diff --git a/lib/mp4_generic.cpp b/lib/mp4_generic.cpp
index c08b5e70..4243cbc2 100644
--- a/lib/mp4_generic.cpp
+++ b/lib/mp4_generic.cpp
@@ -3197,57 +3197,57 @@ namespace MP4 {
 
   void ELST::setSegmentDuration(uint32_t cnt, uint64_t newVal) {
     if (getVersion() == 1) {
-      setInt64(newVal, 28*cnt+8);
+      setInt64(newVal, 20*cnt+8);
     } else {
-      setInt32(newVal, 20*cnt+8);
+      setInt32(newVal, 12*cnt+8);
     }
   }
 
   uint64_t ELST::getSegmentDuration(uint32_t cnt) {
     if (getVersion() == 1) {
-      return getInt64(28*cnt+8);
+      return getInt64(20*cnt+8);
     } else {
-      return getInt32(20*cnt+8);
+      return getInt32(12*cnt+8);
     }
   }
 
   void ELST::setMediaTime(uint32_t cnt, uint64_t newVal) {
     if (getVersion() == 1) {
-      setInt64(newVal, 28*cnt+16);
+      setInt64(newVal, 20*cnt+16);
     } else {
-      setInt32(newVal, 20*cnt+12);
+      setInt32(newVal, 12*cnt+12);
     }
   }
 
   uint64_t ELST::getMediaTime(uint32_t cnt) {
     if (getVersion() == 1) {
-      return getInt64(28*cnt+16);
+      return getInt64(20*cnt+16);
     } else {
-      return getInt32(20*cnt+12);
+      return getInt32(12*cnt+12);
     }
   }
 
   void ELST::setMediaRateInteger(uint32_t cnt, uint16_t newVal) {
     if (getVersion() == 1) {
-      setInt16(newVal, 28*cnt+24);
+      setInt16(newVal, 20*cnt+24);
     } else {
-      setInt16(newVal, 20*cnt+16);
+      setInt16(newVal, 12*cnt+16);
     }
   }
 
   uint16_t ELST::getMediaRateInteger(uint32_t cnt) {
     if (getVersion() == 1) {
-      return getInt16(28*cnt+24);
+      return getInt16(20*cnt+24);
     } else {
-      return getInt16(20*cnt+16);
+      return getInt16(12*cnt+16);
     }
   }
 
   void ELST::setMediaRateFraction(uint32_t cnt, uint16_t newVal) {
     if (getVersion() == 1) {
-      setInt16(newVal, 28*cnt+26);
+      setInt16(newVal, 20*cnt+26);
     } else {
-      setInt16(newVal, 20*cnt+18);
+      setInt16(newVal, 12*cnt+18);
     }
   }
 
diff --git a/src/output/output_progressive_mp4.cpp b/src/output/output_progressive_mp4.cpp
index 699452bd..e96de3a5 100644
--- a/src/output/output_progressive_mp4.cpp
+++ b/src/output/output_progressive_mp4.cpp
@@ -40,6 +40,12 @@ namespace Mist {
     uint64_t res = 36 // FTYP Box
       + 8 //MOOV box
       + 108; //MVHD Box
+    uint64_t firstms = 0xFFFFFFFFFFFFFFFFull;
+    for (std::set<unsigned long>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
+      if (myMeta.tracks[*it].firstms < firstms){
+        firstms = myMeta.tracks[*it].firstms;
+      }
+    }
     for (std::set<unsigned long>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
       DTSC::Track & thisTrack = myMeta.tracks[*it];
       uint64_t tmpRes = 0;
@@ -54,6 +60,9 @@ namespace Mist {
         + 8 //MINF Box
         + 36 //DINF Box
         + 8; // STBL Box
+      if (thisTrack.firstms != firstms){
+        tmpRes += 12;// EDTS entry extra
+      }
 
       //These boxes are empty when generating fragmented output
       tmpRes += 20 + (partCount * 4);//STSZ
@@ -140,7 +149,7 @@ namespace Mist {
     //Then override it to set the correct duration
     uint64_t firstms = 0xFFFFFFFFFFFFFFull;
     uint64_t lastms = 0;
-    for (std::set<unsigned long>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++) {
+    for (std::set<unsigned long>::iterator it = selectedTracks.begin(); it != selectedTracks.end(); it++){
       lastms = std::max(lastms, (uint64_t)myMeta.tracks[*it].lastms);
       firstms = std::min(firstms, (uint64_t)myMeta.tracks[*it].firstms);
     }
@@ -171,6 +180,7 @@ namespace Mist {
       elstBox.setMediaTime(0, 0);
       elstBox.setMediaRateInteger(0, 1);
       elstBox.setMediaRateFraction(0, 0);
+
       edtsBox.setContent(elstBox, 0);
       trakBox.setContent(edtsBox, trakOffset++);