2 files changed, 11 insertions, 3 deletions

diff --git a/apps/codecs/libmusepack/decoder.h b/apps/codecs/libmusepack/decoder.h
index 499cd53137..9031bf29e7 100644
--- a/apps/codecs/libmusepack/decoder.h
+++ b/apps/codecs/libmusepack/decoder.h
@@ -43,7 +43,15 @@
 #include "reader.h"
 #include "streaminfo.h"
 
+// define this to enable/disable support for streamversion SV4-6
 //#define MPC_SUPPORT_SV456
+
+// SCF_HACK is used to avoid possible distortion after seeking with mpc files
+// background: scf's are coded differential in time domain. if you seek to the
+// desired postion it might happen that the baseline is missed and the resulting
+// scf is much too high (hissing noise). this hack uses the lowest scaling until
+// a non-differential scf could be decoded after seek. through this hack subbands
+// are faded out until there was at least a single non-differential scf found.
 #define SCF_HACK
 
 enum {
diff --git a/apps/codecs/libmusepack/mpc_decoder.c b/apps/codecs/libmusepack/mpc_decoder.c
index e63d1efaec..d211980782 100644
--- a/apps/codecs/libmusepack/mpc_decoder.c
+++ b/apps/codecs/libmusepack/mpc_decoder.c
@@ -65,7 +65,7 @@ extern const HuffmanTyp    mpc_table_Region_C [ 4];
 #endif
 
 #ifdef SCF_HACK
-#define SCF_DIFF(SCF, D) (SCF == -128 ? -128 : SCF + D)
+#define SCF_DIFF(SCF, D) (SCF == 127 ? 127 : SCF + D)
 #else 
 #define SCF_DIFF(SCF, D) SCF + D
 #endif
@@ -1565,8 +1565,8 @@ void mpc_decoder_reset_state(mpc_decoder *d) {
     memset(d->Y_L             , 0, sizeof Y_L              );
     memset(d->Y_R             , 0, sizeof Y_R              );
 #ifdef SCF_HACK
-    memset(d->SCF_Index_L     , -128, sizeof d->SCF_Index_L   );
-    memset(d->SCF_Index_R     , -128, sizeof d->SCF_Index_R   );
+    memset(d->SCF_Index_L     , 127, sizeof d->SCF_Index_L   );
+    memset(d->SCF_Index_R     , 127, sizeof d->SCF_Index_R   );
 #else
     memset(d->SCF_Index_L     , 0, sizeof d->SCF_Index_L      );
     memset(d->SCF_Index_R     , 0, sizeof d->SCF_Index_R      );