diff --git a/src/input/input_mp4.cpp b/src/input/input_mp4.cpp
index 2e1c7923..f85911fb 100644
--- a/src/input/input_mp4.cpp
+++ b/src/input/input_mp4.cpp
@@ -159,11 +159,14 @@ namespace Mist{
   }
 
   inputMP4::inputMP4(Util::Config *cfg) : Input(cfg){
-    malSize = 4; // initialise data read buffer to 0;
-    data = (char *)malloc(malSize);
     capa["name"] = "MP4";
     capa["desc"] = "This input allows streaming of MP4 files as Video on Demand.";
-    capa["source_match"] = "/*.mp4";
+    capa["source_match"].append("/*.mp4");
+    capa["source_match"].append("http://*.mp4");
+    capa["source_match"].append("https://*.mp4");
+    capa["source_match"].append("s3+http://*.mp4");
+    capa["source_match"].append("s3+https://*.mp4");
+    capa["source_match"].append("mp4:*");
     capa["source_file"] = "$source";
     capa["priority"] = 9;
     capa["codecs"][0u][0u].append("HEVC");
@@ -173,10 +176,9 @@ namespace Mist{
     capa["codecs"][0u][1u].append("AAC");
     capa["codecs"][0u][1u].append("AC3");
     capa["codecs"][0u][1u].append("MP3");
+    readPos = 0;
   }
 
-  inputMP4::~inputMP4(){free(data);}
-
   bool inputMP4::checkArguments(){
     if (config->getString("input") == "-"){
       std::cerr << "Input from stdin not yet supported" << std::endl;
@@ -199,255 +201,292 @@ namespace Mist{
 
   bool inputMP4::preRun(){
     // open File
-    inFile = fopen(config->getString("input").c_str(), "r");
+    std::string inUrl = config->getString("input");
+    if (inUrl.size() > 4 && inUrl.substr(0, 4) == "mp4:"){inUrl.erase(0, 4);}
+    inFile.open(inUrl);
     if (!inFile){return false;}
+    if (!inFile.isSeekable()){
+      FAIL_MSG("MP4 input only supports seekable data sources, for now, and this source is not seekable: %s", config->getString("input").c_str());
+      return false;
+    }
     return true;
   }
 
+  void inputMP4::dataCallback(const char *ptr, size_t size){readBuffer.append(ptr, size);}
+
   bool inputMP4::readHeader(){
     if (!inFile){
       INFO_MSG("inFile failed!");
       return false;
     }
+    bool hasMoov = false;
+    readBuffer.truncate(0);
+    readPos = 0;
 
     // first we get the necessary header parts
     size_t tNumber = 0;
-    while (!feof(inFile)){
-      std::string boxType = MP4::readBoxType(inFile);
-      if (boxType == "erro"){break;}
+    activityCounter = Util::bootSecs();
+    while (inFile && keepRunning()){
+      //Read box header if needed
+      while (readBuffer.size() < 16 && inFile && keepRunning()){inFile.readSome(16, *this);}
+      //Failed? Abort.
+      if (readBuffer.size() < 16){
+        FAIL_MSG("Could not read box header from input!");
+        break;
+      }
+      //Box type is always on bytes 5-8 from the start of a box
+      std::string boxType = std::string(readBuffer+4, 4);
+      uint64_t boxSize = MP4::calcBoxSize(readBuffer);
       if (boxType == "moov"){
-        MP4::MOOV moovBox;
-        moovBox.read(inFile);
-        // for all box in moov
+        while (readBuffer.size() < boxSize && inFile && keepRunning()){inFile.readSome(boxSize-readBuffer.size(), *this);}
+        if (readBuffer.size() < boxSize){
+          FAIL_MSG("Could not read entire MOOV box into memory");
+          break;
+        }
+        MP4::Box moovBox(readBuffer, false);
 
-        std::deque<MP4::TRAK> trak = moovBox.getChildren<MP4::TRAK>();
+        // for all box in moov
+        std::deque<MP4::TRAK> trak = ((MP4::MOOV*)&moovBox)->getChildren<MP4::TRAK>();
         for (std::deque<MP4::TRAK>::iterator trakIt = trak.begin(); trakIt != trak.end(); trakIt++){
           trackHeaders.push_back(mp4TrackHeader());
           trackHeaders.rbegin()->read(*trakIt);
         }
-        continue;
+        hasMoov = true;
+        break;
       }
-      if (!MP4::skipBox(inFile)){// moving on to next box
-        FAIL_MSG("Error in skipping box, exiting");
-        return false;
+      activityCounter = Util::bootSecs();
+      //Skip to next box
+      if (readBuffer.size() > boxSize){
+        readBuffer.shift(boxSize);
+        readPos += boxSize;
+      }else{
+        readBuffer.truncate(0);
+        if (!inFile.seek(readPos + boxSize)){
+          FAIL_MSG("Seek to %" PRIu64 " failed! Aborting load", readPos+boxSize);
+        }
+        readPos = inFile.getPos();
       }
     }
-    fseeko(inFile, 0, SEEK_SET);
 
     // See whether a separate header file exists.
-    if (readExistingHeader()){return true;}
-    HIGH_MSG("Not read existing header");
+    if (readExistingHeader()){
+      bps = 0;
+      std::set<size_t> tracks = M.getValidTracks();
+      for (std::set<size_t>::iterator it = tracks.begin(); it != tracks.end(); it++){bps += M.getBps(*it);}
+      return true;
+    }
+    INFO_MSG("Not read existing header");
 
     meta.reInit(isSingular() ? streamName : "");
+    if (!hasMoov){
+      FAIL_MSG("No MOOV box found; aborting header creation!");
+      return false;
+    }
 
     tNumber = 0;
     // Create header file from MP4 data
-    while (!feof(inFile)){
-      std::string boxType = MP4::readBoxType(inFile);
-      if (boxType == "erro"){break;}
-      if (boxType == "moov"){
-        MP4::MOOV moovBox;
-        moovBox.read(inFile);
+    MP4::Box moovBox(readBuffer, false);
 
-        std::deque<MP4::TRAK> trak = moovBox.getChildren<MP4::TRAK>();
-        HIGH_MSG("Obtained %zu trak Boxes", trak.size());
+    std::deque<MP4::TRAK> trak = ((MP4::MOOV*)&moovBox)->getChildren<MP4::TRAK>();
+    HIGH_MSG("Obtained %zu trak Boxes", trak.size());
 
-        for (std::deque<MP4::TRAK>::iterator trakIt = trak.begin(); trakIt != trak.end(); trakIt++){
-          MP4::MDIA mdiaBox = trakIt->getChild<MP4::MDIA>();
+    for (std::deque<MP4::TRAK>::iterator trakIt = trak.begin(); trakIt != trak.end(); trakIt++){
+      MP4::MDIA mdiaBox = trakIt->getChild<MP4::MDIA>();
 
-          std::string hdlrType = mdiaBox.getChild<MP4::HDLR>().getHandlerType();
-          if (hdlrType != "vide" && hdlrType != "soun" && hdlrType != "sbtl"){
-            INFO_MSG("Unsupported handler: %s", hdlrType.c_str());
-            continue;
-          }
-
-          tNumber = meta.addTrack();
-
-          MP4::TKHD tkhdBox = trakIt->getChild<MP4::TKHD>();
-          if (tkhdBox.getWidth() > 0){
-            meta.setWidth(tNumber, tkhdBox.getWidth());
-            meta.setHeight(tNumber, tkhdBox.getHeight());
-          }
-          meta.setID(tNumber, tkhdBox.getTrackID());
-
-          MP4::MDHD mdhdBox = mdiaBox.getChild<MP4::MDHD>();
-          uint64_t timescale = mdhdBox.getTimeScale();
-          meta.setLang(tNumber, mdhdBox.getLanguage());
-
-          MP4::STBL stblBox = mdiaBox.getChild<MP4::MINF>().getChild<MP4::STBL>();
-
-          MP4::STSD stsdBox = stblBox.getChild<MP4::STSD>();
-          MP4::Box sEntryBox = stsdBox.getEntry(0);
-          std::string sType = sEntryBox.getType();
-          HIGH_MSG("Found track %zu of type %s", tNumber, sType.c_str());
-
-          if (sType == "avc1" || sType == "h264" || sType == "mp4v"){
-            MP4::VisualSampleEntry &vEntryBox = (MP4::VisualSampleEntry &)sEntryBox;
-            meta.setType(tNumber, "video");
-            meta.setCodec(tNumber, "H264");
-            if (!meta.getWidth(tNumber)){
-              meta.setWidth(tNumber, vEntryBox.getWidth());
-              meta.setHeight(tNumber, vEntryBox.getHeight());
-            }
-            MP4::Box initBox = vEntryBox.getCLAP();
-            if (initBox.isType("avcC")){
-              meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
-            }
-            initBox = vEntryBox.getPASP();
-            if (initBox.isType("avcC")){
-              meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
-            }
-            /// this is a hacky way around invalid FLV data (since it gets ignored nearly
-            /// everywhere, but we do need correct data...
-            if (!meta.getWidth(tNumber)){
-              h264::sequenceParameterSet sps;
-              sps.fromDTSCInit(meta.getInit(tNumber));
-              h264::SPSMeta spsChar = sps.getCharacteristics();
-              meta.setWidth(tNumber, spsChar.width);
-              meta.setHeight(tNumber, spsChar.height);
-            }
-          }
-          if (sType == "hev1" || sType == "hvc1"){
-            MP4::VisualSampleEntry &vEntryBox = (MP4::VisualSampleEntry &)sEntryBox;
-            meta.setType(tNumber, "video");
-            meta.setCodec(tNumber, "HEVC");
-            if (!meta.getWidth(tNumber)){
-              meta.setWidth(tNumber, vEntryBox.getWidth());
-              meta.setHeight(tNumber, vEntryBox.getHeight());
-            }
-            MP4::Box initBox = vEntryBox.getCLAP();
-            if (initBox.isType("hvcC")){
-              meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
-            }
-            initBox = vEntryBox.getPASP();
-            if (initBox.isType("hvcC")){
-              meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
-            }
-          }
-          if (sType == "mp4a" || sType == "aac " || sType == "ac-3"){
-            MP4::AudioSampleEntry &aEntryBox = (MP4::AudioSampleEntry &)sEntryBox;
-            meta.setType(tNumber, "audio");
-            meta.setChannels(tNumber, aEntryBox.getChannelCount());
-            meta.setRate(tNumber, aEntryBox.getSampleRate());
-
-            if (sType == "ac-3"){
-              meta.setCodec(tNumber, "AC3");
-            }else{
-              MP4::ESDS esdsBox = (MP4::ESDS &)(aEntryBox.getCodecBox());
-              meta.setCodec(tNumber, esdsBox.getCodec());
-              meta.setInit(tNumber, esdsBox.getInitData());
-            }
-            meta.setSize(tNumber, 16); ///\todo this might be nice to calculate from mp4 file;
-          }
-          if (sType == "tx3g"){// plain text subtitles
-            meta.setType(tNumber, "meta");
-            meta.setCodec(tNumber, "subtitle");
-          }
-
-          MP4::STSS stssBox = stblBox.getChild<MP4::STSS>();
-          MP4::STTS sttsBox = stblBox.getChild<MP4::STTS>();
-          MP4::STSZ stszBox = stblBox.getChild<MP4::STSZ>();
-          MP4::STCO stcoBox = stblBox.getChild<MP4::STCO>();
-          MP4::CO64 co64Box = stblBox.getChild<MP4::CO64>();
-          MP4::STSC stscBox = stblBox.getChild<MP4::STSC>();
-          MP4::CTTS cttsBox = stblBox.getChild<MP4::CTTS>(); // optional ctts box
-
-          bool stco64 = co64Box.isType("co64");
-          bool hasCTTS = cttsBox.isType("ctts");
-
-          uint64_t totaldur = 0; ///\todo note: set this to begin time
-          mp4PartBpos BsetPart;
-
-          uint64_t entryNo = 0;
-          uint64_t sampleNo = 0;
-
-          uint64_t stssIndex = 0;
-          uint64_t stcoIndex = 0;
-          uint64_t stscIndex = 0;
-          uint64_t cttsIndex = 0;     // current ctts Index we are reading
-          uint64_t cttsEntryRead = 0; // current part of ctts we are reading
-
-          uint64_t stssCount = stssBox.getEntryCount();
-          uint64_t stscCount = stscBox.getEntryCount();
-          uint64_t stszCount = stszBox.getSampleCount();
-          uint64_t stcoCount = (stco64 ? co64Box.getEntryCount() : stcoBox.getEntryCount());
-
-          MP4::STTSEntry sttsEntry = sttsBox.getSTTSEntry(0);
-
-          uint32_t fromSTCOinSTSC = 0;
-          uint64_t tmpOffset = (stco64 ? co64Box.getChunkOffset(0) : stcoBox.getChunkOffset(0));
-
-          uint64_t nextFirstChunk = (stscCount > 1 ? stscBox.getSTSCEntry(1).firstChunk - 1 : stcoCount);
-
-          for (uint64_t stszIndex = 0; stszIndex < stszCount; ++stszIndex){
-            if (stcoIndex >= nextFirstChunk){
-              ++stscIndex;
-              nextFirstChunk =
-                  (stscIndex + 1 < stscCount ? stscBox.getSTSCEntry(stscIndex + 1).firstChunk - 1 : stcoCount);
-            }
-            BsetPart.keyframe = (meta.getType(tNumber) == "video" && stssIndex < stssCount &&
-                                 stszIndex + 1 == stssBox.getSampleNumber(stssIndex));
-            if (BsetPart.keyframe){++stssIndex;}
-            // in bpos set
-            BsetPart.stcoNr = stcoIndex;
-            // bpos = chunkoffset[samplenr] in stco
-            BsetPart.bpos = tmpOffset;
-            ++fromSTCOinSTSC;
-            if (fromSTCOinSTSC < stscBox.getSTSCEntry(stscIndex).samplesPerChunk){// as long as we are still in this chunk
-              tmpOffset += stszBox.getEntrySize(stszIndex);
-            }else{
-              ++stcoIndex;
-              fromSTCOinSTSC = 0;
-              tmpOffset = (stco64 ? co64Box.getChunkOffset(stcoIndex) : stcoBox.getChunkOffset(stcoIndex));
-            }
-            BsetPart.time = (totaldur * 1000) / timescale;
-            totaldur += sttsEntry.sampleDelta;
-            sampleNo++;
-            if (sampleNo >= sttsEntry.sampleCount){
-              ++entryNo;
-              sampleNo = 0;
-              if (entryNo < sttsBox.getEntryCount()){sttsEntry = sttsBox.getSTTSEntry(entryNo);}
-            }
-
-            if (hasCTTS){
-              MP4::CTTSEntry cttsEntry = cttsBox.getCTTSEntry(cttsIndex);
-              cttsEntryRead++;
-              if (cttsEntryRead >= cttsEntry.sampleCount){
-                ++cttsIndex;
-                cttsEntryRead = 0;
-              }
-              BsetPart.timeOffset = (cttsEntry.sampleOffset * 1000) / timescale;
-            }else{
-              BsetPart.timeOffset = 0;
-            }
-
-            if (sType == "tx3g"){
-              if (stszBox.getEntrySize(stszIndex) <= 2 && false){
-                FAIL_MSG("size <=2");
-              }else{
-                long long packSendSize = 0;
-                packSendSize = 24 + (BsetPart.timeOffset ? 17 : 0) + (BsetPart.bpos ? 15 : 0) + 19 +
-                               stszBox.getEntrySize(stszIndex) + 11 - 2 + 19;
-                meta.update(BsetPart.time, BsetPart.timeOffset, tNumber,
-                            stszBox.getEntrySize(stszIndex) - 2, BsetPart.bpos, true, packSendSize);
-              }
-            }else{
-              meta.update(BsetPart.time, BsetPart.timeOffset, tNumber,
-                          stszBox.getEntrySize(stszIndex), BsetPart.bpos, BsetPart.keyframe);
-            }
-          }
-        }
+      std::string hdlrType = mdiaBox.getChild<MP4::HDLR>().getHandlerType();
+      if (hdlrType != "vide" && hdlrType != "soun" && hdlrType != "sbtl"){
+        INFO_MSG("Unsupported handler: %s", hdlrType.c_str());
         continue;
       }
-      if (!MP4::skipBox(inFile)){// moving on to next box
-        FAIL_MSG("Error in Skipping box, exiting");
-        return false;
+
+      tNumber = meta.addTrack();
+
+      MP4::TKHD tkhdBox = trakIt->getChild<MP4::TKHD>();
+      if (tkhdBox.getWidth() > 0){
+        meta.setWidth(tNumber, tkhdBox.getWidth());
+        meta.setHeight(tNumber, tkhdBox.getHeight());
+      }
+      meta.setID(tNumber, tkhdBox.getTrackID());
+
+      MP4::MDHD mdhdBox = mdiaBox.getChild<MP4::MDHD>();
+      uint64_t timescale = mdhdBox.getTimeScale();
+      meta.setLang(tNumber, mdhdBox.getLanguage());
+
+      MP4::STBL stblBox = mdiaBox.getChild<MP4::MINF>().getChild<MP4::STBL>();
+
+      MP4::STSD stsdBox = stblBox.getChild<MP4::STSD>();
+      MP4::Box sEntryBox = stsdBox.getEntry(0);
+      std::string sType = sEntryBox.getType();
+      HIGH_MSG("Found track %zu of type %s", tNumber, sType.c_str());
+
+      if (sType == "avc1" || sType == "h264" || sType == "mp4v"){
+        MP4::VisualSampleEntry &vEntryBox = (MP4::VisualSampleEntry &)sEntryBox;
+        meta.setType(tNumber, "video");
+        meta.setCodec(tNumber, "H264");
+        if (!meta.getWidth(tNumber)){
+          meta.setWidth(tNumber, vEntryBox.getWidth());
+          meta.setHeight(tNumber, vEntryBox.getHeight());
+        }
+        MP4::Box initBox = vEntryBox.getCLAP();
+        if (initBox.isType("avcC")){
+          meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
+        }
+        initBox = vEntryBox.getPASP();
+        if (initBox.isType("avcC")){
+          meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
+        }
+        /// this is a hacky way around invalid FLV data (since it gets ignored nearly
+        /// everywhere, but we do need correct data...
+        if (!meta.getWidth(tNumber)){
+          h264::sequenceParameterSet sps;
+          sps.fromDTSCInit(meta.getInit(tNumber));
+          h264::SPSMeta spsChar = sps.getCharacteristics();
+          meta.setWidth(tNumber, spsChar.width);
+          meta.setHeight(tNumber, spsChar.height);
+        }
+      }
+      if (sType == "hev1" || sType == "hvc1"){
+        MP4::VisualSampleEntry &vEntryBox = (MP4::VisualSampleEntry &)sEntryBox;
+        meta.setType(tNumber, "video");
+        meta.setCodec(tNumber, "HEVC");
+        if (!meta.getWidth(tNumber)){
+          meta.setWidth(tNumber, vEntryBox.getWidth());
+          meta.setHeight(tNumber, vEntryBox.getHeight());
+        }
+        MP4::Box initBox = vEntryBox.getCLAP();
+        if (initBox.isType("hvcC")){
+          meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
+        }
+        initBox = vEntryBox.getPASP();
+        if (initBox.isType("hvcC")){
+          meta.setInit(tNumber, initBox.payload(), initBox.payloadSize());
+        }
+      }
+      if (sType == "mp4a" || sType == "aac " || sType == "ac-3"){
+        MP4::AudioSampleEntry &aEntryBox = (MP4::AudioSampleEntry &)sEntryBox;
+        meta.setType(tNumber, "audio");
+        meta.setChannels(tNumber, aEntryBox.getChannelCount());
+        meta.setRate(tNumber, aEntryBox.getSampleRate());
+
+        if (sType == "ac-3"){
+          meta.setCodec(tNumber, "AC3");
+        }else{
+          MP4::ESDS esdsBox = (MP4::ESDS &)(aEntryBox.getCodecBox());
+          meta.setCodec(tNumber, esdsBox.getCodec());
+          meta.setInit(tNumber, esdsBox.getInitData());
+        }
+        meta.setSize(tNumber, 16); ///\todo this might be nice to calculate from mp4 file;
+      }
+      if (sType == "tx3g"){// plain text subtitles
+        meta.setType(tNumber, "meta");
+        meta.setCodec(tNumber, "subtitle");
+      }
+
+      MP4::STSS stssBox = stblBox.getChild<MP4::STSS>();
+      MP4::STTS sttsBox = stblBox.getChild<MP4::STTS>();
+      MP4::STSZ stszBox = stblBox.getChild<MP4::STSZ>();
+      MP4::STCO stcoBox = stblBox.getChild<MP4::STCO>();
+      MP4::CO64 co64Box = stblBox.getChild<MP4::CO64>();
+      MP4::STSC stscBox = stblBox.getChild<MP4::STSC>();
+      MP4::CTTS cttsBox = stblBox.getChild<MP4::CTTS>(); // optional ctts box
+
+      bool stco64 = co64Box.isType("co64");
+      bool hasCTTS = cttsBox.isType("ctts");
+
+      uint64_t totaldur = 0; ///\todo note: set this to begin time
+      mp4PartBpos BsetPart;
+
+      uint64_t entryNo = 0;
+      uint64_t sampleNo = 0;
+
+      uint64_t stssIndex = 0;
+      uint64_t stcoIndex = 0;
+      uint64_t stscIndex = 0;
+      uint64_t cttsIndex = 0;     // current ctts Index we are reading
+      uint64_t cttsEntryRead = 0; // current part of ctts we are reading
+
+      uint64_t stssCount = stssBox.getEntryCount();
+      uint64_t stscCount = stscBox.getEntryCount();
+      uint64_t stszCount = stszBox.getSampleCount();
+      uint64_t stcoCount = (stco64 ? co64Box.getEntryCount() : stcoBox.getEntryCount());
+
+      MP4::STTSEntry sttsEntry = sttsBox.getSTTSEntry(0);
+
+      uint32_t fromSTCOinSTSC = 0;
+      uint64_t tmpOffset = (stco64 ? co64Box.getChunkOffset(0) : stcoBox.getChunkOffset(0));
+
+      uint64_t nextFirstChunk = (stscCount > 1 ? stscBox.getSTSCEntry(1).firstChunk - 1 : stcoCount);
+
+      for (uint64_t stszIndex = 0; stszIndex < stszCount; ++stszIndex){
+        if (stcoIndex >= nextFirstChunk){
+          ++stscIndex;
+          nextFirstChunk =
+              (stscIndex + 1 < stscCount ? stscBox.getSTSCEntry(stscIndex + 1).firstChunk - 1 : stcoCount);
+        }
+        BsetPart.keyframe = (meta.getType(tNumber) == "video" && stssIndex < stssCount &&
+                             stszIndex + 1 == stssBox.getSampleNumber(stssIndex));
+        if (BsetPart.keyframe){++stssIndex;}
+        // in bpos set
+        BsetPart.stcoNr = stcoIndex;
+        // bpos = chunkoffset[samplenr] in stco
+        BsetPart.bpos = tmpOffset;
+        ++fromSTCOinSTSC;
+        if (fromSTCOinSTSC < stscBox.getSTSCEntry(stscIndex).samplesPerChunk){// as long as we are still in this chunk
+          tmpOffset += stszBox.getEntrySize(stszIndex);
+        }else{
+          ++stcoIndex;
+          fromSTCOinSTSC = 0;
+          tmpOffset = (stco64 ? co64Box.getChunkOffset(stcoIndex) : stcoBox.getChunkOffset(stcoIndex));
+        }
+        BsetPart.time = (totaldur * 1000) / timescale;
+        totaldur += sttsEntry.sampleDelta;
+        sampleNo++;
+        if (sampleNo >= sttsEntry.sampleCount){
+          ++entryNo;
+          sampleNo = 0;
+          if (entryNo < sttsBox.getEntryCount()){sttsEntry = sttsBox.getSTTSEntry(entryNo);}
+        }
+
+        if (hasCTTS){
+          MP4::CTTSEntry cttsEntry = cttsBox.getCTTSEntry(cttsIndex);
+          cttsEntryRead++;
+          if (cttsEntryRead >= cttsEntry.sampleCount){
+            ++cttsIndex;
+            cttsEntryRead = 0;
+          }
+          BsetPart.timeOffset = (cttsEntry.sampleOffset * 1000) / timescale;
+        }else{
+          BsetPart.timeOffset = 0;
+        }
+
+        if (sType == "tx3g"){
+          if (stszBox.getEntrySize(stszIndex) <= 2 && false){
+            FAIL_MSG("size <=2");
+          }else{
+            long long packSendSize = 0;
+            packSendSize = 24 + (BsetPart.timeOffset ? 17 : 0) + (BsetPart.bpos ? 15 : 0) + 19 +
+                           stszBox.getEntrySize(stszIndex) + 11 - 2 + 19;
+            meta.update(BsetPart.time, BsetPart.timeOffset, tNumber,
+                        stszBox.getEntrySize(stszIndex) - 2, BsetPart.bpos, true, packSendSize);
+          }
+        }else{
+          meta.update(BsetPart.time, BsetPart.timeOffset, tNumber,
+                      stszBox.getEntrySize(stszIndex), BsetPart.bpos, BsetPart.keyframe);
+        }
       }
     }
-    clearerr(inFile);
 
     // outputting dtsh file
-    M.toFile(config->getString("input") + ".dtsh");
+    std::string inUrl = config->getString("input");
+    if (inUrl.size() > 4 && inUrl.substr(0, 4) == "mp4:"){inUrl.erase(0, 4);}
+    if (inUrl != "-" && HTTP::URL(inUrl).isLocalPath()){
+      M.toFile(inUrl + ".dtsh");
+    }else{
+      INFO_MSG("Skipping header write, as the source is not a local file");
+    }
+    bps = 0;
+    std::set<size_t> tracks = M.getValidTracks();
+    for (std::set<size_t>::iterator it = tracks.begin(); it != tracks.end(); it++){bps += M.getBps(*it);}
     return true;
   }
 
@@ -474,23 +513,48 @@ namespace Mist{
         ++nextKeyNum;
       }
     }
-    if (fseeko(inFile, curPart.bpos, SEEK_SET)){
-      FAIL_MSG("seek unsuccessful @bpos %" PRIu64 ": %s", curPart.bpos, strerror(errno));
-      thisPacket.null();
-      return;
+    if (curPart.bpos < readPos || curPart.bpos > readPos + readBuffer.size() + 512*1024 + bps){
+      INFO_MSG("Buffer contains %" PRIu64 "-%" PRIu64 ", but we need %" PRIu64 "; seeking!", readPos, readPos + readBuffer.size(), curPart.bpos);
+      readBuffer.truncate(0);
+      if (!inFile.seek(curPart.bpos)){
+        FAIL_MSG("seek unsuccessful @bpos %" PRIu64 ": %s", curPart.bpos, strerror(errno));
+        thisPacket.null();
+        return;
+      }
+      readPos = inFile.getPos();
+    }else{
+      //If we have more than 5MiB buffered and are more than 5MiB into the buffer, shift the first 4MiB off the buffer.
+      //This prevents infinite growth of the read buffer for large files
+      if (readBuffer.size() >= 5*1024*1024 && curPart.bpos > readPos + 5*1024*1024 + bps){
+        readBuffer.shift(4*1024*1024);
+        readPos += 4*1024*1024;
+      }
     }
-    if (curPart.size > malSize){
-      data = (char *)realloc(data, curPart.size);
-      malSize = curPart.size;
+
+    while (readPos+readBuffer.size() < curPart.bpos+curPart.size && inFile && keepRunning()){
+      inFile.readSome((curPart.bpos+curPart.size) - (readPos+readBuffer.size()), *this);
     }
-    if (fread(data, curPart.size, 1, inFile) != 1){
-      FAIL_MSG("read unsuccessful at %ld", ftell(inFile));
-      thisPacket.null();
-      return;
+    if (readPos+readBuffer.size() < curPart.bpos+curPart.size){
+      FAIL_MSG("Read unsuccessful at %" PRIu64 ", seeking to retry...", readPos+readBuffer.size());
+      readBuffer.truncate(0);
+      if (!inFile.seek(curPart.bpos)){
+        FAIL_MSG("seek unsuccessful @bpos %" PRIu64 ": %s", curPart.bpos, strerror(errno));
+        thisPacket.null();
+        return;
+      }
+      readPos = inFile.getPos();
+      while (readPos+readBuffer.size() < curPart.bpos+curPart.size && inFile && keepRunning()){
+        inFile.readSome((curPart.bpos+curPart.size) - (readPos+readBuffer.size()), *this);
+      }
+      if (readPos+readBuffer.size() < curPart.bpos+curPart.size){
+        FAIL_MSG("Read retry unsuccessful at %" PRIu64 ", aborting", readPos+readBuffer.size());
+        thisPacket.null();
+        return;
+      }
     }
 
     if (M.getCodec(curPart.trackID) == "subtitle"){
-      unsigned int txtLen = Bit::btohs(data);
+      unsigned int txtLen = Bit::btohs(readBuffer + (curPart.bpos-readPos));
       if (!txtLen && false){
         curPart.index++;
         return getNext(idx);
@@ -499,14 +563,14 @@ namespace Mist{
       thisPack.null();
       thisPack["trackid"] = curPart.trackID;
       thisPack["bpos"] = curPart.bpos; //(long long)fileSource.tellg();
-      thisPack["data"] = std::string(data + 2, txtLen);
+      thisPack["data"] = std::string(readBuffer + (curPart.bpos-readPos) + 2, txtLen);
       thisPack["time"] = curPart.time;
       if (curPart.duration){thisPack["duration"] = curPart.duration;}
       thisPack["keyframe"] = true;
       std::string tmpStr = thisPack.toNetPacked();
       thisPacket.reInit(tmpStr.data(), tmpStr.size());
     }else{
-      thisPacket.genericFill(curPart.time, curPart.offset, curPart.trackID, data, curPart.size, 0, isKeyframe);
+      thisPacket.genericFill(curPart.time, curPart.offset, curPart.trackID, readBuffer + (curPart.bpos-readPos), curPart.size, 0, isKeyframe);
     }
     thisTime = curPart.time;
     thisIdx = curPart.trackID;
diff --git a/src/input/input_mp4.h b/src/input/input_mp4.h
index b5987d3b..4ab9f36e 100644
--- a/src/input/input_mp4.h
+++ b/src/input/input_mp4.h
@@ -1,5 +1,6 @@
 #include "input.h"
 #include <mist/dtsc.h>
+#include <mist/urireader.h>
 #include <mist/mp4.h>
 #include <mist/mp4_generic.h>
 namespace Mist{
@@ -70,10 +71,10 @@ namespace Mist{
     bool stco64;
   };
 
-  class inputMP4 : public Input{
+  class inputMP4 : public Input, public Util::DataCallback {
   public:
     inputMP4(Util::Config *cfg);
-    ~inputMP4();
+    void dataCallback(const char *ptr, size_t size);
 
   protected:
     // Private Functions
@@ -85,7 +86,10 @@ namespace Mist{
     void seek(uint64_t seekTime, size_t idx = INVALID_TRACK_ID);
     void handleSeek(uint64_t seekTime, size_t idx);
 
-    FILE *inFile;
+    HTTP::URIReader inFile;
+    Util::ResizeablePointer readBuffer;
+    uint64_t readPos;
+    uint64_t bps;
 
     mp4TrackHeader &headerData(size_t trackID);
 
@@ -94,11 +98,6 @@ namespace Mist{
 
     // remember last seeked keyframe;
     std::map<size_t, uint32_t> nextKeyframe;
-
-    // these next two variables keep a buffer for reading from filepointer inFile;
-    uint64_t malSize;
-    char *data; ///\todo rename this variable to a more sensible name, it is a temporary piece of
-                /// memory to read from files
   };
 }// namespace Mist