XQ C SDK Examples

This project contains sample projects that demonstrate how to use the XQ C Library:

• Starter Tutorial: Demonstrates basic usage of the XQ library.
• Video Proxy Demo: A sample project demonstrating encrypted data proxy, suitable for media streaming.

Installation

Both projects require the XQ C Library to be available on the target system.

Once this is done, build the sample projects.The path to the XQ C build folder and headers will be necessary in this step:

mkdir build && cd build
cmake -Dsdk=/path/to/xqc/build -Dheaders=/path/to/xqc/headers .. 
make

To build an Xcode project, add the -G Xcode flag to the cmake command above:

mkdir xcode && cd xcode
cmake -G Xcode -Dsdk=/path/to/xqc/build -Dheaders=/path/to/xqc/headers .. 

1. Starter Tutorial

No additional configuration is required. Navigate to the bin folder and run the application, providing the path to a valid xq.ini configuration file, as well as a valid email address:

cd bin
./starter /path/to/xq.ini email@domain.com

The tutorial performs all the following steps.

• SDK initialization
• User access request
• PIN validation
• User information retrieval
• Message encryption
• Message decryption
• Message revocation

2. Video Proxy Demo

To use the proxy, you will need to have ffmpeg installed.

Linux:

sudo apt install ffmpeg

MacOS ( with Homebrew):

brew install ffmpeg

A startup helper script may also be copied from the extras folder to build/bin:

cp ../extra/start-proxy bin
 chmod +x bin/start-proxy

Note: If thestart-proxy file was copied, its parameters may need to be updated as desired. A description of all parameters are shown at the end of this doc. The xq.ini configuration file should also be updated with valid API keys if necessary.

Once all values are up to date, the proxy can be started with the start-proxy script:

cd bin
./start-proxy

Start streaming data from a camera to the video proxy Note that another console window will need to be opened, or the previous command moved to background.

Linux:

ffmpeg -f v4l2 -i /dev/video0 -profile:v high -pix_fmt yuv420p -level:v 4.1 -preset ultrafast -tune zerolatency -vcodec libx264 -r 60 -b:v 256k -s 640x360 -f mpegts -flush_packets 0 udp://0.0.0.0:3081

MacOS:

ffmpeg -f avfoundation -framerate 30 -i default -preset fast  -s 640x360 -tune zerolatency  -framerate 60 -f mpegts udp://0.0.0.0:3081

The final argument above is the host and port where packets are sent to. This should correspond with the host and enc_port parameters set in start-proxy. The parameter /dev/video0 refers to the camera on the local device.

Encrypted video packets should now be getting streamed to the enc_out_host on enc_out_port (pointing to the 2nd device which will receive the signal). The above ffmpeg settings only do video. This can be configured for audio as well (provided there is a microphone available).

Repeat the above steps on a 2nd machine (again, making sure to configure the settings correctly).

Finally, start up a media player (e.g. VLC) on each of the devices, and begin playback of the network stream on port 5000 or whatever port is set as dec_out_port on the local proxy.

Start-Proxy Arguments

Parameter Name	Description	Default
host	The host IP address that this application will be bound to.	0.0.0.0
enc_port	The host port for incoming packets that need to be encrypted. After encryption, UDP packets will be sent to enc_out_host on port enc_out_port.	3081
dec_port	The port on the host for incoming packets that need to be decrypted. After decryption, UDP packets will be sent to dec_out_host on port dec_out_port.	3082
enc_out_host	The target address that will receive UDP packets from this application after they have been processed (either encrypted or decrypted). Encrypted packets will be sent on port enc_out_port and decrypted packets sent on dec_out_port	host
enc_out_port	The port on the target address where encrypted packets will be sent.	3082
dec_out_host	The target address that will receive UDP packets from this application after they have been decrypted. Encrypted packets will be sent on port enc_out_port and decrypted packets sent on dec_out_port	host
dec_out_port	The port on the target address where decrypted packets will be sent. The application that accepts the decrypted packets should be listening on this port ( e.g. VLC for video ).	5000
rotate	The number of packets to process for each encryption key. Note that a number that is too low may increase latency.	9000
user	The XQ account to use. If an email address is specified (e.g. email@domain.com ), the confirmation code sent to that email address will need to be entered. Otherwise, if a simple name alias is entered, an XQ anonymous email address is used based on that alias.	xq-proxy
recipients	A comma delimited list of email addresses (not names) that are allowed to view this stream. By default, this will be configured to the email address of the user ( if an alias was used, the actual address will be detected).
config	The path to the xq configuration file to use. By default, an xq.ini config file is expected to be located in the application directory.	xq.ini