Adobe Flash chuyên nghiệp - p 33 pot

You’ll place the video of the zoo director at the end of the musical introduction at the same time the stop action appears frame 50.. The keyframe at frame 86 ensures that the video of t

where the background of the video is totally transparent and can show weather

graphics behind the person

Transparencies in video (called alpha channels) are supported only in the FLV

for-mat using the On2VP6 codec When encoding a video with an alpha channel from

Adobe Media Encoder, be sure to choose Edit > Export Settings, click the Video

tab, and then select the Encode Alpha Channel option

You’ll import the video file, which is already in FLV format, into Flash for display

with the playback component

importing the video clip

Now you’ll use the Import Video wizard to import the Popup.flv file, which has

already been encoded with an alpha channel

1 Insert a new layer called popupvideo.

2 Insert a keyframe at frame 50 and insert another keyframe at frame 86

You’ll place the video of the zoo director at the end of the musical introduction

at the same time the stop action appears (frame 50) The keyframe at frame 86

ensures that the video of the zoo director disappears from the Stage when the

animal videos appear

3 Select the keyframe at frame 50

4 Choose File > Import > Import Video

6 Select Load external video with playback component Click Next or Continue

7 Select the same skin that you’ve been using from the Skin menu and click Next

or Continue

8 Click Finish to place the video

The video of the zoo director with a transparent background appears on the Stage

9 Preview the video on the Stage by clicking the play button on the skin

10 Choose Control > Test Movie > in Flash Professional

After the musical introduction, the zoo director appears If you click on one of the animal video buttons, the popup video is removed from the Timeline

 Note: If you don’t

stop one video before

navigating to another

keyframe containing a

second video, the audio

can overlap To prevent

overlapping sounds,

use the command

SoundMixer.

stopAll() to stop

all sounds before

starting a new video

The ActionScript in the

first keyframe of the

actions layer in your

08_workingcopy.fla file

contains the correct

code to stop all sounds

before navigating to a

new animal video.

using a green Screen

Professionals often film people in front of solid green or blue backgrounds so they

can easily remove, or key, the background in a video editing application such as

Adobe After Effects Then the person is merged with a different background The

image of the zoo director was filmed in front of a green screen, which was removed

in After Effects Follow these steps to use a green screen:

1 Shoot footage in front of a green

screen:

• Use a green background that is flat,

smooth, and free of shadows so the

color is as pure as possible.

• Minimize the light that reflects off

the green screen onto the subject.

• Keep movement to a minimum for

Flash Video; use a tripod if possible.

2 Remove the background in After

Effects or other video editing

application:

• In After Effects, import the file as

footage, create a new composition,

and drag it onto the Composition

Timeline.

• Create a garbage mask to roughly

outline the shape and remove most

of the background But be sure the

subject never moves outside the

mask!

• Use the Color Range keying

effect to delete the rest of the

background You may need to do

some fine-tuning with the Matte

Choker and Spill Suppressor effects

A spill suppressor removes the light

that splashes onto the edges of the

subject.

3 Export the file to FLV format:

Export the video file to Flash Video

(FLV) format directly from the video

editing application Be sure to select

Encode Alpha Channel The alpha

channel is the selection around the

subject Encoding the alpha channel

using Cue Points

Cue points are special markers that you place in your video that Flash can detect with ActionScript There are two ways to use cue points Cue points can trigger

an ActionScript command, letting you synchronize the video with other Flash ele-ments Or, you can jump to particular cue points in the video with ActionScript

Both types of cue points add more functionality to video

In this section, you’ll add cue points to the zoo director video so relevant informa-tion can be displayed on the Stage as he speaks New to Flash Professional CS5 is the ability to add cue points directly to video on the Stage

inserting cue points

There are four points in the zoo director video at which you’ll want to synchronize the display of additional information First, when he introduces himself, you’ll show his name Second, when he instructs the audience to click on a video, you’ll high-light the videos Third, when he refers to the sounds, you’ll highhigh-light the sounds

Fourth, you’ll add a cue point to mark the end of the video

1 Select frame 50 (the first keyframe in which the zoo director video appears) of the popupvideo layer

2 Select the video of the zoo director on the Stage

3 Click the play button on the skin and pause the video when the zoo director says, “…my name is Paul Smith.”

The numeric counter that displays the elapsed time should read about two seconds

 Note: Recall that

you can add cue points

to video with Adobe

Media Encoder You can

also add cue points to

video with ActionScript

in the Actions panel,

which is not discussed

in this book.

 Note: If the

FLVPlayback

component on the

Stage doesn’t show a

preview of the video,

right-click/Ctrl-click on

the video and make

sure that the Preview

option is selected.

4 In the Properties inspector, click the Plus button in the Cue Points section to

add a cue point at the two-second mark

A cue point appears in the Cue Points section of the Properties inspector

5 Click the name of the cue point in the Properties inspector and rename it

namecue

6 Continue playing the video and pause it when the zoo director says, “…so click

on a video.”

The numeric counter that displays the elapsed time should read about 12

seconds

7 In the Properties inspector, click the Plus button in the Cue Points section to

add a cue point at the 12-second mark, and rename the cue point videocue. 

Note: If you need to

adjust the time of any of the cue points, you can click and drag over the time or click to enter a time with millisecond precision.

8 Continue playing the video and pause it when the zoo director says, “… click on

a sound.”

9 In the Properties inspector, add a third cue point and rename it soundcue The

third cue point should be at the 14-second mark

10 Continue playing the video until it reaches the end In the Properties inspector,

add a fourth cue point and rename it endcue

detecting and responding to cue points

Now you’ll add the ActionScript to detect the cue points and respond to them The Code Snippets panel can help do much of the ActionScript coding

1 Move the playhead to frame 50 and select the video of the zoo director on the

Stage In the Properties inspector, enter paulsmithvideo as the instance name.

2 Open the Code Snippets panel (Window > Code Snippets)

 Note: In the

Properties inspector,

double-click any cue

point in the Type

column and your

video on the Stage

will immediately jump

to that particular cue

point.

 Note: To delete a

cue point, select it in

the Properties inspector

and click the Minus sign.

3 Expand the Audio and Video folder in the Code Snippets panel and double-click

the On Cue Point Event option

The Actions panel automatically opens and adds the necessary code to detect

cue points on your selected video The stop() command that you see on line 1

was already present in the Flash file

4 Now you must add conditional statements to check which of the cue points has

been encountered and respond appropriately. Replace lines 16–19 with the

following code:

if (event.info.name=="namecue") {

gotoAndStop("zoodirector");

}

if (event.info.name=="videocue") {

gotoAndStop("videos");

if (event.info.name=="soundcue") { gotoAndStop("sounds");

}

if (event.info.name=="endcue") { gotoAndStop("home");

}

The final code checks the name of each cue point as it’s detected, and if there is

a match, the playhead goes to a specific named keyframe on the Timeline

adding the synchronized Flash elements

The Timeline already contains several named keyframes In these keyframes, you’ll place additional Flash elements that appear as the cue points in the video are detected

1 Select the keyframe named zoodirector in the hilights layer

2 Drag the symbol called zoo director name from the Library panel to the Stage

and place it close to the video

The graphic of the name appears when the playhead moves to the zoodirector

keyframe

3 Select the keyframe named videos in the hilights layer

4 Select the Rectangle tool with a red 3.0 stroke and no fill Draw a rectangle

around the video buttons to highlight them

5 Select the keyframe named sounds in the hilights layer

6 Draw another rectangle with the same stroke and fill settings around the sound buttons to highlight them

The rectangular red outline appears when the playhead moves to the sounds keyframe

7 Choose Control > Test Movie > in Flash Professional

As the zoo director speaks, various Flash graphic elements pop up in synchrony