The QTPlgVideoPresentation class extends the properties and methods defined into its super class , to provide support for display and or playback of image data.
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The class has not constructor at all (you can always use the Realbasic common constructor syntax, of course, but you will obtain an usless object). Its destructor, will be implicitly invoked every time one of its derived classes will be destroyed.
Anyway, once a new instance of a class derived from QTPlgVideoPresentation is returned, it is good practice to check the class property to be sure that the new object can be used. See the QTPlgVideoPresentation’s validity conditions for more details.
determines whether or not the images will be displayed into the rectangle, contained into the specified area (see the
class methods below),
that best fits with the original dimensions of the video data. If you do not care to maintain the original video proportions, you can disable this property.
By default, this property is set to true
determines the brigthness to apply to the data. The values can range from –100 to
+100 with 0 meaning no change
determines the contrast to apply to the data. The values can range from –100 to
+100 with 0 meaning no change
specifies the set of graphics transformations to apply to the data being displayed
(w as window, r as
)
determines the region of the window where the image data have be displayed. If you pass
nil into the r parameter, then will be used the entire window as drawing space.
Note that the class will try to conserve the original proportions of image data when using the specified rectangle; that is,
if the display region specified does not fit to the original dimensions of the image data (i.e. the region is a square
while the images are rectangular), the images will be displayed into the rectangle, contained into the specified area,
that best fits with the original images dimensions. If this behavior it is not satisfactorily for you, you can disable it by setting the
class property to false. In order to create an offscreen data presentation session, simply set the
w parameter to nil
(context as canvas, [r as
])
determines the region of the window where the image data have to be displayed. If you omit the optional
r parameter, then will be used the entire canvas as drawing space; otherwise, the data will be displayed into the region of canvas identified by the
coordinates specified. Such a coordinates are intended to be expressed as local to the Canvas control.
Note that the class will try to conserve the original proportions of image data when using the specified rectangle; that is,
if the display region specified does not fit to the original dimensions of the image data (i.e. the region is a square
while the images are rectangular), the images will be displayed into the rectangle, contained into the specified area,
that best fits with the original images dimensions. If this behavior it is not satisfactorily for you, you can disable it by setting the
class property to false
(r as ,
[handleEvents as boolean=false])
use this function to puts the presentation in full–screen mode; the parameter r defines the
area in which display the data. If you pass nil into this parameter the class will set the display
boundaries to the entire available screen area. You can choose if handling the presentation by yourself or pass the control of it
to the class instance by setting the optional handleEvents parameter; if you set this parameter to
true, you can instruct the class to perform some specific action by using the following keyboard keys:
Escape : exits from full screen presentationDown Arrow : starts or stops the data playbackLeft Arrow : stops the data playback, then plays the sample data just before the current sampleRight Arrow : stops the data playback, then plays the sample data just after the current samplePage Up : stops the data playback, then rewinds the presentation to the beginPage Down : stops the data playback, then plays the last sample data
()
use this function to terminate a full–screen session began by a call to the
class method
(gc as )
as picture
use this method to obtain a picture of the actually played image data; this data are modified according to the
graphics transformations specified by the
of the class instance passed into the
gc parameter. If you want to obtain a picture of the source frame without any modification, pass
nil into the gc parameter
(gc as ,
format as )
as
use this method to obtain the raw data counterpart of the actually played image data; this data are modified according to the
graphics transformations specified by the
of the class instance passed into the
gc parameter. If you want to obtain a picture of the source frame without any modification, pass
nil into the gc parameter. The original pixel data will be converted according to the
specifified
(gc as )
as picture
use this method to obtain a picture of the actually played image data combining the graphics transformations specified by the
of the
class instance passed into the
gc parameter along with the values of
and
in use.
If you want to obtain a picture that reflects just the brightness and
contrast values applied, set the gc parameter to nil
(gc as ,
format as )
as
use this method to obtain the raw data counterpart of the actually played image data; this data are modified by combining the
graphics transformations specified by the
of the class instance passed into the
gc parameter along with the values of
and
in use. If you want to obtain a picture that reflects just
the brightness and
contrast values applied, set the gc parameter to nil. The original pixel data
will be converted according to the
specifified
()
use this method to force the re–draw of the image data onto the screen
(dst as folderitem,
params as ,
timeRange as )
use this function to "freeze" the current presentation status into the movie file specified by the
dst parameter; if the destination file already exists, the method deletes and replaces it with a new one.
This method adds a single video track to the destination movie and populates it with the data obtained by playing in sequence
all of the images contained into the current presentation; of course, the resulting output will reflect every transformations
defined for the presentation.
You establish the characteristics of the data output and the details of the compression process by using the
of the
params parameter. Notably, the values of the
,
and
indicated into the params object, will temporarly override those defined for the current presentation.
Finally, you can determine if the entire presentation, or just a portion of it, has to be saved by setting the
timeRange parameter appropriately. If you pass nil into this parameter,
all of the presentation images are added to the new movie; otherwise, the method adds to the movie only the images falling into
the interval defined by the
and
properties of the
timeRange object