1 files changed, 35 insertions, 7 deletions
diff --git a/api/rtp_parameters.h b/api/rtp_parameters.h
index 7fe9f2bc83..a098bad6b0 100644
--- a/api/rtp_parameters.h
+++ b/api/rtp_parameters.h
@@ -246,6 +246,18 @@ struct RTC_EXPORT RtpHeaderExtensionCapability {
 
 // RTP header extension, see RFC8285.
 struct RTC_EXPORT RtpExtension {
+  enum Filter {
+    // Encrypted extensions will be ignored and only non-encrypted extensions
+    // will be considered.
+    kDiscardEncryptedExtension,
+    // Encrypted extensions will be preferred but will fall back to
+    // non-encrypted extensions if necessary.
+    kPreferEncryptedExtension,
+    // Encrypted extensions will be required, so any non-encrypted extensions
+    // will be discarded.
+    kRequireEncryptedExtension,
+  };
+
   RtpExtension();
   RtpExtension(absl::string_view uri, int id);
   RtpExtension(absl::string_view uri, int id, bool encrypt);
@@ -260,17 +272,28 @@ struct RTC_EXPORT RtpExtension {
   // Return "true" if the given RTP header extension URI may be encrypted.
   static bool IsEncryptionSupported(absl::string_view uri);
 
-  // Returns the named header extension if found among all extensions,
-  // nullptr otherwise.
+  // Returns the header extension with the given URI or nullptr if not found.
+  static const RtpExtension* FindHeaderExtensionByUri(
+      const std::vector<RtpExtension>& extensions,
+      absl::string_view uri,
+      Filter filter);
+  ABSL_DEPRECATED(
+      "Use RtpExtension::FindHeaderExtensionByUri with filter argument")
   static const RtpExtension* FindHeaderExtensionByUri(
       const std::vector<RtpExtension>& extensions,
       absl::string_view uri);
 
-  // Return a list of RTP header extensions with the non-encrypted extensions
-  // removed if both the encrypted and non-encrypted extension is present for
-  // the same URI.
-  static std::vector<RtpExtension> FilterDuplicateNonEncrypted(
-      const std::vector<RtpExtension>& extensions);
+  // Returns the header extension with the given URI and encrypt parameter,
+  // if found, otherwise nullptr.
+  static const RtpExtension* FindHeaderExtensionByUriAndEncryption(
+      const std::vector<RtpExtension>& extensions,
+      absl::string_view uri,
+      bool encrypt);
+
+  // Returns a list of extensions where any extension URI is unique.
+  static const std::vector<RtpExtension> DeduplicateHeaderExtensions(
+      const std::vector<RtpExtension>& extensions,
+      Filter filter);
 
   // Encryption of Header Extensions, see RFC 6904 for details:
   // https://tools.ietf.org/html/rfc6904
@@ -357,6 +380,11 @@ struct RTC_EXPORT RtpExtension {
   static constexpr char kVideoFrameTrackingIdUri[] =
       "http://www.webrtc.org/experiments/rtp-hdrext/video-frame-tracking-id";
 
+  // Header extension for Mixer-to-Client audio levels per CSRC as defined in
+  // https://tools.ietf.org/html/rfc6465
+  static constexpr char kCsrcAudioLevelsUri[] =
+      "urn:ietf:params:rtp-hdrext:csrc-audio-level";
+
   // Inclusive min and max IDs for two-byte header extensions and one-byte
   // header extensions, per RFC8285 Section 4.2-4.3.
   static constexpr int kMinId = 1;