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Diffstat (limited to 'media/libstagefright/codecs/aacdec/inv_long_complex_rot.cpp')
| -rw-r--r-- | media/libstagefright/codecs/aacdec/inv_long_complex_rot.cpp | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/aacdec/inv_long_complex_rot.cpp b/media/libstagefright/codecs/aacdec/inv_long_complex_rot.cpp new file mode 100644 index 0000000..84a7ec8 --- /dev/null +++ b/media/libstagefright/codecs/aacdec/inv_long_complex_rot.cpp @@ -0,0 +1,408 @@ +/* ------------------------------------------------------------------ + * 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: .inv_long_complex_rot.c + Funtions: inv_long_complex_rot + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Change the input argument, no shifts information from long fft_rx4 + , do not have to check for shifts. + + 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 + + Description: + + ------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + + Data_in = Input vector (sized for long windows + TWICE_INV_LONG_CX_ROT_LENGTH), with time domain samples + type Int32 * + + Data_out = Output vector with a post-rotation by exp(j(2pi/N)(k+1/8)), + (sized for long windows TWICE_INV_LONG_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 + + inv_long_complex_rot() performs the complex rotation for the inverse MDCT + for the case of long windows. It also performs digit reverse ordering of + the first and second halves of the input vector "Data_in", as well as + reordering of the two half vectors (following radix-2 decomposition) + Word normalization is also done to ensure 16 by 16 bit multiplications. + +------------------------------------------------------------------------------ + REQUIREMENTS + + inv_long_complex_rot() should execute a post-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 "digit_reversal_tables.h" +#include "inv_long_complex_rot.h" +#include "imdct_fxp.h" +#include "inv_long_complex_rot.h" +#include "pv_normalize.h" + +#include "fxp_mul32.h" +#include "aac_mem_funcs.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 inv_long_complex_rot( + Int32 *Data, + Int32 max) +{ + Int i; + Int16 I; + const Int32 *p_rotate; + Int32 temp_re; + Int32 temp_im; + + Int32 exp_jw; + Int32 *pData_in_1; + Int32 *pData_in_2; + Int exp; + Int32 *pData_in_ref1; + Int32 *pData_in_ref2; + + + Int16 temp_re_0; + Int16 temp_im_0; + Int16 temp_re_1; + Int16 temp_im_1; + Int16 *p_Data_Int_precision; + Int n = 2048; + Int n_2 = n >> 1; + Int n_4 = n >> 2; + Int n_3_4 = n_2 + n_4; + + Int16 *px_1; + Int16 *px_2; + Int16 *px_3; + Int16 *px_4; + + Int16 J; + const Int32 *p_rotate2; + + + + + p_rotate = &exp_rotation_N_2048[255]; + p_rotate2 = &exp_rotation_N_2048[256]; + + pData_in_ref1 = Data; + pData_in_ref2 = &Data[TWICE_INV_LONG_CX_ROT_LENGTH]; + + + /* + * Apply A/2^(diff) + B + */ + + p_Data_Int_precision = (Int16 *)Data; + + exp = 16 - pv_normalize(max); + + + /* + * px2--> <--px1 px4--> <--px3 + * + * | | | + * |+++++++++++++|+++++++++++++|+++++++++++++|+++++++++++++| + * | | | | + * n/4 n/2 3n/4 + */ + + I = 255; + J = 256; + + pData_in_1 = pData_in_ref2 + I; + + px_1 = (Int16 *)pData_in_1; + px_1++; + + pData_in_2 = pData_in_ref2 + J; + + px_4 = (Int16 *)pData_in_2; + + + + exp -= 1; + + + for (i = INV_LONG_CX_ROT_LENGTH >> 1; i != 0; i--) + { + + pData_in_2 = pData_in_ref1 + J; + + temp_im = *(pData_in_2++); + temp_re = *(pData_in_2); + + + /* + * cos_n + j*sin_n == exp(j(2pi/N)(k+1/8)) + */ + exp_jw = *p_rotate2++; + + /* + * Post-rotation + */ + + + + temp_re_0 = (Int16)(cmplx_mul32_by_16(temp_re, -temp_im, exp_jw) >> exp); + temp_im_0 = (Int16)(cmplx_mul32_by_16(temp_im, temp_re, exp_jw) >> exp); + + + pData_in_1 = pData_in_ref2 + I; + + /* + * Use auxiliary variables to avoid double accesses to memory. + * Data in is scaled to use only lower 16 bits. + */ + + temp_re = *(pData_in_1--); + temp_im = *(pData_in_1); + + /* + * cos_n + j*sin_n == exp(j(2pi/N)(k+1/8)) + */ + exp_jw = *p_rotate--; + + + /* + * Post-rotation + */ + + temp_re_1 = (Int16)(cmplx_mul32_by_16(temp_re, -temp_im, exp_jw) >> exp); + temp_im_1 = (Int16)(cmplx_mul32_by_16(temp_im, temp_re, exp_jw) >> exp); + + + /* + * Repeat procedure for odd index at the output + */ + + pData_in_2 = pData_in_ref2 + J; + J += 2; + + temp_im = *(pData_in_2++); + temp_re = *(pData_in_2); + + + *(px_1--) = temp_re_0; + *(px_1--) = temp_im_1; + *(px_4++) = temp_im_0; + *(px_4++) = temp_re_1; + + + exp_jw = *p_rotate2++; + + + *(px_1--) = (Int16)(cmplx_mul32_by_16(temp_re, -temp_im, exp_jw) >> exp); + *(px_4++) = (Int16)(cmplx_mul32_by_16(temp_im, temp_re, exp_jw) >> exp); + + + + /* + * Repeat procedure for odd index at the output + */ + + pData_in_1 = pData_in_ref1 + I; + I -= 2; + + temp_re = *(pData_in_1--); + temp_im = *(pData_in_1); + + + exp_jw = *p_rotate--; + + + *(px_4++) = (Int16)(cmplx_mul32_by_16(temp_re, -temp_im, exp_jw) >> exp); + *(px_1--) = (Int16)(cmplx_mul32_by_16(temp_im, temp_re, exp_jw) >> exp); + + } + + /* + * <--px1 px4--> + * + * | | | + * |-------------|-------------|/////////////|\\\\\\\\\\\\\| + * | | | | + * n/4 n/2 3n/4 + */ + + + px_1 = p_Data_Int_precision + n_2 - 1; + px_2 = p_Data_Int_precision; + + px_4 = p_Data_Int_precision + n_3_4 - 1; + + for (i = 0; i<INV_LONG_CX_ROT_LENGTH >> 1; i++) + { + + Int16 temp_re_0 = *(px_4--); + Int16 temp_im_1 = *(px_4--); + Int16 temp_re_2 = *(px_4--); + Int16 temp_im_3 = *(px_4--); + *(px_1--) = temp_re_0; + *(px_1--) = temp_im_1; + *(px_1--) = temp_re_2; + *(px_1--) = temp_im_3; + + *(px_2++) = (-temp_re_0); + *(px_2++) = (-temp_im_1); + *(px_2++) = (-temp_re_2); + *(px_2++) = (-temp_im_3); + + } + + + px_4 = p_Data_Int_precision + n_2; + + + pv_memcpy(px_4, pData_in_ref2 + 256, TWICE_INV_LONG_CX_ROT_LENGTH*sizeof(*px_4)); + + + + /* + * px2--> <--px1 px4--> <--px3 + * + * | | | + * |+++++++++++++|+++++++++++++|+++++++++++++|+++++++++++++| + * | | | | + * n/4 n/2 3n/4 + */ + px_3 = p_Data_Int_precision + n - 1; + + + for (i = 0; i<INV_LONG_CX_ROT_LENGTH >> 1; i++) + { + + Int16 temp_im_0 = *(px_4++); + Int16 temp_re_1 = *(px_4++); + Int16 temp_im_2 = *(px_4++); + Int16 temp_re_3 = *(px_4++); + *(px_3--) = temp_im_0; + *(px_3--) = temp_re_1; + *(px_3--) = temp_im_2; + *(px_3--) = temp_re_3; + + } + + + return (exp + 1); +} + |