diff --git a/mpp/codec/mpp_dec.cpp b/mpp/codec/mpp_dec.cpp
index 03a315e8..6880802f 100644
--- a/mpp/codec/mpp_dec.cpp
+++ b/mpp/codec/mpp_dec.cpp
@@ -286,6 +286,7 @@ void *mpp_dec_hal_thread(void *data)
     MppDec    *dec      = mpp->mDec;
     HalTaskGroup tasks  = dec->tasks;
     mpp_list *frames    = mpp->mFrames;
+    MppBuffer buffer    = NULL;
     MppBufSlots frame_slots = dec->frame_slots;
     MppBufSlots packet_slots = dec->packet_slots;
 
@@ -324,7 +325,13 @@ void *mpp_dec_hal_thread(void *data)
              * 3. add frame to output list
              * repeat 2 and 3 until not frame can be output
              */
+            mpp_buf_slot_get_prop(packet_slots, task_dec->input,  SLOT_BUFFER, &buffer);
+            if (buffer) {
+                mpp_buffer_put(buffer);
+                buffer = NULL;
+            }
             mpp_buf_slot_clr_flag(packet_slots, task_dec->input,  SLOT_HAL_INPUT);
+
             mpp_buf_slot_clr_flag(frame_slots, task_dec->output, SLOT_HAL_OUTPUT);
             for (RK_U32 i = 0; i < MPP_ARRAY_ELEMS(task_dec->refer); i++) {
                 RK_S32 index = task_dec->refer[i];
diff --git a/mpp/mpp.cpp b/mpp/mpp.cpp
index ea08fd34..e879ae09 100644
--- a/mpp/mpp.cpp
+++ b/mpp/mpp.cpp
@@ -70,7 +70,7 @@ Mpp::Mpp(MppCtxType type, MppCodingType coding)
 
         mpp_buffer_group_get_internal(&mInternalGroup, MPP_BUFFER_TYPE_ION);
         mpp_buffer_group_get_internal(&mPacketGroup, MPP_BUFFER_TYPE_ION);
-        mpp_buffer_group_limit_config(mPacketGroup, 0, 4);
+        mpp_buffer_group_limit_config(mPacketGroup, 0, 2);
 
     } break;
     case MPP_CTX_ENC : {
@@ -226,4 +226,8 @@ MPP_RET Mpp::get_packet(MppPacket *packet)
     }
     return MPP_OK;
 }
+MPP_RET Mpp::control(MpiCmd cmd, MppParam param)
+{
+    return MPP_OK;
+}