Edits to DTSC lib for live buffering

lib/dtsc.cpp

@@ -13,17 +13,19 @@ DTSC::Stream::Stream(){
   datapointertype = DTSC::INVALID;
   datapointer = 0;
   buffercount = 1;
+  buffertime = 0;
 }
 
 /// Initializes a DTSC::Stream with a minimum of rbuffers packet buffers.
 /// The actual buffer count may not at all times be the requested amount.
-DTSC::Stream::Stream(unsigned int rbuffers){
+DTSC::Stream::Stream(unsigned int rbuffers, unsigned int bufferTime){
   datapointertype = DTSC::INVALID;
   datapointer = 0;
   if (rbuffers < 1){
     rbuffers = 1;
   }
   buffercount = rbuffers;
+  buffertime = bufferTime;
 }
 
 /// Returns the time in milliseconds of the last received packet.
@@ -47,6 +49,7 @@ bool DTSC::Stream::parsePacket(std::string & buffer){
       }
       unsigned int i = 0;
       metadata = JSON::fromDTMI((unsigned char*)buffer.c_str() + 8, len, i);
+      metadata.removeMember( "moreheader" );
       buffer.erase(0, len + 8);
       if (buffer.length() <= 8){
         return false;
@@ -122,6 +125,7 @@ bool DTSC::Stream::parsePacket(Socket::Buffer & buffer){
       unsigned int i = 0;
       std::string wholepacket = buffer.remove(len + 8);
       metadata = JSON::fromDTMI((unsigned char*)wholepacket.c_str() + 8, len, i);
+      metadata.removeMember( "moreheader" );
       if (!buffer.available(8)){
         return false;
       }
@@ -220,6 +224,7 @@ std::string & DTSC::Stream::outHeader(){
 void DTSC::Stream::advanceRings(){
   std::deque<DTSC::Ring>::iterator dit;
   std::set<DTSC::Ring *>::iterator sit;
+  if (rings.size()) {
     for (sit = rings.begin(); sit != rings.end(); sit++){
       ( *sit)->b++;
       if (( *sit)->waiting){
@@ -231,18 +236,32 @@ void DTSC::Stream::advanceRings(){
         ( *sit)->b = 0;
       }
     }
+  }
+  if (keyframes.size()){
     for (dit = keyframes.begin(); dit != keyframes.end(); dit++){
       dit->b++;
+    }
+    bool repeat;
+    do {
+      repeat = false;
+      for (dit = keyframes.begin(); dit != keyframes.end(); dit++){
         if (dit->b >= buffers.size()){
           keyframes.erase(dit);
+          repeat = true;
           break;
         }
       }
+    } while( repeat );
+  }
   if ((lastType() == VIDEO) && (buffers.front().isMember("keyframe"))){
     keyframes.push_front(DTSC::Ring(0));
   }
-  //increase buffer size if no keyframes available
-  if ((buffercount > 1) && (keyframes.size() < 1)){
+  int timeBuffered = 0;
+  if (keyframes.size() > 1){
+  //increase buffer size if no keyframes available or too little time available
+    timeBuffered = buffers[keyframes[keyframes.size() - 1].b]["time"].asInt() - buffers[keyframes[0].b]["time"].asInt();
+  }
+  if (((buffercount > 1) && (keyframes.size() < 2)) || (timeBuffered < buffertime)){
     buffercount++;
   }
 }
@@ -278,6 +297,34 @@ void DTSC::Stream::dropRing(DTSC::Ring * ptr){
   }
 }
 
+void DTSC::Stream::updateHeaders(){
+  if( keyframes.size() > 1 ) {
+    metadata["keytime"].shrink(keyframes.size() - 2);
+    metadata["keytime"].append(buffers[keyframes[1].b]["time"].asInt());
+    metadata.toPacked();
+    updateRingHeaders();
+  }
+}
+
+void DTSC::Stream::updateRingHeaders(){
+  std::set<DTSC::Ring *>::iterator sit;
+  if (!rings.size()){
+    return;
+  }
+  for (sit = rings.begin(); sit != rings.end(); sit++){
+    ( *sit)->updated = true;
+  }
+}
+
+unsigned int DSTSC::Stream::msSeek(unsigned int ms) {
+  for( std::deque<DTSC::Ring>::iterator it = keyframes.begin(); it != keyframes.end(); it++ ) {
+    if( buffers[it->b]["time"].asInt( ) < ms ) {
+      return it->b;
+    }
+  }
+  ///\todo Send PauseMark
+}
+
 /// Properly cleans up the object for erasing.
 /// Drops all Ring classes that have been given out.
 DTSC::Stream::~Stream(){
@@ -438,6 +485,11 @@ void DTSC::File::seekNext(){
     jsonbuffer.null();
     return;
   }
+  if (memcmp(buffer, DTSC::Magic_Header, 4) == 0){
+    readHeader(lastreadpos);
+    jsonbuffer = metadata;
+    return;
+  }
   if (memcmp(buffer, DTSC::Magic_Packet, 4) != 0){
     fprintf(stderr, "Invalid header - %.4s != %.4s\n", buffer, DTSC::Magic_Packet);
     strbuffer = "";

lib/dtsc.h

@@ -56,6 +56,7 @@ namespace DTSC {
     VIDEO, ///< Stream Video data
     META, ///< Stream Metadata
     PAUSEMARK, ///< Pause marker
+    MODIFIEDHEADER, ///< Modified header data.
     INVALID ///< Anything else or no data available.
   };
 
@@ -100,6 +101,7 @@ namespace DTSC {
       volatile unsigned int b; ///< Holds current number of buffer. May and is intended to change unexpectedly!
       volatile bool waiting; ///< If true, this Ring is currently waiting for a buffer fill.
       volatile bool starved; ///< If true, this Ring can no longer receive valid data.
+      volatile bool updated; ///< If true, this Ring should write a new header.
   };
 
   /// Holds temporary data for a DTSC stream and provides functions to utilize it.
@@ -109,7 +111,7 @@ namespace DTSC {
     public:
       Stream();
       ~Stream();
-      Stream(unsigned int buffers);
+      Stream(unsigned int buffers, unsigned int bufferTime = 0);
       JSON::Value metadata;
       JSON::Value & getPacket(unsigned int num = 0);
       datatype lastType();
@@ -123,13 +125,17 @@ namespace DTSC {
       Ring * getRing();
       unsigned int getTime();
       void dropRing(Ring * ptr);
+      void updateHeaders();
+      unsigned int msSeek(unsigned int ms);
     private:
       std::deque<JSON::Value> buffers;
       std::set<DTSC::Ring *> rings;
       std::deque<DTSC::Ring> keyframes;
       void advanceRings();
+      void updateRingHeaders();
       std::string * datapointer;
       datatype datapointertype;
       unsigned int buffercount;
+      unsigned int buffertime;
   };
 }