ActionScript Fundamentals for Sound Control in Flash Presentations

Flash: Controlling Sound Presentation by Mindy McAdams

ActionScript (so far) • From Lessons 1 through 7: • stop(); • play(); • gotoAndStop("someframelabel"); • gotoAndPlay("otherframelabel"); • The script can be written on a button or on a frame

ActionScript for buttons • If script is on a button: on (release) { stuff here } • Alternatively -- if a button has an instance name, you can put the script on the Timeline this way: rewind_btn.onRelease = function (){ stuff here } on (release) { stuff here } rewind_btn.onRelease = function () { stuff here }

ActionScript & movie clips • If you need to make a movie clip stop playing (if the instance name is clouds_mc) from the main Timeline: • Or if the movie clip needs to tell the main Timeline to stop playing: clouds_mc.stop(); _parent.stop();

New, exciting ActionScript • What is a variable? • A kind of container for data • Each variable has a name (static) • Each variable has a value (dynamic) • Examples of variables (name, left; and value, right): • n = 27; • myColor = "orange";

ActionScript 2.0 variables • Not in the book: • AS 2.0 would like script to be more formal in style • Examples of the initial declaration of variables in AS 2.0: • var n = 27; • var myColor = "orange";

ActionScript 2.0 variables • In fact, AS 2.0 would like things to be EVEN MORE formal: • Examples of the initial declaration of variables in AS 2.0, including “strict data typing”: • var n:Number = 27; • var myColor:String = "orange";

Selecting ActionScript version • To make life easy, when following the book, you can simply change the Publish Settings to AS 1.0 • But eventually, people will use AS 2.0 for everything

ActionScript variables • We should formally declare our variables: • var n = 27; • var myColor = "orange"; • You can do that in AS 1.0 or 2.0 • However – we need not use strict data typing (:Number, :String, etc.)

ActionScript variables • How does a variable work? • var n = 27; • n = n + 1; • if (n == 28) { stuff here } • Another example: • var myColor = "orange"; • if (myColor != " blue") { stuff here }

ActionScript operators • == “is equivalent to” • != “is NOT equivalent to” • > “is greater than” • < “is less than” • >= “is greater than or equal to” • <= “is less than or equal to”

Variables in Lesson 8 (Sound) • The book says: x = new Sound(); • Here the variable is x – and we are declaring it for the first time • So to be more formal and correct: var x = new Sound(); • Only the first time you use x in a movie – do not write var after the first appearance of the variable

Variables in Lesson 8 (Sound) • A variable name can be any word (except the “reserved words”; see pp. 479 - 480) • It’s common to use letters such as x, y, and z as names of variables • It’s also common to use “camel case” in the name -- e.g. mySound, theMusic, etc.

Variables in Lesson 8 • After we have declared a variable (with var), we can use it to do things -- rather like an instance name x.start(0, 0); x.stop(); • These are the basics of audio in Flash • (We’ll get back to this shortly)

Bringing sound into the FLA • The only script difference between the two methods for the Sound object concerns how you associate your audio file with your variable: x.attachSound("crossroads"); • … or … x.loadSound("rainforest.mp3", true); x.attachSound("crossroads"); x.loadSound("rainforest.mp3", true);

External MP3 files (loadSound) • To load an external audio file, the file MUST BE in the MP3 file format • Also, the file must have a sampling rate of one of these three values (on pp. 216 – 217): • 11.025 kHz (doesn’t sound great) • 22.05 kHz (usually best choice) • 44.1 kHz (CD quality; big file size) • Otherwise, you will have distorted sound

Starting and stopping sound • To stop a Sound object represented by the variable name x: x.stop(); • (Exactly like stopping a movie clip) • To play a Sound object (from the beginning): x.start(0, 0); • Script can be on a button or on a frame x.stop(); x.start(0, 0);

Options for starting sound • This will start the sound from the beginning AND play it only once: • - • This will start the sound from the beginning and loop it 100 times: • - • This will start the sound 20 seconds after the beginning and play it only once: • - x.start(0, 0); x.start(0, 100); x.start(20, 0);

Pausing sound • Before you pause an audio file, you must determine how much has already played • Then you will be able to start it (later) from the same point • This property is called position var p; p = Math.floor(x.position/1000);

Pausing sound (2) • Say the sound file had already played for 5.2 seconds (5,200 milliseconds) • This script will get the number 5,200 and divide it by 1,000: • Then it will round down the result to a whole number (not a decimal) • Result: p = 5 p = Math.floor(x.position/1000);

Pausing sound (3) • If you have the value of p, you can use that value to restart the audio file at the correct point after it has been paused: • P • x • If the value of p were 5, then the audio would immediately start playing from the point 5 seconds into the file p = Math.floor(x.position/1000); x.start(p, 0);

Adjusting the volume • If all you need to do is mute the audio (while it continues to play): • - • If you then need to return the audio to the maximum volume: • - • The volume range is exactly 0 to 100 x.setVolume(0); x.setVolume(100);

ActionScript basics • From Lessons 1 through 7: • stop(); • play(); • gotoAndStop("someframelabel"); • gotoAndPlay("otherframelabel"); • You will use these in almost every Flash movie

ActionScript for audio (basics) • From Lesson 8 (x can be any name): • var x = new Sound(); • x.attachSound(); • x.loadSound(); • x.start(0, 0); • x.stop(); • You will use these to control sound in any Flash movie that requires it

ActionScript/audio (advanced) • From Lesson 8 (x can be any name): • var x = new Sound(); • var p = 0; • p = Math.floor(x.position/1000); • x.start(p, 0); • x.setVolume(0); • x.setVolume(100); • You will use these to control sound in conjunction with buttons in the Flash movie

Flash: Controlling Sound The End Presentation by Mindy McAdams > Flash Journalism: Lesson 8

ActionScript Fundamentals for Sound Control in Flash Presentations