The compression and effect processing of sound in Flash

Compression

Add sound in Flash can greatly enrich the performance of the animation, but if we work hard to edit the sound can not be very good with the animation, or the sound file too large impact on the speed of flash, the effect will be greatly reduced. So how do you get the best results out of flash sounds? Let's explore the problem together.

　　The compression of sound files in Flash

When we import a flash file into a Web page, we have to consider the size of the Flash animation, especially the Flash animation with sound, due to the speed limit of the network. Is there any way to reduce the amount of data while not affecting the animation effect? A feasible method is to use sound compression, the effect is very obvious.

To import a sound file into flash, double-click the sound file in the component library to eject the Sound Properties dialog box (Figure 1).

Figure 1

Flash MX provides us with four different voice compression formats: ADPCM, MP3, raw, and speech. Compression can be done by selecting the appropriate compression format. The level of sound compression in a variety of formats differs from the quality and size of the generated sound files. To achieve the best results, it is necessary to repeatedly carry out different experiments to find the most appropriate compression rate.

　　1, ADPCM compression

The "ADPCM" compression option is used for compression settings for 8-bit or 16-bit sound data. such as the click of a short event sound, the general selection of "ADPCM" compression, as shown in Figure 2.

Figure 2

"Preprocessing": Select "Convert Stereo to Single sound" to convert mixed stereo to mono (non stereo).

The sample ratio option controls the full and file size of the file. A lower sample rate reduces the file, but it also lowers the sound quality. Flash does not improve the sampling rate for imported sounds. If you import an audio of 11kHz sound, even if you set it to 22kHz, it is only 11kHz output effect. The ratio option is as follows:

The 5kHz sampling rate can only reach the sound quality of people speaking.
The 11kHz sampling rate is the lowest standard for playing small pieces of sound, One-fourth of CD quality.
The 22kHz sampling rate of the sound can reach half of the CD quality, most of the sites are currently selected such sampling rate.
The 44kHz sampling rate is the standard CD quality and can achieve good hearing effect.

　　2, MP3 compression

The MP3 compression option lets you output sounds in MP3 format. When exporting long audio streams such as music, it is recommended that the MP3 option be selected (Figure 3).

Figure 3

For the bit rate, determines the number of bits per second that the exported sound file plays. Flash supports 8Kbps to 160Kbps CBR (constant bit rate). When you export a sound, you need to set the bit rate to Kbps or higher for best results.

The quality option is used to determine compression speed and sound quality.
"Fast" can speed up the sound and reduce the sound quality.
"Medium" can achieve a slightly slower compression speed and a higher quality of sound;
"Best" can achieve the slowest compression speed and the highest sound quality.

　　3, Raw (original) compression and speech (voice) compression

The original compression option exports a sound file that is not compressed. The speech compression option exports sounds using a compression method that is particularly appropriate for speech. The author recommends a 11KHz ratio for speech use.

　　Second, the sound effect of the editor

After the sound file is successfully imported into the animation, you can edit the sound effect as needed. In the Properties panel, Flash provides us with some common sound effects (Figure 4). Select the appropriate options to achieve the corresponding effect, if we want to give a section of the title animation voice, need to slowly enhance the sound, just select the effect drop-down menu in the "Fade in" command.

Figure 4

Select None Option: Indicates the effect is not applied to the sound file. Selecting this option will remove the previously applied effect.

If we are not satisfied with these common effects, we can also use the "Custom" option to edit themselves. Below the "fade out" effect as an example, talk about the specific use.

Click the "Custom" or "Edit" button, pop-up editing window, under the Panel, Flash provides us with some simple auxiliary tools. The zoom tool "+"-"is used to scale the wave graph, next to the second and frame buttons, which determine whether the horizontal axis is" time "or" shadow "(Figure 5) when the waveform is displayed.

Figure 5

Depending on your needs, use the Zoom tool to scale the waveform to the appropriate size, drag the left two small squares (adjust handles) to the lower left (the volume set to the minimum), and then click on the line to create adjustment handles, and drag to the highest (the volume set to maximum), note that with the first adjustment handle to maintain a certain tilt, Fade in and create the top adjustment handle and the bottom adjustment handle on the volume line (Figure 6). This fade effect will be completed, is not very convenient? Don't forget to click on the play button to enjoy your own editing effect.

Figure 6

In the sound Properties panel, we can also edit the "sync" type of the sound and the "loop Count" (Figure 7).

Figure 7

The events option synchronizes the sound with the process of an event. If you trigger an event that plays a sound, it will play automatically until it is finished, and in the process the stop of the sound is not restricted by the animation itself. For example, we make a sound play button in Flash, if the event sound is playing, and then click Again, the first instance continues to play, and another sound instance starts playing at the same time.

The start option is the same as the event option, except that a new sound instance is not played if the sound is playing.

The Stop option allows you to mute the specified sound (Figure 8). We import sounds into the first frame of the movie, create keyframes at 50 frames, select the sounds you want to stop, and when you select Stop in the Sync option, the sound stops playing when it plays to 50 frames.

Br> Figure 8

Data flow is used to play sounds synchronously on the internet. Flash coordinates the animation with the sound stream, synchronizing the animation with the sound. If Flash does not show the animation frame fast enough, Flash will automatically skip some frames. Unlike an event sound, if the sound is too long and the animation is too short, the sound stream stops playing as the animation ends. When you play a movie, the sound stream is mixed together.

Fill in a specific value in the loop at the right of the picture to make the sound play at a specific number of times. For example, to loop through a 15-second song for 90 seconds, enter 6.