HLS-related buffer size optimizes

lib/dtsc.h

@@ -289,6 +289,7 @@ namespace DTSC {
       void reset();
       void toPrettyString(std::ostream & str, int indent = 0, int verbosity = 0);
       void finalize();
+      uint32_t biggestFragment();
       
       std::string getIdentifier();
       std::string getWritableIdentifier();

lib/dtscmeta.cpp

@@ -1218,6 +1218,17 @@ namespace DTSC {
   void Track::finalize(){
     keys.rbegin()->setLength(lastms - keys.rbegin()->getTime() + parts.rbegin()->getDuration());
   }
+
+  /// Returns the duration in ms of the longest-duration fragment.
+  uint32_t Track::biggestFragment(){
+    uint32_t ret = 0;
+    for (unsigned int i = 0; i<fragments.size(); i++){
+      if (fragments[i].getDuration() > ret){
+        ret = fragments[i].getDuration();
+      }
+    }
+    return ret;
+  }
   
   ///\brief Returns a key given its number, or an empty key if the number is out of bounds
   Key & Track::getKey(unsigned int keyNum) {

src/input/input_buffer.cpp

@@ -208,15 +208,28 @@ namespace Mist {
   }
 
   bool inputBuffer::removeKey(unsigned int tid) {
+    DTSC::Track & Trk = myMeta.tracks[tid];
     //Make sure we have at least 3 whole fragments at all times,
     //unless we're shutting down the whole buffer right now
-    if (myMeta.tracks[tid].fragments.size() < 5 && config->is_active) {
+    if (Trk.fragments.size() < 5 && config->is_active) {
       return false;
     }
     //If we're shutting down, and this track is empty, abort
     if (!myMeta.tracks[tid].keys.size()) {
       return false;
     }
+    if (config->is_active && Trk.fragments.size() > 1){
+      ///Make sure we have at least 3X the target duration.
+      //The target duration is the biggest fragment, rounded up to whole seconds.
+      uint32_t targetDuration = (Trk.biggestFragment() / 1000 + 1) * 1000;
+      //The start is the second fragment's begin
+      uint32_t fragStart = Trk.getKey((++Trk.fragments.begin())->getNumber()).getTime();
+      //The end is the last fragment's begin
+      uint32_t fragEnd = Trk.getKey(Trk.fragments.rbegin()->getNumber()).getTime();
+      if ((fragEnd - fragStart) < targetDuration * 3){
+        return false;
+      }
+    }
     DEBUG_MSG(DLVL_HIGH, "Erasing key %d:%lu", tid, myMeta.tracks[tid].keys[0].getNumber());
     //remove all parts of this key
     for (int i = 0; i < myMeta.tracks[tid].keys[0].getParts(); i++) {

src/output/output_hls.cpp

@@ -57,21 +57,8 @@ namespace Mist {
     updateMeta();
     std::stringstream result;
     //parse single track
-    int longestFragment = 0;
+    result << "#EXTM3U\r\n#EXT-X-TARGETDURATION:" << (myMeta.tracks[tid].biggestFragment() / 1000) + 1 << "\r\n";
-    if (!myMeta.tracks[tid].fragments.size()){
+
-      INFO_MSG("liveIndex called with track %d, which has no fragments!", tid);
-      return "";
-    }
-    for (std::deque<DTSC::Fragment>::iterator it = myMeta.tracks[tid].fragments.begin(); (it + 1) != myMeta.tracks[tid].fragments.end(); it++){
-      if (it->getDuration() > longestFragment){
-        longestFragment = it->getDuration();
-      }
-    }
-    if ((myMeta.tracks[tid].lastms - myMeta.tracks[tid].firstms) / myMeta.tracks[tid].fragments.size() > longestFragment){
-      longestFragment = (myMeta.tracks[tid].lastms - myMeta.tracks[tid].firstms) / myMeta.tracks[tid].fragments.size();
-    }
-    result << "#EXTM3U\r\n#EXT-X-TARGETDURATION:" << (longestFragment / 1000) + 1 << "\r\n";
-        
     std::deque<std::string> lines;
     for (std::deque<DTSC::Fragment>::iterator it = myMeta.tracks[tid].fragments.begin(); it != myMeta.tracks[tid].fragments.end(); it++){
       long long int starttime = myMeta.tracks[tid].getKey(it->getNumber()).getTime();