diff --git a/libpostproc/postprocess_template.c b/libpostproc/postprocess_template.c
index 7eddb22922..4a3b4d0114 100644
--- a/libpostproc/postprocess_template.c
+++ b/libpostproc/postprocess_template.c
@@ -108,7 +108,7 @@
 /**
  * Check if the middle 8x8 Block in the given 8x16 block is flat
  */
-static inline int RENAME(vertClassify)(uint8_t src[], int stride, PPContext *c){
+static inline int RENAME(vertClassify)(const uint8_t src[], int stride, PPContext *c){
     int numEq= 0, dcOk;
     src+= stride*4; // src points to begin of the 8x8 Block
     __asm__ volatile(
@@ -1989,7 +1989,7 @@ MEDIAN((%%REGd, %1), (%%REGd, %1, 2), (%0, %1, 8))
 /**
  * Transpose and shift the given 8x8 Block into dst1 and dst2.
  */
-static inline void RENAME(transpose1)(uint8_t *dst1, uint8_t *dst2, uint8_t *src, int srcStride)
+static inline void RENAME(transpose1)(uint8_t *dst1, uint8_t *dst2, const uint8_t *src, int srcStride)
 {
     __asm__(
         "lea (%0, %1), %%"REG_a"                \n\t"
@@ -2074,7 +2074,7 @@ static inline void RENAME(transpose1)(uint8_t *dst1, uint8_t *dst2, uint8_t *src
 /**
  * Transpose the given 8x8 block.
  */
-static inline void RENAME(transpose2)(uint8_t *dst, int dstStride, uint8_t *src)
+static inline void RENAME(transpose2)(uint8_t *dst, int dstStride, const uint8_t *src)
 {
     __asm__(
         "lea (%0, %1), %%"REG_a"                \n\t"
@@ -2155,7 +2155,7 @@ static inline void RENAME(transpose2)(uint8_t *dst, int dstStride, uint8_t *src)
 
 #if !TEMPLATE_PP_ALTIVEC
 static inline void RENAME(tempNoiseReducer)(uint8_t *src, int stride,
-                                    uint8_t *tempBlurred, uint32_t *tempBlurredPast, int *maxNoise)
+                                    uint8_t *tempBlurred, uint32_t *tempBlurredPast, const int *maxNoise)
 {
     // to save a register (FIXME do this outside of the loops)
     tempBlurredPast[127]= maxNoise[0];
@@ -2544,7 +2544,7 @@ Switch between
 /**
  * accurate deblock filter
  */
-static av_always_inline void RENAME(do_a_deblock)(uint8_t *src, int step, int stride, PPContext *c){
+static av_always_inline void RENAME(do_a_deblock)(uint8_t *src, int step, int stride, const PPContext *c){
     int64_t dc_mask, eq_mask, both_masks;
     int64_t sums[10*8*2];
     src+= step*3; // src points to begin of the 8x8 Block