Initial check in of stagefright software AAC decoder based on PV source code.

1 files changed, 170 insertions, 0 deletions

diff --git a/media/libstagefright/codecs/aacdec/pv_pow2.cpp b/media/libstagefright/codecs/aacdec/pv_pow2.cpp
new file mode 100644
index 0000000..8dfca23
--- /dev/null
+++ b/media/libstagefright/codecs/aacdec/pv_pow2.cpp
@@ -0,0 +1,170 @@
+/* ------------------------------------------------------------------
+ * Copyright (C) 1998-2009 PacketVideo
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ * -------------------------------------------------------------------
+ */
+/*
+
+ Filename: pv_pow2.c
+
+
+------------------------------------------------------------------------------
+ REVISION HISTORY
+
+
+ Who:                                   Date: MM/DD/YYYY
+ Description:
+
+------------------------------------------------------------------------------
+ INPUT AND OUTPUT DEFINITIONS
+
+Input
+    Int32 x             32-bit integer input  Q27
+
+Output
+    Int32               32-bit integer in Q25
+
+
+------------------------------------------------------------------------------
+ FUNCTION DESCRIPTION
+
+    Implement the power base 2 for positive numbers lesser than 5.999999
+------------------------------------------------------------------------------
+ REQUIREMENTS
+
+
+------------------------------------------------------------------------------
+ REFERENCES
+
+------------------------------------------------------------------------------
+ PSEUDO-CODE
+
+------------------------------------------------------------------------------
+*/
+#ifdef AAC_PLUS
+
+/*----------------------------------------------------------------------------
+; INCLUDES
+----------------------------------------------------------------------------*/
+#include "pv_pow2.h"
+#include "fxp_mul32.h"
+
+/*----------------------------------------------------------------------------
+; MACROS
+; Define module specific macros here
+----------------------------------------------------------------------------*/
+
+
+/*----------------------------------------------------------------------------
+; DEFINES
+; Include all pre-processor statements here. Include conditional
+; compile variables also.
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL FUNCTION DEFINITIONS
+; Function Prototype declaration
+----------------------------------------------------------------------------*/
+#define POW_2_TABLE_LENGTH          6
+#define POW_2_TABLE_LENGTH_m_2      (POW_2_TABLE_LENGTH - 2)
+
+/*----------------------------------------------------------------------------
+; LOCAL STORE/BUFFER/POINTER DEFINITIONS
+; Variable declaration - defined here and used outside this module
+----------------------------------------------------------------------------*/
+
+#define R_SHIFT     29
+#define Q_fmt(x)   (Int32)(x*((Int32)1<<R_SHIFT) + (x>=0?0.5F:-0.5F))
+
+#define Q27fmt(x)   (Int32)(x*((Int32)1<<27) + (x>=0?0.5F:-0.5F))
+
+const Int32 pow2_table[6] =
+{
+    Q_fmt(0.00224510927441F),   Q_fmt(0.00777943379416F),
+    Q_fmt(0.05737929218747F),   Q_fmt(0.23918017179889F),
+    Q_fmt(0.69345251849351F),   Q_fmt(0.99996347120248F)
+};
+
+
+/*----------------------------------------------------------------------------
+; EXTERNAL FUNCTION REFERENCES
+; Declare functions defined elsewhere and referenced in this module
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
+; Declare variables used in this module but defined elsewhere
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; FUNCTION CODE
+----------------------------------------------------------------------------*/
+
+
+/*
+ *      z in Q27 format
+ */
+
+Int32 pv_pow2(Int32 z)
+{
+    const Int32 *pt_table = pow2_table;
+    Int32 multiplier = 0;
+    Int32 shift_factor;
+    Int32 i;
+    Int32 v_q;
+    Int32 y;
+
+
+    if (z > Q27fmt(1.0f))
+    {
+        v_q = z - (z & 0xF8000000);
+        shift_factor =   z >> 27;
+    }
+    else
+    {
+        v_q = z;
+        shift_factor = 0;
+    }
+
+    if (v_q < Q27fmt(0.5f))
+    {
+        v_q += Q27fmt(0.5f);
+        multiplier = Q_fmt(0.70710678118655F);
+    }
+
+    v_q = v_q << 2;
+
+    y  = fxp_mul32_Q29(*(pt_table++), v_q);
+
+    for (i = POW_2_TABLE_LENGTH_m_2; i != 0; i--)
+    {
+        y += *(pt_table++);
+        y  = fxp_mul32_Q29(y, v_q);
+    }
+    y += *(pt_table++);
+
+    if (multiplier)
+    {
+        y = fxp_mul32_Q29(y, multiplier);
+    }
+
+    /*
+     *  returns number on Q25
+     */
+    return (y >> (4 - shift_factor));
+
+}
+
+#endif