MediaBoard (mb)

Syntax

Description

Command Line Arguments

• -sa sessionAddr
  sessionAddr is of the form address/port[/ttl]. It specifies the address and port on which MediaBoard will send and receive data. Point-to-point conferences are initiated by supplying a standard IP address, while multi-party conferences should use a Class D group address (224.0.0.2 to 239.255.255.255). Internally MediaBoard uses 2 ports, one for data and one for control. The data port is always an even number and the control port is always the data port number plus one. The number port is taken to be the value of either the data or control port depending on whether it is even or odd. If ttl is specified, then it specifies the TTL (Time-To-Live) value for IP multicast, which controls the scope of data distribution. The TTL value defaults to 31.

• -follow followActive
  followActive is either 1 or 0. followActive control whether the "follow active source" feature is turned on or off. When this feature is on, mb will automatically switch to a page with activity. Turning on this value is useful when following a lecture style presentation. Default value is 1 (on).

• -dp delayParams
  delayParams is a list of the form "C1 C2 D1 D2" which specifies the delay parameters to be used by the underlying SRM protocol. The default values are: "1.0 2.0 1.0 2.0". Adjustments of these parameters is almost never required.

• -K sessionKey
  sessionKey Specifies the encryption key for encripted sessions. (This only works if you have a binary with encryption support. Because of U.S. export controls, the standard distribution from Berkeley may not include this support.)

• -C conference
  Use conference as the title of the MediaBoard window. If the -C flag is omitted, the destination address and port are used as the window title.

• -u uid
  Use uid as the user id to identify this instance of MediaBoard. This shouldn't be set normally, since it will default to the user id of UNIX hosts.

*Mb.followActive: 0

Additional resource settings

• canvWidth (500)
  default startup width of the drawing area in pixels.
• canvHeight (430)
  default startup height of the drawing area in pixels.
• omitButtons ()
  omitButtons specifies a list of buttons that will be omitted from the toolbar on the right. Possible values are: import, unerase, erase, copy, move, oval, rect, line, freehand, and text
• imageOffset (0 0)
  imageOffset is of the form "x y". It specifies the x and y pixel offset from the top left corner at which imported GIF images will be placed. If imageOffset is "none", then the user will be required to specify the location imported GIF's will be placed. This option does not apply to imported PostScript files.
• hilitC (blue)
  Specifies the color that will be used for indicating the current image on the drawing space.
• font<i>
  Specifics a list of fonts to be used for text items. The font names must be in X-LFD format for X-Windows. MediaBoard recognizes all resources of the form font<i> starting from font1 (the angle brackets are to be omitted) to the largest value of i where font<i> is not defined.

User Interface

1. Menu Bar

   • File
     • Save: save the current content into a ".mb" format.
     • Save As Postscript: save MediaBoard content into postscript.
     • Load: loads ".mb" format into MediaBoard. Note that this simply loads the items, ownership and timing information are not preserved.
     • Quit: this allows a user to exit the program
   • Edit
     • Erase Last: Erases the last created item on the page, this is equivalent to clicking on the right mouse button.
     • Unerase: Unerase the last erased item on the page, this is equivalent to clicking on the unerase button on the toolbar.
     • New Page: Creates a new blank page.
     • Import
       Imports an external object into MediaBoard. Currently only PostScript and GIF files are supported. File extensions are used to decide the content of the files. When the import button is clicked, a dialog box for choosing the file is presented. Pressing "import" or double-clicking on a file imports a file.
       • GIFs
         If imageOffset is set to a value other than "none", you will also have to specify the first corner where the file will be imported by clicking on the drawing space.
       • PostScript
         For this to work, you must have ghostscript installed and have gs in your path. After choosing the file, press and hold down button 1 on one corner and release it on another to define the size and location where you want the file to be rendered.
       Pressing the import all button imports all files currently shown in the dialog box. This option only applies to GIFs. The first imported file is placed on the current page. For each additional file, a new page is created for it. MediaBoard assumes that files imported are named as [imagename][n].gif, where imagename contains only alphabets and n is a number. The files are imported in sorted order of the values of n. This is the way PowerPoint saves GIFs when converted from the ".ppt" format.
   • View
     • Members...
       opens a window that lists the members in the session.
     • Past Activity...
       This activates the View Past Activity mode
     • Session Info...
       Opens the session dialog box, which displays information about the current session, such as addresses. The dialog box allows you to change your name that is announced to other members and the encryption key to be used. You will have to click on the 'key' entry box to start typing.
     • Follows Activity
       If this is activated, whenever MediaBoard detects newer activity on a different page that is not the current one, it will automatically switch to it.
     • Page:
       Selects the page to view from a list.
     • Tips:
       • When drawn: if checked, banner windows showing the user names will pop up as new items are being rendered.
       • Under cursor: if checked, banner windows showing the user names associated with the item under the cursor will pop up.
     • Options: Change debugging options.
       • Simulate Packet Drop
         This simulates packet drops at the local end.
       • Toggle Trace Window
         Toggles displaying the window to control the amount of trace information to output.
       • Status bar on top
         Controls the location of the status bar.
     • Debug info: view debugging information.
       • Timestamps: displays the timestamps of MediaBoard data on all pages.
       • Canvas: displays items on the current canvas.
     • Help
       Displays help information.
       Currently there is only "about" which displays the version of the MediaBoard application.

2. Toolbar

   The toolbar on to right allows the use to choose different editing modes. The button corresponding to the currently active mode will have a sunken look.

   The first set of buttons allows you to create new items.

   • Text Mode
     Clicking button 1 on the drawing space creates a text item. A text cursor is displayed, allowing entering of text. To erase the last character typed, press the backspace key. Creation of a text item ends when the mouse is clicked on another location, or when another mode is selected.
   • Freehand sketch Mode
     Press and hold down mouse button 1 in the drawing space to start a new sketch segment. A sketch segment ends with the mouse button is released.
   • Line/Arrow, Rectangle, Oval modes
     Press and hold down button 1 at one corner of the drawing space to define the first corner of the object. Release the button at the point where you want the second corner to be.

   The second set of buttons allows you to edit existing objects. Note that you can only change objects that are created by you.

   • Move
     Place the mouse button over to the item that you want to be moved. A rectangle will appear around the current item. Press and hold down button 1 to start the move. Release button 1 at the location where you want the item to be relocated.
   • Copy
     This works the same way as Move, except that the original item is left untouched.
   • Erase
     Clicking on a current item when in this mode deletes it. In addition, clicking on button 3 will always delete the last created item on the current page.
   • Unerase
     Undo the last delete action on the current page.

3. Drawing space

   The drawing space displays the contents of the current page. the behavior of mouse actions in the drawing space is dependent on the current active mode.

4. Status Bar

   • Properties Panel
     When creating a drawing object, the applicable properties of new objects can be selected from using dropdown lists displayed on the left of the status bar, in the properties panels.
   • Current Page Indicator
     This is a dropdown list that displays the name of the current page and allows switching to different pages.
   • Page Navigation buttons
     On the extreme right are page navigation buttons that changes a adjacent page to be the current page.
   • Zoom Panel
     This is a combination box (drop down list + text entry) that allows changing of the zoom level for the current page. You can enter a zoom value that you want into the entry box, or select one of the following options:
     • fix to view
       When this is selected, resizing the window causes the zoom scale to be changed so that the current view is preserved.
     • numbers e.g. 100
       Preset numbers for switching to zoom levels. This is equivalent to typing in the zoom level in the entry box.
     • fit width, fit height or fit all
       This changes the zoom level so that the width, height, or width and height of all items on the current page can be seen.

5. Source Window

   
   The source list window lists the members in the session. When a session member draws on MediaBoard, his or her name will be highlighted.

   Interface

   • Click on the boxes under the "track" column enables tracking for a member of the session. This means that MediaBoard will automatically switch to the page when the session member switches to a different page.
   • The follow activity check box on the bottom toggles the follow activity feature.
   • When "Auto Raise" is checked, the source list window will be raised when there is MediaBoard activity.

6. Viewing Past Activity

   
   The above panel appears at the bottom of the main window when the view-past-activity mode is activated. Note that in this mode, you cannot add annotations to MediaBoard, but you can still switch between to different pages.

   Interface

   • Step slider: use this slider to change the amount of time to skip over for each frame during animated playback. The time per frame is displayed on top of the slider.
   • Time slider: this shows the current time MediaBoard is displaying. The slider can be used to tell MediaBoard to display another time (click the middle button on the destination time or drag the slider when the left button).
   • Pause button: when this is clicked, the animated playback stops.
   • Play button: starts animated playback in the forward direction.
   • Rewind button: starts animated playback in the reverse direction.
   • Stop button: Stops animated playback.

7. Short-cuts

   • Middle mouse button or hold down shift and press left mouse button or Ctrl-v
     Paste text from the clipboard into the current location, or the current text item, if in text mode.
   • Mouse Button 3
     Erase the last created item on this page.