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.To play back the sound, simply move the playhead.174 Chapter 6 Compressing sounds for exportTo choose sound compression options, you use the options in the Export Settingsarea of the Sound Properties dialog box.The options available depend on thecompression method you select.You can also use the Sound Properties dialogbox to update sounds that you have modified in an external sound editor, or totest the sound.The sampling rate and degree of compression make a significant difference in thequality and size of sounds in exported movies.The more you compress a soundand the lower the sampling rate, the smaller the size and the lower the quality.Youshould experiment to find the optimal balance between sound quality and file size.MP3 sound files are already compressed when imported.However, you canrecompress MP3 files for export if needed.For example, if the MP3 file is to beused as a stream sound, you must recompress the file, because stream sounds mustbe compressed for export.If there are no export settings defined for a sound, Flash exports the sound usingthe sound settings in the Publish Settings dialog box.You can override the exportsettings specified in the Sound Properties dialog box by selecting Override SoundSettings in the Publish Settings dialog box.This option is useful if you want tocreate a larger high-fidelity audio movie for local use, and a smaller low-fidelityversion for the Web.(See Publishing a Flash Player movie on page 322.)Note: In Windows, you can also export all the sounds from a movie as a WAV file usingFile > Export Movie.See Exporting movies and images on page 339.Adding Sound 175 To set export properties for an individual sound:1 Do one of the following:" Double-click the sound s icon in the Library window." Right-click (Windows) or Control-click (Macintosh) a sound file in the Librarywindow and choose Properties from the context menu." Select a sound in the Library window and choose Properties from the LibraryOptions menu." Select a sound in the Library window and click the properties icon at thebottom of the Library window.2 If the sound file has been edited externally, click Update.3 For Compression, choose Default, ADPCM, MP3, or Raw.To select optionsfor the compression format you choose, see the section below corresponding tothe selected format.4 Set export settings.5 Click Test to play and stop the sound, and click Stop to stop the sound.6 Adjust export settings if necessary until the desired sound quality is achieved.7 Click OK.176 Chapter 6 The Default compression optionThe Default compression option uses the default compression settings in thePublish Settings dialog box when you export your movie.If you select Default, noadditional export settings are available.Using the ADPCM compression optionThe ADPCM compression option sets compression for 8-bit or 16-bit sounddata.Use the ADPCM setting when you are exporting short event sounds such asbutton clicks.To use ADPCM compression:1 In the Sound Properties dialog box, choose ADPCM from theCompression menu.2 For Preprocessing, select Convert Stereo to Mono to convert mixed stereosounds to mono (monaural).(Mono sounds are unaffected by this option.)3 For Sample Rate, select an option to control sound fidelity and file size.Lower rates decrease file size but can also degrade sound quality.Rate optionsare as follows:" 5 kHz is barely acceptable for speech." 11 kHz is the lowest recommended quality for a short segment of music and isone-quarter of the standard CD rate." 22 kHz is a popular choice for Web playback and is half the standard CD rate." 44 kHz is the standard CD audio rate.Note: Flash cannot increase the kHz rate of an imported sound above the rate at which itwas imported.Adding Sound 177 Using the MP3 compression optionThe MP3 compression option lets you export sounds with MP3 compression.UseMP3 when you are exporting longer stream sounds such as music sound tracks.To use MP3 compression:1 In the Sound Properties dialog box, choose MP3 from the Compression menu.2 For Bit Rate, select an option to determine the maximum bit rate of the soundproduced by the MP3 encoder.Flash supports 8 kbps through 160 kbps CBR(constant bit rate).When you are exporting music, set the bit rate to 16 Kbpsor higher for the best results.3 For Preprocessing, select Convert Stereo to Mono to convert mixed stereosounds to mono (monaural).(Mono sounds are unaffected by this option.)Note: The Preprocessing option is available only if you select a bit rate of 20 Kbpsor higher.4 For Quality, select an option to determine the compression speed andsound quality:" Fast yields faster compression but lower sound quality." Medium yields somewhat slower compression but higher sound quality." Slow yields the slowest compression and the highest sound quality.Using the Raw compression optionThe Raw compression option exports sounds with no sound compression.To use raw compression:1 In the Sound Properties dialog box, choose Raw from the Compression menu.2 For Preprocessing, select Convert Stereo to Mono to convert mixed stereosounds to mono (monaural) [ Pobierz całość w formacie PDF ]