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Original commit message from CVS: * docs/design/part-playbin2.txt: Add some leftover doc.
69 lines
2.3 KiB
Text
69 lines
2.3 KiB
Text
playbin2
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--------
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The purpose of this element is to decode and render the media contained in a
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given generic uri. The element extends GstPipeline and is typically used in
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playback situations.
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Required features:
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- accept and play any valid uri. This includes
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- rendering video/audio
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- overlaying subtitles on the video
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- optionally read external subtitle files
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- allow for hardware (non raw) sinks
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- selection of audio/video/subtitle streams based on language.
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- perform network buffering/incremental download
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- gapless playback
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- support for visualisations with configurable sizes
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- ability to reject files that are too big, or of a format that would require
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too much CPU/memory usage.
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- be very efficient with adding elements such as converters to reduce the
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amount of negotiation that has to happen.
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- handle chained oggs. This includes having support for dynamic pad add and
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remove from a demuxer.
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Components
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----------
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* decodebin2
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- performs the autoplugging of demuxers/decoders
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- emits signals when for steering the autoplugging
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- to decide if a non-raw media format is acceptable as output
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- to sort the possible decoders for a non-raw format
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- see also decodebin2 design doc
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* uridecodebin
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- combination of a source to handle the given uri, an optional queueing element
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and one or more decodebin2 elements to decode the non-raw streams.
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* playsink
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- handles display of audio/video/text.
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- has request audio/video/text input pad. There is only one sinkpad per type.
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The requested pads define the configuration of the internal pipeline.
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- allows for setting audio/video sinks or does automatic sink selection.
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- allows for configuration of visualisation element.
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- allows for enable/disable of visualisation, audio and video.
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* playbin2
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- combination of one or more uridecodebin elements to read the uri and subtitle
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uri.
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- support for queuing new media to support gapless playback.
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- handles stream selection.
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- uses playsink to display.
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- selection of sinks and configuration of uridecodebin with raw output formats.
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Gapless playback
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----------------
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playbin2 has an "about-to-finish" signal. The application should configure a new
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uri (and optional suburi) in the callback. When the current media finishes, this
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new media will be played next.
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