mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-04 07:26:33 +00:00
96 lines
3.7 KiB
Markdown
96 lines
3.7 KiB
Markdown
# TODO - Future Development
|
||
|
||
## API/ABI
|
||
|
||
- implement return values from events in addition to the gboolean.
|
||
This should be done by making the event contain a GstStructure with
|
||
input/output values, similar to GstQuery. A typical use case is
|
||
performing a non-accurate seek to a keyframe, after the seek you
|
||
want to get the new stream time that will actually be used to update
|
||
the slider bar.
|
||
|
||
- make gst\_pad\_push\_event() return a GstFlowReturn
|
||
|
||
- GstEvent, GstMessage register like GstFormat or GstQuery.
|
||
|
||
- query POSITION/DURATION return accuracy. Just a flag or accuracy
|
||
percentage.
|
||
|
||
- use | instead of + as divider in serialization of Flags
|
||
(gstvalue/gststructure)
|
||
|
||
- rethink how we handle dynamic replugging wrt segments and other
|
||
events that already got pushed and need to be pushed again. Might
|
||
need GstFlowReturn from gst\_pad\_push\_event(). FIXED in 0.11 with
|
||
sticky events.
|
||
|
||
- Optimize negotiation. We currently do a get\_caps() call when we
|
||
link pads, which could potentially generate a huge list of caps and
|
||
all their combinations, we need to avoid generating these huge lists
|
||
by generating them We also need to incrementally return
|
||
intersections etc, for this. somewhat incrementally when needed. We
|
||
can do this with a gst\_pad\_iterate\_caps() call. We also need to
|
||
incrementally return intersections etc, for this. FIXED in 0.11 with
|
||
a filter on getcaps functions.
|
||
|
||
- Elements in a bin have no clue about the final state of the parent
|
||
element since the bin sets the target state on its children in small
|
||
steps. This causes problems for elements that like to know the final
|
||
state (rtspsrc going to PAUSED or READY is different in that we can
|
||
avoid sending the useless PAUSED request).
|
||
|
||
- Make serialisation of structures more consistent, readable and nicer
|
||
code-wise.
|
||
|
||
- pad block has several issues:
|
||
|
||
- can’t block on selected things, like push, pull, pad\_alloc,
|
||
events, …
|
||
|
||
- can’t check why the block happened. We should also be able to
|
||
get the item/ reason that blocked the pad.
|
||
|
||
- it only blocks on datapassing. When EOS, the block never happens
|
||
but ideally should because pad block should inform the app when
|
||
there is no dataflow.
|
||
|
||
- the same goes for segment seeks that don’t push in-band EOS
|
||
events. Maybe segment seeks should also send an EOS event when
|
||
they’re done.
|
||
|
||
- blocking should only happen from one thread. If one thread does
|
||
pad\_alloc and another a push, the push might be busy while the
|
||
block callback is done.
|
||
|
||
- maybe this name is overloaded. We need to look at some more use
|
||
cases before trying to fix this. FIXED in 0.11 with BLOCKING
|
||
probes.
|
||
|
||
- rethink the way we do upstream renegotiation. Currently it’s done
|
||
with pad\_alloc but this has many issues such as only being able to
|
||
suggest 1 format and the need to allocate a buffer of this suggested
|
||
format (some elements such as capsfilter only know about the format,
|
||
not the size). We would ideally like to let upstream renegotiate a
|
||
new format just like it did when it started. This could, for
|
||
example, easily be triggered with a RENEGOTIATE event. FIXED in 0.11
|
||
with RECONFIGURE events.
|
||
|
||
- Remove the result format value in queries. FIXED in 0.11
|
||
|
||
- Try to minimize the amount of acceptcaps calls when pushing buffers
|
||
around. The element pushing the buffer usually negotiated already
|
||
and decided on the format. The element receiving the buffer usually
|
||
has to accept the caps anyway.
|
||
|
||
## IMPLEMENTATION
|
||
|
||
- implement more QOS, [qos](design/qos.md).
|
||
|
||
- implement BUFFERSIZE.
|
||
|
||
## DESIGN
|
||
|
||
- unlinking pads in the PAUSED state needs to make sure the stream
|
||
thread is not executing code. Can this be done with a flush to
|
||
unlock all downstream chain functions? Do we do this automatically
|
||
or let the app handle this?
|