From f3f280284412e7092dc3f547c089d27fa90b39f0 Mon Sep 17 00:00:00 2001
From: Thulinma <jaron@vietors.com>
Date: Thu, 3 Aug 2017 15:06:12 +0200
Subject: [PATCH] Added minKeepAway support to DTSC::Track object, senders and
 parsers

---
 lib/dtsc.h            |  1 +
 lib/dtscmeta.cpp      | 27 +++++++++++++++++++++++++++
 src/output/output.cpp | 12 ++++++------
 3 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/lib/dtsc.h b/lib/dtsc.h
index d557c34b..6f5f7317 100644
--- a/lib/dtsc.h
+++ b/lib/dtsc.h
@@ -297,6 +297,7 @@ namespace DTSC {
       std::string codec;
       std::string type;
       std::string lang;///< ISO 639-2 Language of track, empty or und if unknown.
+      uint32_t minKeepAway;///<Time in MS to never seek closer than live point to
       //audio only
       int rate;
       int size;
diff --git a/lib/dtscmeta.cpp b/lib/dtscmeta.cpp
index 7cfe2535..3e212e6a 100644
--- a/lib/dtscmeta.cpp
+++ b/lib/dtscmeta.cpp
@@ -1105,6 +1105,7 @@ namespace DTSC {
     width = 0;
     height = 0;
     fpks = 0;
+    minKeepAway = 0;
   }
 
   ///\brief Constructs a track from a JSON::Value
@@ -1148,6 +1149,11 @@ namespace DTSC {
         keySizes.push_back((((long unsigned)tmp[i]) << 24) | (((long unsigned)tmp[i+1]) << 16) | (((long unsigned int)tmp[i+2]) << 8) | tmp[i+3]);
       }
     }
+    if (trackRef.isMember("keepaway") && trackRef["keepaway"].isInt()){
+      minKeepAway = trackRef["keepaway"].asInt();
+    }else{
+      minKeepAway = 0;
+    }
   }
 
   ///\brief Constructs a track from a JSON::Value
@@ -1199,6 +1205,11 @@ namespace DTSC {
         keySizes.push_back((((long unsigned)tmp[i]) << 24) | (((long unsigned)tmp[i+1]) << 16) | (((long unsigned int)tmp[i+2]) << 8) | tmp[i+3]);
       }
     }
+    if (trackRef.getMember("keepaway").getType() == DTSC_INT){
+      minKeepAway = trackRef.getMember("keepaway").asInt();
+    }else{
+      minKeepAway = 0;
+    }
   }
 
   ///\brief Updates a track and its metadata given new packet properties.
@@ -1641,6 +1652,9 @@ namespace DTSC {
     if (!skipDynamic && missedFrags) {
       result += 23;
     }
+    if (minKeepAway){
+      result += 19;
+    }
     return result;
   }
 
@@ -1736,6 +1750,10 @@ namespace DTSC {
       writePointer(p, "\000\004fpks\001", 7);
       writePointer(p, convertLongLong(fpks), 8);
     }
+    if (minKeepAway){
+      writePointer(p, "\000\010keepaway\001", 11);
+      writePointer(p, convertLongLong(minKeepAway), 8);
+    }
     writePointer(p, "\000\000\356", 3);//End this track Object
   }
 
@@ -1813,6 +1831,10 @@ namespace DTSC {
       conn.SendNow("\000\004fpks\001", 7);
       conn.SendNow(convertLongLong(fpks), 8);
     }
+    if (minKeepAway){
+      conn.SendNow("\000\010keepaway\001", 11);
+      conn.SendNow(convertLongLong(minKeepAway), 8);
+    }
     conn.SendNow("\000\000\356", 3);//End this track Object
   }
 
@@ -1965,6 +1987,11 @@ namespace DTSC {
       result["height"] = height;
       result["fpks"] = fpks;
     }
+
+    if(minKeepAway){
+      result["keepaway"] = minKeepAway;
+    }
+
     return result;
   }
 
diff --git a/src/output/output.cpp b/src/output/output.cpp
index da6e444b..ad7be174 100644
--- a/src/output/output.cpp
+++ b/src/output/output.cpp
@@ -624,7 +624,7 @@ namespace Mist{
 
   /// This function decides where in the stream initial playback starts.
   /// The default implementation calls seek(0) for VoD.
-  /// For live, it seeks to the last sync'ed keyframe of the main track, no closer than needsLookAhead ms from the end.
+  /// For live, it seeks to the last sync'ed keyframe of the main track, no closer than needsLookAhead+minKeepAway ms from the end.
   /// Unless lastms < 5000, then it seeks to the first keyframe of the main track.
   /// Aborts if there is no main track or it has no keyframes.
   void Output::initialSeek(){
@@ -640,17 +640,17 @@ namespace Mist{
         bool good = true;
         //check if all tracks have data for this point in time
         for (std::set<unsigned long>::iterator ti = selectedTracks.begin(); ti != selectedTracks.end(); ++ti){
-          if (myMeta.tracks[*ti].lastms < seekPos+needsLookAhead){good = false; break;}
-          if (mainTrack == *ti){continue;}//skip self
           if (!myMeta.tracks.count(*ti)){
             HIGH_MSG("Skipping track %lu, not in tracks", *ti);
             continue;
           }//ignore missing tracks
-          if (myMeta.tracks[*ti].lastms == myMeta.tracks[*ti].firstms){
+          DTSC::Track & thisTrack = myMeta.tracks[*ti];
+          if (thisTrack.lastms < seekPos+needsLookAhead+thisTrack.minKeepAway){good = false; break;}
+          if (mainTrack == *ti){continue;}//skip self
+          if (thisTrack.lastms == thisTrack.firstms){
             HIGH_MSG("Skipping track %lu, last equals first", *ti);
             continue;
           }//ignore point-tracks
-          if (myMeta.tracks[*ti].lastms < seekPos){good = false; break;}
           HIGH_MSG("Track %lu is good", *ti);
         }
         //if yes, seek here
@@ -660,7 +660,7 @@ namespace Mist{
     MEDIUM_MSG("Initial seek to %llums", seekPos);
     seek(seekPos);
   }
-  
+
   void Output::requestHandler(){
     static bool firstData = true;//only the first time, we call onRequest if there's data buffered already.
     if ((firstData && myConn.Received().size()) || myConn.spool()){