Track objects

GESAudioUriSource — outputs a single audio stream from a given file
GESVideoUriSource — outputs a single video stream from a given file
GESTitleSource — render stand-alone text titles
GESAudioTestSource — produce a simple test waveform or silence
GESVideoTestSource — produce solid colors and patterns
GESTextOverlay — render text onto another video stream in a GESLayer
GESTransition — base class for audio and video transitions
GESVideoTransition — implements video crossfade transition
GESAudioTransition — implements audio crossfade transition
GESImageSource — outputs the video stream from a media file as a still image.
GESEffect — adds an effect build from a parse-launch style bin description to a stream in a GESSourceClip or a GESLayer