Minor fixes for (old) OS X builds

Originally committed to SVN as r1664.

aegisub/dialog_options.cpp

@@ -523,7 +523,10 @@ DialogOptions::DialogOptions(wxWindow *parent)
 
 		// Controls
 		wxString choices2[3] = { _("None (NOT RECOMMENDED)"), _("RAM"), _("Hard Disk") };
+#ifdef WIN32
 		wxString choices3[3] = { _T("ConvertToMono"), _T("GetLeftChannel"), _T("GetRightChannel") };
+#endif
+		
 		AddComboControl(audioAdvPage,audioAdvSizer1,_("Audio provider"),_T("Audio Provider"),AudioProviderFactory::GetFactoryList(),true,1);
 		AddComboControl(audioAdvPage,audioAdvSizer1,_("Audio player"),_T("Audio Player"),AudioPlayerFactory::GetFactoryList(),true,1);
 		AddComboControl(audioAdvPage,audioAdvSizer1,_("Cache type"),_T("Audio Cache"),wxArrayString(3,choices2),true);

aegisub/mkv_wrap.cpp

@@ -490,8 +490,8 @@ void MatroskaWrapper::GetSubtitles(AssFile *target) {
 #define std_ftell _ftelli64
 #else
 #define std_fread fread
-#define std_fseek fseeko64
-#define std_ftell ftello64
+#define std_fseek fseeko
+#define std_ftell ftello
 #endif
 
 ///////////////

aegisub/video_context.cpp

@@ -62,7 +62,7 @@
 #include "ass_style.h"
 #include "subs_grid.h"
 #include "vfw_wrap.h"
-#ifndef __WINDOWS__
+#if !defined(__WINDOWS__) && !defined(__APPLE__)
 #include "lavc_keyframes.h"
 #endif
 #include "mkv_wrap.h"
@@ -290,8 +290,10 @@ void VideoContext::SetVideo(const wxString &filename) {
 #ifdef __WINDOWS__
 				KeyFrames = VFWWrapper::GetKeyFrames(filename);
 #else
+#ifndef __APPLE__
 				LAVCKeyFrames k(filename);
 				KeyFrames = k.GetKeyFrames();
+#endif
 #endif
 				keyFramesLoaded = true;
 			}