| Interface and Description |
|---|
| org.gstreamer.elements.DecodeBin2.NEW_DECODED_PAD |
| org.gstreamer.elements.DecodeBin2.REMOVED_DECODED_PAD |
| Class and Description |
|---|
| org.gstreamer.elements.DecodeBin
This element is deprecated and no longer supported. You should use the uridecodebin or decodebin2 element instead (or, even better: playbin2).
|
| org.gstreamer.elements.PlayBin
This element is deprecated and no longer supported. You should use the PlayBin2 element instead.
Playbin provides a stand-alone everything-in-one abstraction for an audio
and/or video player.
It can handle both audio and video files and features
Usage
A playbin element can be created just like any other element using
The file/URI to play should be set via
Playbin is a
Playback can be initiated by setting the PlayBin to PLAYING state using
When playback has finished (an EOS message has been received on the bus) or an error has occured (an ERROR message has been received on the bus) or the user wants to play a different track, playbin should be set back to READY or NULL state, then the input file/URI should be set to the new location and then playbin be set to PLAYING state again.
Seeking can be done using
Applications may query the current position and duration of the stream
via Advanced Usage: specifying the audio and video sink
By default, if no audio sink or video sink has been specified via
If the application wants more control over how audio or video should be
output, it may create the audio/video sink elements itself (for example
using GNOME-based applications, for example, will usually want to create gconfaudiosink and gconfvideosink elements and make playbin use those, so that output happens to whatever the user has configured in the GNOME Multimedia System Selector confinguration dialog.
The sink elements do not necessarily need to be ready-made sinks. It is
possible to create container elements that look like a sink to playbin,
but in reality contain a number of custom elements linked together. This
can be achieved by creating a It is also possible to 'suppress' audio and/or video output by using 'fakesink' elements (or capture it from there using the fakesink element's "handoff" signal, which, nota bene, is fired from the streaming thread!). Retrieving Tags and Other Meta DataMost of the common meta data (artist, title, etc.) can be retrieved by watching for TAG messages on the pipeline's bus (see above). Other more specific meta information like width/height/framerate of video streams or samplerate/number of channels of audio streams can be obtained using the "stream-info" property, which will return a GList of stream info objects, one for each stream. These are opaque objects that can only be accessed via the standard GObject property interface, ie. g_object_get(). Each stream info object has the following properties:
Stream information from the stream-info properties is best queried once playbin has changed into PAUSED or PLAYING state (which can be detected via a state-changed message on the bus where old_state=READY and new_state=PAUSED), since before that the list might not be complete yet or not contain all available information (like language-codes). BufferingPlaybin handles buffering automatically for the most part, but applications need to handle parts of the buffering process as well. Whenever playbin is buffering, it will post BUFFERING messages on the bus with a percentage value that shows the progress of the buffering process. Applications need to set playbin to PLAYING or PAUSED state in response to these messages. They may also want to convey the buffering progress to the user in some way. Here is how to extract the percentage information from the message (requires GStreamer >= 0.10.11):
PlayBin playbin = new PlayBin("player");
playbin.getBus().connect(new Bus.BUFFERING() {
public void bufferingMessage(GstObject element, int percent) {
System.out.printf("Buffering (%u percent done)\n", percent);
}
}
Note that applications should keep/set the pipeline in the PAUSED state when
a BUFFERING message is received with a buffer percent value < 100 and set
the pipeline back to PLAYING state when a BUFFERING message with a value
of 100 percent is received (if PLAYING is the desired state, that is).
Embedding the video window in your applicationBy default, playbin (or rather the video sinks used) will create their own window. Applications will usually want to force output to a window of their own, however. This can be done using the GstXOverlay interface, which most video sinks implement. See the documentation there for more details. Specifying which CD/DVD device to useThe device to use for CDs/DVDs needs to be set on the source element playbin creates before it is opened. The only way to do this at the moment is to connect to playbin's "notify::source" signal, which will be emitted by playbin when it has created the source element for a particular URI. In the signal callback you can check if the source element has a "device" property and set it appropriately. In future ways might be added to specify the device as part of the URI, but at the time of writing this is not possible yet. ExamplesHere is a simple pipeline to play back a video or audio file:
This will play back the given AVI video file, given that the video and audio decoders required to decode the content are installed. Since no special audio sink or video sink is supplied (not possible via gst-launch), playbin will try to find a suitable audio and video sink automatically using the autoaudiosink and autovideosink elements. Here is a another pipeline to play track 4 of an audio CD:
This will play back track 4 on an audio CD in your disc drive (assuming the drive is detected automatically by the plugin).
Here is a another pipeline to play title 1 of a DVD:
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