linux: After building from source, [pix_video] fails to detect any camera

[jamshark70]

I had been using Gem 0.93 installed from Ubuntu 18.04 packages. No problem with pix_film or pix_video. But, some of the help patches were crashing against Pd 0.50, so I thought I should upgrade.

https://packages.debian.org/buster/gem -- unclear to me if this is valid for Ubuntu Studio 18.04.

A member on the Pd forum suggested that I build from source. So I cloned the repository, 'autogen' 'configure' 'make' etc. This went relatively painlessly, except that I had to do it twice because the current README, as far as I can see, doesn't mention required packages to build the video plug-ins. After installing those packages, [pix_film] is working.

BUT [pix_video] is not.

At startup: GEM: video capture plugins: dc1394

Opening a patch that contains a [pix_video] object: [pix_video]: backend #0='dw1394' : dw1394 iidc (and for some reason, at this point, I can no longer copy text from the console)

Turning on rendering: [pix_video]: no valid video backend found and the camera light doesn't turn on.

So I suppose I need to install some other package(s), but the current README contains not much detail about building in Linux Linux build requirements.

In any case, the current situation is that a Linux user can build Gem from source, but some features are disabled. So the documentation seems insufficient.

Operating-System (kernel-version,...)

Linux ---- 4.15.0-70-lowlatency #79-Ubuntu SMP PREEMPT Tue Nov 12 11:30:17 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

video-card, driver

No problems with video rendering.

other hardware that is related to your problem (e.g.: camera)
does your system work with similar applications (e.g.: capture-software,
openGL (games, "glxgears")

Can't find the camera ID but Skype can open the camera without any problem. Also, the older version of Gem could use the camera.

what is the output of pd when you start it with the "-verbose" flag
(e.g.:"pd -verbose -lib Gem")

"tried /usr/local/lib/pd/extra/Gem/Gem.pd_linux and succeeded" but others failed.

[kubriel]

i believe you are missing libv4l-dev package, so your gem_videoV4L2.so is not builded

[jamshark70]

i believe you are missing libv4l-dev package, so your gem_videoV4L2.so is not builded

Ah, OK, installed libv4l-dev and rebuilt. Now it's working.

$ grep libv4l ~/share/pd/Gem/README.txt
$

Feel free to close (though I'd suggest this sort of detail should be documented with the build instructions).