Helper Apps:

SOUND & IMAGE

By Chris Oakes

Bummer.You're cruising along, having just a grand old time on the Web, and suddenly, your browser is stumped. CheezPage of the 70s, for example, tempts you with a Humperdink song clip (Englebert, that is). But when you click the link, the file downloads, followed with a message like, "No Sound Device is Available." Or, a thumbnail image of a scantily clad Fabio fails to deliver the promised full-sized view because your browser says it isn't configured to display a JPEG file.

So, what's the problem? Well, most popular browsers are born with the ability to display common types of images - GIF, JPEG, and XBM, to name a few ugly examples. Your browser may read such an image by using the code flowing through its own software veins. Or, it may be pre-configured to call on a little side-car application to do the job. But when browsers saunter into a snooty Web party full of less common image and sound formats, they need more help. In fact, they need a "helper application" - a heroic little program that hups-to and deals with that special little file. The side-car application that some browsers come with is one example of such a helper application (helper "app" and "viewer" are the breezier terms, by the way).

That Helping Hand

When you use a helper app, you're telling your browser: When you encounter this kind of sound or image, launch this particular application to play or display it. Want a sports analogy? It's like a quarterback handing off the football (the image or sound) to a running back (the helper app). The running back is better equipped to carry the ball through a wall of muscle, bone, and fat.

The browser/helper app tango is really just an automated version of a familiar online routine: downloading a file and viewing it with a compatible application. But let's not pull the man all the way out from behind the wizard's curtain here: this is much snazzier. And, in the case of a helper app like RealAudio, which lets you hear sound as soon as you click, it's really a whole different kinda magic.

The trickiest part of setting up this wizardry comes when telling your browser what file type to look for - key in determining which app it hands off the file to. But we'll save that bit for last; first, we'll see which files scattered about the Web usually call out for help, and look at some helper applications that will give it to them.

How Do I Know What I'm Looking For?

Actually, there's a really easy way to tell when you're in need of a particular helper application. In the example described previously, you find yourself suddenly unable to view a sound or image whose link you've clicked on. Your browser tells you that it's not set up to deal with a file of this type. There. That's a file you need a helper application for. Helpful Web sites will even direct you to another site that contains the necessary software for viewing or listening to their files.
But we can round up the usual suspects that will give you trouble. Typical image and sound file types in need of a helper app are JPEG, GIF, TIFF, MPEG video, QuickTime video, and PDF, Adobe's portable document format. (To the seasoned netter, those aren't just acronyms - they're meaningful words. Get used to them.) Images most commonly in need of a helper app are less common formats like video, PDF, and TIFF images. Audio formats, on the other hand, almost always stump the unsuspecting browser. The common audio file types are AU, AIFF, WAV, RealAudio, AU, and MPEG audio. As you'll see below, one helper app each for video, sound, and images will take care of many of the image and sound formats you'll encounter.

Where Do I Get My Helper Apps?

Luckily, for the Web crawler that you are (or are becoming), it couldn't be easier to get these applications. Your Web browser itself can get to and even download the software to your computer. In addition to HTTP sites, most browsers can navigate FTP and gopher sites. (Just enter the FTP address as you would an HTTP address.)

Above are just a few of the software sites that are abundantly stocked and/or accessible (i.e., when I knocked on the virtual door, I was let in). There are many more FTP and gopher sites loaded with helpful helper apps. The most popular can be difficult to access, so be ready to try alternatives. The Adobe site listed contains only the reader for PDF documents (Mac and Windows); the RealAudio site contains only the RealAudio Player (Mac and Windows).

Some Rough-and-Ready Helpers

Before you can expect to tell your browser to get help with a head-banging song clip or some beautiful bodyscape, the helper app first needs to reside somewhere on your hard disk. No
problem - just pick a reputable program, download it, and install it in some folder or directory on your hard disk.

Your browser actually won't care which program you use or where it's tucked away on your drive. All it wants to know is the pathway to its directory (covered in the next section). When it comes time to get some help, your browser will launch the helper app wherever you've shelved it, and the application will open and play, or display, the file. And all you have to do is click.

But what apps should you look for? Well, on page 78 is a list of some popular applications for Windows and Macintosh that will fill in on a moment's notice to play that "Batman Forever" clip or let Englebert sing. To help you find them, we've included a sampling of sites that boast a good software selection, including most of these programs. The applications listed here are mostly freeware, which costs nothing to use, or shareware, which comes with a small registration fee. But much more software for viewing images and playing sounds or movies thrives out there. If you find or hear about some other handy app, don't hesitate to check it out.

The Worst for Last: Configuring

The best way to pair off a browser and a helper app is to let them meet and sort of shake hands. Go back and click on that stranger of a file that got you into this mess in the first place. Via its charming dialog-speak, your browser will indicate that it isn't familiar with this here type of file. Super-sociable browsers like Netscape Navigator and the America Online browser will ask you in the same dialog if you'd like to configure a "viewer."This is very polite and you should give thanks. All you'll have to do is show your browser the way to the appropriate helper application.

For example, Netscape Navigator, upon encountering an as yet-unfamiliar RealAudio file, will say: "No Viewer Configured for File Type: audio/x-pn-realaudio."The same dialog will ask: "How would you like to handle this file?"Your buttoned choices: Save to Disk, Cancel Transfer, and Configure a Viewer. That last one is your opportunity to walk down Helper App Easy Street.

All that remains is to bring the blind date to the door. The quizzical dialog will lead you (often via a button labeled "Browse") to a familiar Windows or Mac file dialog. Just use that dialog to light the path to the helper app in question. (Alternatively, Windows browsers will usually let you type in the file path by hand.) Once the introduction has been made, a romance is inevitable. The next time you click on a link leading to that type of file, your browser will automatically open up that boy scout
of a helper app.

The Hand-Picked Way

When your browser doesn't offer the on-the-spot configuration we just described - Spry Mosaic is one such browser that only goes half-way, like a shy date - you have to attend to the details yourself. (This was bound to get a little sticky at some point.)

This class of browsers will still produce an inquisitive dialog. It just won't offer to set up the helper app immediately. But the dialog has an important ingredient: the mystery file's awkward identification. This long, strange text will appear in either the dialog's title bar or within its message text.

Thus, the message may read, "You don't have a viewer defined for content type audio/x-wav. Do you want to save it to disk?" For other types of files, the content type would vary. A RealAudio file, for example, would show the file type audio/x-pn-realaudio. A Wave sound file would show audio/x-wav, or (just one more, because this is so dang fun) a video file would show video/MPEG as its file type.

You don't really want to save the file to disk until you've set up a viewer, so your answer will be No - but wait! You need to jot down the file type first.

That identifying format is called, sadly, the MIME type and the sub-type. A RealAudio file, for example, has the MIME type audio and the sub-type x-pn-realaudio. Together, they're written, as you saw above, as audio/x-pn-realaudio - quite a lovely thing, isn't it? A JPEG image file has the MIME/sub-type code: image/JPEG (a bit simpler). So write down that MIME/sub-type, Bones, and you'll be ready to configure your browser for that content type. ("Dammit Jim, I'm a browser, not a configurer!")

Take heart, the rest is easy.

The Dialog Dance of MIME

For the next and final steps, you need to get your little mouse pointer into the helper app dialog. Different browsers keep these in different places, so check your browser's documentation. Usually, you'll find it under an Options menu, which will lead to a Preferences, Setup, or Configure command. That command will lead (quick breaths) to a button or pop-up menu for configuring your helper apps. (But remember - some browsers call them "viewers.") In Netscape Navigator, for example, you'd choose Preferences from the Options menu, and select Helper Applications in the resulting dialog's pop-up menu.

Once you're in, you'll find a pleasant sight: Most browsers are already aware of a slew of file MIMEs, subtypes, and their ugly extensions. Just how many such types are already known depends on the sophistication of your browser and how up to date it is.

What the browser doesn't know is with which application to open these file types. But that's what you've come to kindly tell it. If you look through the browser's list of file types, you'll see, for example, the type image/jpeg. Where an action or application is indicated, it will most likely say "Internal,""Browser," or an existing helper application's name, indicating that the browser is manfully equipped to handle that easy file type as is.

But when you scroll to find the mystery file type you just jotted down, you'll see that the dialog is much more uncertain in mood. "Ask User,""Unknown," or the most honest "????" is the typical action/
application listed for the unrecognized file. The Prodigy browser's Viewer Setup dialog just shows an asterisk in the Viewer field when no viewer has been assigned. Poor thing.

Well, you're there to give your browser some confidence back. Click on the mystery file type in the list. (What? You say it's not in there? Then just hold on until the next paragraph...) Now you'll associate your happy helper application with the mystery file type by pointing out the helper app's location to your browser.

But you already know how to do that, don't you? It's the same procedure we used in applications that will configure a helper app right on the spot. Just show your browser the way to the app. In Spry Mosaic, after selecting the file type from the dialog list, you click Browse or type in the directory path (Windows only) to the helper app. In Netscape Navigator, you click the Launch Application radio button and type in the path (again Windows only) or use the Browse button (Mac and Windows) that leads to a standard file dialog. When you've located the app for your browser, you can finally click O.K., Save, Close - whatever it takes to save your changes and exit the dialogs. Done. Finís.

Your browser knows yet another file type and the proper way to handle it. Have a beer.

Gasp! The File Type Is Missing!

I know, I know. One last nagging question remains: What if the file type wasn't listed in the helper app/viewer dialog?

Well, don't worry, you're ready for that one, too. You can just create the file type. Sure - I knew you could. The helper application/viewers dialog will offer a button bestowing you with this creative power. A button labeled something like Add Type, New Type, Add Document Type, or Add New Type is your ticket.

When you click that god-like button, you'll be prompted to enter the new file type. No problem - you wrote it down, in all its MIME-sub-type glory. Go ahead - type it in, just as you wrote it. Click O.K. Now you can assign that new type a helper app too, just like you did for the pre-existing types. (I know, "pre-existing" is redundant. See if I care.)

But what of the extensions field? Well, each beautiful MIME type has one or more extensions commonly used to indicate a file of that type. Your browser can identify a file based on its MIME alone, however (can't we all?). The extension serves as a backup ID, kind of like a credit card.

If you know the file type's common extension(s), go ahead and enter it (or them). You may have to put a period before each extension. To find out, just look at the format for extensions accompanying other file types. (Clicking on them will display the extensions.)
If you don't know the extension, there's an easy way to find out. Browse to the Web page that has the file in question. Move your pointer over the link to that file. Most browsers will show the file's path and name at the bottom of the browser window. The very end of the path will show the extension after the file's name (such as .ram for a RealAudio file). That's your extension. Go back to the helper app dialog and type it in.

O.K. Now you're really done.

Windows Sites

ftp://ftp.cica.indiana.edu
ftp://ftp.ncsa.uiuc.edu/mosaic/windows/
ftp://ftp.support.apple.com/pub/apple_sw_updates (for QuickTime for Windows)

Macintosh Sites

ftp://ftp.ncsa.uiuc.edu/mosaic/mac/helpers
http://wwwhost.ots.utexas.edu/mac/main.html
http://www.msc.wku.edu/dept/msc/macintosh/search_umich.html

Windows/Mac

Adobe Acrobat Reader Site
http://www.adobe.com/software.html#acrordr

Progressive Networks RealAudio Site
http://www.realaudio.com

After you've downloaded your helper app, do with it what you do with most any download: decompress it (if it's compressed) and stash it in the directory of your choice. Even though I might use the applications for non-browsing tasks, I keep all my helper apps in a directory inside
my browser's directory.

But that's just me.

Apps & The Files They Help With
Image/Video AppsKey File Formats Supported
MPEG PlayerMPEG video
QuickTime Player for WindowsQuickTime video
LViewJPEG, GIF
Acrobat Reader (Macintosh)PDF (portable document format)
Sparkle (System 7.5 or later)MPEG video, QuickTime video
JPEGViewJPEG, JFIF, GIF, PICT, LZW-compressed TIFF
GraphicConverterPICT, TIFF, JPEG, JFIF, GIF

Sound AppsKey File Formats Supported
WPlanyAU, AIFF, VOC, WAV
SoundAppAIFF, AIFF-C, MooV, AU, WAV
SoundMachineAU, AIFF, AIFC
MPEG AudioMPEG audio
RealAudio PlayerRealAudio (real-time audio broadcast on the net)