Sound/Video Formats

	Formats	Tutorials	Activities	Resources	Teaching Guide
	A WIT 2001 Advanced Module Developed by Pamela Greyer
Sound Adapted and Updated from a 1999 Special Topics Module by Michael Lach

Music & Movies On The Web

 

Topics How It Works MIDI Sound Format Audio Sound Formats Video Formats Streaming Audio & Video   How It Works Audio and video files are created in various formats. These files play either through a browser plug-in or in media players, software that is generally included free on all computers that allows you to listen to songs or view video. Some sound files play in the background of a Web page, others, including video files, are downloaded onto your hard drive or can be delivered through streaming audio and video technology. All you need to hear sounds and see video is a computer with a sound card and speakers and the software or plug-ins that will play the files. Formats Sound Sound files come in several different formats. The ones most commonly used on the Web today are MIDI, WAV, MP3, RAM or RM. The formats differ in the manner in which the sound is recorded and fall into two categories. Music data only (General MIDI) Audio formats (Wave, AU, MP3, RAM & RM) MIDI MIDI stands for Musical Instrument Digital Interface and is a popular music format on the Web. MIDI files actually play your sound card which produces notes and synthesized sounding music. If you have visited a Web page and heard instrumental music playing in the background most likely you have experienced MIDI. In the early days of the Internet, MIDI files were a quick way to add sound to a Web page and you can still find many sites that use MIDI sounds. The advantages of MIDI files are their small in size which makes them ideal for using as background sounds in Web pages. The disadvantage is the quality of the sound is dependent on your sound card so still most MiDI's are far from the richness in clarity and quality of MP3's or WAV's.   Audio Formats: WAV, MP3, RAM, and RM The other formats of sound files are known simply as audio formats and include .wav, .au, .mp3, .ram, and .rm. Audio files in these formats that download to your hard drive are transferred at the rate of your Internet connection. The larger the file and slower your connection, the longer it will take for the file to download completely. Once downloaded, you can keep the file on your hard drive and play it as often as you like. When you visit a Web page that has audio or video files included, you may have noticed that if you click on the file it doesn't play immediately. If a compression has not been applied to the sound, it may take several minutes to download the large amount of bytes uncompressed sound files generally take up. . Movies Video formats The formats of movies include: AVI MOV MPG, MPEG RAM or RM Movies on the Web come in many formats with the most widely used being AVI (PC) MOV (QuickTime), or RAM/RM Real Media files. Windows Media Player, the QuickTime Player and plug-in, or Real Player will allow you to watch just about every movie format available on the Web. Once you have all the players installed, you are ready to sit back and enjoy the show. Will all these formats work in my Web pages? An <A HREF> tag that links to a file on a server will play the file in a media player. The <EMBED> command will place the file in an HTML document and plays files in MIDI WAV, MP3, AIFF, AU,AVI, MOV, MPG, MPEG, RAM, RM formats as well as other audio sound/movie formats. Below is a explanation and comparison of sound and movie formats.   MIDI (.mid) format synthesized sound whose quality is dependent on soundcard. WAV (.wav) format was developed for used with Microsoft's Windows. The sound quality is not as good as MIDI, but the file is smaller. MP3 (mpeg_audio layer 3)format uses audio coding and compression to produce high quality sound and small files AU (.au) format creates files that are relatively small AIFF (.aiff) Apple extension for music and high quality sound. As QuickTime will play WAV files, this format is shrinking in use for the Web. MOV (.mov) format Quicktime movie format. RAM/RM (.ram/.rm) formats are files created or converted in Real Producer and will only play in Real Media's Real Player or with the Real Player plug-in. Streaming Audio & Video If you choose to stream your audio or video files, you will eliminate one of the most frustrating steps in listening to or watching movies on the web, waiting for the download to finish. Streaming allows your content to play as it is downloaded, or streamed, from your server to a media player or a Web page. In order to stream files, you will need to embed the file in the page versus linking to it directly with a <a href src=> tag. You can determine if you want the file to open separately in a media player or play directly in a Web page. Streaming audio and video files do not download first so they can be heard, viewed, but not saved on your hard drive. We've covered formats, now let's become familiar with the software you need to listen to sound files.   Playing Sound & Movie Files Media Players To play sound or movie files on your computer, all you need is a media player; Windows Media Player , RealPlayer, or QuickTime Player. Media players will play sound and music files stored on your hard drive or those you download from the Internet. Here are three media players. There are also a variety of media compressors/ convertors/mixers that will play sound files as well. As you get comfortable with the features of each, you may choose one to set as your default media player and play all local and downloaded files through this player.   Browser Plug-ins Web text and multimedia files that can not be natively displayed by a Web browser require the addition of "plug-in" or "helper" applications to enable browsers to display or play files in the other formats. Without these additional programs you will not be able to view or hear many files on the WWW. Just as an HTML file needs a "Web browser" to display it, sound, movie, and other multimedia file formats need special software or"helper applications" that will play or display the files within a Web browser and are free for the downloading. If QuickTime or Real Player did not come pre-installed on your computer, you can download the players for free which also inlcudes the plug-ins. When you install the players, the software will ask you where you want o install the plug-in. Make sure you select the plug-ins folder of either Netscape Communicator or Internet Explorer and install it there.   Get Quicktime Get Real Player   The sound and movie formats mentioned here are the ones that have been most popular over the last few years with computer and Web users such as.mid, .wav, .au, .aiff, .mov or ones that have gained popularity lately such as Real Media's .rm, and .ram formats. Macromedia's Flash .swf and Shockwave .spf and.spl formats as well as other graphics and multimedia formats such as .png, .viv, and .vdo are also becoming standard formats for sound and movies. If you need additional plug-ins, you can find them at the sources below. More Sound and Video/Animation Plug-ins   Visit the sites below to download these and other sound and movie plug-ins. Netscape Plug-Ins Download http://home.netscape.com/plugins/index.html Internet.com Browser Plug-Ins http://browserwatch.internet.com/plug-in.html Now you're ready to make Web pages that include sound and movies! Let's go to the tutorials.