diff --git a/libavcodec/iirfilter.c b/libavcodec/iirfilter.c
index a8c9b9b826..b202515827 100644
--- a/libavcodec/iirfilter.c
+++ b/libavcodec/iirfilter.c
@@ -278,7 +278,8 @@ av_cold struct FFIIRFilterState *ff_iir_filter_init_state(int order)
 
 void ff_iir_filter(const struct FFIIRFilterCoeffs *c,
                    struct FFIIRFilterState *s, int size,
-                   const int16_t *src, int sstep, int16_t *dst, int dstep)
+                   const int16_t *src, ptrdiff_t sstep,
+                   int16_t *dst, ptrdiff_t dstep)
 {
     if (c->order == 2) {
         FILTER_O2(int16_t, S16)
@@ -291,7 +292,8 @@ void ff_iir_filter(const struct FFIIRFilterCoeffs *c,
 
 void ff_iir_filter_flt(const struct FFIIRFilterCoeffs *c,
                        struct FFIIRFilterState *s, int size,
-                       const float *src, int sstep, float *dst, int dstep)
+                       const float *src, ptrdiff_t sstep,
+                       float *dst, ptrdiff_t dstep)
 {
     if (c->order == 2) {
         FILTER_O2(float, FLT)
diff --git a/libavcodec/iirfilter.h b/libavcodec/iirfilter.h
index 6f7bba67ac..5ffa1ce53a 100644
--- a/libavcodec/iirfilter.h
+++ b/libavcodec/iirfilter.h
@@ -27,7 +27,8 @@
 #ifndef AVCODEC_IIRFILTER_H
 #define AVCODEC_IIRFILTER_H
 
-#include "avcodec.h"
+#include <stddef.h>
+#include <stdint.h>
 
 struct FFIIRFilterCoeffs;
 struct FFIIRFilterState;
@@ -61,7 +62,7 @@ typedef struct FFIIRFilterContext {
     */
     void (*filter_flt)(const struct FFIIRFilterCoeffs *coeffs,
                         struct FFIIRFilterState *state, int size,
-                        const float *src, int sstep, float *dst, int dstep);
+                        const float *src, ptrdiff_t sstep, float *dst, ptrdiff_t dstep);
 } FFIIRFilterContext;
 
 /**
@@ -125,7 +126,7 @@ void ff_iir_filter_free_statep(struct FFIIRFilterState **state);
  * @param dstep  destination stride
  */
 void ff_iir_filter(const struct FFIIRFilterCoeffs *coeffs, struct FFIIRFilterState *state,
-                   int size, const int16_t *src, int sstep, int16_t *dst, int dstep);
+                   int size, const int16_t *src, ptrdiff_t sstep, int16_t *dst, ptrdiff_t dstep);
 
 /**
  * Perform IIR filtering on floating-point input samples.
@@ -140,6 +141,7 @@ void ff_iir_filter(const struct FFIIRFilterCoeffs *coeffs, struct FFIIRFilterSta
  */
 void ff_iir_filter_flt(const struct FFIIRFilterCoeffs *coeffs,
                        struct FFIIRFilterState *state, int size,
-                       const float *src, int sstep, float *dst, int dstep);
+                       const float *src, ptrdiff_t sstep,
+                       float *dst, ptrdiff_t dstep);
 
 #endif /* AVCODEC_IIRFILTER_H */
diff --git a/libavcodec/mips/iirfilter_mips.c b/libavcodec/mips/iirfilter_mips.c
index 87db9ffe55..74f036fde6 100644
--- a/libavcodec/mips/iirfilter_mips.c
+++ b/libavcodec/mips/iirfilter_mips.c
@@ -67,9 +67,9 @@ typedef struct FFIIRFilterState {
     float x[1];
 } FFIIRFilterState;
 
-static void ff_iir_filter_flt_mips(const struct FFIIRFilterCoeffs *c,
-                                   struct FFIIRFilterState *s, int size,
-                                   const float *src, int sstep, float *dst, int dstep)
+static void iir_filter_flt_mips(const struct FFIIRFilterCoeffs *c,
+                                struct FFIIRFilterState *s, int size,
+                                const float *src, ptrdiff_t sstep, float *dst, ptrdiff_t dstep)
 {
     if (c->order == 2) {
         int i;
@@ -202,7 +202,7 @@ static void ff_iir_filter_flt_mips(const struct FFIIRFilterCoeffs *c,
 void ff_iir_filter_init_mips(FFIIRFilterContext *f) {
 #if HAVE_INLINE_ASM
 #if !HAVE_MIPS32R6 && !HAVE_MIPS64R6
-    f->filter_flt = ff_iir_filter_flt_mips;
+    f->filter_flt = iir_filter_flt_mips;
 #endif /* !HAVE_MIPS32R6 && !HAVE_MIPS64R6 */
 #endif /* HAVE_INLINE_ASM */
 }