Index: uspace/lib/pcm/include/pcm/format.h
===================================================================
--- uspace/lib/pcm/include/pcm/format.h	(revision ea6c83870417e73e052e92cb12eed894e739dbca)
+++ uspace/lib/pcm/include/pcm/format.h	(revision 1de97fe6462d672ed1e88df7ccd3b67da8be0d13)
@@ -69,4 +69,5 @@
 	return pcm_format_same(f, &AUDIO_FORMAT_ANY);
 }
+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,
     size_t src_size, const pcm_format_t *sf, const pcm_format_t *df);