You can send an audio stream to a call in two cases:
- The call is answered
- The call is not answered yet
Input into a connected call
The second case is about sending an audio stream to an already active call. Sending an audio stream to a connected call will replace the previous one since each call can receive only one audio stream at a time (if you want to mix two or more streams, use conferences instead).
You can send media by using a Player instance:
Early media on a non-connected call
This case requires the usage of so-called early media. You might have heard an announcement or music instead of dialing tones when trying to call a hotline – this is what early media is. You can do it like this: