Welcome my dudes and dudettes to Emacs Central where you get a crazy
guy who does many things with Emacs like video editing, image editing
audio, editing and many other multimedia things that people wouldn't
usually think Emacs user would do.  What I wanted to share is why do I
love using Emacs; because it grants user a freedom to take on the
responsibility if they choose so to make their everyday workflow
amazing.  I don't consider Emacs being a text editor.  It is a lisp
interpreter on C core and that to me is the greatest beauty of the
application.  It doesn't install plug-ins.  It changes itself and does
it on the fly which means it is very fun and efficient to develop
workflow optimizations through wonderful tools that optimize your
everyday work.  It's awesome that many talented Emacs users and
developers have shared their work through incredibly nifty elisp code.
Yet sometimes there is no need for generalized solution or it's not
there yet.  And in those cases Emacs can become the most direct
communication layer between your brain and central processing unit off
your computer.  And that is something I wholeheartedly believe every
Emacs users should look into.  That is something that will solidify
your love for Emacs and that is something that blows any competition
for away.  Emacs is an interpreter of ultimate high-level symbolic
hackable language and it provides you with many fun and addicting ways
to pimp up your editor of life-time.  It is a whole new world that
out-compete any similar software and for me maybe the most important
reason why I use Emacs.  I have created many solutions that make me
happy Emacs user and efficient in doing so.  Today I wanted to share
with you one of my thoughts realized through this hacker's approach.
It is a simple yet powerful trick to use your system to its full
potential.  Blender is another example of an awesome free software
application, yet it's known for being quite slow with rendering videos
with any encoder settings.  Though if we take a look at the use of
system resources, we can notice a very interesting fact that Blender
primarily uses just single core of your CPU.  So if you own a powerful
system you can see how it can be quite an inefficient use of your
system resources.  But as I mentioned previously Blender primarily
uses just a single core of your system.  There must be a way to use
more and the good news is that yes, you can use your system smarter
and spawn multiple processes that will use your system more
efficiently.  So, let's lay out the solution: we have to use single
blend file; we have to split it in parts; we have to spawn Blender
instances for each part; render that part out; and then somehow
combine those parts together in a single-file.  Luckily there exists
another incredible free software application called ffmpeg that if you
have videos of the same format let you to do exactly that.  So, if we
wrap it all up into a single idea, what we need is: a user interface
that lets you to specify the blend file and parameters; get info from
that file; spawn multiple blender instances; render parts; when that's
done, take all the parts and concatenate them instantaneously using
ffmpeg into a single final product.  Here can see visual
representation of what the implementation does.

So guys, let's get to the demo itself.  Here we are in a folder named
"Example" containing a video file named Example.mp4.  Now, let's go
Blender itself and let's open video editing view.  There let's add the
previously mentioned video file and set some parameters like the
length of the video in frames.  Now, let's get back to the default
view and there we are going to set parameters like the name of the
exported video.  Let's name the blend file that is going to be called
"Untitled.blend" and let's I try to render all the video by the means
that Blender offers itself.  Now if you are looking at the use of
system resources, you can see that primarily only single core of the
CPU is being used.  Dismiss a little higher system resource usage,
because the screen is being recorded.  Let's go back to Emacs and
let's find the "Untitled.blend" file.  Let's mark it and choose the
functionality that I have implemented.  Let's specify the amount of
the Blender instances to spawn.  Now we can look at the newly-created
buffers.  We can see that there are three new buffers created.  If we
are looking into those buffers, we can look at the current rendering
progress.  There are also other information that is posted in messages
buffer.  The good news is that it doesn't really affect our work in
Emacs.  We can create a new file call it "" and just
type of way.  Now, if we are looking at the system resource usage we
can see that the system is fully utilized.  Initially, we rendered out
just a single PNG file, which was incorrect.  The good news is that
it's really easy to change blend file parameters.  So let's just do
that.  Let's get back to the blend file and there let's change and
call their parameters.  This time we are going to specify to render
out video.  Let's also make the video a little bit longer, so we can
have more time to observe the system use.  This now is a new
opportunity to check out how the final product is being created.
Let's go to the folder where there and the render parts are being
created.  We can see that the file sizes are constantly changing and
we could even preview those parts.  As we specified to create 3
Blender instance again we have three buffers.  We can observe the
progress there.  But, not only that, we can open a buffer and list
processes that are currently active in Emacs.  We have three processes
of those blender instances we spawned.  We can stop them or manage
them in any other way.  If we look at system resource use again and
filter for Blender, we can see three Blender instances actively
working in the background in memory.  You can see them in a white
color.  Let's take a look side by side at the system resource use and
Blender processes.  Here we can see how rendering is finishing up and
system usage is falling back down to normal.  Also, you can see how
Blender processes have disappeared from the list in Emacs.  Now if we
would add some additional content to our "" file, you
could see down there below in "messages" line that there are messages
that tell you that the rendering has finished.  We can also take a
separate look at messages buffer and what messages were printed.  Now,
finally, we can go to our "Example" directory and see that we have a
final product: file called "result.avi".  Let's preview the file.  You
can see it plays back wonderfully and we did it many times faster than
we would do just by rendering out of Blender itself.

That's it guys.  Thank you so much for watching this video.  If you
want to know a little bit more or want to get your hands on this
implementation, please check us out on interwebs.  I'll see you next