Tutorials > How to play Internet streams

There are two main types of Internet stream:

•	Broadcasting streams

•	Sound files available on a web site

These streams cannot be loaded through the LoadSound method: for this purpose you must use the LoadInternetStream method which gives the possibility to pass a URL in place of a pathname. Let's see how to manage these different streams.

Broadcasting streams

Internet radio is a broadcasting service which transmits one or more sound streams via the Internet: for this kind of streams, the control will connect to the remote server and will fire the following sequence of events:

•	StreamConnecting to notify about the beginning of the connection to the server.

•	In case the connection should fail, the StreamLoaded event would report the failure.

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In case of successful connection the DownloadBuffering event would be fired with its nState parameter set to STREAMING_BUFFERING to notify that connection with the server was established and that buffering begins. This would be followed by a number of DownloadPercentage events to notify about buffering percentage.

•	Once there will be enough data to play, the control will fire the StreamLoaded event allowing the container application to start the playback session through a call to the PlaySound method.

Immediately after starting playback, the control will fire again the DownloadBuffering event with its nState parameter set to STREAMING_PLAYING: note that, during the playback session, the control will continue buffering data from the Internet: if for any reason, for example for a slow connection, the download should stall, the control will notify the container application firing again the DownloadBuffering event with the nState parameter set to STREAMING_BUFFERING: when there will be again enough data to play, the control will automatically resume playback notifying the container application through the DownloadBuffering event with the nState parameter set to STREAMING_PLAYING.

After a stall situation, the Internet stream provider could also close the connection: in this case the control will fire the ServerClosed event.

During playback, the server will usually send information about the radio station and about the song in playback: the control has the capability to notify in real-time the availability of this information, usually called "tags", and to retrieve the various strings composing the same tag: for this purpose the control will fire the MetaTagChanged event: at this point the container application will have the possibility to perform the following sequence of tasks:

•	instruct the control to retrieve the tag contents through a call to the ReadSoundInfo method

•	verify the effective availability of the tags and the number of strings composing the tag through a call to the IsTagAvailable method

•	retrieve each of the various strings composing the tag through a call to the GetTagString method.

Sound files available on a web site

Loading a sound file from a web site is very similar to loading a broadcast stream with the following differences:

•	The remote server will not send metadata so the control will never fire the MetaTagChanged event

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Differently from streams, that can be created in real-time, sound files have a limited size: this means that, at a certain extent, the download of the file will be completed: the control will in this case fire a DownloadComplete method allowing the container application to gain access to tags like ID3V1 which, for MP3 files, are stored on the file's bottom.

A sample of access to Internet streams in Visual C# and Visual Basic.NET can be found inside the following sample installed with the product's setup package:

- InternetRadio