Use xine's inttypes.
The file config_types.h is generated from config_types.h.in in musepack SVN.

Index: src/libmusepack/musepack/config_types.h
===================================================================
RCS file: /home/valtri/CVS/xine-lib/src/libmusepack/musepack/config_types.h,v
retrieving revision 1.1.1.2
diff -u -p -u -p -r1.1.1.2 config_types.h
--- src/libmusepack/musepack/config_types.h	3 Feb 2005 00:19:24 -0000	1.1.1.2
+++ src/libmusepack/musepack/config_types.h	3 Feb 2005 00:21:06 -0000
@@ -1,7 +1,7 @@
 #ifndef __CONFIG_TYPES_H__
 #define __CONFIG_TYPES_H__
 
-#include <stdint.h>
+#include "os_types.h"
 
 #ifdef WORDS_BIGENDIAN
   #undef MPC_LITTLE_ENDIAN
Index: src/libmusepack/synth_filter.c
===================================================================
RCS file: /cvsroot/xine/xine-lib/src/libmusepack/synth_filter.c,v
retrieving revision 1.1
diff -u -r1.1 synth_filter.c
--- src/libmusepack/synth_filter.c	14 Jan 2005 15:24:25 -0000	1.1
+++ src/libmusepack/synth_filter.c	7 Jan 2006 10:54:27 -0000
@@ -39,8 +39,6 @@
 #include "musepack/musepack.h"
 #include "musepack/internal.h"
 
-typedef mpc_int32_t ptrdiff_t;
-
 /* C O N S T A N T S */
 #undef _