GStreamer to combine 2 streams into Side-by-Side Stereo3D?

Nathan Clark nathan at
Sat Jun 25 05:21:58 PDT 2011

Hi Martin,

Thanks for your brilliantly fragmented email! :D
Indeed that was me that contacted you re. your anaglyph filter for
Its great to hear of your continued enthusiasm! The Apertus Open Source
Cinema Stereoscopic Rig has come quite a way since then!

You can see some test footage on youtube (link 1 below) or vimeo (link 2).
Please excuse the excessive disparity (ie. broken background), I couldnt get
the cameras close together on this occasion.

I have been working closely with Sebastian over at and he has
implemented stereoscopic support into the existing ElphelVision software-
which has enabled us to capture synchronized, raw, stereoscopic footage! The
next step is sorting out a solution for monitoring the cameras on location.

Please don't worry about insulting me, as I can confirm that I am completely
uneducated with regards to programming / development. So my capacity to
develop this small app, as basic as it may be- depends solely on the
patience and assistance of the community!

Luckily, my partner is doing her PHD in stereoscopic cinema and has several,
particularly *geeky* friends. One of whom has agreed to have a look at the
requirements and may be able to assist in developing the tool.

Since my initial email to this mailing list, the scope of the project has
grown to include a live debayering plugin (link 3)- prior to assembling them
into a stereo pair. This process is quite cpu intensive- but it allows us to
shoot and monitor in RAW, which significantly improves the final quality of

Furthermore, I have thought it would be ideal if the resulting stereo pair
could be transcoded to a lower resolution and restreamed over the local
network- for monitoring on less powerful devices.

Finally, the implementation of your anaglyph plug-ins would be the icing on
the cake! I do have concerns, however, about the CPU usage becoming and
issue. (is your anaglyph plugin cpu intensive?)

All in all, the concept has matured considerably, but if it manages to come
into fruition- I belive it will be of great significance to the open source
cinema community!

(Link 1)
(Link 2)
(Link 3)

PS #1 ;)
I know this email has gone off on a bit of a tangent- and I apologize for
rambling! but I did think it might be of interest to provide a bit more of a
detailed account of where the project is at the moment!

PS #2
Back on topic now: Hopefully my partners friend will take up the development
of the actual software tool, within which GStreamer will be implemented. He
is a seasoned linux developer and as such will not require any basic
instruction / tuition regarding programming (unlike myself!) But he is not
familiar with GStreamer as of yet, so he will undoubtedly require some
pointers along the way- especially when it comes to the inclusion of your
anaglyph plugin. Would you be happy for me to suggest to him to use this
thread to ask any technical questions of you?

On Fri, Jun 24, 2011 at 3:31 PM, Martin Bisson <martin.bisson at>wrote:

> **
> I worked on the GStreamer side-branch for stereo video.
> But what you are looking for is really "basic" GStreamer usage, i.e.
> copying video streams to sub parts of the screen.  What I mean by "basic" is
> that I don't think you would have to create new elements in the pipelines to
> do what you described, you just need to use existing ones and configure an
> appropriate pipeline.  Take a look at the way to create a basic pipeline,
> the way to use the video scale, video crop, etc, elements to do what you
> want to do.  I don't have access to it right now, but I could send you the
> pipeline I used to create that video which seems to be a bit what you are
> trying to do :
> (If I remember correctly : top left = left view, top right = right view,
> bottom left = "gray" anaglyph, bottom right = color anaglyph)
> However, you'd probably have to understand the pipeline workflow in order
> to be able to do what you're trying to do...
> Hope this helps, available to answer some questions,
> Mart
> P.S.  I wrote this e-mail, but then when I got internet access again I
> re-read it before sending it to you and realized I might have read your
> e-mail too quickly and I might not be answering your actual question...
> There are probably many ways to to what you want to do, the easiest I see
> right now is to have an embedded GStreamer window in your application.  Your
> application would be managing events (such as the arrow key events) and
> setting the GStreamer pipeline to use accordingly.
> Anyway, hope this helps a little.  I don't know how comfortable you are
> with GStreamer or general programming, so I don't want to waste my
> time/insult you by giving you very basic information, but I'm willing to
> help you by answering questions and pointing your to the right sources to do
> what you want to do.
> End of P.S.!
> P.S. #2 another view you could add to your software is the anaglyph view
> ;).  But it's not integrated in the main GStreamer branch yet.  But the more
> people want it, the more it will be prioritized and the quicker it will get
> "accepted".
> P.S. #3 I just remembered...  Someone from Apartus contacted me regarding
> possible uses of GStreamer for stereo video in Apertus.  I'm pretty sure it
> was you.  I re-iterate my strong interest in the project, I think what you
> guys are doing is very cool and would like to help as much as I can, but I
> have very, very limited free time these days so I can't do actual
> development.  I'd be glad to orient you in the right direction if I can.
> Sorry for "split/incoherent email", I was offline for a while...
> On 20/06/2011 11:24 AM, Nathan Clark wrote:
> Hi Guys,
> My name is Nathan.
> I am building a *Fully OpenSource 3D Cinema Camera-Rig* as part of the
> Apertus <> "Open Source Cinema" project.
> I am writing to introduce myself, with hopes to muster up some enthusiasm
> for the project; and also to seek assistance in the development of a tool,
> built on GStreamer- for monitoring the stereoscopic rig during production.
> As I do not have any experience with program development, I am here to see
> if:
> a) this tool is easy/difficult to create, and
> b) if anyone is interested helping with it's development.
> The basic function of the tool (*"S3DView"*) is as follows:
> 2 x synchronized IP cameras send 2 x unicast rtsp streams over the network
>  rtsp:// (left)
> rtsp:// (right)
> *"S3DView"* takes the 2 streams and displays them in one of 4 ways:
>  1. Side-by-Side
>  Left image is squashed 50% and positioned to the left
> Right image is squashed 50% and positioned to the right
>  2. Overlay
>  Both images are displayed- one overlaid on the other, with 50% opacity
>  3. Left Only
>  Left image only is show (with unobtrusive text overlay - "left")
>  3. Right Only
>  Right image only is show (with unobtrusive text overlay - "right")
>  These four display modes could then be switched on the fly using
> shortcuts for example:
>  Side-by-Side: Up Arrow
> Overlay: Down Arrow
> Left Only: Left Arrow
> Right Only: Right Arrow
> The window should be able to optionally go into "fullscreen" mode and
> retain the ability to switch between the 4 viewing modes.
> Until this point, i have been attempting to use VLC's mosaic to do this,
> but very quickly have I realized that GStreamer looks to be far better
> suited to the job.
> Unfortunately, it is beyond my scope to develop the *"S3DView" *tool
> myself- if anyone is interested in becoming involved, or if anyone has any
> questions / ideas / input*-- * please let me know*.
> *Thanks for your time.
> Kind regards,
> Nathan Clark*
> *
> _______________________________________________
> gstreamer-devel mailing listgstreamer-devel at lists.freedesktop.org
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