mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-07-26 00:08:21 +00:00
fe37c5aad2
Original commit message from CVS: * docs/design/draft-klass.txt: Proposal for klass field values. * docs/design/part-streams.txt: Start of a doc describing stream anatomy.
48 lines
1.2 KiB
Plaintext
48 lines
1.2 KiB
Plaintext
Streams
|
|
-------
|
|
|
|
This document describes the objects that are passed from element to
|
|
element in the streaming thread.
|
|
|
|
|
|
Stream objects
|
|
--------------
|
|
|
|
The following objects are to be expected in the streaming thread:
|
|
|
|
- events
|
|
- NEW_SEGMENT (NS)
|
|
- EOS (EOS) *
|
|
- TAG (T)
|
|
- buffers (B) *
|
|
|
|
Objects marked with * need to be synchronised to the clock in sinks
|
|
and live sources.
|
|
|
|
|
|
Typical stream
|
|
--------------
|
|
|
|
A typical stream starts with a newsegment event that marks the
|
|
buffer timestamp range. After that buffers are send one after the
|
|
other. After the last buffer an EOS marks the end of the stream. No
|
|
more buffer are to be processed after the EOS event.
|
|
|
|
+--+ +-++-+ +-+ +---+
|
|
|NS| |B||B| ... |B| |EOS|
|
|
+--+ +-++-+ +-+ +---+
|
|
|
|
1) NEW_SEGMENT, rate, start/stop, time
|
|
- marks valid buffer timestamp range
|
|
- marks stream_time of buffers in NEW_SEGMENT
|
|
- marks playback rate
|
|
|
|
2) N buffers
|
|
- displayable buffers are between start/stop of the NEW_SEGMENT
|
|
- display_time: (B.timestamp - NS.start) * NS.abs_rate
|
|
- stream_time: display_time + NS.time
|
|
- sync_time: display_time + base_time
|
|
|
|
3) EOS
|
|
- marks the end of data, nothing is to be expected after EOS
|