Files
advanced-camera-card/docs/usage/2-way-audio.md
T
Dermot Duffy 11cc543406 fix: Hold the 2-way audio backchannel open for the shortest possible time (#2697)
The card claimed a camera's ONVIF audio backchannel in two places that
had
nothing to do with a call: the capability probe at camera init
(`&microphone`),
and a pre-armed `sendonly` audio transceiver on every live WebRTC offer.
Merely
looking at a dashboard occupied the camera's speaker line. Outbound
audio now
travels on its own audio-only WebRTC connection, opened when a call is
answered
and closed when it ends.

- The backchannel is claimed only for the duration of a call. Idle
viewing
  claims nothing.
- Two-way audio now works in `mse`, `mp4` and `mjpeg` modes (note: the
outbound
  audio still traverses WebRTC).
- No renegotiation and no video blink at call start or end.
- A call that cannot carry audio now reports it and ends, instead of
showing a
  live microphone that goes nowhere.
- `live.microphone.always_connected` is now purely about the browser
microphone
  permission prompt.
- Call setup measured at 66ms (LAN) and ~260ms (cellular) for ICE and
DTLS, plus
  ~300ms for `go2rtc` to open an RTSP backchannel.

Verified against a live Frigate + `go2rtc` instance, and by unit tests
at 100%
coverage.

 - Closes #2691
 - Closes #2039
 - Closes #2178

Ref #2299 -- the probe no longer opens a backchannel, but it still runs
per
camera on every load and reconnect, and still dials the camera on the
direct-`go2rtc` path. Caching remains to be done.

Ref AlexxIT/go2rtc#1860 -- once a call has opened a backchannel,
`go2rtc` keeps
that media set up on the camera's RTSP session for the life of the
producer.

Diagnoses #2678
2026-08-21 20:13:58 -07:00

133 lines
6.1 KiB
Markdown

# 2-way Audio
This card supports 2-way audio (e.g. transmitting audio from a microphone to a
suitably equipped camera). In general, due to the myriad of different cameras,
security requirements and browser limitations getting 2-way to work may be
challenging.
## Requirements
### Environmental requirements
- Must have a camera that supports audio out (otherwise what's the point!)
- Camera must be supported by `go2rtc` for 2-way audio (see [supported cameras](https://github.com/AlexxIT/go2rtc#two-way-audio)).
- Must be accessing your Home Assistant instance over `https`. The browser will enforce this.
### Card requirements
- Only Frigate cameras are supported.
- Only the `go2rtc` and `go2rtc-experimental` live providers are supported.
- The browser must be able to reach `go2rtc` over WebRTC. Outbound audio always
travels on its own WebRTC connection, regardless of what mode is carrying the
video.
If your setup supports 2-way audio but detection is intermittent on load:
- Increase `cameras[].go2rtc.metadata_fetch_timeout_seconds`.
- Or force the capability with `cameras[].capabilities.force: ['2-way-audio']`.
If detection never succeeds for a camera, the `go2rtc` stream itself may not
offer 2-way audio -- see
[`go2rtc` live provider configuration](../configuration/cameras/live-provider.md?id=go2rtc).
## Example configuration
```yaml
type: custom:advanced-camera-card
cameras:
- camera_entity: camera.office
live_provider: go2rtc
go2rtc:
modes:
- webrtc
# Optional: For slower cameras increase timeout (default: 2)
metadata_fetch_timeout_seconds: 10
```
## Usage
Two-way audio is driven by the **call** menu button (a phone icon). It is
enabled by default and appears in the `live` view whenever the selected camera
-- or one of its [dependencies](../configuration/cameras/README.md?id=dependencies)
-- supports 2-way audio.
- Tap the call button to start an **outbound** call. An on-screen overlay
appears with controls to mute/unmute the microphone, mute/unmute the inbound
audio, and end the call. When more than one 2-way-audio camera is available
the button becomes a submenu with one entry per camera.
- **Inbound** calls (started by a
[`view.triggers.actions.trigger: call`](../configuration/view.md?id=trigger-action-configuration)
trigger -- e.g. a doorbell) open the overlay in a ringing state with only
two buttons: a red **Reject** and a green **Answer**.
- The **call** menu button itself tracks the call state: tap it to start or
answer a call and to hang up an active one, and while an inbound call is
ringing **hold** it to reject. This lets you drive the whole call from the
menu when the standard call controls are hidden with
[`live.controls.call.enabled: false`](../configuration/live.md?id=call) -- see
[Driving calls from the menu](../examples.md?id=driving-calls-from-the-menu).
- When a call is answered (outbound calls are answered by definition) the
inbound audio is unmuted automatically, so the caller can be heard. The
microphone stays muted by default (push-to-talk) -- tap the microphone button
in the overlay to speak. Both behaviors are configurable via
[`live.microphone.auto_unmute`](../configuration/live.md?id=microphone) and
[`live.auto_unmute`](../configuration/live.md).
- The camera loads _without_ the microphone connected, unless the
[`always_connected`](../configuration/live.md?id=microphone) microphone option
is set to `true`. Starting a call opens a separate connection that carries your
voice to the camera; ending the call closes it. The camera's audio input is
therefore occupied only while a call is in progress, leaving it free for other
applications the rest of the time. Expect under half a second between starting
a call and being audible on a local network, and a little more remotely. The
video keeps playing throughout.
- The browser asks for microphone permission when a call needs it. How often it
asks depends on the browser: Chrome remembers the choice for the site, Safari
asks once per page load, and Firefox asks for every call unless _Remember this
decision_ is ticked. Set
[`always_connected`](../configuration/live.md?id=microphone) to `true` to be
asked once at card load instead.
- While a call is in progress the card locks disruptive actions (camera and
substream changes, casting, reload, etc.) so an accidental tap, swipe, or
button press doesn't cut the call off. Set
[`live.controls.call.lock`](../configuration/live.md?id=call) to `false` to
disable this.
- End the call with the overlay's end-call button. When the call ends the
microphone and inbound audio are muted again, and the microphone is
disconnected. The exception is
[`always_connected`](../configuration/live.md?id=microphone), which holds the
microphone connected for as long as the card is running.
Calls can also be controlled programmatically with the
[`call_start`](../configuration/actions/custom/README.md?id=call_start),
[`call_answer`](../configuration/actions/custom/README.md?id=call_answer), and
[`call_end`](../configuration/actions/custom/README.md?id=call_end) actions --
for example, from an [automation](../configuration/automations.md) that fires
when a doorbell sensor triggers. The [`call` condition](../configuration/conditions-triggers.md?id=call)
can be used to show or hide elements while a call is in progress.
### Call lifecycle
The diagram below traces a call from start to finish:
![Call lifecycle sequence diagram](../images/call-sequence.svg ':size=600')
## Talking with a single tap
By default, two taps are needed to speak: start (or answer) the call so you can
hear, then unmute the microphone via the in-call overlay so you can be heard.
This push-to-talk default keeps the microphone muted until you explicitly choose
to speak.
To collapse that to a single tap, unmute the microphone automatically when a
call is answered:
```yaml
live:
microphone:
auto_unmute: ['call']
```
For outbound calls the microphone opens the moment the call starts; for inbound
calls it opens the moment you press the green answer button. Leave
[`auto_unmute`](../configuration/live.md?id=microphone) empty (the default) to
always start muted regardless.