diff --git a/mpp/mpp.cpp b/mpp/mpp.cpp
index efd96cfd..fac6a4b9 100644
--- a/mpp/mpp.cpp
+++ b/mpp/mpp.cpp
@@ -199,9 +199,10 @@ MPP_RET Mpp::get_frame(MppFrame *frame)
                 prev = next;
             }
         }
+        *frame = first;
+        return MPP_OK;
     }
-    *frame = first;
-    return MPP_OK;
+    return MPP_NOK;
 }
 
 MPP_RET Mpp::put_frame(MppFrame frame)
diff --git a/test/mpi_test.c b/test/mpi_test.c
index 84afce73..7ce25fd8 100644
--- a/test/mpi_test.c
+++ b/test/mpi_test.c
@@ -46,6 +46,7 @@ int mpi_test()
 
     MpiCmd cmd          = MPP_CMD_BASE;
     MppParam param      = NULL;
+    RK_U32 output_block = 1;
 
     RK_S32 i;
     char *buf = NULL;
@@ -71,7 +72,8 @@ int mpi_test()
     }
 
     // NOTE: decoder do not need control function
-
+    cmd = MPP_SET_OUTPUT_BLOCK;
+    param = &output_block;
     ret = mpi->control(ctx, cmd, param);
     if (MPP_OK != ret) {
         mpp_err("mpi->control failed\n");