No video feedback on Sphinx

Hi !
I run Sphinx on ElementaryOS Loki version (which is based on Ubuntu 16.04) and so far I’ve been able to run the simulator, to fly a simulated Bebop and a simulated Disco with my SkyController2 and OnePlus2, but with either one of them I haven’t succeed so far to get a video stream feedback :confused: The phone keeps displaying “not recording” :confused:

Had anyone already have this issue ?

Thanks !

Hi !

I know this might not seem obvious unless you’ve read the documentation carefully but have you enabled the video option (sphinx --enable-video) ?
On Bebop and Disco, the front camera rendering is deactivated by default to save some precious FPS :wink:

If that does not solve your problem could you please give us some details on your configuration (gpu reference, gpu driver version, …).

Please have a look at the system requirements page :

Matching the minimal system requirements is not sufficient to enjoy every simulator features. This is particularly true if you want to activate the drone cameras **(--enable-video option)** or access the simulated drone WiFi from a FreeFlight application on your smartphone. See the recommended system requirements below for more information.

Graphics card

An NVIDIA graphics card using the latest proprietary drivers is strongly recommended. Besides, when activating cameras, especially fisheye cameras, a high-end GPU (e.g. GTX 980 Ti) becomes necessary.

For your information it is probable that in a future release of sphinx we may remove the enable-video option in favor of a more consistent solution.


Indeed I misread the documentation, I read that the --enable-video is only required for the minidrones and I interpreted that as “the other don’t need the option, it is activated by default” :confused:

In the drone file for each of my drones, the sdf params contains :
Bebop :
> <sdf_params


Disco :

sdf_params low_gpu=“true” with_front_cam=“true”/>

(I tried with low-gpu true and false :confused: )

When I add the --enable-video option, the freeflight pro is not able to connect anymore to those drones, the console keeps spamming :

[Err] [] Socket 76 hung up
[Err] [] Socket 76 hung up
[Err] [] Socket 76 hung up
[Err] [] Error on socket 76, closing it

But yeah, just as you, I suspected my GPU :confused: I didn’t expect a 10fps, but at least 1 image, even when not flying, for tests purpose :confused:

Here is the result of :

sudo lshw -C video

description: VGA compatible controller
produit: Intel Corporation
fabriquant: Intel Corporation
identifiant matériel: 2
information bus: pci@0000:00:02.0
version: 02
bits: 64 bits
horloge: 33MHz
fonctionnalités: pciexpress msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
ressources: irq:129 mémoire:eb000000-ebffffff mémoire:a0000000-afffffff portE/S:f000(taille=64) mémoire:c0000-dffff

Thanks for your time ! :smile:

I would expect you to experience a ~0.10 real time factor with low_gpu=true (also I don’t want to give you some false hope…)

Anyway, the socket hung up error might be a symptom of a simulated firmware crash. This should not happen even with an Intel GPU with the low_gpu option enabled. That would explain why FreeFlight is no longer able to connect to the drone… :wink:

I will try to reproduce and investigate this issue. Let me get back to you when I’ll have more information.

Hi guys,

I am having similar problem.With active front camera settings on Disco model with_front_cam=“true”
Simulator is crashing constantly with similar messages in the logs:
[Err] [] Socket 82 hung up
E pomp: recvmsg(fd=84) err=104(Connection reset by peer)
[Err] [] Error on socket 82, closing it
E pomp: recvmsg(fd=81) err=104(Connection reset by peer)
[Err] [] Socket 82 hung up
[Wrn] [] Queue limit reached for topic /gazebo/default/user_camera/pose, deleting message. This warning is printed only once.

The strange thing is that I am getting nearly constant FPS around 60, but the Real Time Factor is dropping bellow 0.05 (it stays in range of 0.95+ without front camera) and I don’t see any video stream on my phone at all.
I tried to create complex world without front camera and I don’t get any problems rendering it.

OS: Ubuntu 16.04
Wifi: EP-N8531
Skycontroller2 flashed with latest firmware
RAM: 12GB @ 1333MHZ
VIDEO: Saphire Nitro+ RX480 8GB DDR5 + amdgpu-pro 16.30-3 + vulkan SDK 1.0.37

I am really out of ideas what could be the problem. Any help will be greatly appreciated.


Gazebo is known to run better with Nvidia cards. You could try running sphinx with the option low_gpu=“true” to ease off graphics demand. You could also install the “radeon” driver and see if that works better but I doubt it.