Add generic rtp::extension::HeaderExtension

Author: lookback-hugotunius

rtp/CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+* Adds a new generic header extensions type `rtp::extension::HeaderExtension` which allows abstracting over all known extensions as well as custom extensions.
+
 ## v0.6.7
 
 * Bumped util dependecy to `0.6.0`.

rtp/src/extension/mod.rs

@@ -1,4 +1,79 @@
+use std::borrow::Cow;
+use std::fmt;
+
+use util::{Marshal, MarshalSize};
+
 pub mod abs_send_time_extension;
 pub mod audio_level_extension;
 pub mod transport_cc_extension;
 pub mod video_orientation_extension;
+
+/// A generic RTP header extension.
+pub enum HeaderExtension {
+    AbsSendTime(abs_send_time_extension::AbsSendTimeExtension),
+    AudioLevel(audio_level_extension::AudioLevelExtension),
+    TransportCc(transport_cc_extension::TransportCcExtension),
+    VideoOrientation(video_orientation_extension::VideoOrientationExtension),
+
+    /// A custom extension
+    Custom {
+        uri: Cow<'static, str>,
+        extension: Box<dyn Marshal + Send + Sync + 'static>,
+    },
+}
+
+impl HeaderExtension {
+    pub fn uri(&self) -> Cow<'static, str> {
+        use HeaderExtension::*;
+
+        match self {
+            AbsSendTime(_) => "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time".into(),
+            AudioLevel(_) => "urn:ietf:params:rtp-hdrext:ssrc-audio-level".into(),
+            TransportCc(_) => {
+                "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01".into()
+            }
+            VideoOrientation(_) => "urn:3gpp:video-orientation".into(),
+            Custom { uri, .. } => uri.clone(),
+        }
+    }
+}
+
+impl MarshalSize for HeaderExtension {
+    fn marshal_size(&self) -> usize {
+        use HeaderExtension::*;
+        match self {
+            AbsSendTime(ext) => ext.marshal_size(),
+            AudioLevel(ext) => ext.marshal_size(),
+            TransportCc(ext) => ext.marshal_size(),
+            VideoOrientation(ext) => ext.marshal_size(),
+            Custom { extension: ext, .. } => ext.marshal_size(),
+        }
+    }
+}
+
+impl Marshal for HeaderExtension {
+    fn marshal_to(&self, buf: &mut [u8]) -> util::Result<usize> {
+        use HeaderExtension::*;
+        match self {
+            AbsSendTime(ext) => ext.marshal_to(buf),
+            AudioLevel(ext) => ext.marshal_to(buf),
+            TransportCc(ext) => ext.marshal_to(buf),
+            VideoOrientation(ext) => ext.marshal_to(buf),
+            Custom { extension: ext, .. } => ext.marshal_to(buf),
+        }
+    }
+}
+
+impl fmt::Debug for HeaderExtension {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        use HeaderExtension::*;
+
+        match self {
+            AbsSendTime(ext) => f.debug_tuple("AbsSendTime").field(ext).finish(),
+            AudioLevel(ext) => f.debug_tuple("AudioLevel").field(ext).finish(),
+            TransportCc(ext) => f.debug_tuple("TransportCc").field(ext).finish(),
+            VideoOrientation(ext) => f.debug_tuple("VideoOrientation").field(ext).finish(),
+            Custom { uri, extension: _ } => f.debug_struct("Custom").field("uri", uri).finish(),
+        }
+    }
+}