diff --git a/src/mxf_op1a/OP1AFile.cpp b/src/mxf_op1a/OP1AFile.cpp
index 4833aac4..953968a1 100644
--- a/src/mxf_op1a/OP1AFile.cpp
+++ b/src/mxf_op1a/OP1AFile.cpp
@@ -416,7 +416,9 @@ void OP1AFile::PrepareHeaderMetadata()
     for (i = 0; i < mTracks.size(); i++)
         mTracks[i]->PrepareWrite(mTrackCounts[mTracks[i]->GetDataDef()]);
     if (HAVE_PRIMARY_EC) {
-        mCPManager->SetStartTimecode(mStartTimecode);
+        Timecode start_timecode = mStartTimecode;
+        start_timecode.AddOffset(- mOutputStartOffset, mFrameRate);
+        mCPManager->SetStartTimecode(start_timecode);
         mCPManager->PrepareWrite();
         mIndexTable->PrepareWrite();
     }
diff --git a/src/mxf_reader/MXFFileReader.cpp b/src/mxf_reader/MXFFileReader.cpp
index 0ad91dff..5cc80f39 100644
--- a/src/mxf_reader/MXFFileReader.cpp
+++ b/src/mxf_reader/MXFFileReader.cpp
@@ -2325,7 +2325,15 @@ bool MXFFileReader::HaveInterFrameEncodingTrack() const
                 essence_type == MPEG2LG_MP_HL_1440_1080P ||
                 essence_type == MPEG2LG_MP_HL_720P ||
                 essence_type == MPEG2LG_MP_H14_1080I ||
-                essence_type == MPEG2LG_MP_H14_1080P)
+                essence_type == MPEG2LG_MP_H14_1080P ||
+                essence_type == AVC_BASELINE ||
+                essence_type == AVC_CONSTRAINED_BASELINE ||
+                essence_type == AVC_MAIN ||
+                essence_type == AVC_EXTENDED ||
+                essence_type == AVC_HIGH ||
+                essence_type == AVC_HIGH_10 ||
+                essence_type == AVC_HIGH_422 ||
+                essence_type == AVC_HIGH_444)
             {
                 return true;
             }
diff --git a/src/rdd9_mxf/RDD9File.cpp b/src/rdd9_mxf/RDD9File.cpp
index 430401cb..15b16959 100644
--- a/src/rdd9_mxf/RDD9File.cpp
+++ b/src/rdd9_mxf/RDD9File.cpp
@@ -332,7 +332,9 @@ void RDD9File::PrepareHeaderMetadata()
     for (i = 0; i < mTracks.size(); i++)
         mTracks[i]->PrepareWrite(mTrackCounts[mTracks[i]->GetDataDef()]);
 
-    mCPManager->SetStartTimecode(mStartTimecode);
+    Timecode start_timecode = mStartTimecode;
+    start_timecode.AddOffset(- mOutputStartOffset, mFrameRate);
+    mCPManager->SetStartTimecode(start_timecode);
     mCPManager->PrepareWrite();
     mIndexTable->PrepareWrite();