Media Backend Services

The media backend service does the work of decoding, playing and controlling the media based on requests from the Storyboard application over a Storyboard IO channel. The default Storyboard IO channel name is com.crank.media_backend. This value can be overwritten by setting the SBMEDIA_CHANNEL_NAME environment variable to a new value. The FFmpeg plugin is loaded automatically when it is present in the Storyboard plugins directory. If the gstreamer-backend is going to be used to play media, the FFmpeg plugin needs to be removed from the Storyboard plugins directory or else both backends will compete to service media requests.

GStreamer Application

This media backend uses the gstreamer framework to play and control audio and video files. In order to use this backend the platform must have gstreamer and the required plugins installed. It is a good idea to try and play content with the "gst-launch" application to ensure a proper installation before running gstreamer-backend. This backend also uses Storyboard IO for communication with the Storyboard application so please ensure Storyboard IO is functional and the application has the "greio" plugin loaded.

Options:

-e : Render the video content with an external buffer

-p pipeline: Use the defined gstreamer pipeline to play the media

-v: increase verbosity, debug output

Action Data The "new.audio" and "new.video" actions take an extra_data argument. This argument is a string which can contain the following options which must be separated by a ";".

GStreamer Pipeline

You can specify the gstreamer pipeline used to play the particular media by either passing it on the command line to gstreamer-backend with the -p option or by passing it to the actions. The pipeline can be passed in as:

"pipeline:[your pipeline]"

This pipeline can be similar to the one used with the gst-launch application with a few minor modifications. In order to allow the changing of the media file the first part of the pipeline must contain a named filesrc element as follows:

"pipeline:filesrc location=video.mov name=media-src"

Doing this will allow the code to find the named element and replace the location with a new video file.

FFmpeg Plugin

This is a plugin to Storyboard which uses the FFmpeg libraries to play and control audio and video files. In order to use this backend, the plugin must be included with in the runtime engine. You can play a video from the Storyboard Designer Simulator, as well as using the Storyboard Engine on supported platforms. Note that at this time, FFmpeg ships with only WebM video format support and Ogg audio format support.

Action Data The "new.audio" and "new.video" actions take an extra_data argument. When using FFmpeg, extra data is ignored and this argument should be empty.