Deliver WebRTC streams to viewers using the Wowza Streaming Cloud REST API

WebRTC lets you capture video from your browser without installing plug-ins or downloading third-party software. With Wowza Streaming Cloud, you can deliver WebRTC streams to viewers or other video services directly from the transcoder. Egress costs for direct playback are typically greater than the costs associated with delivering streams to viewers through a CDN. For more information about cost, audience size, and other workflow considerations, see WebRTC workflows in Wowza Streaming Cloud.

You'll need to choose which workflow you'll use, live stream or transcoder, before you begin this task. See Decide between a live stream or transcoder workflow for more information about these workflows.

Before you start


You should be familiar with the following concepts:

  • An API authentication method. Use HMAC authentication for production environments. For testing or proof of concept purposes only, use API key and access key authentication.
  • We use environment variables for the API version and your API and access keys in the cURL API request examples in this topic to make it easier for you to copy, paste, and run commands in your Terminal or Command Prompt window. If you don't set environment variables for these values, you'll need to manually enter the correct values in the code samples throughout this tutorial. See Tools for testing the API for instructions.

     

Live stream workflow

1. Create a live stream

Create a live stream that receives a WebRTC source by sending a POST request to the /live_streams endpoint.

You can use the following sample request, making sure to:

  • Set encoder to other_webrtc.
  • Set aspect_ratio_height to 1280. Recommended value for WebRTC streams.
  • Set aspect_ratio_width to 720. Recommended value for WebRTC streams.
  • Set broadcast_location to the region that's closest to your video source.
  • Set delivery_method to push. Wowza Streaming Cloud doesn't support pull or cdn connections for WebRTC.
  • Change any values unique to your broadcast, using the API reference documentation as a resource. See the Endpoint Reference button below.

Sample request

Endpoint Reference

curl -X POST \
-H "Content-Type: application/json" \
-H "wsc-api-key: ${WSC_API_KEY}" \
-H "wsc-access-key: ${WSC_ACCESS_KEY}" \
-d '{
   "live_stream": {
     "aspect_ratio_height": 720,
     "aspect_ratio_width": 1280,
     "billing_mode": "pay_as_you_go",
     "broadcast_location": "us_west_california",
     "delivery_method": "push",
     "encoder": "other_webrtc",
     "name": "MyWebRTCStream",
     "transcoder_type": "transcoded"
   }
}' "${WSC_HOST}/api/${WSC_VERSION}/live_streams"

Sample response

The response includes:

  • An id for the live stream you'll use in the next step.
  • source_connection_information you'll use in the next step to configure the WebRTC publish page.
    • sdp_url, application_name, and stream_name
  • An array of direct_playback_urls. You'll use the URL with the name webrtc.
{
   "live_stream": {
     "id": "1234abcd",
     "name": "MyWebRTCStream",
     ...
     "encoder": "other_webrtc",
     ...
     "source_connection_information": {
       "sdp_url": "wss://[subdomain].entrypoint.cloud.wowza.com/webrtc-session.json",
       "application_name": "app-30zl5349",
       "stream_name": "32a5814b",
     },
     ...
     "direct_playback_urls": {
      ...
     "webrtc": [
        {
            "name": "source",
            "url": "wss://[subdomain].entrypoint.cloud.wowza.com/webrtc-session.json",
            "application_name": "app-1880020Q",
            "stream_name": "3f8f1889"
        },
        {
            "name": "webrtc",
            "url": "wss://[subdomain].entrypoint.cloud.wowza.com/webrtc-session.json",
            "application_name": "app-1880020Q",
            "stream_name": "3f8f1889_stream1",
            "output_id": "wpdlffwf"
        }
      ]
    },
    ...
  }
}

(Optional) Decrease latency

The default buffer size for a live stream is 4 seconds. To decrease the latency of the stream and get closer to real-time, you can change the buffer to 0. You'll make this change on the transcoder created for the live stream.

  1. Send a request to GET /transcoders to get the transcoder ID for your live stream. See the API reference for more information about this endpoint. 
  2. Send a request to PATCH /transcoders/[ID], where ID is the transcoder ID returned in the previous step, and set the buffer_size to 0. See the API reference for more information about this endpoint.

2. Start the live stream  


Before you can connect to the stream through the WebRTC publish page in the next step, you need to start the live stream. You'll need the [live_stream_id]returned in step 1.

Endpoint Reference

curl -X PUT \
-H "wsc-api-key: ${WSC_API_KEY}" \
-H "wsc-access-key: ${WSC_ACCESS_KEY}" \
"${WSC_HOST}/api/${WSC_VERSION}/live_streams/[live_stream_id]/start"

3. Publish the WebRTC live stream


With the live stream started, you can now configure the WebRTC publish page as the source of the stream.

  1. Go to wowza.com/webrtc/publish and grant access to your camera and microphone when prompted.
     
    Note: The WebRTC hosted publish page is supported on the latest versions of Chrome and Safari, as well as Edge version 79 and later.

  2. Click the Settings button on the upper-right corner of the page.
  3. Specify the following settings:
     
    • SDP URL – The sdp_url from the WebRTC source_connection_information object.
    • Application Name – The application_name from the WebRTC source_connection_information object.
    • Stream Name – The stream_name from the WebRTC source_connection_information object.
    • Audio Bitrate – You can leave Audio Bitrate set to the default value, 64.
    • Video Bitrate – You can leave Video Bitrate set to the default value, 3500.

       
  4. Close the Settings dialog box to apply your changes.
  5. To change which microphone to use, click the arrow next to the microphone icon.
  6. To change the video source, click the arrow next to the video camera icon. To share your screen, select Screen Share.
     
    Notes:
    • The video source can’t be changed after the broadcast is started.
    • Screen share functionality isn't supported on mobile devices or Safari.
  7. Click Publish.

The stream now has source video that you can view on the WebRTC playback page.

4. Play the WebRTC live stream


You can test the playback using our WebRTC playback page. See the Distributable viewer URL section to get a URL you can send to your viewers.

  1. In a new browser tab, go to wowza.com/webrtc/play.
     
    Note: The WebRTC hosted playback page is supported on the latest versions of Chrome and Safari, as well as Edge version 79 and later.


  2. Click the Settings button on the upper-right corner of the page.
  3. Specify the following settings:
     
    • SDP URL – The url from the webrtc rendition of the WebRTC direct_playback_urls object.
    • Application Name – The application_name from the webrtc rendition of the WebRTC direct_playback_urls object.
    • Stream Name – The stream_name from the webrtc rendition of the WebRTC direct_playback_urls object.
       
      Make sure you don't use the stream_name from source_connection_information. That object should not be distributed to viewers.
  4. Close the Settings dialog box to apply your changes.
  5. Click Play.

Distributable viewer URL

You can get a URL to distribute to your viewers so they can watch the WebRTC stream on a preconfigured, hosted page in one of two ways:

  • Log into Wowza Streaming Cloud and use the WebRTC Playback Page URL on the Overview page for the live stream.
  • Using the information in step 3, build the URL with the following format:
     
    https://wowza.com/webrtc/play?playApplicationName=[application_name]&playSdpURL=[sdp_url]&playStreamName=[stream_name]&title=[title]

    Where sdp_url is escaped as in this example: wss%3A%2F%2F[subdomain].entrypoint.cloud.wowza.com%2Fwebrtc-session.json

5. Stop the live stream


To avoid incurring additional billing charges, remember to stop the live stream after the stream broadcast is over.

Endpoint Reference

curl -X PUT \
-H "wsc-api-key: ${WSC_API_KEY}" \
-H "wsc-access-key: ${WSC_ACCESS_KEY}" \ 
"${WSC_HOST}/api/${WSC_VERSION}/live_streams/[live_stream_id]/stop"

More live stream resources


Transcoder workflow

1. Create a transcoder

Create a transcoder that receives a WebRTC source by sending a POST request to the /transcoders endpoint.

You can use the following sample request, making sure to:

  • Set protocol to webrtc.
  • Set delivery_method to push. Wowza Streaming Cloud doesn't support pull or cdn connections for WebRTC.
  • Set broadcast_location to the region that's closest to your video source.
  • Set buffer_size to 0. The default buffer size for a stream is 4 seconds. Changing the buffer size to 0 decreases the latency of the stream and gets it closer to real-time.
  • Set transcoder_type to transcoded. We recommend that you use an adaptive bitrate transcoder (transcoded) when performing direct playback of a WebRTC stream for maximum viewer connections and a larger feature set, however the transcoder workflow allows you to select passthrough. The transcoder type affects how many viewers can connect to your stream directly through the transcoder:
    • transcoded results in a larger transcoder that can handle more viewer connections.
    • passthrough results in a smaller transcoder which can result in lower overall costs, but also means fewer viewer connections and other limitations. If you choose passthrough, make sure you do sufficient testing to ensure your streaming goals are met.
  • Change any values unique to your broadcast, using the API reference documentation as a resource. See the Endpoint Reference button below.

Sample request 

Endpoint Reference

curl -X POST \
-H "Content-Type: application/json" \
-H "wsc-api-key: ${WSC_API_KEY}" \
-H "wsc-access-key: ${WSC_ACCESS_KEY}" \
-d '{    
  "transcoder": { 
    "billing_mode": "pay_as_you_go",      
    "broadcast_location": "us_west_california",
    "buffer_size": 0,
    "delivery_method": "push",      
    "name": "MyWebRTCTranscoder",      
    "protocol": "webrtc",      
    "transcoder_type": "transcoded"
  } 
}' "${WSC_HOST}/api/${WSC_VERSION}/transcoders"

Sample response

The response includes:

  • An id for the live stream you'll use in the next step.
  • source_connection_information you'll use in the next step to configure a WebRTC source encoder for the live stream.
    • sdp_url, application_name, and stream_name
  • An array of outputs that contains an output for WebRTC. When you create a WebRTC transcoder, Wowza Streaming Cloud automatically creates a WebRTC output on the transcoder and you don't have to manually create and associate the output as you would with other protocols.
  • An array of direct_playback_urls. You'll use the URL with the name webrtc.
{ 
  "transcoder": { 
    "id": "tmd8ybp2", 
    "name": "MyWebRTCTranscoder", 
    "transcoder_type": "transcoded", 
    "billing_mode": "pay_as_you_go", 
    "broadcast_location": "us_west_california", 
    ... 
    "protocol": "webrtc", 
    "delivery_method": "push", 
    "source_port": 443, 
    "domain_name": "[hostname].entrypoint.cloud.wowza.com",
    "application_name": "app-V5840271",
    "stream_name": "R1gxG3Ja",
    ...
    "direct_playback_urls": {
         ...
         "webrtc": [
        {
           "name": "source",
           "url": "wss://[subdomain].entrypoint.cloud.wowza.com/webrtc-session.json",
           "application_name": "app-1880020Q",
           "stream_name": "3f8f1889"
        },
        {
           "name": "webrtc",
           "url": "wss://[subdomain].entrypoint.cloud.wowza.com/webrtc-session.json",
           "application_name": "app-1880020Q",
           "stream_name": "3f8f1889_stream1",
           "output_id": "wdplffwf"
        }
      ]
    },
    "outputs": [
      {
        "id": "bdnvb0l",
        "name": "WebRTC Output: Video + Audio",
        "transcoder_id": "tmd8ybp2",
        ...
        "output_stream_targets": [] 
      }
    ]
  }
} 

2. Start the transcoder


Before you can connect to the stream through the WebRTC publish page in the next step, you need to start the transcoder. You'll need the [transcoder_id]returned in step 1.

Endpoint Reference

curl -X PUT \
-H "wsc-api-key: ${WSC_API_KEY}" \
-H "wsc-access-key: ${WSC_ACCESS_KEY}" \
"${WSC_HOST}/api/${WSC_VERSION}/transcoders/[transcoder_id]/start"

3. Publish the WebRTC stream


With the stream started, you can now configure the WebRTC publish page as the source of the stream.

  1. Go to wowza.com/webrtc/publish and grant access to your camera and microphone when prompted.
     
    Note: The WebRTC hosted publish page is supported on the latest versions of Chrome and Safari, as well as Edge version 79 and later.

  2. Click the Settings button on the upper-right corner of the page.
  3. Specify the following settings:
     
    • SDP URL – Enter wss://[address]/webrtc-session.json where address is the domain_name in the API response.
    • Application Name – The application_name in the API response.
    • Stream Name – The stream_name in the API response. This is not the object in the direct playback object.
    • Audio Bitrate – You can leave Audio Bitrate set to the default value, 64.
    • Video Bitrate – You can leave Video Bitrate set to the default value, 3500.
  4. Close the Settings dialog box to apply your changes.
  5. To change which microphone to use, click the arrow next to the microphone icon.
  6. To change the video source, click the arrow next to the video camera icon. To share your screen, select Screen Share.
     
    Notes:
    • The video source can’t be changed after the broadcast is started.
    • Screen share functionality isn't supported on mobile devices or Safari.
  7. Click Publish.

The stream now has source video that you can view on the WebRTC playback page.

4. Play the WebRTC stream


You can test the playback using our WebRTC playback page. See the Distributable viewer URL section to get a URL you can send to your viewers.

  1. In a new browser tab, go to wowza.com/webrtc/play.
     
    Note: The WebRTC hosted playback page is supported on the latest versions of Chrome and Safari, as well as Edge version 79 and later.

  2. Click the Settings button on the upper-right corner of the page.
  3. Specify the following settings:
     
    • SDP URL – The url from the webrtc rendition of the WebRTC direct_playback_urls object.
    • Application Name – The application_name from the webrtc rendition of the WebRTC direct_playback_urls object.
    • Stream Name – The stream_name from the webrtc rendition of the WebRTC direct_playback_urls object.
  4. Close the Settings dialog box to apply your changes.
  5. Click Play.

Distributable viewer URL

You can get a URL to distribute to your viewers so they can watch the WebRTC stream on a preconfigured, hosted page in one of two ways:

  • Log into Wowza Streaming Cloud and use the WebRTC Playback Page URL on the Overview page for the transcoder.
  • Using the information in step 3, build the URL with the following format:
    https://wowza.com/webrtc/play?playApplicationName=[application_name]&playSdpURL=[sdp_url]&playStreamName=[stream_name]&title=[title]

    Where sdp_url is escaped as in this example: wss%3A%2F%2F[subdomain].entrypoint.cloud.wowza.com%2Fwebrtc-session.json

5. Stop the transcoder


To avoid incurring additional billing charges, remember to stop the transcoder after the stream broadcast is over. 

Endpoint Reference

curl -X PUT \
-H "wsc-api-key: ${WSC_API_KEY}" \
-H "wsc-access-key: ${WSC_ACCESS_KEY}" \
"${WSC_HOST}/api/${WSC_VERSION}/transcoders/[transcoder_id]/stop"

More transcoder resources