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94 lines
2.2 KiB
Text
94 lines
2.2 KiB
Text
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This document contains some ideas that can be used to implement
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interactivity in media content.
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Possible application: DVD navigation, flash,...
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Requirements
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------------
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- capture mouse clicks, mouse position, movement occuring on
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a video display plugin
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- transport these events to the interested plugins
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- allow for automation (ie, the technique should work without
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a video plugin too)
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- the core doesn't care
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Capturing events
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----------------
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- the videosink element captures mouse events
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- event is encapsulated into a generic data structure
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describing the event (need to define a caps?)
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- event is signalled to the app?.
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- event is sent upstream?
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* videosink has to add something to the main_loop to
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be able to grab events
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* thread issues?
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* does the app need to know about the events?
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- app captures mouse events
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- no idea if that's possible
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- app sends events upstream
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Sending events to plugins
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-------------------------
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- are sent upstream using the event methods
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* more generic
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* less app control
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- are sent to the appropriate plugin by the app
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* app needs to know what plugins are interested,
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less generic.
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* more app control
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automation will always work, the app can construct navigation
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events and insert them into the pipeline.
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What about flushing to minimize latency?
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Defining an event
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-----------------
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some ideas:
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GST_CAPS_NEW (
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"videosink_event",
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"application/x-gst-navigation"
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"type", "click",
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"x_pos", 30,
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"y_pos", 40
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)
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GST_CAPS_NEW (
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"videosink_event",
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"application/x-gst-navigation"
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"type", "move",
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"x_pos", 30,
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"y_pos", 40
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)
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...
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do we need a library for this?
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do we use custom events and use the mime type to detect the
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type? do we creat a GST_EVENT_NAVIGATION?
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can we encapsulate all events into a GstCaps? I would think so
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Random thoughts
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---------------
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- we're basically defining an event model, I don't think there is
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anything wrong with that.
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- how is our coordinate system going to work? do
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we use normalized values, 0-1000000 (or floats)
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or real pixel values? real pixel values require scalers to adjust
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the values (I don't think I like that)
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