The QTPlgMovieMediaDesc QuickTime structure contains informations that describe the characteristics of a track movie track.
The QTPlgMovieMediaDesc class allows you to provide the required initialization parameters to the class in order to embed movies into other movies.
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The QTPlgMovieMediaDesc class constructors are called when you create a new instance of the class, while the ˜QTPlgImageDesc 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. Use this constructor to create a completely new data descriptor container in memory.
All of the class properties are intialized to 0
(other as QTPlgMovieMediaDesc)
This is the copy constructor. The properties of the object to be copied will be used to initialize the
new class instance properties
specifies the data reference currently used by the track movie media
specifies the total number of data reference objects present
as a track movie media can contain more than one data reference, you can use this property to obtain a list of all of the data references present
identifies the rectangle (if any) to be used in place of the track box when applying the
. If no clipping rectangle is specified, then
the coordinates of the containing track’s box will be used
specifies how the embedded movie will loop. You can set this property by using one of the
defined by the class. This property is only used
if the TimeBase of the embedded movie is not
to the parent movie. This
property defaults to
indicates how the embedded movie should be scaled to fit the track box. You can set this property by using one of the
defined by the class. The default value for this
property is
indicates whether or not the TimeBase of the embedded movie should be slaved to the TimeBase of the parent movie.
If the TimeBase is slaved, the embedded movie’s zero time will correspond to the start time of its movie media sample.
Further, the playback rate of the embedded movie will always be the same as the parent movie’s.
If the TimeBase is not slaved, the embedded movie will default to a rate of zero, and a default time of whatever default time value it instantiated with (which may not be zero).
If the TimeBase is not slaved, the embedded movie can be played by either setting the
property to true
or by using a Wired Action (not yet supported). This property defaults to false
indicates whether or not the audio properties of the embedded movie should be slaved to those of the parent movie. When audio is slaved, all audio properties
of the containing track are duplicated in the embedded movie. These properties include sound volume, balance, bass and treble, and level metering.
This property defaults to false
determines how the Movie Media Handler should react when the duration of the embedded movie is different than the duration of the movie media sample that it is contained by.
When the movie media sample is created, the duration of the embedded movie may not yet be known.
Therefore, the duration of the media sample may not be correct. In this case, the Movie Media Handler can do one of two things.
If this property is set to false, the Movie Media Handler will respect the duration of media sample that contains the embedded movie.
If the embedded movie has a longer duration than the movie media sample, the embedded movie will be truncated to the duration of the containing movie media sample.
If the embedded movie is shorter, there will be a gap after it is finished playing. If this property is set to true,
the duration of the movie media sample will be adjusted to match the actual duration of the embedded movie.
Because it is not possible to change an existing media sample, this will cause a new media sample to be added to the movie and the track’s edit list to be updated to
reference the new sample instead of the original sample. This property defaults to false
when the duration of the embedded movie’s sample is adjusted, by default no other tracks are adjusted. This can cause the overall temporal composition to change in
unintended ways. To maintain the complete temporal composition, a higher level data structure which describes the temporal relationships between the various tracks
must also be included with the movie.
specifies how the graphics mode of the containing track is applied to the embedded movie. If the graphics mode is not slaved, then the entire embedded movie is imaged
using its own graphics modes. Then the result of the drawing of the embedded movie is composited onto the containing movie using the graphics mode of the containing track.
If the property is false, then the graphics mode of each track in the embedded movie is ignored and instead the graphics mode of the containing track is used.
In this case, the tracks of the embedded movie composite their drawing directly into the parent movie’s contents.
Graphics mode slaving is useful for compositing semi–transparent media (i.e. a PNG with an
alpha channel) on top of other media. This property defaults to false
indicates whether or not the embedded movie should start playing immediately after being instantiated. This property is only used if the TimeBase of the embedded movie is
not . If auto play is requested, the movie will be played at its
preferred rate after being instantiated.
This property defaults to false
determines the color used for filling the background when the movie is being instantiated or when it fails to instantiate
specifies text that will be displayed to the user when the embedded movie is being instantiated or if the embedded movie cannot be instantiated. If no text is specified,
the name of the
(typically the file name) will be used
specifies that the embedded movie will not loop
specifies that the embedded movie will loop normally (that is, when it reaches the end it will loop back to the beginning)
specifies that the embedded movie will use palindrome looping
if the media is larger than the track box, it will be clipped; if it is smaller, any additional area will be transparent
the media will be scaled to completely fill the track box
the media will be proportionally scaled so that it is entirely visible in the track box and fills the largest area possible without changing the aspect ratio
the media will be scaled proportionally so that the smaller dimension is completely visible
it currently has the same behavior as .
When implemented, it will have the behavior described in the SMIL specification for a scrolling layout element