With RealPix you can create streaming images, combining these images with other types of media such as audio or text. RealPix can stream images in these formats:
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Additional Information |
For information about the STiNG image format, visit http:// www.iterated.com. |
When you have your images ready, you simply create a RealPix file with mark-up similar to HTML. This mark-up describes how and when the images display, specifying special effects such as a fade to a solid color or a "wipe" transition between two images.
For a RealPix presentation, you can use scanned pictures, clip art, or images downloaded from the Web. When preparing your presentation, maintain three separate sets of images:
The original set includes the unedited files you start with, such as original images off a scanner. Keep this set in case you need to change an image in the working set by, for example, restoring an area you cropped out. Leave these images uncompressed.
The working set comprises the files you have edited. You may have cropped the original images or combined them to form new images, for example. Keep these files uncompressed so that you can edit them later if necessary.
This set consists of the compressed files used in the presentation. For a given working set, you may have several presentation sets. For instance, you may have slightly compressed images for a high-bandwidth presentation, heavily compressed images for a low-bandwidth version.
If your presentation consists solely of streaming RealPix images, you have full control over the RealPix timeline. When you combine RealPix with another component such as RealAudio or RealText, however, the other component may establish the timeline. You then need to coordinate the RealPix images with the other media file's existing timeline. In these cases it is better to finish the other component first, then assemble your RealPix presentation to the final timeline.
When working with an audio track, for example, think about the order of the images, deciding at which points in the audio timeline each image must display. When you are ready to assemble your RealPix presentation, play back the audio and note where you want to add an image. This will establish your RealPix presentation timeline.
Once you have a timeline for your presentation and have ideas about how to place the images, you are ready to create a RealPix presentation. You may find it easier to create a storyboard to lay out the transitions and effects. Or you may want to dive right in, using the presentation in progress as your guide. Either way, carefully consider the bandwidth implications as you place your image and set the start times and durations.
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Additional Information |
For more on bandwidth, see "RealPix Bandwidth Usage". |
The following steps describe how to create a RealPix file. A following section describes the RealPix mark-up tags in detail.
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Additional Information |
For more on this utility, see "JPEGTRAN". |
<imfl>
...All Other Mark-up Goes Between These Tags...
</imfl>
<imfl>
...
<image handle="1" name="drums.jpg"/>
<image handle="2" name="franklin.jpg"/>
...
</imfl>
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Additional Information |
See "RealPix Mark-Up Tags". |
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Note |
Playing a RealPix file on your local machine indicates whether the RealPix mark-up is correct. However, it does not guarantee that the file will stream across a network well. See "RealPix Bandwidth Usage" for information on making a RealPix presentation stream well. |
<smil>
<body>
<par>
<ref src="rtsp://realserver.company.com/pix/ads.rp"/>
<audio src="rtsp://realserver.company.com/pix/ads.ra"/>
</par>
</body>
</smil>
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Additional Information |
See RealMedia Production Guide available at http:// www.real.com for information about creating a SMIL file. |
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Additional Information |
RealMedia Production Guide available at http:// www.real.com explains the options for linking your Web page to your presentation. It also explains how to play your RealPix presentation in your Web page rather than in RealPlayer. |
In your RealPix file you set a presentation display size. When RealPlayer plays your presentation, it expands its display window to this size. To create a simple presentation such as a basic slide show, you can simply fade the images in and out of the display window. Images the same size as the presentation window appear full-size. Larger images shrink to fit the window, smaller images expand.
You may want to display just a portion of a source image, however. Or you may want to display two images side-by-side. RealPix lets you specify the area of a source image that appears in the display window. It also lets you determine the size and placement of images in the display window. To understand how this works, keep in mind the following definitions:
To use just a portion of a source image or the display window for an effect, you define the source or destination rectangle (or both) in a RealPix tag. To do this, you work with these attributes:
For example, the upper, left-hand corner of the source image is identified as srcx="0", srcy="0". The upper, left-hand corner of the destination window is identified as dstx="0", dsty="0".
In the example below, both the source image and destination window are 256 pixels high by 256 pixels wide. The source tags make the top, left quadrant of the source image display in the destination window, effectively magnifying the source rectangle by a factor of 2. Because the destination rectangle defaults to the destination window size, no destination rectangle coordinates are needed.
In this next example, the source image displays in the top, right quadrant of the destination window, effectively reducing the size of the source image by half. No source coordinates are included, so the entire source image displays in the destination rectangle.
This last example shows a portion of the source image displayed at a slightly larger size in the display window. In this case, both source and destination coordinates are given to define the source and destination rectangles.
In the examples above, the source and destination rectangles all have height-to-width ratios of 1:1. This may not always be the case in your RealPix presentations. When source and destination rectangles have different height-to-width ratios, the RealPix <head> tag's aspect attribute determines how the source image displays.
When aspect is "true," RealPix keeps a source rectangle's height-to-width ratio constant when the destination rectangle has a different ratio. For example, a source rectangle's height-to-width ratio of 1:1 stays constant even if the destination rectangle's height-to-width ratio is 2:3.
In these cases RealPix centers the source rectangle in the destination rectangle. It scales the source and preserves its height-to-width ratio until one dimension reaches the rectangle's boundaries and the other dimension is within the boundaries. The existing background shows through any part of the destination rectangle not filled by the source rectangle.
If you turn the aspect feature off, the width-to-height ratio in the source rectangle changes as necessary to fill the destination rectangle fully. This may distort the source image. The following figure shows how a source image fills different destination rectangles when aspect is "false" or "true."