View Source Membrane.RTC.Engine.Endpoint.WebRTC.TrackReceiver (Membrane RTC Engine WebRTC Endpoint v0.1.0)

Element responsible for handling WebRTC track.

Its main responsibility is to request the highest available track variant. If currently used track variant becomes inactive, TrackReceiver will switch to the next available variant.

Outgoing RTP packets belong to the same sequence number and timestamp spaces but they are not guaranteed to be in order and contiguous.

To unpack RTP see Membrane.RTC.Engine.Track.get_depayloader/1.

To control TrackReceiver behavior see control_messages/0.

TrackReceiver also emits some notifications. They are defined in notifications/0.

Element options

Passed via struct Membrane.RTC.Engine.Endpoint.WebRTC.TrackReceiver.t/0

track
```
Track.t()
```
Required
Track this adapter will maintain
initial_target_variant
```
Membrane.RTC.Engine.Track.variant()
```
Required
Track variant that will be forwarded whenever it is active. Can be changed with t:set_target_variant_msg/0.
keyframe_request_interval
```
Membrane.Time.t() | nil
```
Default value: nil
Defines how often keyframe requests should be sent for currently used track variant.
This option should be used in very specific cases (e.g. see HLS endpoint) as generating keyframes increases track bitrate and might introduce additional delay.
connection_allocator_module
```
module()
```
Default value: Membrane.RTC.Engine.Endpoint.WebRTC.NoOpConnectionAllocator
Module implementing Membrane.RTC.Engine.Endpoint.WebRTC.ConnectionAllocator behavior that should be used by the TrackReceiver.
connection_allocator
```
pid() | nil
```
Default value: nil
PID of the instance of the ConnectionAllocator that should be used by the TrackReceiver
allocation_negotiable?
```
boolean()
```
Default value: false
Option defining whether allocation for this Track Receiver should be negotiable.
Trying to enable negotiability for tracks that are inherently non-negotiable, also known as non-simulcast tracks, will result in a crash.
This value can later be changed by sending a set_negotiable?/0 control message to this Element.
telemetry_label
```
Membrane.TelemetryMetrics.label()
```
Default value: []
Label passed to Membrane.TelemetryMetrics functions

Pads

`:input`

Accepted formats:

Membrane.RTP

Direction:	`:input`
Availability:	`:always`
Flow control:	`:push`
Demand unit:	`nil`

`:output`

Accepted formats:

Membrane.RTP

Direction:	`:output`
Availability:	`:always`
Flow control:	`:push`
Demand unit:	`nil`

Summary

Types

control_messages()

Messages that can be sent to TrackReceiver to control its behavior.

notifications()

Notifications that TrackReceiver emits.

set_negotiable?()

Changes negotiability status of the TrackReceiver.

set_target_variant()

Changes target track variant.

t()

Struct containing options for Membrane.RTC.Engine.Endpoint.WebRTC.TrackReceiver

variant_switch_reason()

Reason of track variant switch.

variant_switched()

Notification emitted whenever TrackReceiver starts receiving a new track variant.

voice_activity_changed()

Notfication emitted when TrackReceiver receives an update on voice activity

Functions

options()

Returns description of options available for this module

Types

control_messages()

@type control_messages() :: set_target_variant() | set_negotiable?()

Messages that can be sent to TrackReceiver to control its behavior.

notifications()

@type notifications() :: variant_switched() | voice_activity_changed()

Notifications that TrackReceiver emits.

set_negotiable?()

@type set_negotiable?() :: {:set_negotiable?, boolean()}

Changes negotiability status of the TrackReceiver.

Negotiability refers to the setting in Membrane.RTC.Engine.Endpoint.WebRTC.ConnectionAllocator that determines if the allocation for the TrackReceiver can be negotiated.

set_target_variant()

@type set_target_variant() ::
  {:set_target_variant, Membrane.RTC.Engine.Track.variant()}

Changes target track variant.

Target track variant is variant that will be forwarded whenever it is active.

t()

@type t() :: %Membrane.RTC.Engine.Endpoint.WebRTC.TrackReceiver{
  allocation_negotiable?: boolean(),
  connection_allocator: pid() | nil,
  connection_allocator_module: module(),
  initial_target_variant: Membrane.RTC.Engine.Track.variant(),
  keyframe_request_interval: Membrane.Time.t() | nil,
  telemetry_label: Membrane.TelemetryMetrics.label(),
  track: Membrane.RTC.Engine.Track.t()
}

Struct containing options for Membrane.RTC.Engine.Endpoint.WebRTC.TrackReceiver

variant_switch_reason()

@type variant_switch_reason() :: :low_bandwidth | :variant_inactive | :other

Reason of track variant switch.

:low_bandwidth - bandwidth was too low to maintain current track quality
:variant_inactive - variant became inactive
:other - it was hard to determine the exact reason

variant_switched()

@type variant_switched() ::
  {:variant_switched, Membrane.RTC.Engine.Track.variant(),
   variant_switch_reason()}

Notification emitted whenever TrackReceiver starts receiving a new track variant.

voice_activity_changed()

@type voice_activity_changed() :: {:voice_activity_changed, :silence | :speech}

Notfication emitted when TrackReceiver receives an update on voice activity

Functions

options()

@spec options() :: keyword()

Returns description of options available for this module

Settings View Source Membrane.RTC.Engine.Endpoint.WebRTC.TrackReceiver (Membrane RTC Engine WebRTC Endpoint v0.1.0)

control_messages()

notifications()

set_negotiable?()

set_target_variant()

t()

variant_switch_reason()

variant_switched()

voice_activity_changed()

options()

View Source Membrane.RTC.Engine.Endpoint.WebRTC.TrackReceiver (Membrane RTC Engine WebRTC Endpoint v0.1.0)