Add RSID-based demuxing to RtpDemuxer

webrtc/common_types.cc

Index: webrtc/common_types.cc
diff --git a/webrtc/common_types.cc b/webrtc/common_types.cc
index c9f7fa1e738fbbd1b61b704bb5d4458667a49e5d..5cbc452db33f82735092fd28460a56859f70e982 100644
--- a/webrtc/common_types.cc
+++ b/webrtc/common_types.cc
@@ -11,6 +11,7 @@
 #include "webrtc/common_types.h"
 
 #include <string.h>
+#include <algorithm>
 #include <limits>
 #include <type_traits>
 
@@ -23,6 +24,11 @@ StreamDataCounters::StreamDataCounters() : first_packet_time_ms(-1) {}
 
 constexpr size_t StreamId::kMaxSize;
 
+bool StreamId::IsLegalName(rtc::ArrayView<const char> name) {
+  return (name.size() <= kMaxSize && name.size() > 0 &&
+          std::all_of(name.data(), name.data() + name.size(), isalnum));
+}
+
 void StreamId::Set(const char* data, size_t size) {
   // If |data| contains \0, the stream id size might become less than |size|.
   RTC_CHECK_LE(size, kMaxSize);