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

1 files changed, 261 insertions, 0 deletions

diff --git a/media/libstagefright/codecs/aacdec/fwd_short_complex_rot.cpp b/media/libstagefright/codecs/aacdec/fwd_short_complex_rot.cpp
new file mode 100644
index 0000000..964f766
--- /dev/null
+++ b/media/libstagefright/codecs/aacdec/fwd_short_complex_rot.cpp
@@ -0,0 +1,261 @@
+/* ------------------------------------------------------------------
+ * 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.
+ * -------------------------------------------------------------------
+ */
+/*
+ Pathname: ./src/fwd_short_complex_rot.c
+ Funtions:  fwd_short_complex_rot
+
+------------------------------------------------------------------------------
+ REVISION HISTORY
+
+ Date: 10/18/2002
+ Description:
+            (1) Change the input argument, only a single max is passed.
+            (2) Eliminate search for max, a fixed shift has replaced the
+                search for max with minimal loss of precision.
+            (3) Eliminated unused variables
+
+ Date: 10/28/2002
+ Description:
+            (1) Added comments per code review
+            (2) Eliminated hardly used condition on if-else (exp==0)
+
+ Description:
+
+ ------------------------------------------------------------------------------
+ INPUT AND OUTPUT DEFINITIONS
+
+ Inputs:
+
+    Data_in   = Input vector (sized for short windows
+                2*FWD_SHORT_CX_ROT_LENGTH elements), with freq. domain samples
+                type Int32 *
+
+    Data_out  = Output vector with a post-rotation by exp(-j(2pi/N)(k+1/8)),
+                (sized for short windows 2*FWD_SHORT_CX_ROT_LENGTH)
+                type Int32 *
+
+    max       = Input, carries the maximum value of the input vector
+                "Data_in"
+                type Int32
+
+
+ Local Stores/Buffers/Pointers Needed:
+    None
+
+ Global Stores/Buffers/Pointers Needed:
+    None
+
+ Outputs:
+    exp = shift factor to reflect signal scaling
+
+ Pointers and Buffers Modified:
+    Results are return in "Data_out"
+
+ Local Stores Modified:
+    None
+
+ Global Stores Modified:
+    None
+------------------------------------------------------------------------------
+ FUNCTION DESCRIPTION
+
+    fwd_short_complex_rot() performs the complex rotation for the MDCT
+    for the case of short windows. It performs digit reverse ordering as well
+    word normalization to ensure 16 by 16 bit multiplications.
+
+------------------------------------------------------------------------------
+ REQUIREMENTS
+
+    fwd_short_complex_rot() should execute a pre-rotation by
+    exp(-j(2pi/N)(k+1/8)), digit reverse ordering and word normalization
+------------------------------------------------------------------------------
+ REFERENCES
+
+------------------------------------------------------------------------------
+ RESOURCES USED
+   When the code is written for a specific target processor the
+     the resources used should be documented below.
+
+ STACK USAGE: [stack count for this module] + [variable to represent
+          stack usage for each subroutine called]
+
+     where: [stack usage variable] = stack usage for [subroutine
+         name] (see [filename].ext)
+
+ DATA MEMORY USED: x words
+
+ PROGRAM MEMORY USED: x words
+
+ CLOCK CYCLES: [cycle count equation for this module] + [variable
+           used to represent cycle count for each subroutine
+           called]
+
+     where: [cycle count variable] = cycle count for [subroutine
+        name] (see [filename].ext)
+
+------------------------------------------------------------------------------
+*/
+
+
+/*----------------------------------------------------------------------------
+; INCLUDES
+----------------------------------------------------------------------------*/
+
+#include "fwd_short_complex_rot.h"
+#include "digit_reversal_tables.h"
+#include "imdct_fxp.h"
+#include "pv_normalize.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
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; LOCAL VARIABLE DEFINITIONS
+; Variable declaration - defined here and used outside this module
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; EXTERNAL FUNCTION REFERENCES
+; Declare functions defined elsewhere and referenced in this module
+----------------------------------------------------------------------------*/
+
+/*----------------------------------------------------------------------------
+; EXTERNAL VARIABLES REFERENCES
+; Declare variables used in this module but defined elsewhere
+----------------------------------------------------------------------------*/
+
+Int fwd_short_complex_rot(
+    Int32 *Data_in,
+    Int32 *Data_out,
+    Int32  max)
+
+{
+    Int     i;
+    Int16     I;
+    const   Int16 *pTable;
+    const   Int32 *p_rotate;
+
+    Int32   *pData_in_1;
+    Int     exp;
+    Int32   temp_re;
+    Int32   temp_im;
+
+    Int32   cos_n;
+    Int32   sin_n;
+    Int32   temp_re_32;
+    Int32   temp_im_32;
+
+    Int32   *pData_in_ref;
+
+    Int32   *pData_out_1;
+    Int32   *pData_out_2;
+    Int32   *pData_out_3;
+    Int32   *pData_out_4;
+
+    pTable    =  digit_reverse_64;
+    p_rotate  =  exp_rotation_N_256;
+
+    pData_in_ref  =  Data_in;
+
+    exp = 16 - pv_normalize(max);
+
+    if (exp < 0)
+    {
+        exp = 0;
+    }
+
+    pData_out_1 = Data_out;
+    pData_out_2 = &Data_out[TWICE_FWD_SHORT_CX_ROT_LENGTH_m_1];
+    pData_out_3 = &Data_out[TWICE_FWD_SHORT_CX_ROT_LENGTH];
+    pData_out_4 = &Data_out[FOUR_FWD_SHORT_CX_ROT_LENGTH_m_1];
+
+    /*
+     *  Data_out
+     *                                   >>>>                   <<<<
+     *                                pData_out_3             pData_out_4
+     *      |             |             |             |             |
+     * pData_out_1               pData_out_2
+     *      >>>>                     <<<<
+     */
+
+
+    for (i = FWD_SHORT_CX_ROT_LENGTH; i != 0; i--)
+    {
+        /*
+         *   Perform digit reversal by accessing index I from table
+         */
+
+        I = *pTable++;
+        pData_in_1 = pData_in_ref + I;
+
+        /*
+         * cos_n + j*sin_n == exp(j(2pi/N)(k+1/8))
+         */
+
+        sin_n = *p_rotate++;
+        cos_n = sin_n >> 16;
+        sin_n = sin_n & 0xFFFF;
+
+        /*
+         *  Use auxiliary variables to avoid double accesses to memory.
+         *  Data in is scaled to use only lower 16 bits.
+         */
+
+        temp_re =  *(pData_in_1++) >> exp;
+        temp_im =  *(pData_in_1) >> exp;
+
+        /*
+         *   Pre-rotation
+         */
+
+        temp_re_32 = (temp_re * cos_n + temp_im * sin_n) >> 16;
+        temp_im_32 = (temp_im * cos_n - temp_re * sin_n) >> 16;
+
+        *(pData_out_1++) = - temp_re_32;
+        *(pData_out_2--) =   temp_im_32;
+        *(pData_out_3++) = - temp_im_32;
+        *(pData_out_4--) =   temp_re_32;
+
+        /*
+         *   Pointer increment to jump over imag (1 & 4) or real parts
+         *   (2 & 3)
+         */
+
+        pData_out_1++;
+        pData_out_2--;
+        pData_out_3++;
+        pData_out_4--;
+
+    } /* for(i) */
+
+    return (exp);
+}