Creating RealMedia Metafiles

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Music Humanities
Online Reserves

Using the Online Music Humanities Reserves

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One of the interesting aspects of having the Music Humanities Reserves online is that instructors and students can create their own set of tracks to be listened sequentially. For example, an instructor may want to create a set of clips made up of different works by different composers. The example can also include timing information so that a clip plays a segment of a particular track. The following illustrates the step necessary to create such a link on your web page.

Creating Metafiles

Metafiles contain the addresses of RealAudio (.ra) files that the RealMedia server will play. The filetype for the metafiles is .ram. This file is the file that you will reference in your html code. (If you want to embed the plug-in within the web page, you must follow different direction. See the RealMedia web pages for this information.)
The metafile will contain addresses in the form of a URL. They begin with a locator type, pnm, followed by a specific address on the RealMedia server.
To obtain this information, you must check out the catalog information for each CD that has been encoded.
Let's illustrate the process with our example. We want to make a "virtual tape" that consists of the following:
Example 1.

track 1 (Clouds) from Three Nocturnes by Claude Debussy
tracks 5 and 8 of Hildegard von Bingen: A Feather on the Breath of God
track 6 of Part I of Igor Stravinsky: The Rite of Spring

Using a text editor, create a file containing the RealAudio URL(s). The contents of the file should be in the following form:
pnm://media.cc.columbia.edu/path
Our file would then have the following lines:
pnm://media.cc.columbia.edu/music/humanities/cd355/track01.ra pnm://media.cc.columbia.edu/music/humanities/cd577/track05.ra pnm://media.cc.columbia.edu/music/humanities/cd577/track08.ra pnm://media.cc.columbia.edu/music/humanities/cd365/track12.ra
The file is saved as text-only with a suffix of .ram. Place this file, which we'll call digtape.ram, into your web pages directory. Make it a html link just like here: virtual tape.
Example 2.
Let's make our example a little more complex. Suppose we only need use certain part of the tracks mentioned above. If that is the case, the syntax of the ram file would change as shown below.
pnm://media.cc.columbia.edu/music/humanities/ cd355/track01.ra?start="30"&end="1:00"&title="30 seconds of Debussy" pnm://media.cc.columbia.edu/music/humanities/ cd577/track05.ra?end="1:18" pnm://media.cc.columbia.edu/music/humanities/ cd577/track08.ra pnm://media.cc.columbia.edu/music/humanities/ cd365/track12.ra?title="Last clip"&end="1:00"
Note that each track must be on one line. It is shown here with a break for viewing purposes. The ram file sets a number of additional parameters, including start and end times. Also modified is the title field that will appear on the RealMedia player.
Again, the file is saved as text-only with a suffix of .ram. Place this file, which we'll call digtape2.ram, into your web pages directory. Make it a html link just like here: virtual tape two.
Example 3.

We can also create a synchronized multimedia event. This means that for any one ra clip, you can have a different html document appear at specified times within the clip. To do this, first mark down the times in the ra file when the documents should change. Once that is done, create an input file.
The input file is essentially a list of the URLs that will be shown and the times within the ra clip when they should be displayed. The syntax format is:
u starttime endtime EventURL
If we take the first track in Hildegard von Bingen's Ordo Vitutum and have the lyrics for that piece appear for the first minute then have this page appear again for the rest of the piece, the input file <synch.txt> would look like this:
u 00:00:00.0 00:01:00.0 http://www.columbia.edu/itc/music/landies/tape1/ecce.html u 00:01:00.9 00:03:36.0 http://www.columbia.edu/itc/music/reserves/metafiles.html
If you are using a PC, the rmmerge.exe tool that comes with RealEncoder 5.0 and RealPublisher 5.0 can be used with the following syntax:
rmmerge -f rmevents <event file> <input media file> <output media file>

where:
event file is the inpurt events file created in the previous step
input media file is your input .rm file
output file is the resulting synchronized presentation file

For our example:
rmmerge -f rmevents synch.txt track05.rm synch.rm

However, the shared rmevents file must be specified. In other words, if the rmevents file is not in the current directory that you are attempting to use rmmerge in, the path of the rmevents file must be specified.
Create a ramfile that contains the RealAudio URL. Now create a link: virtual tape three.

Academic Information Systems
acis@columbia.edu - 23 September 1997 - 212 854.1919

Academic Information Systems		Music Humanities Online Reserves
		Using the Online Music Humanities Reserves
Get the tools needed to receive audio and video streams. Visit the RealAudio Sampler and the RealVideo Sampler. Visit the troubleshooting FAQ page for answers to most common problems. Have comments or need to report a problem? Please use our feedback page.		One of the interesting aspects of having the Music Humanities Reserves online is that instructors and students can create their own set of tracks to be listened sequentially. For example, an instructor may want to create a set of clips made up of different works by different composers. The example can also include timing information so that a clip plays a segment of a particular track. The following illustrates the step necessary to create such a link on your web page.
		Creating Metafiles
		Metafiles contain the addresses of RealAudio (.ra) files that the RealMedia server will play. The filetype for the metafiles is .ram. This file is the file that you will reference in your html code. (If you want to embed the plug-in within the web page, you must follow different direction. See the RealMedia web pages for this information.) The metafile will contain addresses in the form of a URL. They begin with a locator type, pnm, followed by a specific address on the RealMedia server. To obtain this information, you must check out the catalog information for each CD that has been encoded. Let's illustrate the process with our example. We want to make a "virtual tape" that consists of the following: Example 1. track 1 (Clouds) from Three Nocturnes by Claude Debussy tracks 5 and 8 of Hildegard von Bingen: A Feather on the Breath of God track 6 of Part I of Igor Stravinsky: The Rite of Spring Using a text editor, create a file containing the RealAudio URL(s). The contents of the file should be in the following form: `pnm://media.cc.columbia.edu/path` Our file would then have the following lines: `pnm://media.cc.columbia.edu/music/humanities/cd355/track01.ra pnm://media.cc.columbia.edu/music/humanities/cd577/track05.ra pnm://media.cc.columbia.edu/music/humanities/cd577/track08.ra pnm://media.cc.columbia.edu/music/humanities/cd365/track12.ra` The file is saved as text-only with a suffix of .ram. Place this file, which we'll call digtape.ram, into your web pages directory. Make it a html link just like here: virtual tape. Example 2. Let's make our example a little more complex. Suppose we only need use certain part of the tracks mentioned above. If that is the case, the syntax of the ram file would change as shown below. `pnm://media.cc.columbia.edu/music/humanities/ cd355/track01.ra?start="30"&end="1:00"&title="30 seconds of Debussy" pnm://media.cc.columbia.edu/music/humanities/ cd577/track05.ra?end="1:18" pnm://media.cc.columbia.edu/music/humanities/ cd577/track08.ra pnm://media.cc.columbia.edu/music/humanities/ cd365/track12.ra?title="Last clip"&end="1:00"` Note that each track must be on one line. It is shown here with a break for viewing purposes. The ram file sets a number of additional parameters, including start and end times. Also modified is the title field that will appear on the RealMedia player. Again, `t`he file is saved as text-only with a suffix of .ram. Place this file, which we'll call digtape2.ram, into your web pages directory. Make it a html link just like here: virtual tape two. Example 3. We can also create a synchronized multimedia event. This means that for any one ra clip, you can have a different html document appear at specified times within the clip. To do this, first mark down the times in the ra file when the documents should change. Once that is done, create an input file. The input file is essentially a list of the URLs that will be shown and the times within the ra clip when they should be displayed. The syntax format is: `u starttime endtime EventURL` If we take the first track in Hildegard von Bingen's Ordo Vitutum and have the lyrics for that piece appear for the first minute then have this page appear again for the rest of the piece, the input file <synch.txt> would look like this: `u 00:00:00.0 00:01:00.0 http://www.columbia.edu/itc/music/landies/tape1/ecce.html u 00:01:00.9 00:03:36.0 http://www.columbia.edu/itc/music/reserves/metafiles.html` If you are using a PC, the rmmerge.exe tool that comes with RealEncoder 5.0 and RealPublisher 5.0 can be used with the following syntax: rmmerge -f rmevents <event file> <input media file> <output media file> where: event file is the inpurt events file created in the previous step input media file is your input .rm file output file is the resulting synchronized presentation file For our example: rmmerge -f rmevents synch.txt track05.rm synch.rm However, the shared rmevents file must be specified. In other words, if the rmevents file is not in the current directory that you are attempting to use rmmerge in, the path of the rmevents file must be specified. Create a ramfile that contains the RealAudio URL. Now create a link: virtual tape three.
		Academic Information Systems acis@columbia.edu - 23 September 1997 - 212 854.1919