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Original commit message from CVS: * docs/design/part-dynamic.txt: * docs/design/part-events.txt: * docs/design/part-seeking.txt: Some more docs in the works. * gst/base/gstbasetransform.c: (gst_base_transform_transform_caps), (gst_base_transform_getcaps), (gst_base_transform_configure_caps), (gst_base_transform_setcaps), (gst_base_transform_get_size), (gst_base_transform_buffer_alloc), (gst_base_transform_event), (gst_base_transform_handle_buffer), (gst_base_transform_sink_activate_push), (gst_base_transform_src_activate_pull), (gst_base_transform_set_passthrough), (gst_base_transform_is_passthrough): Refcounting fixes. * gst/gstbus.c: (gst_bus_source_dispatch), (gst_bus_poll): Cleanups. * gst/gstevent.c: (gst_event_finalize): Set SRC to NULL. * gst/gstutils.c: (gst_element_unlink), (gst_pad_get_parent_element), (gst_pad_proxy_getcaps), (gst_pad_proxy_setcaps): * gst/gstutils.h: Add _get_parent_element() to get a pads parent as an element.
71 lines
1.9 KiB
Plaintext
71 lines
1.9 KiB
Plaintext
Seeking
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-------
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Seeking in GStreamer means configuring the pipeline for playback of the
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media between a certain start and stop time.
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Different kinds of seeking exist:
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- immeditate seeking with low latency (FLUSH seek)
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- seeking without flush, playback will start from the new
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position after all the queues are emptied with old data.
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- segment seeking with and without FLUSH, this can be used to
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implement seamless looping or NLE functionality.
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Seeking can be performed in different formats such as time, frames
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or samples.
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Seeking can be performed to an absolute position or relative to the
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current playback position.
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For seeking to work reliably, all plugins in the pipeline need to follow
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the well-defined rules in this document.
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Non segment seeking will make the pipeline emit EOS when the configured
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playback range has been played.
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Segment seeking will not emit an EOS at the end of the range but will
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post a SEGMENT_STOP message on the bus. This message is posted by the
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earliest element in the pipeline, typically a demuxer. After receiving
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the message, the application can reconnect the pipeline or issue other
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seek events in the pipeline.
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Generating seeking events
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-------------------------
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The different kinds of seeking methods and their internal workings are
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described below.
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FLUSH seeking
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-------------
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This is the most common way of performing a seek in a playback application.
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The application issues a seek on the pipeline and the new media is immediatly
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played after the seek calls returns.
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seeking without FLUSH
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---------------------
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This seek type is typically performed after issuing segment seeks to finish
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the playback of the pipeline.
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segment seeking with FLUSH
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--------------------------
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This seek is typically performed when starting seamless looping.
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segment seeking without FLUSH
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-----------------------------
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This seek is typically performed when continuing seamless looping.
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