Index: mp4property.cpp
===================================================================
--- mp4property.cpp	(revision 12)
+++ mp4property.cpp	(working copy)
@@ -390,7 +390,9 @@
 	}
 	if (m_useCountedFormat) {
 		pFile->WriteCountedString(m_values[index],
-			(m_useUnicode ? 2 : 1), m_useExpandedCount);
+                                          (m_useUnicode ? 2 : 1), 
+                                          m_useExpandedCount,
+                                          m_fixedLength);
 	} else if (m_fixedLength) {
 		pFile->WriteBytes((uint8_t*)m_values[index], m_fixedLength);
 	} else {
Index: mp4file.h
===================================================================
--- mp4file.h	(revision 12)
+++ mp4file.h	(working copy)
@@ -644,7 +644,9 @@
 	void WriteFloat(float value);
 	void WriteString(char* string);
 	void WriteCountedString(char* string, 
-		uint8_t charSize = 1, bool allowExpandedCount = false);
+                                uint8_t charSize = 1, 
+                                bool allowExpandedCount = false,
+                                uint8_t fixedLength = 0);
 	void WriteBits(uint64_t bits, uint8_t numBits);
 	void PadWriteBits(uint8_t pad = 0);
 	void FlushWriteBits();
Index: atom_avc1.cpp
===================================================================
--- atom_avc1.cpp	(revision 12)
+++ atom_avc1.cpp	(working copy)
@@ -41,6 +41,7 @@
 	MP4StringProperty* pProp = 
 		new MP4StringProperty("compressorName");
 	pProp->SetFixedLength(32);
+        pProp->SetCountedFormat(true);
 	pProp->SetValue("AVC Coding");
 	AddProperty(pProp); /* 6 */
 
Index: atom_mp4v.cpp
===================================================================
--- atom_mp4v.cpp	(revision 12)
+++ atom_mp4v.cpp	(working copy)
@@ -41,6 +41,7 @@
 	MP4StringProperty* pProp = 
 		new MP4StringProperty("compressorName");
 	pProp->SetFixedLength(32);
+        pProp->SetCountedFormat(true);
 	pProp->SetValue("");
 	AddProperty(pProp); /* 6 */
 
Index: atom_encv.cpp
===================================================================
--- atom_encv.cpp	(revision 12)
+++ atom_encv.cpp	(working copy)
@@ -41,7 +41,8 @@
 
 	MP4StringProperty* pProp = 
 		new MP4StringProperty("compressorName");
-	pProp->SetFixedLength(32);
+	pProp->SetFixedLength(32); 
+        pProp->SetCountedFormat(true);
 	pProp->SetValue("");
 	AddProperty(pProp); /* 6 */
 	AddReserved("reserved4", 4); /* 7 */
Index: mp4file_io.cpp
===================================================================
--- mp4file_io.cpp	(revision 12)
+++ mp4file_io.cpp	(working copy)
@@ -443,11 +443,17 @@
 }
 
 void MP4File::WriteCountedString(char* string, 
-	uint8_t charSize, bool allowExpandedCount)
+                                 uint8_t charSize, bool allowExpandedCount, 
+                                 uint8_t fixedLength)
 {
 	uint32_t byteLength;
+        uint8_t zero[1];
+
 	if (string) {
 		byteLength = strlen(string);
+                if (byteLength >= fixedLength) {
+                    byteLength = fixedLength-1;
+                }
 	} else {
 		byteLength = 0;
 	}
@@ -458,16 +464,27 @@
 			WriteUInt8(0xFF);
 			charLength -= 0xFF;
 		}		
+                // Write the count
 		WriteUInt8(charLength);
 	} else {
 		if (charLength > 255) {
 			throw new MP4Error(ERANGE, "Length is %d", "MP4WriteCountedString", charLength);
 		}
+                // Write the count
 		WriteUInt8(charLength);
 	}
 
 	if (byteLength > 0) {
-		WriteBytes((uint8_t*)string, byteLength);
+            // Write the string (or the portion that we want to write)
+            WriteBytes((uint8_t*)string, byteLength);
+            // Write any padding if this is a fixed length counted string
+            if (fixedLength) {
+                zero[0] = 0;
+                while (byteLength < fixedLength-1) {
+                    WriteBytes(zero, 1);
+                    byteLength++;
+                }
+            }
 	}
 }
 
Index: atom_video.cpp
===================================================================
--- atom_video.cpp	(revision 12)
+++ atom_video.cpp	(working copy)
@@ -41,6 +41,7 @@
 	MP4StringProperty* pProp = 
 		new MP4StringProperty("compressorName");
 	pProp->SetFixedLength(32);
+        pProp->SetCountedFormat(true);
 	pProp->SetValue("");
 	AddProperty(pProp); /* 6 */