djifpvvideoout

This is a port of the dji fpv videooutscript (from here) to golang

The intersting thing is that it starts working in low power mode as well

Also this script should support unplugging and replugging USB, disconnecting / reconnecting the drone and should not care if it is started while the goggles are off

It will also work with multiple googles at once, so if you connect new ones while it is running it will open new ffplay instances for you

FFMpeg (or gstreamer) needs to be available in your path, it will be started by the go binary automatically

libusb-1.0-dev needs to be available if you want to build this from source

Running

Make sure you have go and ffmpeg installed, then run like this:

go run .

Per default this will use ffplay, if you want to use gstreamer though use it like this go run . --output gstreamer

The sync option is usefull when running on raspberrypi and directly using the framebuffer (when not using the desktop environment) It seems to work better

Other options are fifo and ffplay (default)

Crosscompilation does not work in an easy way due to the dependency on libusb If you find any new intersting things about this let me know on the discordserver @s00500 or here in the issue section

Using with OBS

The best way to work with OBS (at least on mac) I found was by creating a fifo, this is basically a special file where I pipe in the data from the googles. Then the obs-gstreamer plugin can be used to read and decode the stream from this file and directly open it in OBS.

Install th eOBS gstreamer plugin from here https://github.com/fzwoch/obs-gstreamer

On mac create a folder in /Library/Application Support/obs-studio/plugins called obs-gstreamer. Then make a subfolder called bin and move in the .so file from the downloaded zip from the repo

On macOS you can use the prebuilt binary, but carefull: this requires gstreamer to be installed via macports, not brew.

If you installed it with brew you will need to copy over the binaries to where the plugin expects them. Here is a list of paths I had to copy, versions might differ in the future or you system

cp /usr/local/Cellar/gstreamer/1.18.4/lib/libgstreamer-1.0.0.dylib /opt/local/lib/
cp /usr/local/Cellar/gst-plugins-base/1.18.4/lib/libgstapp-1.0.0.dylib /opt/local/lib/
cp /usr/local/Cellar/gst-plugins-base/1.18.4/lib/libgstaudio-1.0.0.dylib /opt/local/lib/
cp /usr/local/Cellar/gst-plugins-base/1.18.4/lib/libgstvideo-1.0.0.dylib /opt/local/lib/
cp /usr/local/Cellar/glib/2.68.2/lib/libgobject-2.0.0.dylib /opt/local/lib/

Then create a new gstreamer source in obs and enter this command:

filesrc location=/Path/To/your/stream.fifo ! decodebin3 ! videoconvert n-threads=8 ! video.

if at some point your OBS does not start anymore make sure to remove any fifo files left, that should fix it

Test status

For now I tested this with macOS bigsur, no additional drivers installd, although I might have a few on my computer anyway

Used Caddx Vista and GooglesV2

Next thing todo is testing this on a Raspberry Pi

Also I found that this works with a regular USB 2 cable (no need for the usb 3 one)

Raspberry Pi Image

After playing a bit with different setupd (buildroot, alpine, customPiOS) i have decided that running on alpine linux is teh cleanest setup. I have therefore included a new alpine image to test in this repository. If you are interested in the other setups just write me an email. I have a running image based on custompios and raspbian lite to test as well.

This has so far been tested on

Raspberry Pi 4 with 4GB
Raspberry Pi 3B+
Raspberry Pi 2

Please let me know if you find it works for you on a different PI

RaspberryPi 0 and RaspberryPi 1 are currently not supported. I have also created images for these though, but I have only gotten kind of inconsistent playback with long delays.

The image includes a pre-built version of the hello_pi example to display video via OpenMaxIL and a brebuilt version of this code here to handle connection and googles.

This right now should not really be used with multiple googles connected, it will probably not work anyway

Other than that it is super easy to connect and reconnect quad or googles, connect the Piu to power, wait 45 seconds and enjoy your video on the HDMI out

Flashing

Simply extract the tar file on to a freshly formated fat32 sdcard and plug it into a PI, no balena etcher / pi imager / dd required :-)

Basic layout:

in /etc there is a binary called fpvout, and hello_video.bin. They get started by a initscript in /etc/init.d/djifpv The splashscreen comes from the boot partition (fbsplash.ppm) The pi also starts dhcp on ethernet and opens a ssh server. login is root/djifpv

If you make any changes do not forget run lbu commit and keep in mind that it only includes files in /etc or the ones specified using lbu include <path>

s00500 / djifpvvideoout