README.md

Simulated camera application

This code sample shows you an implementation of a simulated camera streaming, which is looping through the files in a images folder and streaming those frames at the following rates: 2/6/12 frames per minute or respectively in manual mode where you specify the frame rate event yourself.

To run the application

1. Start chariott runtime by executing cargo run from the root directory

2. Navigate to examples/applications/simulated-camera directory

3. Create a images directory and place there all the .jpg files you want the camera application to stream

4. Start camera application by executing cargo run from the examples/applications/simulated-camera directory.

5. In another terminal, open a channel to the simulated-camera with grpcurl -v \ -plaintext -import-path proto -proto \ proto/chariott/streaming/v1/streaming.proto localhost:50066 \ chariott.streaming.v1.ChannelService/Open and take a note of the returned channel id in the metadata x-chariott-channel-id.

6. In yet another terminal, call the following, using the channel id from the previous step:

   grpcurl -v -plaintext -d @ localhost:4243 chariott.runtime.v1.ChariottService/Fulfill <<EOM
   {
       "namespace": "sdv.camera.simulated",
       "intent": {
           "subscribe": {
               "channel_id": "",
               "sources": ["camera.12fpm"]
           }
       }
   }
   EOM

   This makes a single request for a subscription intent for simulated camera frames arriving at the desired frame per minute rate. Chariott then passes these intents to the simulated camera application that can fulfill it.

   Other allowed sources (i.e. event rate) can be found via Inspect intent:

   grpcurl -v -plaintext -d @ localhost:4243 chariott.runtime.v1.ChariottService/Fulfill <<EOM
    {
        "namespace": "sdv.camera.simulated",
        "intent": {
            "inspect": {
                "query": "*"
            }
        }
    }
   EOM

To run the application in manual mode

You follow the same procedure as in the previous section, but instead of running step 4 you exchange it with the following command

cargo run -- -m

This will start the application in manual mode, where you can specify the images through a stdin stream. The syntax for the stream is as follows:

load <path to image file> <frame rate in frames per minute>

For example, to load an image image.jpg at 2 frames per minute, you would send the following to the application:

load image.jpg camera.2fpm

Valid frame rates are camera.2fpm, camera.6fpm and camera.12fpm. The image path is relative from where you start the application.