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Adding Audio to Your Web Site

Adding Audio to Your Web Site. Adventures in Information February 17, 1999 presented byEileen Flick, ISD. What it takes:. Computer (Pentium or PowerMac recommended) with a sound card Plenty of hard drive space for uncompressed sound Source (CD, video tape, voice, etc)

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Adding Audio to Your Web Site

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  1. Adding Audio to Your Web Site Adventures in Information February 17, 1999 presented byEileen Flick, ISD

  2. What it takes: • Computer (Pentium or PowerMac recommended) with a sound card • Plenty of hard drive space for uncompressed sound • Source (CD, video tape, voice, etc) • Input device (microphone, CD player, etc) • connectors (1/8” stereo to RCA cord) for external devices • Recording/editing software

  3. Embedded vs anchored sounds • <embed> tag features: • Launch sounds automatically • Embed the player in the flow of a page • When you leave a page, sound stops and file isn’t saved • Supported by version 3+ of Netscape & IE Ex: <embed src=“audio/song.mid” controls=“console” height=60 width=145 autostart=“true”></embed> • <A> tag features: • Sounds downloaded to local drive, nothing plays until entire file is downloaded • Player launched separately, easy to save files, supported by all browsers Ex: <A HREF=“audio/song.mid”>play the song</A> • <META> tag sound: • Automatic launch, user has no control • Client pull, goes in <HEAD> tag area - EX: <META http-equiv=“refresh” content=“1”;url=audio/song.mid”> - page will refresh and sound will play after one second • Supported by Netscape and later versions of IE - use with caution • <BGSOUND> supported only by IE - avoid this one!

  4. Things to Keep in Mind While adding sound to web pages is fun, remember not all computers are created equal so: • Use embedded sound (automatic play) judiciously - this can be a real pain on slow connections • This includes sound files using the <EMBED>, <BGSOUND> and <META> tags • Keep it small: best to keep non-streaming clips under 20 seconds • Watch your formats! If necessary, provide multiple options (ex: WAV and AIFF) so all can listen

  5. When digitizing • Check the sample rate • 44.1 recommended - higher the setting, the better the quality • Check compression • If the sound file will be going on the Web as a Real Audio file, sound must be digitized with NO compression. • For other file formats, 3:1 compression produces best balance of quality and small file size.

  6. Software (commercial tools) • SoundEdit (Mac) http://www.macromedia.com/ • Component of Macormedia Director Studio, also available as stand-alone app • Saves files in a variety of formats • Downside: expensive, memory-intensive • Upside: available in computer user rooms at USC • SoundForge (PC)http://www.soundforge.com • Win 95+ • Pro-level editing, saves in a variety of formats • Downside: expensive • Not available at USC

  7. Other software • Kaboom (PC or Mac) http://www.novadevcorp.com/products/kaboom/index.html • Records and saves sound files in a variety of formats • 2 minute recording limit • Limited compression settings • GoldWave (PC) http://www.goldwave.com/ • Nice shareware app (under $50) offers extensive editing capabilities • Simple interface

  8. Sampling Rates & Bit Depth • Sampling Rate • Higher the rate, better the quality, larger the file • 44.1KHz - CD quality, music • 22.0 KHz - good for voice, lower quality music • 11 KHZ and below - okay for voice, grainy sound • Bit Depth • Higher the bit, better the quality • 16-bit best for high-quality source (like a CD) • 8-bit okay for voice, produces grainy sound • Samples • 20 seconds @ 44/16 = 1.7MB • 20 seconds @ 22/8 = 512K • 20 seconds @ 11/8 = 288K

  9. Compression • Best to compress after digitizing • More compression produces smaller files • Higher compression can reduce quality • Ranges from 1:1 (none) to 12:1 • Samples • 18 seconds @ 22KHz, 16-bit, 1:1 = 805K • 18 seconds @22KHz, 8-bit, 3:1 = 131K • 18 seconds @ 22KHz, 8-bit, 6:1 = 68K • Note: If you want to encode your sound file for Real Audio, you must use no compression

  10. Sound formats • Web-compatible formats: • .WAV - PC standard, good quality, large files, supports variable sampling rates and bit depths • .AIFF - Mac standard, good quality, large files, supports variable sampling rates and bit depths • .AU - UNIX standard, small files, okay quality, not as popular as it once was • MIDI - usually produced using instruments connected to your computer, very small files, requires special plug-in or helper app (though Quicktime 3 can handle it) • .MOV - Quicktime 3 now cross-platform, handles both audio and video, excellent quality, good compression, now streams • MPEG- audio and video, MPG-1 earliest, poorest quality. MP-3 produces CD-quality, small files • RM - Real audio/video, streams sound and video, produces very small files, quality varies depending on encoding settings

  11. MP3 - What it’s all about MPEG Layer 3, known as MP3, is a digital audio format for quick-downloading files that sound almost as good as CDs. Compresses at 12:1; a five-minute CD song takes about 50 megabytes of storage space, an MP3 file of the same time length, occupies only about 4~5MB. 20 second 44KHz 16-bit 1:1 = 1.7MB || Same file encoded to MP3 = 333K • What you need to listen to MP3: • Player like WinAmp (PC) or MacAmp (Mac) • Portable player, like the Rio from Diamond Multimedia • What you need to create MP3: • Digitized sound & an encoder to copy sound from a source (like a CD) • Various shareware tools can do this: • MusicMatch Jukebox (PC) - can record sounds (ripper) & encode them • MPecker (Mac) - encodes already digitized sound • MP3 on the Web: http://www.mp3.com/

  12. Streaming vs Non-Streaming • Streaming (Real Audio, Shockwave Flash, Liquid Audio) • Starts playing immediately • Files delivered from servers make longer clips possible • Requires special players or plug-ins, Real Audio needs the Real Server (available at USC) • Non-streaming (WAV, AIFF, AU, etc) • Downloads to your computer, then plays • Files can be large and slow • Uses standard helpers or plug-ins

  13. Real Audio • Streaming technology • Can be delivered live (as in a webcast) or offline • What you’ll need: • Lots of hard drive space • Pentium PC or Power Mac, faster the better • Real Producer for encoding • Things to remember when encoding: • Choosing a low connection speed (14.4 voice) produces smallest file • Choosing a high connection speed (ISDN+) produces highest quality • Quality will never be any better than the source file, so make sure the original is as good as possible

  14. Using the Real Media Server at USC • Important facts: • Files must be loaded on CWIS • Users must have signed & submitted the Real Media agreement • For more information: • http://www.usc.edu/uscweb/authoring/RealMedia

  15. Audio Samples • Real audio webcasts: • http://www.usc.edu/webcast/ • http://www.npr.org • Quicktime 3: • http://www.apple.com/quicktime/samples/showcase/index.html • Shockwave: • http://www.shockrave.com/t/home_more.html • Internet Underground Music Archive (IUMA): • http://www.iuma.com/ • MP3 files: • http://www.mp3.com/ • Builder.com: • Make Some Noise tutorial: http://builder.cnet.com/Authoring/Audio/index.html

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