From 972315959248b4b4501cd142a790634367e5cb8b Mon Sep 17 00:00:00 2001
From: Thulinma <jaron@vietors.com>
Date: Wed, 4 Jul 2018 11:43:29 +0200
Subject: [PATCH] Improved selectDefaultTracks function to give feedback on
 selection changes.

---
 src/output/output.cpp      | 29 ++++++++++++++++++++++++++---
 src/output/output.h        |  2 +-
 src/output/output_json.cpp |  6 ++++++
 src/output/output_rtmp.cpp |  7 ++-----
 4 files changed, 35 insertions(+), 9 deletions(-)

diff --git a/src/output/output.cpp b/src/output/output.cpp
index 20d94182..649679cf 100644
--- a/src/output/output.cpp
+++ b/src/output/output.cpp
@@ -255,16 +255,31 @@ namespace Mist{
     }
   }
 
-  void Output::selectDefaultTracks(){
+  /// Automatically selects the tracks that are possible and/or wanted.
+  /// Returns true if the track selection changed in any way.
+  bool Output::selectDefaultTracks(){
     if (!isInitialized){
       initialize();
-      if (!isInitialized){return;}
+      if (!isInitialized){return false;}
     }
+
+    //First, back up and wipe the existing selections, if any.
+    std::set<unsigned long> oldSel = selectedTracks;
+    selectedTracks.clear();
+
+    bool autoSeek = buffer.size();
+    uint64_t seekTarget = currentTime();
+
     //check which tracks don't actually exist
     std::set<unsigned long> toRemove;
     for (std::set<unsigned long>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
       if (!myMeta.tracks.count(*it)){
         toRemove.insert(*it);
+        continue;
+      }
+      //autoSeeking and target not in bounds? Drop it too.
+      if (autoSeek && myMeta.tracks[*it].lastms < seekTarget - 6000){
+        toRemove.insert(*it);
       }
     }
     //remove those from selectedtracks
@@ -344,6 +359,7 @@ namespace Mist{
               if (myMeta.live){
                 for (std::map<unsigned int, DTSC::Track>::reverse_iterator trit = myMeta.tracks.rbegin(); trit != myMeta.tracks.rend(); trit++){
                   if ((!byType && trit->second.codec == strRef.substr(shift)) || (byType && trit->second.type == strRef.substr(shift)) || strRef.substr(shift) == "*"){
+                    if (autoSeek && trit->second.lastms < seekTarget - 6000){continue;}
                     selectedTracks.insert(trit->first);
                     found = true;
                     if (!multiSel){break;}
@@ -352,6 +368,7 @@ namespace Mist{
               }else{
                 for (std::map<unsigned int, DTSC::Track>::iterator trit = myMeta.tracks.begin(); trit != myMeta.tracks.end(); trit++){
                   if ((!byType && trit->second.codec == strRef.substr(shift)) || (byType && trit->second.type == strRef.substr(shift)) || strRef.substr(shift) == "*"){
+                    if (autoSeek && trit->second.lastms < seekTarget - 6000){continue;}
                     selectedTracks.insert(trit->first);
                     found = true;
                     if (!multiSel){break;}
@@ -381,6 +398,12 @@ namespace Mist{
     if (!selectedTracks.size() && myMeta.tracks.size() && capa["codecs"][bestSoFar].size()){
       WARN_MSG("No tracks selected (%u total) for stream %s!", myMeta.tracks.size(), streamName.c_str());
     }
+    bool madeChange = (oldSel != selectedTracks);
+    if (autoSeek && madeChange){
+      INFO_MSG("Automatically seeking to position %llu to resume playback", seekTarget);
+      seek(seekTarget);
+    }
+    return madeChange;
   }
   
   /// Clears the buffer, sets parseData to false, and generally makes not very much happen at all.
@@ -825,7 +848,7 @@ namespace Mist{
     if (buffer.size() != selectedTracks.size()){
       std::set<uint32_t> dropTracks;
       if (buffer.size() < selectedTracks.size()){
-        //prepare to drop any selectedTrack without buffe entry
+        //prepare to drop any selectedTrack without buffer entry
         for (std::set<unsigned long>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); ++it){
           bool found = false;
           for (std::set<sortedPageInfo>::iterator bi = buffer.begin(); bi != buffer.end(); ++bi){
diff --git a/src/output/output.h b/src/output/output.h
index d58cdfae..4db104be 100644
--- a/src/output/output.h
+++ b/src/output/output.h
@@ -51,7 +51,7 @@ namespace Mist {
       uint64_t endTime();
       void setBlocking(bool blocking);
       void updateMeta();
-      void selectDefaultTracks();
+      bool selectDefaultTracks();
       bool connectToFile(std::string file);
       static bool listenMode(){return true;}
       uint32_t currTrackCount() const;
diff --git a/src/output/output_json.cpp b/src/output/output_json.cpp
index ca7b682c..610619b1 100644
--- a/src/output/output_json.cpp
+++ b/src/output/output_json.cpp
@@ -28,6 +28,12 @@ namespace Mist {
   }
 
   void OutJSON::sendNext(){
+    if (keepReselecting){
+      //If we can select more tracks, do it and continue.
+      if (selectDefaultTracks()){
+        return;//After a seek, the current packet is invalid. Do nothing and return here.
+      }
+    }
     JSON::Value jPack = thisPacket.toJSON();
     if (dupcheck){
       if (jPack.compareExcept(lastVal, nodup)){
diff --git a/src/output/output_rtmp.cpp b/src/output/output_rtmp.cpp
index b0115571..27405122 100644
--- a/src/output/output_rtmp.cpp
+++ b/src/output/output_rtmp.cpp
@@ -160,12 +160,9 @@ namespace Mist {
         lastMeta = Util::epoch();
         updateMeta();
         if (myMeta.tracks.size() > 1){
-          size_t prevTrackCount = selectedTracks.size();
-          selectDefaultTracks();
-          if (selectedTracks.size() > prevTrackCount){
-            INFO_MSG("Picked up new track - selecting it and resetting state.");
+          if (selectDefaultTracks()){
+            INFO_MSG("Track selection changed - resending headers and continuing");
             sentHeader = false;
-            initialSeek();
             return;
           }
         }