Refactored DTSC::Stream to prepare for proper inheritance in the Buffer process.

lib/dtsc.cpp

@@ -27,6 +27,10 @@ DTSC::Stream::Stream(unsigned int rbuffers, unsigned int bufferTime){
   buffertime = bufferTime;
 }
 
+/// This function does nothing, it's supposed to be overridden.
+/// It will be called right before a buffer position is deleted.
+void DTSC::Stream::deletionCallback(livePos deleting){}
+
 /// Returns the time in milliseconds of the last received packet.
 /// This is _not_ the time this packet was received, only the stored time.
 unsigned int DTSC::Stream::getTime(){
@@ -213,8 +217,16 @@ void DTSC::Stream::waitForMeta(Socket::Connection & sourceSocket){
   }
 }
 
+/// Resets the stream by clearing the buffers and keyframes, making sure to call the deletionCallback first.
+void DTSC::Stream::resetStream(){
+  for (std::map<livePos, JSON::Value >::iterator it = buffers.begin(); it != buffers.end(); it++){
+    deletionCallback(it->first);
+  }
+  buffers.clear();
+  keyframes.clear();
+}
+
 void DTSC::Stream::addPacket(JSON::Value & newPack){
-  bool updateMeta = false;
   long long unsigned int now = Util::getMS();
   livePos newPos;
   newPos.trackID = newPack["trackid"].asInt();
@@ -223,15 +235,13 @@ void DTSC::Stream::addPacket(JSON::Value & newPack){
     livePos lastPos = buffers.rbegin()->first;
     if (newPos < lastPos){
       if ((lastPos.seekTime > 1000) && newPos.seekTime < lastPos.seekTime - 1000){
-        metadata["reset"] = 1LL;
-        buffers.clear();
-        keyframes.clear();
+        resetStream();
       }else{
         newPos.seekTime = lastPos.seekTime+1;
       }
     }
   }else{
-    buffers.clear();
+    resetStream();
   }
   std::string newTrack = trackMapping[newPos.trackID];
   while (buffers.count(newPos) > 0){
@@ -265,7 +275,6 @@ void DTSC::Stream::addPacket(JSON::Value & newPack){
   if (buffercount > 1){
     #define prevKey metadata["tracks"][newTrack]["keys"][keySize - 1]
     if (newPack.isMember("keyframe") || !keySize || (datapointertype != VIDEO && newPack["time"].asInt() - 5000 > prevKey["time"].asInt())){
-      updateMeta = true;
       metadata["tracks"][newTrack]["lastms"] = newPack["time"];
       keyframes[newPos.trackID].insert(newPos);
       JSON::Value key;
@@ -337,14 +346,20 @@ void DTSC::Stream::addPacket(JSON::Value & newPack){
       buffercount = buffers.size();
       if (buffercount < 2){buffercount = 2;}
     }
-    if (updateMeta && metadata["buffer_window"].asInt() < timeBuffered){
+    if (metadata["buffer_window"].asInt() < timeBuffered){
       metadata["buffer_window"] = (long long int)timeBuffered;
     }
   }
 
   while (buffers.size() > buffercount){
+    cutOneBuffer();
+  }
+}
+
+/// Deletes a the first part of the buffer, updating the keyframes list and metadata as required.
+/// Will print a warning to std::cerr if a track has less than 2 keyframes left because of this.
+void DTSC::Stream::cutOneBuffer(){
   if (buffercount > 1 && keyframes[buffers.begin()->first.trackID].count(buffers.begin()->first)){
-      updateMeta = true;
     //if there are < 3 keyframes, throwing one away would mean less than 2 left.
     if (keyframes[buffers.begin()->first.trackID].size() < 3){
       std::cerr << "Warning - track " << buffers.begin()->first.trackID << " doesn't have enough keyframes to be reliably served." << std::endl;
@@ -365,10 +380,6 @@ void DTSC::Stream::addPacket(JSON::Value & newPack){
   }
   buffers.erase(buffers.begin());
 }
-  if (updateMeta){
-    //metadata.netPrepare();
-  }
-}
 
 /// Returns a direct pointer to the data attribute of the last received packet, if available.
 /// Returns NULL if no valid pointer or packet is available.

lib/dtsc.h

@@ -13,42 +13,6 @@
 #include "socket.h"
 #include "timing.h"
 
-/// Holds all DDVTECH Stream Container classes and parsers.
-///length (int, length in seconds, if available)
-///video:
-/// - codec (string: H264, H263, VP6)
-/// - width (int, pixels)
-/// - height (int, pixels)
-/// - fpks (int, frames per kilosecond (FPS * 1000))
-/// - bps (int, bytes per second)
-/// - init (string, init data)
-/// - keycount (int, count of keyframes)
-/// - keyms (int, average ms per keyframe)
-/// - keyvar (int, max ms per keyframe variance)
-/// - keys (array of byte position ints - first is first keyframe, last is last keyframe, in between have ~equal spacing)
-///
-///audio:
-/// - codec (string: AAC, MP3)
-/// - rate (int, Hz)
-/// - size (int, bitsize)
-/// - bps (int, bytes per second)
-/// - channels (int, channelcount)
-/// - init (string, init data)
-///
-///All packets:
-/// - datatype (string: audio, video, meta (unused))
-/// - data (string: data)
-/// - time (int: ms into video)
-///
-///Video packets:
-/// - keyframe (int, if set, is a seekable keyframe)
-/// - interframe (int, if set, is a non-seekable interframe)
-/// - disposableframe (int, if set, is a disposable interframe)
-///
-///H264 video packets:
-/// - nalu (int, if set, is a nalu)
-/// - nalu_end (int, if set, is a end-of-sequence)
-/// - offset (int, unsigned version of signed int! Holds the ms offset between timestamp and proper display time for B-frames)
 namespace DTSC {
   bool isFixed(JSON::Value & metadata);
 
@@ -215,7 +179,9 @@ namespace DTSC {
       DTSC::livePos getNext(DTSC::livePos & pos, std::set<int> & allowedTracks);
       void endStream();
       void waitForMeta(Socket::Connection & sourceSocket);
-    private:
+    protected:
+      void cutOneBuffer();
+      void resetStream();
       std::map<livePos,JSON::Value> buffers;
       std::map<int,std::set<livePos> > keyframes;
       void addPacket(JSON::Value & newPack);
@@ -223,5 +189,6 @@ namespace DTSC {
       unsigned int buffercount;
       unsigned int buffertime;
       std::map<int,std::string> trackMapping;
+      void deletionCallback(livePos deleting);
   };
 }