Probably THE most important thing to keep in mind when making flash is file size! If your flash is 2 minutes long but takes up 10 megs, nobody is going to wait to download it, or if they do they won’t respect your work.
Flash has been designed to automatically compress audio, but simply importing the audio, especially for music purposes is not always a good idea.
First things first, cut down the audio length.
If your flash animation is 3 minutes long, do not under any circumstances include an mp3 that is any more than 3 minutes long, in fact it’s probably not necessary to have one longer than 1 minute long.
Find out how much of the music you really need, and edit the wav/mp3 file with a decent audio editor, before importing it. The audio program that I currently use the most is Adobe Audition (don’t worry Adobe didn’t make it, they bought it from Syntrillium).
Now that you have cut down your music to an acceptable level, ask yourself, “is this song repetitive?”… If it is, then you are in luck! Some songs are so repetitive that if you played one specific part of it over and over, the audience might not even notice, especially if you change the volume frequently for dramatic effect. Looping one segment of the song, then ending/beginning with another segment can considerably reduce your file size. Again to create an audio loop use a program like Audition, but this time cut out the part you want to loop, with an additional half a second. Then using amplifying effects make that last half second fade out to silence, then make the first 10th of a second fade in. This way you will eliminate the chance of audio popping. Then instead of using the “loop” effect, restart the audio segment with another event or stream effect just before the previous segment ends (that ½ second), this way as the previous wav is fading out, the new one will fade in, and in the end it will sound seamless. This will also prevent your looping audio from going out of sync, as they have been known to do.
So, now you have your musical segment/s cut down to their appropriate length and it’s time to import them into flash. You may think to yourself, what if I compress them BEFORE importing them, with this superior program, wouldn’t I get better quality in the end product? You would be wrong. Why? I am not completely certain, but I’ve tried doing this several times, and it ends up screwing up the quality completely. Just import the HIGHEST quality audio into flash that you can, then comes the compression choices…
Now, by default flash will compress all audio down to 16kbps mono, which is usually the best choice. If your animation is very short, lets say a signature or mini-clip, then you might go higher with the quality, to lets say 32k or maybe even as high as 64k, but there is really no need to go any higher, and there is definitely no need for going to stereo, as I will discuss in the next tutorial.
Whatever music and compression ratios you choose, remember this. Music is to complement animation, not make it… Since music is usually the larges part of an swf file, you must try to balance out an audio quality that meets the length and quality of your flash. Ie. A 10 minute movie should usually come to about 5 megs. A 2 minute movie should come to about a meg, and so on…
If you want to find out how to make mono music sound like stereo, see the next tutorial…
