QuickTime Streaming

Client Movies

You incorporate streaming content in a client movie by adding at least one streaming track. The simplest form of client movie has only one track: a streaming track with the URL of a movie on a server.

A streaming track has a media type of kQTSStreamMediaType ('strm') and contains a single media sample: typically either an RTSP:// URL of a streaming movie or the SDP text describing a multicast.

The following code example shows how to create a streaming track, insert a sample description, and add a URL media sample.

Listing 5 Creating a streaming ('strm') track with an RTSP:// URL



 
Handle dataRef;

long dataLength;

char url[] = "rtsp://myserver.bigcompany.com/mystreaming.mov";



dataRef = NewHandle(strlen(url) + 1);

BlockMoveData(url, *urlDataRef, strlen(url) + 1);



dataLength = GetHandleSize(dataRef);



newMedia = NewTrackMedia(newTrack, kQTSStreamMediaType,

        kQTSMediaTimeScale, handleDataRef, HandleDataHandlerSubType);



err = BeginMediaEdits(newMedia);



qtsDesc = 

(QTSSampleDescriptionHandle)NewHandleClear(sizeof(QTSSampleDescription));



(**qtsDesc).descSize = sizeof(QTSSampleDescription);

(**qtsDesc).dataFormat = 'rtsp';

(**qtsDesc).dataRefIndex = 1;

(**qtsDesc).version = kQTSSampleDescriptionVersion;



duration = kQTSInfiniteDuration;



err = AddMediaSample(newMedia, dataRef, 0, dataLength, duration,

        (SampleDescriptionHandle)qtsDesc, 1, 0, nil);



err = EndMediaEdits(newMedia);

err = InsertMediaIntoTrack(newTrack, 0, 0, GetMediaDuration(newMedia),

        kQTSNormalForwardRate);

A movie that contains streaming tracks can be played from a local disk or served via HTTP. You can create a client movie with a streaming track that contains the URL of a server movie, then embed the client movie in a website or distribute it on a CD-ROM. When the movie is played, the user's computer will establish a network connection to the specified server for each streaming track.

A streaming track in a client movie can point to a server movie containing audio, video, text, and MIDI tracks. Any or all of the tracks in the server movie can appear as a single streaming track in the client movie.

To sum up:

A client-side streaming movie contains at least one streaming 'strm' track.
A streaming track contains a single media sample, typically an RTSP URL that points to streaming content. It can also contain SDP information for a multicast.
The streaming content can be a live stream or a stored movie on a streaming server.
The movie on the server can contain any number of tracks; multiple tracks in the server movie may be represented in the client movie as a single streaming track.