Internet Applications

This chapter is from the book 

Video and Audio Conferencing: iChat AV

Computers have linked the world. The ability to carry on real-time chats—through text, audio, and video—bridges cultures and people around the globe. Unfortunately, the process of actually making a connection is often more difficult than it needs to be.

There are numerous shareware/freeware conferencing solutions—Apple’s own QuickTime Broadcaster can even be coaxed into filling the niche (see Chapter 25, "Darwin Streaming Server and QuickTime Broadcaster," for details). None of these, however, approach the ease-of-use of Apple’s iChat AV. iChat allows ordinary users to hold high-quality full-motion video/audio conferences with their friends and colleagues. New with Tiger’s iChat AV is the ability to host and join multiparty video and audio chats. Up to 10 people (including yourself) can participate in an audio chat, and up to 4 in a video chat. Unfortunately, with the new features come lofty new system requirements.

Figure 3.45 shows an example of a video chat session in progress.

iChat AV allows you to communicate in real-time with people who use Mac.com, have an AOL Instant Messenger (AIM) account, or a corporate Jabber server account.

Even if you have no intention of using the text messaging capabilities of iChat, you’ll still need one of these accounts to establish the initial audio or video connection. You can sign up for a free AOL Instant Messenger (AIM) account at http://www.aim.com or an iChat-only (free) .Mac username at http://www.mac.com.

Required Conferencing Hardware

iChat AV works with recognized Mac OS X video sources—FireWire camcorders, webcams, and analog A/V conversion devices, such as the Dazzle FireWire Bridge. Apple’s own iSight camera (http://www.apple.com/isight/) is cost effective and produces high-quality images. If the $150 price tag is within range, I recommend the iSight purchase. If not, the iBot camera is available for the $30–60 range on eBay and works fine with iChat AV.

If you do not have a video camera, you can use iChat AV as an audio-conferencing solution with any system-recognized microphone and you can still participate in one-way video conferences.

On the computer side, iChat AV requires at least a 600MHz G3 for single-party videoconferencing. If you attempt to use video on a slower machine, it reports that video is not available on your computer.

The requirements for multiparty conferencing is even higher. If you plan to use the multiperson video/audio chat features, you’ll need at least a dual 1GHz G4 to host a video chat and at least a single processor 1GHz G4 or a dual-processor 800MHz G4 to join one.

Finally, no matter what high-end CPU platform or video hardware you own, you’ll need network bandwidth to accommodate audio or video streams. The low-end requirements are 56kbps for audio, and 128kbps for video and 1000kbps for hosting multiparty conferences.

Realistically, 56k modem users might be able to audio conference if they have a stable and noise-free connection, but the best experience comes from a dedicated digital connection. xDSL, Cable, and LAN users should be able to carry high-quality audio/video streams easily but even these connections might not be able to host multiperson chats.

Setting Up iChat AV

Unless you entered a .Mac username during the installation of Tiger, the first time you start iChat AV it will walk you through a simple setup process. First, iChat prompts for your name and either your AIM or .Mac iChat account information, as shown in Figure 3.46. To register for a free .Mac username, click the Get an iChat Account button. Click the Continue button to move on.

Next, iChat prompts to set up Jabber Instant Messaging. Unless your company or organization has a Jabber Server, you’ll want to skip this configuration and click Continue. If you do have a Jabber server, check the Use Jabber Instant Messaging box and supply an account name and password. Click Continue to carry on setting up iChat AV.

You are now prompted to turn on Bonjour Messaging. If you have a relatively contained local network, turning on Bonjour probably isn’t an issue. If you’re part of a subnet with hundreds of clients, however, Bonjour is going to overwhelm your buddy list. Click Continue to move on.

Finally, iChat provides a preview of your audio and video input. Make sure that if you have a camera and a microphone attached the inputs are visible before continuing. Your setup is now complete. Click the Done button to begin using iChat AV.

Adding and Editing Additional Accounts

To edit or modify accounts after iChat AV has complete the initial setup process choose iChat, Preferences from the menu. Click the Accounts icon, to open the Account manager, as shown in Figure 3.47.

Much like Mail, the iChat accounts settings are laid out with accounts on the left side of the window and account settings on the right. To edit an existing account, chose it in the list—the settings will appear to the right.

While you can only have one of each account type active at a time, you can create as many AIM, .Mac, or Jabber accounts you’d like and switch between them at will. The accounts that are currently active have checkmarks by their name. To add an account, click the + button. An account creation dialog will appear, as shown in Figure 3.48.

Use the Account Type pop-up menu to choose between AIM, .Mac, or Jabber, and then supply your account information and a description of the account in the provided fields. If you want the account to become the default active account, select the Use This Account check box. Click Add to save the account information.

Advanced Account and Server Settings

After an account is added, selecting it in the account list will display its associated properties in the pane on right side of the window. There are up to three settings views that you can switch to using the buttons at the top of the right-hand pane:

• Account Information—Basic settings for the account, username, password, and so on. These settings also determine whether an account is currently active (Use This Account) or if it will automatically be logged in to when iChat starts (When iChat Opens, Automatically Log In).

• Security—Determines who can (or can’t) see that you are online. We will look at the iChat security options later in this chapter.

• Server Settings—The server settings can be used to configure proxy connections for your IM servers or set non-standard ports for communication. With Jabber servers, these settings also control SSL encryption of the chat session.

When you are finished adding and configuring all of your accounts and account settings, close the application preferences. You can now begin using iChat AV.

Logging In to Your IM Accounts

Unless you’ve configured the Account Information settings otherwise, iChat AV will automatically log in to your default accounts when it starts up and log out when you quit. To manually log in to or out of an account, use the Log In and Log Out selections under the iChat application menu. If you have multiple AIM, .Mac, or Jabber accounts, you can switch between them by choosing Switch To from the iChat menu.

Activating the iChat Menu Extra

While starting and stopping iChat is an effective means of logging in and out of your accounts, it also means that you have to remember to do it. If you’re like many people, instant messaging is one of your primary means of communications and should be active whenever you are using your computer. To make logging in and out of iChat easier (and automatic), you can activate the iChat status menu extra by opening the General application preferences pane, as shown in Figure 3.49.

Click the Show status in Menu Bar check box to display as a speech bubble on the right side of your menu bar. While in the General preferences, you might also want to uncheck the option When I Quit iChat, Set My Status to Offline—this will allow you to quit the iChat application but still receive messages.

When the iChat status menu is active, you do not have to have iChat AV open to set your online status, or to initiate a chat session. Simply activate the menu and choose Available to log in or Offline to log out. The last status setting you’ve chosen will automatically be applied when you log in to your Tiger user account.

Configuring Your Online Information

There are a number of pieces of information that other users can see when you’re online—such as your account status, an AIM profile, and a picture you’ve chosen to represent yourself. You’ll want to get a grip on how to control these settings so that you can be certain that your buddies are seeing what you expect them to.

Setting Your Account Status

When you are logged in to iChat AV, other members can see whether you are available for a chat. There are just two status states you can set your account to use: Available and Away—accessed from either the iChat Status menu extra or the drop-down menu under your name at the top of the Buddy List window. If your machine has been idle for several minutes, it automatically kicks into an idle state to show that you haven’t been using your computer.

By default, your status, as well as the status of your buddies, is indicated by green (available), red (away), and orange (idle) dots next to each name (including yours) in the Buddy List window and iChat AV Status menu. If you have trouble differentiating between the colors or just want a change of pace, the availability dots can be changed to shapes using the General pane within the iChat AV application preferences.

Even though there are only two real states that your account can be set to manually, you can apply your own custom labels to these states. A custom available state called Current iTunes Track is included in Tiger. Choosing this state will show you as available and display the current iTunes track you are listening to—perhaps warning off potential chatters if they see you’ve spent the last two hours listening to Marilyn Manson.

To create additional states, use the two Custom selections found under the Buddy List availability menu (click directly below your iChat name in the Buddy List heading). You are allowed to type your own custom label to be displayed in your buddies’ chat clients. For even greater control, choose Edit Status Menu; the dialog shown in Figure 3.50 will appear.

Click the + button under the appropriate column to add messages to your Available or Away pool. Use the - button to delete existing messages. If you want iChat to remember the messages you’ve typed between sessions, be sure the Remember Custom Messages check box is selected.

Changing Your AV Capability Status

In addition to the availability status, iChat also sends your AV capability status to your buddies. This information tells the remote systems if you are capable of accepting video and/or audio chats. While presumably you do want to use these features (that’s why you’re reading about iChat AV, after all), sometimes you might want to temporarily disable them.

To disable/enable your Microphone and Camera devices, uncheck the Microphone Enabled or Camera Enabled menu items under the main Video menu (or Audio menu, if you have no video capabilities). Your AV capabilities will immediately update in your friends’ buddy lists.

Updating Your Profile

Your AIM profile is nothing more than a few paragraphs of text that describe yourself, or say whatever you want. You can use the profile as a means of communicating with your friends or leaving a note larger than just a custom Away or Available message. In addition, the profile is visible even if you aren’t online.

To change your profile, choose Buddies, Change My Profile from the menu bar. The profile window, shown in Figure 3.51 will appear.

Enter your text into the Profile window then choose OK to save it to the AIM servers.

Setting Your iChat AV Buddy Icon

A unique feature of the AIM service is the capability to set custom thumbnails of all your contacts and yourself—these are known as buddy icons (or buddy pictures depending on what label Apple decided to use where). Your buddy icon is automatically transmitted to your friends so that they can see whatever you’ve set your icon to be. Similarly, if they’ve set custom icons, they will automatically show up on your system.

By default your personal AIM buddy icon is the image set in the Address Book application or the icon used for your account image. To replace it with one of your choosing, drag a new image into the image well beside your name at the top of the Buddy List window or choose Buddies, Change My Picture from the menu bar to edit your existing icon.

An editing window appears to allow you to position and scale the image, as shown in Figure 3.52. Drag the image so that the section you want to use as an icon is centered in the bright square in the middle of the window; then use the zoom slider underneath the image to zoom in and out. The center square shows the icon that will be set—albeit not necessarily the same size it will be in iChat AV. When you’re satisfied with the image, click Set.

If you want to choose another image from a file, click the Choose button, and you are presented with a standard file selection dialog box. Users with a camera attached will notice the Take Video Snapshot button at the bottom of their window. Clicking this button displays a live video preview, gives you roughly 3 seconds to primp and preen, and then automatically takes a snapshot that you can use as a buddy icon. This provides an easy way to create a new icon for your mood du jour.

Given that it is so easy to create and switch button icons, you’ll soon end up with a library of icons. To switch to any icon you’ve used recently, click your thumbnail image in the Buddy List window. A palette of frequently used icons displays, enabling you to quickly switch to icons on the fly.

Managing Your Buddy List

Virtually everything that goes on in iChat starts with the Buddy List. When you log in to AIM through iChat, the full Buddy List window appears onscreen to show which of your friends are online (not grayed out), whether they’re available to chat, and what conferencing capabilities (Audio/Video) are available to them, as demonstrated in Figure 3.53.

The video camera icon shows video availability, whereas the telephone represents an audio-chat ready contact. If you see multiple stacked video/audio icons, it this indicates that your buddy can join a multiparty video or audio chat. You can customize what details are displayed in the Buddy List and sort it by different criteria using the iChat AV View menu.

Bonjour and Jabber chatting, if active, open virtually identical windows displaying the active users on your local subnet and Jabber server, respectively.

Adding Buddies

Because your buddy list is stored on the AIM servers, you must be logged in to manage the list. To add a buddy, click the + button at the bottom of the iChat Buddy List window or choose Buddies, Add Buddy.

A dialog containing your Address Book entries appears, as shown in Figure 3.54. If the person you want to add to your Buddy List has an AIM or Mac.com listing, highlight the person and click Select Buddy.

If the person doesn’t show an instant messaging name, you are prompted for the information. If the buddy-to-be isn’t currently in your Address Book at all, click the New Person button to create a new entry. Enter the person’s screen name, as well as his real name and email address in the window that appears. You can drag an image file (if available) into the image well to set a custom buddy icon. Click the Add button to save your new Buddy.

Address Book and iChat are integrated such that adding a new buddy to iChat automatically adds a new card in Address Book. However, because your buddy list is stored on the Instant Messenger server, you can’t remove a buddy by deleting an Address Book card. Instead, you must select the buddy in the Buddy List and choose Buddies, Remove Buddy.

Also, keep in mind that deleting a buddy from the Buddy List does not remove the person’s card from the Address Book.

Editing Buddy Info

To edit any information for a buddy that is already stored, select the buddy in the list; then choose Buddies, Get Info, or Control-click on the buddy herself and select Get Info. The Buddy Info, shown in Figure 3.55, provides quick access to your Address Book buddy information.

As with the initial setup, here you can set all the contact information for your buddy, as well as a custom buddy icon. If you do set a custom icon, you can choose to always use it in your buddy list. If this option is not set, your buddy icon can be overridden by any custom icon set on the remote system. Depending on how well you know your friends, this could lead to some embarrassment in the workplace.

Setting Buddy Actions

From the Get Info window, you can also access Buddy Actions by choosing Actions from the Show pop-up menu. A Buddy Action, displayed in Figure 3.56, is something that happens when one of your contacts becomes available or does something interesting.

In this example, I’ve chosen to speak the text "Anne is here!" and bounce the Dock item repeatedly when my buddy becomes available. Additionally, by checking the box Perform Actions Only Next Time Event Occurs, the action automatically is removed after the first time it is used. I have something very important to say to Anne, but usually could care less whether she is online, thus the setting. (No, Anne, that isn’t true, I’m just putting on airs for the reader.)

Seven possible events can be used to trigger a buddy action:

• Buddy Becomes Available—Your buddy has become available for instant messaging.

• Buddy Becomes Unavailable—Your buddy is no longer available for instant messaging.

• Message received—Your buddy has received an IM that you sent.

• Text Invitation—Your buddy has sent you a text chat invitation.

• Audio Invitation—Your buddy has sent you an audio chat invitation.

• Video Invitation—Your buddy has sent you a video chat invitation.

• Buddy Accepted A/V Invitation—Your buddy has accepted an A/V chat invitation that you have sent.

As you set actions for events, a megaphone icon appears beside the event that contains an action. This lets you keep track of what events trigger actions without having to select and inspect each one.

Before you ask, no, in the current release of iChat AV, there is no action for speaking the contents of the messages sent to you.

Viewing a Buddy’s Capabilities and Profile

Much as you have capabilities (the ability to conduct audio chats, hold video conferences, basic ninja skills, and so on), so do your buddies. To get a summary of what IM capabilities a buddy on your list has along with a copy of their profile, select them in your buddy list, and then press Command+I to open the Get Info window. Next, use the Show menu to choose their account name, as seen in Figure 3.57.

The profile is shown at the top of the window, following by a text area where you can type your own notes that will be stored locally. Finally, the supported IM features supported are at the bottom of the window. If you have problems communicating with one of the methods discussed in this chapter, chances are it is not an available capability.

Managing Buddy Groups

If you’re the sort who actually has friends, you might find yourself with a long-scrolling list of buddies in your window. To better manage your buddy list, you can arrange them into groups such as "People I know," "People who are stalking me," and "People I am stalking." After creating the groups, you can choose which group or groups are displayed at once.

To access the groups feature of iChat AV choose View, Use Groups. Collapsible headings for each group appear in the Buddy List, as shown in Figure 3.58. Clicking the heading will toggle between hiding and showing the group members. A default group Buddies contains all your buddies.

To add a new group, click the + button at the bottom of the Buddy List and choose Add Group. When prompted, type a name for the group and click Add. The empty group will be added to your buddy list.

To edit existing groups, click the + button again and choose Edit Groups to open a group management dialog box. Groups can be renamed by double-clicking their names in the list or selecting them and clicking Rename. Groups (and the buddies they contain) can be removed by selecting their name and clicking the - button. You can also add new groups within this view using the + button.

After adding a group, populate it with buddies by dragging their names in the Buddy List onto the group names. To remove a buddy from a group, drag the buddy back into the default Buddies group.

Blocking and Allowing Buddies

Your buddies are, presumably, actually your buddies—or at least people that you have some intention of talking to. If you’re like me, however, you rarely want to talk to everyone all the time. iChat AV provides the ability to selectively choose who can see you are online and who can start a chat session with you. This information is configured on an account by account basis, meaning that different accounts can allow or block different people.

To configure your block/allow list, open the Accounts application preference pane, choose the account you want to configure, and then click the Security button, as shown in Figure 3.59.

By default, your IM account will allow anyone to see you are online and initiate a chat with you. Using the radio buttons, you can choose to be visible to those individuals you’ve added to your buddy list, or a specific list of people.

An alternative approach is to configure who is blocked rather than allowed. The block everyone button will prevent anyone from seeing you are online. The Block Specific People setting, on the other hand, will allow everyone except individuals that you choose.

To edit either the allow or block list, click the Edit List button. Use the + and - buttons in the dialog that appears to add and remove screen names from the list. Note that you must use the screen names in the allow/block lists, iChat will not warn you if you don’t, but it will not work as expected.

Initiating IM and A/V Conferencing

In iChat AV, there are three types of messaging that you can choose to use to communicate with your friends: text, audio, and video—represented by the A, Phone, and Video camera icons at the bottom of your buddy list. To start a messaging session with one of your buddies, just select her name in the list and click the appropriate icon at the bottom of the Buddy List.

Alternatively, you can double-click your buddy’s name to start a text chat, or click the telephone or video icon by her buddy picture to start an audio or video chat.

If your buddies’ icons display multiple overlapping telephone and video camera icons, this indicates they can participate in a multiparty chat. If you are equipped to host a multiparty conference, select all the participants by Command+Clicking their buddy list entries, and then clicking the camera or phone icon at the bottom of the Buddy List. If not all the participants are available when you start the session, don’t worry—you can add audio and video conference members on the fly at any time during the session.

For those who want to mouse around and use their menus, the Buddies menu also allows you to initiate conferencing sessions—including two special chat types: one-way audio and one-way video. These are useful if you want to send audio or video to someone without a camera. They can type their responses to you and watch/hear your audio/video stream.

Now, let’s take an in depth look at how each of the communications methods works they are initiated.

Communicating via Text Messaging

Starting a text messaging session opens an empty message window. Type your message in the field at the bottom of the window and press Return on your keyboard. If you’re into sending emoticons (smiley faces) there is a convenient pull-down smiley menu on the right side of the input field. Basic formatting controls (Bold, Underline, Font, and so on) are found under the Format menu and can be used to style your text on-the-fly.

After sending your message, it appears in the upper portion of the window, along with whatever reply the other person sends. The text of a conversation can be saved by choosing File, Save a Copy As.

If you receive a message while not already engaged in a chat session with the sender, you are alerted, and a message window appears. If you click on the window, it displays an area for you to type a response (immediately accepting the invitation) or provides you the option of clicking Block to block the request and further messages from the buddy, Decline to turn down the chat with your buddy, or Accept to start chatting. Again, if you enter a response and press Return, it is assumed that you have accepted the chat.

You can add the person you’re currently chatting with to your Buddy list using Buddies, Add Buddy or show their Address Book entry with Show in Address Book.

Customizing the Chat Window Appearance

If you find the conversation bubbles cute but overwhelming (or perhaps just downright annoying), you can use View, Show as Text to disable them (and Show as Balloons to turn them back on when your Windows friends are over). You can also customize the font and font and color for both your and your buddies’ messages.

Further chat window View settings include the option to choose how buddies are identified in a chat (using their pictures, names, or both), the capability to set a customized picture as the chat background, and finally the option to clear the background picture after you’ve decided that it is way too silly a feature to enable.

Sending and Receiving Files

In addition to sending ordinary text messages, iChat allows you to send files. To send a file, drag its icon into the message area of a chat window and press Return on your keyboard. The recipient can then drag the file onto his desktop. If you send image files, they appear inside the chat window as part of the conversation. (For maximum compatibility with people using AIM programs other than iChat, it’s recommended that you stick with JPEG and GIF image formats.)

When you find yourself on the receiving end of a file transfer, the file will appear as a small icon with link in your iChat message window. Clicking the link will open a status window that displays the copy progress. By default, all downloads are made to the Desktop folder. This can be changed in the General application preference pane.

Sending and Receiving Links

Hyperlinks can also be sent as a special iChat object. To send a hyperlink, drag the bookmark from your browser, use the Edit, Add Hyperlink option to enter in a clickable URL, or just type or paste it in, and the URL will automatically be recognized.

If you receive a link in an instant message, it will appear as underlined text, just like a web browser. Click the link to open the URL in your default browser.

Direct Messages

AIM messages are not (usually) a direct line of communication between people. Instead, all IM traffic is routed through instant messaging servers, in the case of AIM—AOL’s servers. Although this conveniently avoids many connection problems with firewalls and inbound traffic, it also leads to privacy concerns about who could potentially be watching your chat. In addition, the extra time required to transmit through a central server can slow file transfers between individuals. To avoid this, users can activate a direct instant messaging session where all information is passed directly between the participants’ computers.

To do this, choose the buddy to send a direct IM to, and choose Buddies, Send Direct Message (Command-Option-Shift-M). If both you and the recipient are connected directly to the Internet, an IM session starts, exactly as it would through the AOL servers.

Multiparty Chat Sessions

As you’ve probably guessed, you can easily participate in chats with different people simultaneously, but each chat session would be in its own separate window. You can also start a chat session with multiple people where all participants can see messages and type simultaneously.

To start a group chat:

1. Highlight the buddies you want to invite to chat; then Control-click on any of the names and choose Invite To Chat, or just click the A button at the bottom of the

2. Type a message inviting the participants. When the invited buddies receive the chat request, they can choose to accept or decline. If they accept, they can send and receive messages as part of the group.

To add additional buddies to a chat, use the + button at the bottom of the participants drawer to select their name, as seen in Figure 3.60.

All multiparty chats are given a Chat Name that can be used by any AIM user to join the chat, even if they aren’t on your buddy list. To choose a Chat name, select View, Chat Options and type a Chat Name in the provided field.

To join a chat given the Chat Name, choose File, Go To Chat and enter the Chat Name. Other AIM clients should offer the same feature, but how it is accessed obviously will vary.

Creating/Joining a Persistent Chat Room

The Go To Chat feature can also be used to create a persistent Chat room that other users can join. To start a persistent chat choose File, Go To Chat (Command-G). When prompted, type the name of an existing chat room (if you want to join a chat someone else has created), or make up your own name. The iChat AV chat window appears with no participants. Others can join your chat room using the Go To Chat feature on their copy of iChat AV.

Saving Chat/Messaging Transcripts

To save the contents of a chat to a text file, choose File, Save a Copy As from the menu bar. This will create a file that you can later open and review in iChat by choosing File, Open. If you prefer, you can automatically save transcripts of all your text chats by choosing Automatically Save Chat Transcripts in the Messages pane of the application preferences.

Conversing via Audio Chats

Believe it or not, it’s actually easier to describe the options for audio and video chats than it is for text messaging. When an audio chat has been initiated, a window containing the names and icons of each of the participants appears. Beside each conference member is a volume meter; as the person speaks, the meter flashes, making it easy to determine who is talking at any given point in time. A multiparty audio conference is shown in progress in Figure 3.61.

At the bottom of the conference window is your own volume input meter along with controls for adding participants, muting your microphone, and controlling the output volume of your speaker.

The input level meter can be used to gauge whether your microphone is positioned correctly, or whether you need to adjust the input level (gain) within the Sound System Preferences Pane. An iSight user in an average office environment should see 1/8-1/4-inch of flicker (background noise) on the left side of the bar. If background noise approaches 1/3-inch or 1/2-inch of the bar length, you might need to reduce the gain or find a quieter place to chat.

During a chat, you can adjust the volume using the chat window’s volume slider, or quickly mute the conversation (so that you can swear loudly) by clicking the crossed-out microphone button.

If the volume is too high, you might experience feedback as the microphone starts to pick up the speaker sounds. You can fix this by lowering your gain, lowering the volume, or positioning the microphone farther away from your speaker.

Inviting Additional Audio Chat Participants

To invite additional members to an audio chat, click the + button in the audio window and choose the audio-enabled member from the pop-up list. You can only add participants that meet the minimum requirements for an audio chat—meaning they have Tiger and at least a 1GHz G4 (or dual 800MHz G4).

If you start an audio chat with a user that doesn’t support multiparty conferencing, you will not be able to add additional members.

Responding to an Audio Chat Request

If you are on the receiving end of an audio chat request, you are prompted with an incoming chat alert (similar to an incoming text message) and, after the alert window is clicked, given the option of accepting or declining the chat—or making a text reply. If you choose a text reply, you effectively open a new text chat with the remote party, and the audio chat is canceled.

Conducting Video Chats

A video chat works virtually identically to an audio chat but with the added bonus of being able to see as well as hear the remote participants. When a video chat is initiated, you see a preview of yourself until the chat is accepted. In the case of a single-part chat, after a connection has been established, your image shrinks to the lower-right corner of the window, and your buddy’s smiling face fills the rest of the window.

You can resize your mini preview by moving your cursor over it and then dragging the resize handle that appears. You can also click and drag the mini preview to any of the four corners of the window.

Multiparty chats are a bit more interesting, as seen in Figure 3.62. When multiple individuals are invited to a chat, each person’s image is displayed as a 3D panel surrounding the smaller image of yourself. The effect is similar to sitting at a table with your colleagues. You can see them and they can see you without having to search the screen for a window with their picture.

At the bottom of the video chat window is a microphone button for muting the audio portion of chat and a button with two opposing arrows for expanding the view to fill the whole screen (Control+Command+F). The + button is also present and active in multiparty-capable chats and can but clicked to display a menu allowing you to invite another person to the conference. Up to four (including yourself) individuals can participate in a video conference simultaneously.

When in full-screen mode, moving the mouse displays several button controls above your preview image: an X to close the chat, a microphone to mute, and double arrows to shrink back to a windowed view. Again, use the drag handle that appears in the upper-left corner of the preview to resize your own image onscreen or click and drag the entire mini preview window to move it to another corner.

To pause the video display at any time, use Video, Pause Video.

Responding to a Video Chat Request

When receiving a video chat request, clicking the alert window gives you a preview of your own video feed so that you can make sure that you’ve dressed yourself properly before clicking the Accept button to start the chat. Like the audio chat, you can also decline a chat request or send a text reply instead of video.

Applying Parental Controls

As with Mail, if you have children, you probably want to know who they are chatting with or at least protect them from unwanted chat requests. To set parental controls for non-administrative user accounts, open the Accounts system preference panel, select the user you want to restrict, and click the Parental Controls button. Click the Configure button to create a buddy list for the account, as shown in Figure 3.63.

Use the + button to open an address book window and select an address book entry with an AIM account or create a new entry. This works identically to the process of setting up your own buddy list, discussed earlier in the chapter. To remove buddies, click the - button. When finished, click OK; the account is now restricted.

Setting Event Alerts

iChat is a great way to converse with friends and family, especially if you have a computer that is always on. In the default iChat configuration, however, you have to pay attention to your screen to see who is logged in or what is going on—not very helpful for an always-on communications tool. To change this, Alerts can be set to notify you of events such as logins and logouts.

Under the Alerts pane of the application preferences, choose what iChat does when you or your buddies log in or out. Use the Event pop-up menu to choose an event to modify; then click the check boxes for the actions you want to apply, such as playing sounds, speaking text, and bouncing icons. This is similar to the individual Buddy Actions discussed earlier but applies to everyone not just a specific person.

Turning Repeated Ring On and Off

When a conference request first comes it, your computer will ring...and ring...and ring...and ring.... If you absolutely despise hearing this sound over and over, Apple provides a way to force the iChat from playing it repeatedly.

Within the Video application preference pane (great location for an alert setting, isn’t it?) uncheck Play Repeated Ring Sound When Invited to a Conference.

Diagnostics with the Connection Doctor

Depending on you and your buddies’ connections, video and audio chats might be a bit choppy or sporadic. As you’ve already learned, you need at least a 1000kbps upstream connection to host a multiparty video chat. If something isn’t working, it could very well be a lack of network bandwidth.

To get an idea of the throughput of your connection, choose Video, Connection Doctor. The Connection Doctor (which doesn’t really make anything better) is displayed in Figure 3.64. There are two display views—Statistics and Error Log, selected using the Show menu at the top of the window.

Watch the audio and video quality during the conversation. If they are not in the 90–100% range, you might have an unsatisfactory conferencing experience. The bitrate measurement will tell you exactly how much data is being sent locally and remotely.

Adjusting Bandwidth

Some choppiness problems can be rectified by limiting the amount of data being streamed to your chat partner. Usually iChat AV determines the proper streaming rate automatically, but in some cases you might want to try setting the value yourself. To do this, use the Video preferences pane within the iChat AV preferences, shown in Figure 3.65.

The bandwidth limit is initially set to none, meaning that iChat attempts to stream data as quickly as possible to the remote site. You can limit the bandwidth to anywhere from 100kbps to 2Mbps. Low-end (ISDN) connections should restrict the bandwidth to 100kbps, whereas cable and xDSL users might be able to get away with 200kbps or possibly 500kbps. (For those saying "hey, my cable modem can max out at 3Mbps!"—that’s true but is almost always the downstream speed. Upstream rates usually range from 192kbps to 500kbps.) Only local or high bandwidth (T1/T3/ATM) connections should attempt the upper settings.

Firewalls and Connection Errors

The Connection Doctor can also be used to view errors that occur in making the connection to remote audio and video chat partners. To view the error log, open the connection doctor and choose Error Log from the Show menu. IChat AV will display all the connections it attempted to make and what failed.

Most often, failure of a conference is due to a firewall conflict. iChat AV’s audio and video features work well as long as one side of a connection is not behind a firewall or connection sharing device. To use video/audio conferencing behind a firewall, you must enable ports 5060 UDP (conference notifications) and 16384-16403 UDP (audio and video) to be passed through to the iChat AV computer. To read Apple’s tech note on this topic, visit http://docs.info.apple.com/article.html?artnum=93208.