[Bf-committers] Re: Need summer of code advice

Peter Schlaile peter at schlaile.de
Sun Mar 18 08:58:21 CET 2007


Hi,

maybe you should really focus on one usefull idea (like motion tracking)
and do that well. Problem with GSOC-projects is, that you need a clear
focus. Otherwise, noone can really tell at the end, if this was a success.
(Even worse, the project might get rejected all together by google in the
first place. This happened to the guy, that wanted to add
gstreamer-support after ffmpeg was already in.)

Or you could finally start discussing your ideas on the wiki and
we can try to make up a reasonable "package" idea.

> Some of unmentioned ideas would fall in this category.  For example,
> the sequencer re-renders each frame of a 3D scene every time a preview
> is drawn, this makes real time playback impossible.
> I was thinking
> about a Persistant Render Cache, it would stores the rendered output
> to disk and only rendered.  The compositor and the animation system
> could both take advantage of this.
>
> Another big improvement would be to use OpenGL to render the scenes
> for the sequencer preview.  This wouldn't be a perfect solution, but
> for editing, the timing is more important than the fine details.

You noticed, that this is all the same?

a) Add an option to the preview windows, which set preview quality,
   ranging from full quality to no output at all. (Means basically
   enhancing your patch a little bit.)
b) Implement different preview strategies for the different track types.
   Most will need a (pluggable) way of preview-proxies, but scene-tracks
   could get away with opengl-preview rendering.

Maybe a week of work, but not 2 months.

> I understand your position, but I there are a lot of users who need at
> least minimal support for multichannel audio mixing.  Jashaka and
> cinerella are going nowhere, for the forseeble future Blender will be
> the best OSS NLE (a sad statement.)  I think there is a happy middle
> ground.  With an extensable architecture, the sequencer can stay
> extremely simple, but can grow to fit the needs of its user.

Yupe, make everything pluggable. I'm working on this right now.

> I think that neither OpenAL or SDL are well suited to provide even
> basic multichannel mixing (we can debate if this is an important
> feature later.)

Sorry, to interrupt you here, but neither of the two libraries had
_intended_ to do mixing... Both are libraries for sound _output_...
OpenAL does additionally some 3D-sound processing, but that's it.

And yes, multichannel mixing _is_ important, but also not very hard to
code (or to steel from cinelerra ;-).

> I think OpenAL is still the best solution for the
> game system, but the SDL has to go.

Nope. Sound input/output should be pluggable. (Has to be, to get ffmpeg
and OpenAL out of the core.) 3D-sound mixing should be redone in Blender
core.

> The audio system is bad shape, on
> my system playback is completely broken in the latest official
> release.

Hmmm? You tried "blender -g noaudio" on startup? And: some onboard sound
cards only work at 48 khz, try switching audio output sample rate
_before_ doing any audio work.

It is clumsy right now, correct. But it should definitely work.

> I will go into details later, but I think that fixing this
> is more important than any of my editing ideas.
> I appreciate the feedback,

Again: I would definitely appreciate, if we could first work out some
direction on the wiki instead of throwing ideas into every corner.

Regarding compositor integration:

If you had read the wiki, you would have noticed, that Brecht already
wrote a patch for compositor integration which was rejected by Ton.

Please read that, and when you understand his concerns, be invited
to come up with some new ideas, that might convince him, but please do not
repeat things as new ideas, that are already coded, but are not included
for other reasons! (Otherwise I promise, that he will add the keyword
combination of "sequencer", "compositor" and "integration" to his
kill-file making any effort in this direction doomed by definition ;-)

Reading this blendernation article might be usefull, too:
http://www.blendernation.com/2006/11/29/give-your-feedback-for-improving-blenders-sequencer-non-linear-film-editing/

Brecht's patch and comments:
https://projects.blender.org/tracker/index.php?func=detail&aid=4920&group_id=9&atid=127

Greetings,
Peter



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