Index: uspace/lib/pcm/include/pcm/format.h
===================================================================
--- uspace/lib/pcm/include/pcm/format.h	(revision cecba66ea48d60cfa59865e98aeda663808e42c7)
+++ uspace/lib/pcm/include/pcm/format.h	(revision e211ea04fccf33d4cb2092f630a29e893e096a02)
@@ -99,8 +99,8 @@
 }
 void pcm_format_silence(void *dst, size_t size, const pcm_format_t *f);
-int pcm_format_convert_and_mix(void *dst, size_t dst_size, const void *src,
+errno_t pcm_format_convert_and_mix(void *dst, size_t dst_size, const void *src,
     size_t src_size, const pcm_format_t *sf, const pcm_format_t *df);
-int pcm_format_mix(void *dst, const void *src, size_t size, const pcm_format_t *f);
-int pcm_format_convert(pcm_format_t a, void* srca, size_t sizea,
+errno_t pcm_format_mix(void *dst, const void *src, size_t size, const pcm_format_t *f);
+errno_t pcm_format_convert(pcm_format_t a, void* srca, size_t sizea,
     pcm_format_t b, void* srcb, size_t *sizeb);
 
Index: uspace/lib/pcm/src/format.c
===================================================================
--- uspace/lib/pcm/src/format.c	(revision cecba66ea48d60cfa59865e98aeda663808e42c7)
+++ uspace/lib/pcm/src/format.c	(revision e211ea04fccf33d4cb2092f630a29e893e096a02)
@@ -170,5 +170,5 @@
  * @return Error code.
  */
-int pcm_format_mix(void *dst, const void *src, size_t size, const pcm_format_t *f)
+errno_t pcm_format_mix(void *dst, const void *src, size_t size, const pcm_format_t *f)
 {
 	return pcm_format_convert_and_mix(dst, size, src, size, f, f);
@@ -188,5 +188,5 @@
  * If there are not enough data in the source buffer silent data is assumed.
  */
-int pcm_format_convert_and_mix(void *dst, size_t dst_size, const void *src,
+errno_t pcm_format_convert_and_mix(void *dst, size_t dst_size, const void *src,
     size_t src_size, const pcm_format_t *sf, const pcm_format_t *df)
 {