diff --git a/mpp/mpi_impl.h b/mpp/mpi_impl.h
index b6ce1a87..008ee938 100644
--- a/mpp/mpi_impl.h
+++ b/mpp/mpi_impl.h
@@ -24,7 +24,7 @@
 
 
 
-#define mpi_dbg(flag, fmt, ...)     mpp_dbg(mpi_debug, flag, fmt, ## __VA_ARGS__)
+#define mpi_dbg(flag, fmt, ...)     _mpp_dbg(mpi_debug, flag, fmt, ## __VA_ARGS__)
 
 #define MPI_FUNCTION_ENTER()        mpi_dbg(MPI_DBG_FUNCTION, "%s enter\n", __FUNCTION__)
 #define MPI_FUNCTION_LEAVE()        mpi_dbg(MPI_DBG_FUNCTION, "%s leave\n", __FUNCTION__)
diff --git a/mpp/mpp.cpp b/mpp/mpp.cpp
index 82100bc4..14fa2022 100644
--- a/mpp/mpp.cpp
+++ b/mpp/mpp.cpp
@@ -18,6 +18,7 @@
 
 #include "mpp_log.h"
 #include "mpp_mem.h"
+#include "mpp_env.h"
 #include "mpp_time.h"
 
 #include "mpp.h"
@@ -30,6 +31,8 @@
 
 #define MPP_TEST_FRAME_SIZE     SZ_1M
 
+RK_U32 mpp_debug = 0;
+
 Mpp::Mpp(MppCtxType type, MppCodingType coding)
     : mPackets(NULL),
       mFrames(NULL),
@@ -40,6 +43,7 @@ Mpp::Mpp(MppCtxType type, MppCodingType coding)
       mFrameGetCount(0),
       mTaskPutCount(0),
       mTaskGetCount(0),
+      mInternalGroup(NULL),
       mPacketGroup(NULL),
       mFrameGroup(NULL),
       mTheadCodec(NULL),
@@ -58,6 +62,7 @@ Mpp::Mpp(MppCtxType type, MppCodingType coding)
         mTheadCodec = new MppThread(mpp_dec_thread, this);
         mThreadHal  = new MppThread(mpp_hal_thread, this);
         mTask       = mpp_malloc(MppHalDecTask*, mTaskNum);
+        mpp_buffer_group_normal_get(&mInternalGroup, MPP_BUFFER_TYPE_ION);
         mpp_buffer_group_normal_get(&mPacketGroup, MPP_BUFFER_TYPE_NORMAL);
         mpp_buffer_group_limited_get(&mFrameGroup, MPP_BUFFER_TYPE_ION);
         mpp_buffer_group_limit_config(mFrameGroup, 4, MPP_TEST_FRAME_SIZE);
@@ -69,6 +74,7 @@ Mpp::Mpp(MppCtxType type, MppCodingType coding)
         mTheadCodec = new MppThread(mpp_enc_thread, this);
         mThreadHal  = new MppThread(mpp_hal_thread, this);
         mTask       = mpp_malloc(MppHalDecTask*, mTaskNum);
+        mpp_buffer_group_normal_get(&mInternalGroup, MPP_BUFFER_TYPE_ION);
         mpp_buffer_group_normal_get(&mPacketGroup, MPP_BUFFER_TYPE_NORMAL);
         mpp_buffer_group_limited_get(&mFrameGroup, MPP_BUFFER_TYPE_ION);
     } break;
@@ -84,6 +90,8 @@ Mpp::Mpp(MppCtxType type, MppCodingType coding)
         mThreadHal->start();
     } else
         clear();
+
+    mpp_env_get_u32("mpp_debug", &mpp_debug, 0);
 }
 
 Mpp::~Mpp ()
@@ -118,6 +126,10 @@ void Mpp::clear()
         delete mTasks;
         mTasks = NULL;
     }
+    if (mInternalGroup) {
+        mpp_buffer_group_put(mInternalGroup);
+        mInternalGroup = NULL;
+    }
     if (mPacketGroup) {
         mpp_buffer_group_put(mPacketGroup);
         mPacketGroup = NULL;
diff --git a/mpp/mpp.h b/mpp/mpp.h
index 4661ee04..f56f9cd2 100644
--- a/mpp/mpp.h
+++ b/mpp/mpp.h
@@ -22,6 +22,17 @@
 #include "mpp_thread.h"
 #include "mpp_hal.h"
 
+extern RK_U32 mpp_debug;
+
+#define MPP_DBG_FUNCTION                (0x00000001)
+#define MPP_DBG_PACKET                  (0x00000002)
+#define MPP_DBG_FRAME                   (0x00000004)
+#define MPP_DBG_BUFFER                  (0x00000008)
+
+
+#define mpp_dbg(flag, fmt, ...) _mpp_dbg(mpp_debug, flag, fmt, ## __VA_ARGS__)
+
+
 class Mpp {
 public:
     Mpp(MppCtxType type, MppCodingType coding);
@@ -49,6 +60,16 @@ public:
     RK_U32          mTaskPutCount;
     RK_U32          mTaskGetCount;
 
+    /*
+     * internal buffer group
+     *      - for all kind of table like cabac / scaling list
+     *        fixed to ion buffer group
+     * packet buffer group
+     *      - packets in I/O, can be ion buffer or normal buffer
+     * frame buffer group
+     *      - frames in I/O, normally should be a ion buffer group
+     */
+    MppBufferGroup  mInternalGroup;
     MppBufferGroup  mPacketGroup;
     MppBufferGroup  mFrameGroup;
 
diff --git a/mpp/mpp_buffer_impl.h b/mpp/mpp_buffer_impl.h
index 23d4fbee..d3f8ea6a 100644
--- a/mpp/mpp_buffer_impl.h
+++ b/mpp/mpp_buffer_impl.h
@@ -23,7 +23,7 @@
 
 #define MPP_BUF_DBG_FUNCTION            (0x00000001)
 
-#define mpp_buf_dbg(flag, fmt, ...)     mpp_dbg(mpp_buffer_debug, flag, fmt, ## __VA_ARGS__)
+#define mpp_buf_dbg(flag, fmt, ...)     _mpp_dbg(mpp_buffer_debug, flag, fmt, ## __VA_ARGS__)
 
 #define MPP_BUF_FUNCTION_ENTER()        mpp_buf_dbg(MPP_BUF_DBG_FUNCTION, "%s enter\n", __FUNCTION__)
 #define MPP_BUF_FUNCTION_LEAVE()        mpp_buf_dbg(MPP_BUF_DBG_FUNCTION, "%s leave\n", __FUNCTION__)
diff --git a/osal/android/os_allocator.c b/osal/android/os_allocator.c
index 0fa8dc4a..8fd75f73 100644
--- a/osal/android/os_allocator.c
+++ b/osal/android/os_allocator.c
@@ -97,7 +97,7 @@ static RK_U32 ion_debug = 0;
 #define ION_CLINET                  (0x00000004)
 #define ION_IOCTL                   (0x00000008)
 
-#define ion_dbg(flag, fmt, ...) mpp_dbg(ion_debug, flag, fmt, ## __VA_ARGS__)
+#define ion_dbg(flag, fmt, ...) _mpp_dbg(ion_debug, flag, fmt, ## __VA_ARGS__)
 
 static int ion_ioctl(int fd, int req, void *arg)
 {
diff --git a/osal/inc/mpp_log.h b/osal/inc/mpp_log.h
index 746bf36c..011e3b89 100644
--- a/osal/inc/mpp_log.h
+++ b/osal/inc/mpp_log.h
@@ -30,8 +30,8 @@
 #define mpp_log(fmt, ...) _mpp_log(MODULE_TAG, fmt, ## __VA_ARGS__)
 #define mpp_err(fmt, ...) _mpp_err(MODULE_TAG, fmt, ## __VA_ARGS__)
 
-#define mpp_dbg(debug, flag, fmt, ...) \
-             _mpp_dbg(debug, flag, MODULE_TAG, fmt, ## __VA_ARGS__)
+#define _mpp_dbg(debug, flag, fmt, ...) \
+             __mpp_dbg(debug, flag, MODULE_TAG, fmt, ## __VA_ARGS__)
 
 /*
  * mpp_dbg usage:
@@ -85,7 +85,7 @@ RK_U32 mpp_log_get_flag();
 
 void _mpp_log(const char *tag, const char *fmt, ...);
 void _mpp_err(const char *tag, const char *fmt, ...);
-void _mpp_dbg(RK_U32 debug, RK_U32 flag, const char *tag, const char *fmt, ...);
+void __mpp_dbg(RK_U32 debug, RK_U32 flag, const char *tag, const char *fmt, ...);
 
 #ifdef __cplusplus
 }
diff --git a/osal/mpp_log.cpp b/osal/mpp_log.cpp
index 94a77618..930e0bc6 100644
--- a/osal/mpp_log.cpp
+++ b/osal/mpp_log.cpp
@@ -72,7 +72,7 @@ void _mpp_log(const char *tag, const char *fmt, ...)
     va_end(args);
 }
 
-void _mpp_dbg(RK_U32 debug, RK_U32 flag, const char *tag, const char *fmt, ...)
+void __mpp_dbg(RK_U32 debug, RK_U32 flag, const char *tag, const char *fmt, ...)
 {
     if (debug & flag) {
         va_list args;
diff --git a/osal/mpp_thread.cpp b/osal/mpp_thread.cpp
index 062d2833..12fbcecb 100644
--- a/osal/mpp_thread.cpp
+++ b/osal/mpp_thread.cpp
@@ -23,7 +23,7 @@
 
 static RK_U32 thread_debug = 0;
 
-#define thread_dbg(flag, fmt, ...)  mpp_dbg(thread_debug, flag, fmt, ## __VA_ARGS__)
+#define thread_dbg(flag, fmt, ...)  _mpp_dbg(thread_debug, flag, fmt, ## __VA_ARGS__)
 
 MppThread::MppThread(MppThreadFunc func, void *ctx)
     : mStatus(MPP_THREAD_UNINITED),
diff --git a/osal/test/mpp_log_test.c b/osal/test/mpp_log_test.c
index 69725fcc..3d443dd2 100644
--- a/osal/test/mpp_log_test.c
+++ b/osal/test/mpp_log_test.c
@@ -38,13 +38,13 @@ int main()
 
     mpp_assert(flag_set == flag_get);
 
-    mpp_log("try mpp_dbg test 0 debug %x, flag %x", flag_get, flag_dbg);
-    mpp_dbg(flag_get, flag_dbg, "mpp_dbg printing debug %x, flag %x", flag_get, flag_dbg);
+    mpp_log("try _mpp_dbg test 0 debug %x, flag %x", flag_get, flag_dbg);
+    _mpp_dbg(flag_get, flag_dbg, "mpp_dbg printing debug %x, flag %x", flag_get, flag_dbg);
 
     flag_dbg = 0;
 
-    mpp_log("try mpp_dbg test 0 debug %x, flag %x", flag_get, flag_dbg);
-    mpp_dbg(flag_get, flag_dbg, "mpp_dbg printing debug %x, flag %x", flag_get, flag_dbg);
+    mpp_log("try _mpp_dbg test 0 debug %x, flag %x", flag_get, flag_dbg);
+    _mpp_dbg(flag_get, flag_dbg, "mpp_dbg printing debug %x, flag %x", flag_get, flag_dbg);
 
     mpp_err("mpp log log test done\n");