Ichthyostega
b556d2b770
Some sections of the Lumiera website document meeting minutes, discussion protocols and design proposals from the early days of the project; these pages were initially authored in the »Moin Moin Wiki« operated by Cehteh on pipapo.org at that time; this wiki backed the first publications of the »Cinelerra-3« initiative, which turned into the Lumiera project eventually. Some years later, those pages were transliterated into Asciidoc semi-automatically, resulting in a lot of broken markup and links. This is a long standing maintenance problem problem plaguing the Lumiera website, since those breakages cause a lot of warnings and flood the logs of any linkchecker run.
99 lines
5 KiB
Text
99 lines
5 KiB
Text
2023-11-08 Lumiera Developers Meeting
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=====================================
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:Author: Ichthyo
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:Date: 2023-11-09
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Nov 8, 2023 on #lumiera 22:30 - 23:30 UTC +
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__Participants__
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* ichthyo
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* benny
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* cehteh
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_Summary written by Ichthyo_
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''''
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Wikipedia
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---------
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https://en.wikipedia.org/wiki/User:IgorVladimirsky[Igor Vladimirsky]
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contacted _Ichthyo_ last week regarding a mention of Lumiera in the context of Cinelerra.
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He was involved with the
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https://cinelerra-cv.wikidot.com[Cinelerra-CV project]
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and already contributed several improvements to the Wikipedia entry for Cinelerra,
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which includes a mention of »the Lumiera rewrite« since
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https://en.wikipedia.org/w/index.php?title=Cinelerra&diff=prev&oldid=207875710[April 2008].
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_Igor_ rightfully pointed out that Lumiera is not a fork of Cinelerra and the description of the project's
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origin might be too much biased towards the developer's perspective at that time. This critique extends also
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to the descriptions at the introductory pages of the Lumiera website itself; these characterisations were
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written during the same founding phase and not much reviewed ever since. After some exchange of proposals
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and ideas, an update and reformulation of the introductory pages was accomplished. The update to the
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content at Wikipedia, which _Igor_ thankfully completed, was a good opportunity to add some further
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sources, notably an archive.org link to an article at
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https://web.archive.org/web/20090129083001/https://www.linux.com/feature/126441[Linux.com]
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and remove a ^[citation needed]^ tag.
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-> see the reworked
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link:/project/index.html[``About''] and link:/project/faq.html[``FAQ''] pages +
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-> section in the
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https://en.wikipedia.org/wiki/Cinelerra#Lumiera[Wikipedia page for Cinelerra].
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Development Summary
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-------------------
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As usual, _Ichthyo_ summarises the progress of coding work under the umbrella of the »Playback Vertical Slice«.
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Activities were focussed on integration of developed components and parts forming the *Scheduler Service*
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at the core of the Render Engine. Some further aspects were addressed, notably the proper use of locking
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and a new scheme to distribute available computing capacity in accordance to the planned schedule and
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an integrated load indicator. The Scheduler implementation is now largely complete and passes the
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component integration tests. The level of performance observed using short bursts of load seems adequate
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and scheduling delay is mostly dominated by the leeway of the OS thread scheduling and caching effects.
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The next step would be to setup some meaningful load- and stress testing, using a synthetic load,
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which can be adjusted to reflect typical patterns of the expected load in actual usage. Care has
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to be taken however to distil an indicator actually describing the scheduling overhead and to avoid
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capturing just the overall system performance.
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Investigation: Video Display
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----------------------------
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_Benny_ continued his research regarding solutions for video display in the GUI. We agreed previously
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that the current ``vertical slice'' affords the opportunity to try out available mainstream solutions
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to find out more about their strength and weaknesses. _Benny_ decided to look at *GStreamer* first,
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since this framework is in very widespread use, with tutorials and documentation readily available.
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He conducted some experiments and was able to put together a demo which decodes an AVI file and
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displays the video content into a given GTK window. The following investigations will focus on
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the details how to inject arbitrary content into such a display, without directly relying on the
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complete decoding and rendering pipeline of GStreamer, since we intend to use the Lumiera Render
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Engine to coordinate all processing and manage all resources.
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Another point worth mentioning is the fact that the GTK project intends to discontinue support
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of the Xlib / X.org output backend, focussing entirely on Wayland. GStreamer fully supports
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Wayland already.
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_Ichthyo_ adds that he intends to use directly generated video content for this ``vertical slice'',
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so to avoid involving any file-IO. It seems quite feasible to use libCairo (which is already a project
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dependency and well known) do draw some simple animation. This code could than be packaged as a generator
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node and used in the more or less synthetic node graph, which will be provided by the setup for this
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integration effort.
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Coding News
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-----------
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During all the past years, it was customary to publish a ``coding news'' report at fall time.
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There was much progress in the Lumiera project lately, since _Ichthyo_ was able to quit his regular
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work job this spring to focus entirely on his personal programming and artwork projects. The
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``vertical slice'' however will not be completed this year, and thus we agreed to author the usual
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news update now, while providing an additional report once the work will be completed and we are
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able to demonstrate running video display in the GUI.
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''''
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Next meeting
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------------
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The next meeting will be Wednesday **Dec 13, 20:00 UTC**.
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You are welcome to join.
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''''
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