diff --git a/Source/Common/Output_Mkv.cpp b/Source/Common/Output_Mkv.cpp
index 3599c401..942a060c 100644
--- a/Source/Common/Output_Mkv.cpp
+++ b/Source/Common/Output_Mkv.cpp
@@ -12,7 +12,7 @@
 
 using namespace std;
 
-static const unsigned char matroska_writer_header[]                 = { 0x1A, 0x45, 0xDF, 0xA3, 0xA3, 0x42, 0x86, 0x81, 0x01, 0x42, 0xF7, 0x81, 0x01, 0x42, 0xF2, 0x81, 0x04, 0x42, 0xF3, 0x81, 0x08, 0x42, 0x82, 0x88, 0x6D, 0x61, 0x74, 0x72, 0x6F, 0x73, 0x6B, 0x61, 0x42, 0x87, 0x81, 0x04, 0x42, 0x85, 0x81, 0x02, 0x18, 0x53, 0x80, 0x67, 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x11, 0x4D, 0x9B, 0x74, 0xC6, 0xEC, 0x84, 0x00, 0x00, 0x00, 0x00, 0x4D, 0xBB, 0x8B, 0x53, 0xAB, 0x84, 0x15, 0x49, 0xA9, 0x66, 0x53, 0xAC, 0x81, 0xA1, 0x4D, 0xBB, 0x8B, 0x53, 0xAB, 0x84, 0x16, 0x54, 0xAE, 0x6B, 0x53, 0xAC, 0x81, 0xF3, 0xEC, 0x8D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x15, 0x49, 0xA9, 0x66, 0xCD, 0xEC, 0x84, 0x00, 0x00, 0x00, 0x00, 0x2A, 0xD7, 0xB1, 0x83, 0x0F, 0x42, 0x40, 0x4D, 0x80, 0x8E, 0x44, 0x56, 0x52, 0x65, 0x73, 0x63, 0x75, 0x65, 0x20, 0x30, 0x30, 0x2E, 0x30, 0x30, 0x57, 0x41, 0x8E, 0x44, 0x56, 0x52, 0x65, 0x73, 0x63, 0x75, 0x65, 0x20, 0x30, 0x30, 0x2E, 0x30, 0x30, 0xEC, 0x91, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x89, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x16, 0x54, 0xAE, 0x6B, 0x41, 0x14, 0xEC, 0x84, 0x00, 0x00, 0x00, 0x00, 0xAE, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x98, 0xD7, 0x81, 0x01, 0x73, 0xC5, 0x81, 0x01, 0xEC, 0x89, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x9C, 0x81, 0x00, 0x22, 0xB5, 0x9C, 0x83, 0x75, 0x6E, 0x64, 0x83, 0x81, 0x01, 0x23, 0xE3, 0x83, 0x84, 0x01, 0xFD, 0x22, 0x8A, 0x86, 0x8F, 0x56, 0x5F, 0x4D, 0x53, 0x2F, 0x56, 0x46, 0x57, 0x2F, 0x46, 0x4F, 0x55, 0x52, 0x43, 0x43, 0xE0, 0xA6, 0xB0, 0x82, 0x00, 0x00, 0xBA, 0x82, 0x00, 0x00, 0x9A, 0x81, 0x01, 0x9D, 0x81, 0x06, 0x54, 0xB0, 0x81, 0x04, 0x54, 0xBA, 0x81, 0x03, 0x54, 0xB2, 0x81, 0x03, 0xEC, 0x8A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x63, 0xA2, 0xA8, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x18, 0x00, 0x76, 0x32, 0x31, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x8C, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xAE, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x41, 0xD7, 0x81, 0x02, 0x73, 0xC5, 0x81, 0x02, 0xEC, 0x89, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x9C, 0x81, 0x00, 0x22, 0xB5, 0x9C, 0x83, 0x75, 0x6E, 0x64, 0x86, 0x8D, 0x41, 0x5F, 0x50, 0x43, 0x4D, 0x2F, 0x49, 0x4E, 0x54, 0x2F, 0x4C, 0x49, 0x54, 0x83, 0x81, 0x02, 0xE1, 0x91, 0x9F, 0x81, 0x02, 0xB5, 0x88, 0x40, 0xE7, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x62, 0x64, 0x81, 0x20, 0xEC, 0x9D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+static const unsigned char matroska_writer_header[]                 = { 0x1A, 0x45, 0xDF, 0xA3, 0xA3, 0x42, 0x86, 0x81, 0x01, 0x42, 0xF7, 0x81, 0x01, 0x42, 0xF2, 0x81, 0x04, 0x42, 0xF3, 0x81, 0x08, 0x42, 0x82, 0x88, 0x6D, 0x61, 0x74, 0x72, 0x6F, 0x73, 0x6B, 0x61, 0x42, 0x87, 0x81, 0x04, 0x42, 0x85, 0x81, 0x02, 0x18, 0x53, 0x80, 0x67, 0x01, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x11, 0x4D, 0x9B, 0x74, 0xC6, 0xEC, 0x84, 0x00, 0x00, 0x00, 0x00, 0x4D, 0xBB, 0x8B, 0x53, 0xAB, 0x84, 0x15, 0x49, 0xA9, 0x66, 0x53, 0xAC, 0x81, 0xA1, 0x4D, 0xBB, 0x8B, 0x53, 0xAB, 0x84, 0x16, 0x54, 0xAE, 0x6B, 0x53, 0xAC, 0x81, 0xF3, 0xEC, 0x8D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x93, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x4D, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x15, 0x49, 0xA9, 0x66, 0xCD, 0xEC, 0x84, 0x00, 0x00, 0x00, 0x00, 0x2A, 0xD7, 0xB1, 0x83, 0x0F, 0x42, 0x40, 0x4D, 0x80, 0x8E, 0x44, 0x56, 0x52, 0x65, 0x73, 0x63, 0x75, 0x65, 0x20, 0x30, 0x30, 0x2E, 0x30, 0x30, 0x57, 0x41, 0x8E, 0x44, 0x56, 0x52, 0x65, 0x73, 0x63, 0x75, 0x65, 0x20, 0x30, 0x30, 0x2E, 0x30, 0x30, 0xEC, 0x91, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x89, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x16, 0x54, 0xAE, 0x6B, 0x41, 0x14, 0xEC, 0x84, 0x00, 0x00, 0x00, 0x00, 0xAE, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x98, 0xD7, 0x81, 0x01, 0x73, 0xC5, 0x81, 0x01, 0xEC, 0x89, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x9C, 0x81, 0x00, 0x22, 0xB5, 0x9C, 0x83, 0x75, 0x6E, 0x64, 0x83, 0x81, 0x01, 0x23, 0xE3, 0x83, 0x84, 0x01, 0xFD, 0x22, 0x8A, 0x86, 0x8F, 0x56, 0x5F, 0x4D, 0x53, 0x2F, 0x56, 0x46, 0x57, 0x2F, 0x46, 0x4F, 0x55, 0x52, 0x43, 0x43, 0xE0, 0xA6, 0xB0, 0x82, 0x00, 0x00, 0xBA, 0x82, 0x00, 0x00, 0x9A, 0x81, 0x01, 0x9D, 0x81, 0x06, 0x54, 0xB0, 0x81, 0x04, 0x54, 0xBA, 0x81, 0x03, 0x54, 0xB2, 0x81, 0x03, 0xEC, 0x8A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x63, 0xA2, 0xA8, 0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x18, 0x00, 0x76, 0x32, 0x31, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xEC, 0x8B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xAE, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x41, 0xD7, 0x81, 0x02, 0x73, 0xC5, 0x81, 0x02, 0xEC, 0x89, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x9C, 0x81, 0x00, 0x22, 0xB5, 0x9C, 0x83, 0x75, 0x6E, 0x64, 0x86, 0x8D, 0x41, 0x5F, 0x50, 0x43, 0x4D, 0x2F, 0x49, 0x4E, 0x54, 0x2F, 0x4C, 0x49, 0x54, 0x83, 0x81, 0x02, 0xE1, 0x91, 0x9F, 0x81, 0x02, 0xB5, 0x88, 0x40, 0xE7, 0x70, 0x00, 0x00, 0x00, 0x00, 0x00, 0x62, 0x64, 0x81, 0x20, 0xEC, 0xA1, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 static const unsigned char matroska_writer_header_seek[]            = { 0x4D, 0xBB, 0x92, 0x53, 0xAB, 0x84, 0x1C, 0x53, 0xBB, 0x6B, 0x53, 0xAC, 0x88 };
 static const unsigned char matroska_writer_header_timecode[]        = { 0x41, 0xE4, 0x8A, 0x41, 0xE7, 0x83, 0x31, 0x32, 0x31, 0x41, 0xF0, 0x81, 0x79 };
 static const unsigned char matroska_writer_header_texttrack[]       = { 0xAE, 0xA1, 0xD7, 0x81, 0x03, 0x73, 0xC5, 0x81, 0x03, 0xEC, 0x85, 0x00, 0x00, 0x00, 0x00, 0x00, 0x83, 0x81, 0x11, 0x86, 0x8B, 0x53, 0x5F, 0x54, 0x45, 0x58, 0x54, 0x2F, 0x55, 0x54, 0x46, 0x38, 0x9C, 0x81, 0x00 };
@@ -290,7 +290,7 @@ void matroska_writer::write_header()
 void matroska_writer::write_frame(const char* video_buffer, int video_size, const char* audio_buffer, int audio_size, timecode_struct timecode)
 {
     // Cues
-    double timecode_ms = (double)frame_number * 1000 * framerate_den / framerate_num + 0.5;
+    auto timecode_ms = (frame_number * 1000 * framerate_den + framerate_num / 2 - 1) / framerate_num;
     auto timecode_s = timecode_ms / 1000;
     if (timecode_s >= cues.size())
         cues.push_back({ (unsigned long long)timecode_ms, output_size });
@@ -346,6 +346,8 @@ void matroska_writer::write_frame(const char* video_buffer, int video_size, cons
         store_b2(cur, 0x75A1); // BlockMore
         store_b8(cur, 0x8FA68DEE8179A588LL); // BlockMore size + BlockAddID + BlockAdditional
         store_b8(cur, timecode_value);
+        if (!has_timecode)
+            has_timecode=true; // timecode track header will be written when header is written again with cues
     }
     
     // Audio
@@ -387,15 +389,21 @@ void matroska_writer::write_frame(const char* video_buffer, int video_size, cons
 
 void matroska_writer::close(std::ofstream* output)
 {
-    char buffer[sizeof(matroska_writer_header)];
-    char* cur;
+    auto cues_size = 6 + 27 * cues.size();
+    if (buffer_size < cues_size)
+    {
+        buffer_size = cues_size;
+        delete[] buffer;
+        buffer = new char[buffer_size];
+    }
+    auto cur = buffer;
 
-    // Cues
-    int cues_size = 6 + 27 * (int)cues.size();
-    cur = buffer;
+    // Header
     store_b4(cur, 0x1C53BB6B); // Cues
     store_e4(cur, cues_size);
     cur += 6; // CRC-32
+
+    // Cues
     for (const auto& cue : cues)
     {
         store_b4(cur, 0xBB99B388); // CuePoint + CueTime
@@ -404,22 +412,13 @@ void matroska_writer::close(std::ofstream* output)
         store_b1(cur, 1);
         store_b2(cur, 0xF188); // CueClusterPosition
         store_b8(cur, cue.offset);
-        auto size = cur - buffer;
-        if (sizeof(matroska_writer_header) - size < 27)
-        {
-            output->write(buffer, size);
-            output_size += size;
-            cur = buffer;
-        }
-    }
-    if (cur > buffer)
-    {
-        auto size = cur - buffer;
-        matroska_crc32_store(buffer + 8, cues_size);
-        output->write(buffer, size);
-        output_size += size;
     }
 
+    auto size = cur - buffer;
+    matroska_crc32_store(buffer + 8, cues_size);
+    output->write(buffer, size);
+    output_size += size;
+
     output->seekp(0);
     if (output)
         write_header();