events: Add support for multi-stream VoIP

According to MSC3077 / Matrix 1.10

crates/ruma-events/CHANGELOG.md

@@ -31,6 +31,7 @@ Improvements:
 - Implement `From<JoinRule>` for `SpaceRoomJoinRule`
 - Add `filename` and `formatted` fields to media event contents to support media captions
   as per [MSC2530](https://github.com/matrix-org/matrix-spec-proposals/pull/2530) / Matrix 1.10
+- Add support for multi-stream VoIP, according to MSC3077 / Matrix 1.10
 
 # 0.27.11
 

crates/ruma-events/src/call.rs

@@ -14,8 +14,11 @@ pub mod notify;
 pub mod reject;
 pub mod select_answer;
 
+use ruma_macros::StringEnum;
 use serde::{Deserialize, Serialize};
 
+use crate::PrivOwnedStr;
+
 /// A VoIP session description.
 ///
 /// This is the same type as WebRTC's [`RTCSessionDescriptionInit`].
@@ -44,6 +47,41 @@ impl SessionDescription {
     }
 }
 
+/// Metadata about a VoIP stream.
+#[derive(Clone, Debug, Serialize, Deserialize)]
+#[cfg_attr(not(feature = "unstable-exhaustive-types"), non_exhaustive)]
+pub struct StreamMetadata {
+    /// The purpose of the stream.
+    pub purpose: StreamPurpose,
+}
+
+impl StreamMetadata {
+    /// Creates a new `StreamMetadata` with the given purpose.
+    pub fn new(purpose: StreamPurpose) -> Self {
+        Self { purpose }
+    }
+}
+
+/// The purpose of a VoIP stream.
+#[doc = include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/src/doc/string_enum.md"))]
+#[derive(Clone, PartialEq, Eq, StringEnum)]
+#[ruma_enum(rename_all = "m.snake_case")]
+#[non_exhaustive]
+pub enum StreamPurpose {
+    /// `m.usermedia`.
+    ///
+    /// A stream that contains the webcam and/or microphone tracks.
+    Usermedia,
+
+    /// `m.screenshare`.
+    ///
+    /// A stream with the screen-sharing tracks.
+    Screenshare,
+
+    #[doc(hidden)]
+    _Custom(PrivOwnedStr),
+}
+
 /// The capabilities of a client in a VoIP call.
 #[cfg(feature = "unstable-msc2747")]
 #[derive(Clone, Debug, Default, Serialize, Deserialize)]

crates/ruma-events/src/call/answer.rs

@@ -2,13 +2,15 @@
 //!
 //! [`m.call.answer`]: https://spec.matrix.org/latest/client-server-api/#mcallanswer
 
+use std::collections::BTreeMap;
+
 use ruma_common::{OwnedVoipId, VoipVersionId};
 use ruma_macros::EventContent;
 use serde::{Deserialize, Serialize};
 
 #[cfg(feature = "unstable-msc2747")]
 use super::CallCapabilities;
-use super::SessionDescription;
+use super::{SessionDescription, StreamMetadata};
 
 /// The content of an `m.call.answer` event.
 ///
@@ -34,6 +36,12 @@ pub struct CallAnswerEventContent {
     /// The VoIP capabilities of the client.
     #[serde(default, skip_serializing_if = "CallCapabilities::is_default")]
     pub capabilities: CallCapabilities,
+
+    /// **Added in VoIP version 1.** Metadata describing the streams that will be sent.
+    ///
+    /// This is a map of stream ID to metadata about the stream.
+    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
+    pub sdp_stream_metadata: BTreeMap<String, StreamMetadata>,
 }
 
 impl CallAnswerEventContent {
@@ -46,6 +54,7 @@ impl CallAnswerEventContent {
             version,
             #[cfg(feature = "unstable-msc2747")]
             capabilities: Default::default(),
+            sdp_stream_metadata: Default::default(),
         }
     }
 
@@ -69,6 +78,7 @@ impl CallAnswerEventContent {
             version: VoipVersionId::V1,
             #[cfg(feature = "unstable-msc2747")]
             capabilities: Default::default(),
+            sdp_stream_metadata: Default::default(),
         }
     }
 }

crates/ruma-events/src/call/invite.rs

@@ -2,6 +2,8 @@
 //!
 //! [`m.call.invite`]: https://spec.matrix.org/latest/client-server-api/#mcallinvite
 
+use std::collections::BTreeMap;
+
 use js_int::UInt;
 use ruma_common::{OwnedUserId, OwnedVoipId, VoipVersionId};
 use ruma_macros::EventContent;
@@ -9,7 +11,7 @@ use serde::{Deserialize, Serialize};
 
 #[cfg(feature = "unstable-msc2747")]
 use super::CallCapabilities;
-use super::SessionDescription;
+use super::{SessionDescription, StreamMetadata};
 
 /// The content of an `m.call.invite` event.
 ///
@@ -49,6 +51,12 @@ pub struct CallInviteEventContent {
     /// The invite should be ignored if the invitee is set and doesn't match the user's ID.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub invitee: Option<OwnedUserId>,
+
+    /// **Added in VoIP version 1.** Metadata describing the streams that will be sent.
+    ///
+    /// This is a map of stream ID to metadata about the stream.
+    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
+    pub sdp_stream_metadata: BTreeMap<String, StreamMetadata>,
 }
 
 impl CallInviteEventContent {
@@ -69,6 +77,7 @@ impl CallInviteEventContent {
             #[cfg(feature = "unstable-msc2747")]
             capabilities: Default::default(),
             invitee: None,
+            sdp_stream_metadata: Default::default(),
         }
     }
 
@@ -95,6 +104,7 @@ impl CallInviteEventContent {
             #[cfg(feature = "unstable-msc2747")]
             capabilities: Default::default(),
             invitee: None,
+            sdp_stream_metadata: Default::default(),
         }
     }
 }

crates/ruma-events/src/call/negotiate.rs

@@ -2,12 +2,14 @@
 //!
 //! [`m.call.negotiate`]: https://spec.matrix.org/latest/client-server-api/#mcallnegotiate
 
+use std::collections::BTreeMap;
+
 use js_int::UInt;
 use ruma_common::{OwnedVoipId, VoipVersionId};
 use ruma_macros::EventContent;
 use serde::{Deserialize, Serialize};
 
-use super::SessionDescription;
+use super::{SessionDescription, StreamMetadata};
 
 /// **Added in VoIP version 1.** The content of an `m.call.negotiate` event.
 ///
@@ -37,6 +39,12 @@ pub struct CallNegotiateEventContent {
 
     /// The session description of the negotiation.
     pub description: SessionDescription,
+
+    /// Metadata describing the streams that will be sent.
+    ///
+    /// This is a map of stream ID to metadata about the stream.
+    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
+    pub sdp_stream_metadata: BTreeMap<String, StreamMetadata>,
 }
 
 impl CallNegotiateEventContent {
@@ -49,7 +57,14 @@ impl CallNegotiateEventContent {
         lifetime: UInt,
         description: SessionDescription,
     ) -> Self {
-        Self { call_id, party_id, version, lifetime, description }
+        Self {
+            call_id,
+            party_id,
+            version,
+            lifetime,
+            description,
+            sdp_stream_metadata: Default::default(),
+        }
     }
 
     /// Convenience method to create a version 1 `CallNegotiateEventContent` with all the required