Editing RealMedia with the RealMedia Editor
by Jason Crowder
12/16/02

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We often tell our clients that RealMedia is a “non-editable” format. By this we mean that you cannot use a standard Non-Linear Editing System (NLE), such as Adobe Premiere, to make video editing changes to a file in RealMedia format. There is a way, however, to make simple “cuts only” video edits to these files. This magic is done using the RealMedia Editor, an application that ships with “Producer Plus” line of products from RealNetworks.

Using the RealMedia Editor, you can easily change “clip information” embedded in the file such as the Title, Author, and Copyright, as well as chop the video into smaller segments. Using a little creativity, you can even stitch multiple RealMedia files together to make a larger video segment. All of these issues will be discussed in this tutorial.

Changing Clip Information

There are times I forget to add the correct clip information when encoding a RealMedia file. This occurs most of the time because I do not change the Clip Info fields in the encoding software and just use the values that the last person used before me. You can easily remedy this by following these steps:

1. Open the source RealMedia file in the RealMedia Editor . TIP: You can quickly open files in the RealMedia Editor by dragging and dropping them into the window.
2. Modify the Clip Info fields on the main screen or clip the “Clip Info…” button for more options.
3. Save the file. Note: For larger files, the saving process can take a long time.

Chopping and Trimming-- a RealMedia “Haircut”

Editing with the RealMedia Editor pretty much amounts to giving the RealMedia file a haircut. But as with a real haircut, the more you know about the practice, the prettier the end result. Okay, enough with the metaphor!

It is easy enough to choose the “In” and “Out” points for trimming or chopping. The RealMedia Editor provides a timeline control as well as buttons for selecting the In and Out points. Once you have selected the segment you want to save, you need to make sure the In Point you have selected is on a keyframe. Keyframes are used to reset a video image during encoding. All other frames are created for minor adjustments between the keyframes. If your In Point is not on a keyframe, your final RealMedia output file will playback with black video until it reaches a keyframe. This is why is it so important to make sure your first frame in your new RealMedia file is a keyframe.

Follow these steps to Chop or Trim a RealMedia file:

1. Open the source RealMedia file in the RealMedia Editor
2. Navigate to the location in the video where you want to set your In Point. You can do this by dragging the timeline control handle or by simply playing the video. Stop the video when you have found the appropriate location.
3. Navigate to the Previous Keyframe in the video by clicking the “<<” button. This will ensure that the location you have chosen as your In Point will be included in the actual starting point of the new file. Alternatively, you could have selected the “>>” button to navigate to the next keyframe instead if the location of the next keyframe is an acceptable starting point.
4. Set the In Point by clicking the “In” button (there are keyboard short-cuts and menu options for this as well).
5. Set the Out Point in your video by navigating to the appropriate location in the video and then clicking the “Out” button. It is not necessary to end your video with a keyframe unless you plan to append two video segments together.
6. Enter the appropriate information in the Clip Info fields.
7. Save the file. Because you may not like the newly created RealMedia file, you should save your file with a different filename to prevent overwriting the original source file.

After playing around with the keyframe buttons you will soon discover that you sometimes just have to compromise on the location of your In Point. If your video has lots of motion in it, chances are that you be able to find a keyframe relatively near where you want your video to begin. If you have talking head video with little overall motion, for example, there tends to be less keyframes. TIP: If you enable "Loss Protection" in the preferences section of the "Producer Plus" application, more keyframes than usual will be added during the encoding process which may give you more of an advantage when you edit the RealMedia file later.

Stitching Multiple RealMedia Files Together

The RealMedia Editor does not provide a means for selecting multiple In and Out points. Therefore, if you want to “cut out” a section of the video in the middle of a RealMedia file, you must create a new “first” piece of video and a new “second” piece of video and then append the pieces together.

Create your two video segments by following the steps above for each piece. Be sure to save each video segment with a different filename and do not overwrite the original source file because you may want to go back later and make changes if you do not like the final output. Be sure that whatever piece you designate as the “first” piece ends with a keyframe. This will ensure that the two video segments come together nicely.

Follow these steps to append two RealMedia files together:

1. Open the first RealMedia file in the RealMedia Editor.
2. Select the “Append RealMedia File…” menu option from the File Menu.
3. Browse for the second RealMedia file. Remember, the second RealMedia file will be appended to the end of the first RealMedia file.
4. Enter the appropriate information in the Clip Info fields.
5. Save the file. Be careful not to overwrite the original source file because you may need it later.

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We have discussed how to chop out a middle segment of a RealMedia file, but what if you want to append two RealMedia files that are not from the same source RealMedia file? You can do this, but you must ensure that the RealMedia files are encoded with the same parameters. For example, you cannot combine a RealMedia file encoded at 320 x 240 with a RealMedia file encoded at 400 x 300. The same goes with audio/video codecs, target audiences, etc. The RealMedia editor will display an error message if you try to combine two files with different encoding parameters. You can view the encoding parameters of each file by opening the file with RealMedia Editor, then clicking the “Stream Info…” button.

Another use we have found for this method of editing RealMedia files is for adding an opening “slate” at the beginning of a RealMedia clip. You must, of course, create an opening slate video segment, but once you have one, you can add the slate to any number of RealMedia files (assuming that they were encoded with the same parameters).

Well, that is about it for RealMedia editing. We hope you enjoyed this tutorial and welcome your feedback.