From after effects to flash poetry in motion graphics - part 4 docx

4. Click OK to close the Advanced Settings area of the Flash Video Encoding Settings

dialog box. Click the Start Queue button to start the encoding process. When it fin￾ishes, quit the Video Encoder.

Adding and using alpha channel video in Flash

Adding alpha video to Flash is no different from adding any other video to the application;

it is what you can do with it that moves it from “regular” to “cool” on the Flash technique

scale.

1. Open a new Flash document, pull an FLVPlayback component from the

Components panel to the stage, and link the FLV created in the previous exercise to

the component.

2. Test the video, and you will see the black background you saw in the Video Encoder

preview is gone and the white background of the Flash stage is visible (see Figure 4-14).

Now that you understand how to create, encode, and deploy the video, you are probably

wondering, “What else can I do with it?” The answer is, “Quite a bit.”

When you encode the video, the alpha channel stays with the video and Flash reads it. This

means that Flash really isn’t seeing a video, it is seeing a series of colored pixels enclosed

within a shape. This is the key to playing with alpha video in Flash.

One of the most common shapes used for a Flash animator’s first Flash animation is usu￾ally a circle. Flash sees that circle as being no different from a video. It is a circular shape

filled with colored pixels. In Flash 8, developers and designers were handed a rather seri￾ous set of effects and blend modes that can be applied to objects in movie clips. Knowing

how Flash sees a video with an alpha channel and that effects and blends can be applied

to movie clips, it doesn’t take a degree in rocket science to come to the realization that

alpha video, placed in a movie clip, allows you to apply the Flash blends and effects to the

video. Here’s how:

Figure 4-14.

An alpha channels removes the

background in a video.

If you are going to be encoding an alpha channel video, you must use

the advanced encoding settings.

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1. With the Flash file open, right-click (PC) or Cmd-click (Mac) the component on the

stage and select Convert To Symbol from the Context menu. When the Convert To

Symbol dialog box opens, name the symbol Shadow, and select Movie Clip as its

Type. Click OK.

2. Click the component on the stage to select it and click the Filters tab in the

Property inspector.

3. Click the + sign once in the Filters tab to open the Filters pull-down menu. Select

Drop Shadow.

4. Change the Quality setting to High and test the movie. The talking head now has a

shadow (see Figure 4-15).

In this next exercise, you will apply a blend mode to the video. That major difference here

will be the use of a video object, not the component, in the movie clip. This way you can

see that the blends and effects can be applied to video playing through the video object,

not just the FLVPlayback component. The interesting area of intersection between both

techniques is the use of a movie clip to stream the video.

1. Open the Blend.fla file found in the Blends_Filters folder of your Chapter 4

Exercise folder.

2. Select the video object on the stage and, in the Blend pull-down on the Property

inspector select Screen (see Figure 4-16).

When you apply a filter or blend to the FLVPlayback component, don’t get alarmed

when you see the effect or blend applied to the entire component on the stage. The

component is seen as the object until the Flash Player takes over.

Figure 4-15.

You can apply effects, such as a drop shadow,

to a video containing an alpha channel.

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Figure 4-16. The blend mode can be applied directly to the movie clip containing the video.

3. Test the movie. The video looks somewhat ghostlike.

You don’t need to use the Filters or Blend pull-down to apply these effects. They can just

as easily be applied through the use of ActionScript. Let’s apply the screen mode using

code. Here’s how:

1. Open the Blend_AS.fla file in your Chapter 4 Exercise folder. The only difference

between it and the file you just used is the inclusion of an Actions layer, and the

symbol on the stage has been given the name of mcMyVid.

2. Select the first frame in the Actions layer and open the ActionScript window. Click

once in the Script pane and enter the following code:

mcMyVid.blendMode = "screen";

3. Save and test the movie.

As you can see, applying a blend mode is really quite simple. All you need to do is identify

the movie clip to which the blend mode will apply, apply the blendMode property to each

pixel of the movie clip, and then identify the mode. You can also use a number for the

mode instead of the name. In this instance the code would be

mcMyVid.blendMode = 4;

If you are wondering where the code that drives this video is located, double￾click the video’s movie clip in the Library.

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Here is a list of the modes and their integer values:

"normal" or 1

"layer" or 2

"multiply" or 3

"screen" or 4

"lighten" or 5

"darken" or 6

"difference" or 7

"add" or 8

"subtract" or 9

"invert" or 10

"alpha" or 11

"erase" or 12

"overlay" or 1

"normal" or 13

"hardlight" or 14

Applying a filter using ActionScript is a bit more complicated than tossing a blend mode

onto a movie clip. Filters have their own class in ActionScript, and, to apply a filter, you

have to import the class and then apply the filter.

When you first apply the filter, you are going to be prompted to enter what seems like a

confusing number of values as the parameters for the filter. They really aren’t that confus￾ing because they are exactly the same values you would enter in the Drop Shadow filter

menu (see Figure 4-17). The only difference is the boxes requiring you to add a check

mark will have a value of True or False in the code.

Figure 4-17. The parameters in ActionScript and the dialog box are an exact match.

Be aware the order of the modes and the integers doesn’t follow that in the Blend

pull-down. If they did, the integer value for hardlight would be 8, not 14.

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Here’s how to apply a Drop Shadow filter to the video using ActionScript:

1. Open the Shadow_AS.fla file in your Chapter 4 Exercise folder.

2. Select the first frame of the Actions layer and open the ActionScript Editor.

3. Enter the following code:

import flash.filters.*;

This line imports the entire filter package into the Flash Player. This leaves you the flexibil￾ity to apply multiple filters to a video without having to import each one, as you need it.

4. Press the Return/Enter key and add the following line of code:

var ds:DropShadowFilter= new DropShadowFilter(20,45,0x000000,.8,15,➥

15,1,3,false,false,false);

What you have done is to give the filter a name and created a new instance of the filter.

Let’s go through this to help you understand what you did.

The first thing you may have noticed is the tooltip (shown in Figure 4-18) that appeared

when you pressed the bracket key. This tooltip gives you the order of the values to be

entered and the type of value to be entered.

distance: The distance for the shadow, in pixels.

angle: The angle of the shadow; the values range from 0 to 360.

color: The hexadecimal color of the shadow.

alpha: The alpha transparency value of the shadow. Values are any number between

0 and 1. In this example, the .80 means the alpha value is 80% transparency.

blurX/blurY: The horizontal and vertical blue values.

strength: The strength of the shadow’s spread. The higher the value, the more

contrast there is. Valid values range between 0 and 255.

quality: The quality of the shadow. 1 is low quality. 2 is medium quality. 3 is best

quality.

inner: Determines whether the shadow is an inner shadow. Values are either True

or False.

knockout: Applies a knockout effect if the value is True.

hideObject: If set to True, the video is hidden, but the shadow isn’t.

If you are going to use a code-based approach to using a filter and are unsure

what the final result will be, use the dialog box to set the values, and, if they are

what you are looking for, write them down.

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