# Amazon Kinesis Video Streams with WebRTC SDK in C for embedded devices
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The following step-by-step instructions describe how to download, build, and run the Kinesis Video Streams with WebRTC SDK in C for embedded devices and its corresponding samples.

The following codecs are supported:
+ **Audio: **
  + G.711 A-Law
  + G.711 U-Law
  + Opus
+ **Video:**
  + H.264
  + H.265
  + VP8

## Download the SDK
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To download the Kinesis Video Streams with WebRTC SDK in C for embedded devices, run the following command:

```
$ git clone https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c.git
```

## Build the SDK
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**Important**  
Before you complete these steps on a macOS and depending on the version of the macOS you have, you must run `xcode-select --install` to download the package with the command line tools and header. Then open `/Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg` and follow the installer to install the command line tools and header. You only need to do this once and before invoking `cmake`. If you already have the command line tools and header installed, you do not need to run this command again.

Complete the following steps:

****

1. Install cmake:
   + On macOS, run `brew install cmake pkg-config srtp` 
   + on Ubuntu, run `sudo apt-get install pkg-config cmake libcap2 libcap-dev`

1. Obtain the access key and the secret key of the AWS account that you want to use for this demo.

1. Run the following command to create a `build` directory in your downloaded WebRTC C SDK, and execute `cmake` from it:

   ```
   $ mkdir -p amazon-kinesis-video-streams-webrtc-sdk-c/build; cd amazon-kinesis-video-streams-webrtc-sdk-c/build; cmake ..
   ```

1. Now that you're in the `build` directory you just created with the step above, run `make` to build the WebRTC C SDK and its provided samples.
**Note**  
 The `kvsWebrtcClientMasterGstSample` will NOT be built if the system doesn't have `gstreamer` installed. To make sure it is built (on macOS) you must run: `brew install gstreamer gst-plugins-base gst-plugins-good` 

## Run the SDK samples
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After you complete the procedure above, you end up with the following sample applications in your `build` directory:
+ `kvsWebrtcClientMaster` - This application sends sample H264/Opus frames (path: /samples/h264SampleFrames and /samples/opusSampleFrames) via the signaling channel. It also accepts incoming audio, if enabled in the browser. When checked in the browser, it prints the metadata of the received audio packets in your terminal.
+ `kvsWebrtcClientViewer` - This application accepts sample H264/Opus frames and prints them out. 
+ `kvsWebrtcClientMasterGstSample` - This application sends sample H264/Opus frames from a GStreamer pipeline.

To run any of these samples, complete the following steps:

1. Setup your environment with your AWS account credentials:

   ```
   export AWS_ACCESS_KEY_ID=YourAccessKey
   export AWS_SECRET_ACCESS_KEY=YourSecretKey
   export AWS_DEFAULT_REGION=YourAWSRegion
   ```

   If you're using temporary AWS credentials, also export your session token:

   ```
   export AWS_SESSION_TOKEN=YourSessionToken
   ```

   If you have a custom CA certificate path to set, you can set it using:

   ```
   export AWS_KVS_CACERT_PATH=../certs/cert.pem
   ```
**Note**  
By default, the SSL CA certificate is set to ../certs/cert.pem which points to the file in this repository in [GitHub](https://github.com/awslabs/amazon-kinesis-video-streams-webrtc-sdk-c/blob/master/certs/cert.pem).

1. Run either of the sample applications by passing to it the name that you want to give to your signaling channel. The application creates the signaling channel using the name you provide. For example, to create a signaling channel called `myChannel` and to start sending sample H264/Opus frames via this channel, run the following command: 

   ```
   ./kvsWebrtcClientMaster myChannel
   ```

   When the command line application prints `Connection established`, you can proceed to the next step.

1. Now that your signaling channel is created and the connected master is streaming media to it, you can view this stream. For example, you can view this live stream in a web application. To do so, open the WebRTC SDK Test Page using the steps in [Use the sample application](kvswebrtc-sdk-js.md#build-sdk-js) and set the following values using the same AWS credentials and the same signaling channel that you specified for the master above:
   + Access key ID
   + Secret access key
   + Signaling channel name
   + Client ID (optional)

   Choose **Start viewer** to start live video streaming of the sample H264/Opus frames.

## Video tutorial
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This video demonstrates how to connect your camera and get started with Amazon Kinesis Video Streams for WebRTC.