WS/MP4 reliability edits:

- Stream selecting now obeys new "maxdelay" capa entry
- Output::liveSeek now takes an optional bool argument to indicate only rate control should be applied (no seeking)
- dataWaitTimeout is now configurable per-output, defaults to the old 25s
- WS/MP4 uses the new liveSeek with rate-control only
- WS/MP4 uses the new dataWaitTimeout and sets it to 4.5s
- WS/MP4 uses the new maxdelay capa, sets it to 5s
- WS/MP4 will now auto-reselect tracks if a track is dropped for data wait timeout or disappeared from metadata reasons
- Added support for jitter information in WS/MP4 protocol
- Robustify sendWebsocketCodecData being ran when sendHeader is ran
- Fix race condition when switching video tracks before previous video track has sent a single frame

lib/dtsc.cpp

@@ -2294,7 +2294,7 @@ namespace DTSC{
             MEDIUM_MSG("Jitter lowered from %" PRIu64 " to %" PRIu64 " ms", maxJitter, curJitter);
             maxJitter = curJitter;
           }
-          curJitter = maxJitter*0.75;
+          curJitter = maxJitter*0.90;
         }
         ++x;
         trueTime[x % 8] = curMs;

lib/stream.cpp

@@ -1139,7 +1139,7 @@ std::set<size_t> Util::wouldSelect(const DTSC::Meta &M, const std::string &track
 std::set<size_t> Util::getSupportedTracks(const DTSC::Meta &M, const JSON::Value &capa,
                                           const std::string &type, const std::string &UA){
   std::set<size_t> validTracks = M.getValidTracks();
-
+  uint64_t maxLastMs = 0;
   std::set<size_t> toRemove;
   for (std::set<size_t>::iterator it = validTracks.begin(); it != validTracks.end(); it++){
     // Remove unrequested tracks
@@ -1208,10 +1208,27 @@ std::set<size_t> Util::getSupportedTracks(const DTSC::Meta &M, const JSON::Value
         toRemove.insert(*it);
       }
     }
+    //not removing this track? Keep track of highest lastMs
+    if (capa.isMember("maxdelay")){
+      uint64_t lMs = M.getLastms(*it);
+      if (lMs > maxLastMs){maxLastMs = lMs;}
+    }
   }
   for (std::set<size_t>::iterator it = toRemove.begin(); it != toRemove.end(); it++){
     validTracks.erase(*it);
   }
+  //if there is a max delay configured, remove tracks that are further behind than this
+  if (capa.isMember("maxdelay")){
+    uint64_t maxDelay = capa["maxdelay"].asInt();
+    if (maxDelay > maxLastMs){maxDelay = maxLastMs;}
+    toRemove.clear();
+    for (std::set<size_t>::iterator it = validTracks.begin(); it != validTracks.end(); it++){
+      if (M.getLastms(*it) < maxLastMs - maxDelay){toRemove.insert(*it);}
+    }
+    for (std::set<size_t>::iterator it = toRemove.begin(); it != toRemove.end(); it++){
+      validTracks.erase(*it);
+    }
+  }
   return validTracks;
 }