Workflow: Transmitting Audio by Using the Oracle Radio WebSocket API

Acquire the talk floor, start a transmission, send binary audio, end the transmission, and release the talk token.

Before You Begin

Open an authenticated WebSocket connection. Follow Subscribing to an Oracle Radio WebSocket Channel, and verify that the target channel's subscribed result is true. The Radio user must have talk access, radio.talk.request, and radio.audio.transmit.

Caution

Do not reuse a talk token across connections or continue sending after an interruption, expiration, timeout, error, or disconnect.

Transmitting Audio

Follow Requesting the Oracle Radio WebSocket Talk Floor to send REQUEST_TALK for the subscribed channel.
```
{
  "type": "REQUEST_TALK",
  "channel": "operations",
  "priority": 50
}
```
Wait for GRANTED. Save the returned token and expiresAt. Do not start a transmission after DENIED, QUEUED, or TALK_DENIED.
Follow Starting an Oracle Radio WebSocket Audio Transmission to send START with the granted token and the audio properties that the client will use.
```
{
  "type": "START",
  "token": "550e8400-e29b-41d4-a716-446655440000",
  "format": "opus",
  "sampleRate": 8000,
  "channels": 1,
  "bitrate": 16000,
  "frameSize": 20
}
```
The initiating connection does not receive its own TRANSMISSION_START event. After the client reports that it successfully sent START, continue unless the service sends ERROR.
Follow Sending Oracle Radio WebSocket Audio to send each encoded packet as one unframed binary WebSocket message. Continue only while the connection is open and the talk token is valid.
After sending the final binary packet, follow Ending an Oracle Radio WebSocket Audio Transmission to send END.
```
{
  "type": "END",
  "token": "550e8400-e29b-41d4-a716-446655440000",
  "duration": 3.5
}
```
The initiating connection does not receive its own TRANSMISSION_END event. Stop sending audio after the client reports that it successfully sent END.
Follow Releasing the Oracle Radio WebSocket Talk Floor to send RELEASE_TALK with the talk token and channel.
```
{
  "type": "RELEASE_TALK",
  "token": "550e8400-e29b-41d4-a716-446655440000",
  "channel": "operations"
}
```
Wait for RELEASED. Other channel subscribers can receive CHANNEL_OPEN.

Handling Alternate Outcomes

Use the following outcomes to determine how to continue or recover an audio transmission.

Outcome	Client action
`QUEUED`	Do not send `START`. Retain the request state and wait for a later `GRANTED` response with `fromQueue` set to `true`. If the connection closes first, discard the queued state.
`DENIED`	Do not send audio. Use the returned busy-holder or reason information, if present, to decide whether to request the talk floor later.
`TALK_DENIED`	Do not send audio. Correct the Radio permission or channel-access problem identified by the returned `reason` and `code`.
`INTERRUPTED`	Stop sending binary audio immediately and discard the talk token. Request a new token before attempting another transmission.
`TOKEN_EXPIRED`	Stop sending binary audio, discard the expired token, and request a new token if the user still needs to transmit.
`TRANSMISSION_TIMEOUT`	Stop sending binary audio. The service has automatically released the token, so request a new token before another transmission.
`ERROR` or `TOKEN_INVALID`	Stop sending binary audio. Correct the request or state problem before restarting the talk-floor flow.
WebSocket disconnect	Stop capture and sending, discard the talk token, reconnect, subscribe to the channel again, and start with a new `REQUEST_TALK`.

Oracle Cloud Infrastructure Documentation

Workflow: Transmitting Audio by Using the Oracle Radio WebSocket API

Before You Begin

Transmitting Audio

Handling Alternate Outcomes