diff --git a/libswresample/rematrix.c b/libswresample/rematrix.c
index 8227730056..6b5feaa07b 100644
--- a/libswresample/rematrix.c
+++ b/libswresample/rematrix.c
@@ -384,8 +384,8 @@ av_cold static int auto_matrix(SwrContext *s)
 
 av_cold int swri_rematrix_init(SwrContext *s){
     int i, j;
-    int nb_in  = av_get_channel_layout_nb_channels(s->in_ch_layout);
-    int nb_out = av_get_channel_layout_nb_channels(s->out_ch_layout);
+    int nb_in  = s->used_ch_count;
+    int nb_out = s->out.ch_count;
 
     s->mix_any_f = NULL;
 
diff --git a/libswresample/x86/rematrix_init.c b/libswresample/x86/rematrix_init.c
index d71b41a73e..d6616f83be 100644
--- a/libswresample/x86/rematrix_init.c
+++ b/libswresample/x86/rematrix_init.c
@@ -33,8 +33,8 @@ D(int16, sse2)
 av_cold int swri_rematrix_init_x86(struct SwrContext *s){
 #if HAVE_X86ASM
     int mm_flags = av_get_cpu_flags();
-    int nb_in  = av_get_channel_layout_nb_channels(s->in_ch_layout);
-    int nb_out = av_get_channel_layout_nb_channels(s->out_ch_layout);
+    int nb_in  = s->used_ch_count;
+    int nb_out = s->out.ch_count;
     int num    = nb_in * nb_out;
     int i,j;