Re: [Bino-list] Troubles using Bino with x11 devices (Input/output error)

[Martin Lambers]

Hi Bastien!

On Tue, 20 May 2014 15:35:53 +0200, Bastien Tran wrote:
> Removing the "localhost" part from the x11 devices description worked
> like a charm, now I do grab! Now Bino defaulty outputs to Red/Cyan
> (Dubois) and often crashes when I try to switch to alternate output
> but I assume this could be solved by directly issuing the proper
> command line (and maybe using proper hardware!).

The "alternating left/right" output mode is a bit hacky.

The real solution is to use properly configured "OpenGL stereo", but
vendors like NVIDIA make this functionality only available on their
more expensive graphics cards.

"Alternating left/right" is a cheap emulation that often does not work
reliably.

> > For some unknown reason, the "localhost" part does not seem to
> > work anymore. When I just use ":0.0+100,100", it works fine.
> > Perhaps you have the same problem?
> 
> Is it still possible to define a different host though? I assume
> having 2 computers plotting and a third one grabbing the displays
> from the former two would give nice results.

That would require the hostname part, yes. My guess is that this works
with FFmpeg (see below).

An alternative idea would be to run two additional X servers on your
localhost that do not actually output anything on screen (see e.g.
Xdummy).

Then you can let your plotting programs output to each of these
servers, and let Bino grab the invisible X screens. That way, the image
data does not have to be transferred over the network (in case that is
your bottleneck).

> When I type "ldd /usr/bin/bino" in my terminal as you suggest, I get
> something like this (sample):
> 
>     libXt.so.6 => /usr/lib/x86_64-linux-gnu/libXt.so.6
> (0x00007f91bcfd5000) libpcre.so.3
> => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f91bcd97000)
> libffi.so.6 => /usr/lib/x86_64-linux-gnu/libffi.so.6
> (0x00007f91bcb8f000)
> 
> where all paths are either: "/usr/lib/x86_64-linux-gnu/" or
> "/lib/x86_64-linux-gnu/" while my self-built FFmpeg is in
> /home/bastien/bin. I hope this makes sense.

It makes sense, and it means that your Bino uses system libraries
instead of your own copy of FFmpeg.

This is most likely a problem, since Linux Mint is based on Ubuntu,
which is based on Debian, which ships libav instead of FFmpeg.

Libav is a fork of FFmpeg, but unfortunately it does not work as well
with Bino as FFmpeg does. Since you said X11 grabbing worked for you
with your ffmpeg binary, I assume this is another example of a libav
bug. (To verify this, you could run 'avconv' instead of 'ffmpeg' to
capture your X11 screen and see if this still accepts the host name
part.)

When you build Bino yourself, you can tell it where to find
your FFmpeg libraries by setting the PKG_CONFIG_PATH variable
./configure PKG_CONFIG_PATH=/path/to/your/ffmpeg/lib/pkgconfig ...

Best regards,
Martin