[Bf-committers] Cold Start Developer Help Needed!

dodo1 at videotron.ca dodo1 at videotron.ca
Sun Nov 19 17:33:58 CET 2017

Hello Dear Developers!

I have huge preferences for Open Source projects, and I'm quite willing
and happy to contribute my time whenever I can and when my ideas are
welcome.  I'm a Blender user, mostly the Video Sequence Editor (VSE).
It's the only open source video editing software that works reliably
(I tested all the others that I could find, and they all failed at some
point).  I'm a C Language humble developer who is quite willing to learn
Python for Blender's benefit.  I'm a FreeBSD user, so that may help
address Blender build scripts issues as well.

That being said, I've hit a huge wall using 4K video footage in Blender's
VSE.  The slowdown is so bad that Blender is totally unusable.  I have
ideas to fix this but I need some help to get started.  I checked the
Blender source code and was at a complete loss, unable to pinpoint small
areas of code that I could work on just to add a simple feature
(see later in this email).


The issue has been raised in the mailing list recently.  I think that
info shared on IRC is too volatile.  It's definitely not appropriate
if you want to increase the number of contributors.  There's no
knowledge base, so it's an eternal cold start for every potential

A better solution is to create a developer discordapp.com server
(free service for all).  The benefit is that chats can be structured
around precise topic channels, and there is also the possibility of
voice channels when need be.  There's basic search available as well.

The Wiki is good if it can be kept up to date.  The ultimate solution
is a developer forum.  I vote for that!  Any application usage questions
should be redirected to the other available venues to keep things
relevant for developers.  If you want the developer community to grow,
it's very important for them to have a reliable source of info available
in the simplest and fastest way possible.


When doing video editing, the text font change feature is an absolute
given.  Blender should certainly have it.  Could someone point me in the
right direction within the source code in order to implement this change?
I did a global search of the word TEXT, and never found anything relevant.

Next projects:

Next features I would like to work on is adding a SCALE option in the
IMAGE and VIDEO STRIPS.  Use of a modifier strip on top of them is
totally unnecessary and unproductive for the end-user.  Also,
the modifiers have rendering issues in the current implementation.
But I'll ask help for that later as I'm not quite there as a
developer yet.


Since I'm writing this email, I'm sending this Blender Issue out there
with the hope that it will be received favorably, and kept for further
considerations in upcoming Blender releases.

When editing videos, the preview window is very important on a frame
by frame basis.  In Blender, this is the VSE preview window.  However,
when handling 4K video footage, it becomes very sluggish.  I suspect
that window refreshes are calculated on the fly, redrawn, then user
control interactivity can resume.  This process is no longer viable
when dealing with 4K video footage.  To optimize this process, there
should perhaps be a low priority thread that grabs all the window
refresh requests, and refreshes the window at its own pace (using only
the latest refresh data, discarding the old queued refresh data).
With this parallel process, the user control interactivity (move to
next or previous frame, play, stop, etc...) can happen uninterrupted,
which is utterly important for the end-user.  The preview refresh will
eventually occur when it will be ready, and it's perfectly OK this way.
If one wants it to work faster, one just need to upgrade to a faster
CPU.  Win! Win!  Also Blender can easily be used on slower computers
for users on low budget.

Test case, load a 4K video footage in a video strip.  Move anywhere
within the strip and press the back arrow 5 times quickly in a row.
When the end-user does that, he's not interested to see the
intermediate frames in the VSE preview window.  Only the end result
is important.

That's it for now.  More about me:


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