153 lines
4.8 KiB
C++
153 lines
4.8 KiB
C++
/* ------------------------------------------------------------------
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* Copyright (C) 1998-2009 PacketVideo
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
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* express or implied.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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* -------------------------------------------------------------------
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*/
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/*
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------------------------------------------------------------------------------
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PacketVideo Corp.
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MP3 Decoder Library
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Filename: pvmp3_dct6.cpp
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Date: 09/21/2007
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------------------------------------------------------------------------------
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REVISION HISTORY
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Description:
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------------------------------------------------------------------------------
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INPUT AND OUTPUT DEFINITIONS
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Input
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Int32 vec[] vector of 6 32-bit integers
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Returns
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Int32 vec[] dct computation in-place
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------------------------------------------------------------------------------
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FUNCTION DESCRIPTION
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Returns the dct of length 6 of the input vector
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------------------------------------------------------------------------------
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REQUIREMENTS
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------------------------------------------------------------------------------
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REFERENCES
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------------------------------------------------------------------------------
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PSEUDO-CODE
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------------------------------------------------------------------------------
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*/
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/*----------------------------------------------------------------------------
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; INCLUDES
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----------------------------------------------------------------------------*/
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#include "pvmp3_audio_type_defs.h"
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#include "pv_mp3dec_fxd_op.h"
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#include "pvmp3_mdct_6.h"
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/*----------------------------------------------------------------------------
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; MACROS
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; Define module specific macros here
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; DEFINES
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; Include all pre-processor statements here. Include conditional
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; compile variables also.
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----------------------------------------------------------------------------*/
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#define Qfmt30(a) (Int32)(a*((Int32)1<<30) + (a>=0?0.5F:-0.5F))
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#define cos_pi_6 Qfmt30( 0.86602540378444f)
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#define cos_2_pi_6 Qfmt30( 0.5f)
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#define cos_7_pi_12 Qfmt30( -0.25881904510252f)
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#define cos_3_pi_12 Qfmt30( 0.70710678118655f)
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#define cos_11_pi_12 Qfmt30( -0.96592582628907f)
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/*----------------------------------------------------------------------------
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; LOCAL FUNCTION DEFINITIONS
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; Function Prototype declaration
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; LOCAL STORE/BUFFER/POINTER DEFINITIONS
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; Variable declaration - defined here and used outside this module
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; EXTERNAL FUNCTION REFERENCES
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; Declare functions defined elsewhere and referenced in this module
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
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; Declare variables used in this module but defined elsewhere
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; FUNCTION CODE
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----------------------------------------------------------------------------*/
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void pvmp3_dct_6(int32 vec[])
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{
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Int32 tmp0;
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Int32 tmp1;
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Int32 tmp2;
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Int32 tmp3;
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Int32 tmp4;
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Int32 tmp5;
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/* split input vector */
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tmp0 = vec[5] + vec[0];
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tmp5 = vec[5] - vec[0];
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tmp1 = vec[4] + vec[1];
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tmp4 = vec[4] - vec[1];
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tmp2 = vec[3] + vec[2];
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tmp3 = vec[3] - vec[2];
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vec[0] = tmp0 + tmp2 ;
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vec[2] = fxp_mul32_Q30(tmp0 - tmp2, cos_pi_6);
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vec[4] = (vec[0] >> 1) - tmp1;
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vec[0] += tmp1;
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tmp0 = fxp_mul32_Q30(tmp3, cos_7_pi_12);
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tmp0 = fxp_mac32_Q30(tmp4, -cos_3_pi_12, tmp0);
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vec[1] = fxp_mac32_Q30(tmp5, cos_11_pi_12, tmp0);
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vec[3] = fxp_mul32_Q30((tmp3 + tmp4 - tmp5), cos_3_pi_12);
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tmp0 = fxp_mul32_Q30(tmp3, cos_11_pi_12);
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tmp0 = fxp_mac32_Q30(tmp4, cos_3_pi_12, tmp0);
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vec[5] = fxp_mac32_Q30(tmp5, cos_7_pi_12, tmp0);
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}
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