diff --git a/libavcodec/jpeg2000dwt.c b/libavcodec/jpeg2000dwt.c

index 2bf25a8..36e443d 100644 (file)

--- a/libavcodec/jpeg2000dwt.c
+++ b/libavcodec/jpeg2000dwt.c
@@ -595,6 +595,9 @@ int ff_dwt_encode(DWTContext *s, void *t)
 
 int ff_dwt_decode(DWTContext *s, void *t)
 {
+    if (s->ndeclevels == 0)
+        return 0;
+
     switch (s->type) {
     case FF_DWT97:
         dwt_decode97_float(s, t);
