Call1.Content.MediaDescription.I.RTCPFeedback1 — Telepathy D-Bus Interface Specification

# Interface Call1.Content.MediaDescription.Interface.RTCPFeedback1

Interface Index (Compact) | Summary | Description | Properties | Types

### Properties

FeedbackMessages | a{u(ua(sss))} (RTCP_Feedback_Message_Map) | Read only |  |
DoesAVPF | b | Read only |  |

### Types

RTCP_Feedback_Message_Map | Mapping | a{u(ua(sss))} |
RTCP_Feedback_Message_Properties | Struct | (ua(sss)) |
RTCP_Feedback_Message | Struct | (sss) |

Added in 0.25.2. (as stable API)
Objects implementing this interface must also implement:

- im.telepathy.v1.Call1.Content.MediaDescription

### Description

This codec offer interface provides a method of signalling support for RTCP feedback, documented by Extended RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/AVPF) (RFC 4585).

The codec identifiers used in the description of the Feedback Messages sent in the Accept's should match those used for the RemoteCodecs in the same Accept call.

For more details on what RTCP Feedback can do and how to use it, one should refer to RFC 4585.

# Properties

Accessed using the org.freedesktop.DBus.Properties interface.
(Permalink)

## FeedbackMessages — a{u(ua(sss))} (RTCP_Feedback_Message_Map)

Read only
A map of remote feedback codec properties that are supported.
(Permalink)

## DoesAVPF — b

Read only
True if the remote contact supports Audio-Visual Profile Feedback (AVPF), otherwise False.

# Types

Mapping (Permalink)

## RTCP_Feedback_Message_Map — a{u(ua(sss))}

Added in 0.22.1.
A map of codec and its feedback properties.

- Codec_Identifier — u
Numeric identifier for the codec. This will be used as the PT in the SDP or content description.
- Properties — (ua(sss)) (RTCP_Feedback_Message_Properties)
The RTCP feedback properties for this codec.

Struct (Permalink)

## RTCP_Feedback_Message_Properties — (ua(sss))

Added in 0.22.1.
Changed in 0.23.4. This struct is also used by Call, but in call, the CM should know about RTP profiles, and never use MAXUINT as a default value, because it complicates things unnecessarily.

- RTCPMinimumInterval — u
The minimum interval between two regular RTCP packets in milliseconds for this content. If no special value is required, 5000 (5 seconds) should be used in RTP/AVP, and a lower value in RTP/AVPF (by default, 0).
- Messages — a(sss) (RTCP_Feedback_Message_List)
The RTCP feedback messages for this codec.

Struct (Permalink)

## RTCP_Feedback_Message — (sss)

Added in 0.22.1.
A struct defining an RTCP feedback message.

- Type — s
Feedback type, for example "ack", "nack", or "ccm".
- Subtype — s
Feedback subtype, according to the Type, can be an empty string (""), if there is no subtype. For example, generic nack is Type="nack" Subtype="".
- Parameters — s
Feedback parameters as a string. Format is defined in the relevant RFC