Index: apps/codecs/libmad/bit.c
===================================================================
--- apps/codecs/libmad/bit.c	(revision 26801)
+++ apps/codecs/libmad/bit.c	(working copy)
@@ -94,6 +94,8 @@
 {
   bitptr->ptr     = (uint32_t*)((uintptr_t)byte & ~3);
   bitptr->readbit = ((uintptr_t)byte & 3) << 3;
+  bitptr->buffered_addr  = 0;
+  bitptr->buffered_dword = 0;
 }
 
 /*
@@ -131,19 +133,37 @@
 /*
  * NAME:        bit->read()
  * DESCRIPTION: read an arbitrary number of bits and return their UIMSBF value
+ * ROCKBOX change: To avoid unneeded calls of betoh32() and loads from DRAM 
+   (bitptr->ptr is not located in IRAM) two variables and a logic was introduced.
+   If a new address must be loaded, the loaded and betoh32()-converted data is 
+   saved to a buffer variable that is located in IRAM. Further calls of 
+   mad_bit_read() will use this buffered data as long as the data's address does
+   not change. The check whether a new address needs to be loaded is done via
+   another buffer variable that holds the address of the current buffered data.
  */
 
 uint32_t mad_bit_read(struct mad_bitptr *bitptr, unsigned int len) ICODE_ATTR;
 uint32_t mad_bit_read(struct mad_bitptr *bitptr, unsigned int len)
 {
   uint32_t *curr = &bitptr->ptr[bitptr->readbit>>5];
+  
+  /* rockbox: Do we need to load (and LE-convert) data from a new address? */
+  if (bitptr->buffered_addr != curr)
+  {
+    bitptr->buffered_addr  = curr;
+    bitptr->buffered_dword = betoh32(curr[0]);
+  }
 
   if(len)
   {
-    uint32_t r = betoh32(curr[0]) << (bitptr->readbit & 31);
+    uint32_t r = bitptr->buffered_dword << (bitptr->readbit & 31);
 
     if((bitptr->readbit & 31) + len > 32)
-      r += betoh32(curr[1]) >> (-bitptr->readbit & 31);
+    {
+      bitptr->buffered_addr  = &curr[1];
+      bitptr->buffered_dword = betoh32(curr[1]);
+      r += bitptr->buffered_dword >> (-bitptr->readbit & 31);
+    }
 
     bitptr->readbit += len;
     return r >> (32 - len);
Index: apps/codecs/libmad/bit.h
===================================================================
--- apps/codecs/libmad/bit.h	(revision 26801)
+++ apps/codecs/libmad/bit.h	(working copy)
@@ -25,6 +25,8 @@
 struct mad_bitptr {
   uint32_t *ptr;
   uint32_t readbit;
+  uint32_t *buffered_addr; /* rockbox: buffer bitstream data address */
+  uint32_t buffered_dword; /* rockbox: buffer bitstream data */
 };
 
 void mad_bit_init(struct mad_bitptr *, unsigned char const *);