Using Theora files to play video

• About Theora
• Creating videos in Theora format
• Theora support in WME

About Theora

Beginning with version 1.5 WME supports playing videos compressed with the Theora codec.

Theora is an open and free video codec developed by Xiph Foundation, the creators of the popular Vorbis audio codec. Learn more about Theora at the official website.

Similarly to Vorbis audio, Theora videos use the Ogg file format. Unfortunately that means they use the same file extension as Vorbis audio files (.OGG) so it may be hard to distinguish between audio and video files at first sight.

Compared to AVI files Theora videos have several pros and cons:

Advantages of Theora:

• The video codec is hardcoded in WME, you don't need to install any external codecs with your game.
• Theora codec is license free. Even though it uses patented technology, the patent holder granted an irrevocable free license to Theora developers.
• WME is unable to play compressed audio in AVI files. This is not true for Theora, which means videos with sound will be considerably smaller.
• Unlike AVI files, Theora videos can be stored inside WME packages. No need to store the video files separately.

Disadvantages of Theora:

• The Theora codec is still in development and at the time of this writing it's in Alpha state. That means the code is not yet fully finished and optimized. But the binary file format is already frozen so any videos created today will be playable with any future releases of the codec.
• Being still in development means it's not yet widely supported by many video editing programs. This is likely to change in the future, though, as it did with the Vorbis audio format.

Creating videos in Theora format

Even though the Theora format wasn't yet adopted by many video editing programs, there are several ways of converting existing videos to Theora. There is a forum thread dedicated to Theora video creation. Please visit this knowledge base article to get up-to-date information.

Theora support in WME

There are two ways of using Theora videos in WME:

1) You can play full-screen video using the Game.PlayTheora() method. This method replaces the old Game.PlayVideo() for playing AVI files.

2) WME entities also provide a PlayTheora() method. That means you can place video playback directly to game scenes, for example to simulate a playing television, or Blade Runner-style video billboards. To control the video playback entities also provide the StopTheora(), PauseTheora(), ResumeTheora(), IsTheoraPlaying() and IsTheoraPaused() methods.

Additionally you can control the shape of the video entity by specifying an optional alpha-channel image when calling PlayTheora(). Only the alpha channel of the image will be used and applied to the playing video. Also the AlphaColor property of the entity will affect the color/alpha of video.