diff --git a/ABStudio/FileFormats/PVR/PVRFile.cs b/ABStudio/FileFormats/PVR/PVRFile.cs
index 9691adf..fcf7434 100644
--- a/ABStudio/FileFormats/PVR/PVRFile.cs
+++ b/ABStudio/FileFormats/PVR/PVRFile.cs
@@ -24,6 +24,8 @@ public PVRFile(byte[] pvrData)
             tex = PVRTexLib.PVRTexLibCreateTextureFromData(dataPtr);
             if (ReferenceEquals(tex, null))
                 throw new Exception("Invalid PVR file.");
+
+            Marshal.FreeHGlobal(dataPtr);
         }
 
         public PVRFile(Bitmap bmp, string format="r4g4b4a4")
@@ -45,14 +47,6 @@ public PVRFile(Bitmap bmp, string format="r4g4b4a4")
             if (textureSize == 0)
                 return;
 
-            /*
-            BitmapData bitmapData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
-            var length = bitmapData.Stride * bitmapData.Height;
-            byte[] bytes = new byte[length];
-            Marshal.Copy(bitmapData.Scan0, bytes, 0, length);
-            bmp.UnlockBits(bitmapData);
-            */
-
             uint bytesPerPixel = PVRTexLib.PVRTexLibGetTextureBitsPerPixel(header) / 8U;
 
             // Number of pixel for this (2D) surface
@@ -154,6 +148,9 @@ private IntPtr Transcode(ulong format)
                 throw new Exception("Couldn't get duplicated PVR file header.");
             }
 
+            if (PVRTexLib.PVRTexLibGetTexturePixelFormat(newHeader) == format)
+                return newTex;
+
             PVRTexLibTranscoderOptions options = new PVRTexLibTranscoderOptions();
             options.SizeofStruct = 48;
             options.PixelFormat = format;
diff --git a/ABStudio/FileFormats/ZSTREAM/ZSTREAMFile.cs b/ABStudio/FileFormats/ZSTREAM/ZSTREAMFile.cs
index 7058dfa..b11d686 100644
--- a/ABStudio/FileFormats/ZSTREAM/ZSTREAMFile.cs
+++ b/ABStudio/FileFormats/ZSTREAM/ZSTREAMFile.cs
@@ -278,7 +278,7 @@ public Bitmap GetBitmap(string path)
 
                     string fmt = "";
                     int n = 0x20;
-                    while (streamData[n] != 0 || n == 0x28) {
+                    while (streamData[n] != 0 && n < 0x28) {
                         fmt += (char)streamData[n];
                         n++;
                     }