means to serve up, or transmit, the data streams. QuickTime 5 provides a set of broadcasting functions that allow us to create transmitter applications. For example, we can take the audiovisual data captured by a camcorder attached to one computer and broadcast that data to other computers on a network. Together, the transmitter technologies provided by QuickTime 5 and the receiver technologies provided by QuickTime 4 give us the complete set of tools we need to send audiovisual streams from one computer and view them on another. The good news here is that we need to know virtually nothing about the applicable IETF specifications to do all this; the really good news is that the amount of code we need to write to create a broadcasting application is surprisingly small. Indeed, we'll be able to write this application using fewer than a dozen of these new broadcasting functions.

The Real–Time Streaming Framework featured by the QTPlugin is a set of classes that allow developers to gain access to both the transmitter and receiver technologies provided by the QuickTime APIs within the Realbasic environment.

The QTPlgMovieTrackBroadcaster class is part of the Real–Time Streaming Framework and provides support for broadcasting movies tracks to other computers on a network.

Using this class requires QuickTime 5.0 or later, MacOS.







The QTPlgMovieTrackBroadcaster class constructors are called when you create a new instance of the class, while the ˜QTPlgMovieTrackBroadcaster class destructor, is called automatically when the class is no more in use. Also, you can invoke the class destructor by setting the instance of the class to nil.

Once a new class instance is returned, it is good practice to check the class property to be sure that the new object can be used. See the validity requirements for more details.


The class provides you with the following initializer methods:
()
This is the default constructor. Any class property is set to its default status (that is is set to nil and to false)

returns the movie (if any) associated to the presentation in use. You specify the movie to be streamed by using the class method
specifies if the presentation will loop

()
use this method to roll all of the class properties back to their initial state
returns nothing
(source as ) as boolean
once a new presentation has been , this method allows the user to specify the movie containing the tracks to be streamed. Accepted sources to provide by the source are:
  • objects: in this case the instantiated is retained by the class
  • objects: in this case it is up to the client make sure that the class instance is valid for all of the time is used by the current presentation
The method will look for movie tracks that match with the media streams specified into the used to the current presentation; the first found track that is appropriate for a given media stream will begin the source of data for that stream. For example, if the sdp information specifies one audio stream and one video stream to be broadcasted, the first sound track and the first video track found into the movie will be used to provide data to be streamed to the presentation
returns true if the movie source has been associated to the current presentation with success, otherwise returns false. Check the class property for errors