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IVIPlay User's Guide

Playing a Video | Getting Information | Additional Features

IVIPlay is a tool for playing video files that are in Video for Windows* format (.AVI files). IVIPlay supports the latest Indeo® video interactive features, such as active palettes, alternate-line zoom, and transparency.


Playing a Video

To play a video with IVIPlay:

  1. Copy the file iviplay.exe to your hard drive.
  2. Double-click on the application icon (shown in Figure 1) or run the ivi_play.exe application.
  3. Open the video file you wish to play.

Figure 1. The IVIPlay Icon

The initial IVIPlay window appears, as shown in Figure 2.

Figure 2. The Initial IVIPlay Window

  1. To open a video file, select File > Open….
  2. When the Open dialog box appears, double-click the .AVI file you wish to view.
  3. When you see the movie window (as shown in Figure 3), select Movie > Play.

Figure 3. The IVIPlay Movie Window

The movie window includes a status bar along the bottom, showing the number of frames skipped and the time elapsed during playback. When stepping through a video one frame at a time, the letter K indicates that the currently displayed frame is a key frame

NOTE: Unlike the other information in the status bar, the key frame does not updated during playback.

When the video has finished playing, select File > Close to close the video file or File > Exit to quit the IVIPlay application.

Navigating through Videos
IVIPlay allows you to:

  • stop or pause video playback
  • return to the beginning
  • loop continuously
  • move backward or forward through the file by various increments

View keyboard shortcuts by selecting Movie > Info… and clicking the Shortcuts tab.

Table 1. Navigating Videos

 
Action Menu Item Shortcut Key
Play or pause Movie > Play space bar
Stop playback Movie > Stop N/A
Rewind to first frame Movie > Rewind Home
Loop continuously Movie > Loop N/A
Go to last frame N/A End
Go back one frame N/A left arrow
Go forward one frame N/A right arrow
Go back one second N/A Ctrl-left arrow
Go forward one second N/A Ctrl-right arrow
Go back one-tenth of file N/A Ctrl-Shift-left arrow
Go forward one-tenth of file N/A Ctrl-Shift-right arrow

In addition, you can click the right mouse button inside the IVIPlay movie window to see a slider bar. Use the slider to move to the part of the movie you wish to see.


Getting Information

IVIPlay allows you to access information about both the video file you have opened and program itself.

Information about IVIPlay
To get the version number of IVIPlay and the operating system in which it is currently running, select File > About…. A dialog box appears, such as the one shown in Figure 4.

Figure 4. About… Dialog Box

Information about the Video
To get information about the currently open video, select Movie > Info…. If necessary, select the General tab.

A dialog box appears, such as that shown in Figure 5, indicating:

  • the name of the video file
  • the length of the video clip in seconds
  • its audio format
  • its video resolution (the width and height of the movie window, in pixels)
  • the number of frames in the video
  • the frame rate
  • the codec used to compress it
  • the data rate

Figure 5. General Info Dialog Box


Additional Features

IVIPlay provides access to the features available only with Indeo video interactive.

Setting the Number of Colors
The number of colors IVIPlay uses to display a video file depends on the pixel depth: the number of bits of color information captured per pixel.

  • A system using 8 bits per pixel can display 256 (28) colors.
  • A system using 16 bits per pixel can display 65,536 (216) colors.
  • A system using 24 bits per pixel can display over 16.7 million colors.
  • A system using 32 bits per pixel displays can display the same number of colors as a system in 24­bit mode and reserves the additional eight bits for the operating system to use.

The Options > Bits per pixel menu item allows you to choose the number of bits of color information per pixel to use in playing the video file.

  • RGB 8 (8-bit color)
    Implemented as a palette: a look-up table of 256 color values.
  • RGB 16 (16-bit color)
    Implemented with at least 5­bit values for the red, green, and blue color components.
  • RGB 24 (24-bit color)
    Implemented with 8­bit values for the red, green, and blue color components.
  • RGB 32 (32-bit color)
    Implemented with 8­bit values for the red, green, and blue color components.

If you select more bits per pixel than are currently available on your display, the operating system dithers the video as required. Both image quality and performance can suffer as a result. It's better to set your system color depth for the best quality possible and use IVIPlay to view videos only at or below the system color depth.

The more bits per pixel you use for video playback, the better the image looks but the more demands are placed on the processor. Specifying more bits per pixel requires IVIPlay to handle more data during playback, which can cause the video to drop frames on slower systems.

Using a Different Palette
By default, IVIPlay plays a video file using the codec's native palette. The Options > Palette menu item allows you to choose another palette, perhaps one you have created especially for your application's graphics or a given video clip.

Clipboard plays the video using the palette currently copied to the clipboard.

File opens a file dialog box, allowing you to specify the palette (.PAL) file with which to play the video.

Default plays the video using the Indeo video default palette.

Resizing the Video Window
The Options > Resolution menu item allows you to play the video back at the size in which it was created (its native resolution), or twice as large. The size of the video window can be doubled in two ways:

  • 2x - Pixel doubling enlarges the window by drawing each pixel twice horizontally and twice vertically.
  • 2x - Alternate line enlarges the window by drawing each pixel twice horizontally and, rather than also doubling pixels vertically, drawing a row of black pixels in between each row of image data. This can darken the image somewhat; you may wish to increase the brightness slightly to compensate, using the Options > Indeo Video R4 >Color Controls… documented below.

NOTE: Alternate line window doubling is available only for videos compressed using Indeo video interactive.

Other Indeo Video Interactive Features
IVIPlay supports the special features of Indeo video interactive:

  • scalability across a variety of processors
  • access key file protection
  • control of brightness, contrast, and saturation during playback
  • transparency (a mechanism analogous to chromakeying that gives video developers the ability to composite video foregrounds over graphics or video backgrounds)

Selecting Options > Indeo Video R4 > Scalability… opens the dialog box shown in Figure 6. This dialog box allows you to specify the maximum number of milliseconds to devote to decompressing each frame. If the available processor power does not allow the codec to decompress the frame in the allotted time, then, assuming the file was encoded using the scalability feature, Indeo video interactive can display a less detailed image rather than drop the frame altogether. This feature is useful for multimedia developers who wish to preview playback of their video files on systems with more or less powerful processors.

Figure 6. Scalability Dialog Box

Selecting Options > Indeo Video R4 >Color Controls… opens a dialog box, allowing you to adjust brightness, contrast, and saturation as the video is playing. Moving the slider to the right increases the relevant parameter; moving it to the left decreases it. Click OK to close the dialog box and play the video using the new values; click Reset to return the video to the color settings with which it was created.

Figure 7. Color Controls Dialog Box

Indeo video interactive allows developers to protect their video files by assigning an access key to them during compression. Video files compressed with an access key cannot be played by any application that cannot supply the key. Selecting Options> Indeo Video R4 >Access Key… opens a dialog box, allowing you to enter an access key to play a protected file.

NOTE: This dialog box has no effect on video files compressed without an access key.

Figure 8. Access Key Dialog Box

Indeo video interactive allows multimedia developers to create videos containing transparent areas. Using a digital technique analogous to chroma keying, developers can specify that a color or range of colors be decoded as transparent, allowing a background image to show through. This allows figures of arbitrary shape and size to move through a background image that is separate from the video file. Figure 9 shows an example Indeo video file that is set up for transparency; in this file, the blue background will be rendered as transparent when the video is played over a background image.

Figure 9. Video File Including Transparency

Selecting Options > Indeo Video R4 >Background Image opens a dialog box, allowing you to specify an 8-bit bitmap to use as a background image. The result is shown in Figure 10.

NOTE: Only 8-bit .DIB files can be used as backgrounds. The background must be at least as large as the .AVI video dimensions.

Figure 10. Transparent Video File Playing with Background Image

Although this feature is intended for video files that include transparent objects, you can play any video file over a background image if it was compressed with Indeo video interactive.

NOTE: When playing transparent video files with a background image in place, the Options > Bits per pixel and Options > Resolution menu items are disabled.


* Legal Stuff © 1997 Intel Corporation