| /* ------------------------------------------------------------------ |
| * 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: idct8.c |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| |
| Who: Date: MM/DD/YYYY |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Int32 x 32-bit integer input length 8 |
| |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Implement inverse discrete cosine transform of lenght 8 |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| #ifdef AAC_PLUS |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| #include "idct8.h" |
| |
| #include "fxp_mul32.h" |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| |
| |
| #define R_SHIFT 29 |
| #define Qfmt(x) (Int32)(x*((Int32)1<<R_SHIFT) + (x>=0?0.5F:-0.5F)) |
| |
| #define Qfmt15(x) (Int16)(x*((Int32)1<<15) + (x>=0?0.5F:-0.5F)) |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL FUNCTION DEFINITIONS |
| ; Function Prototype declaration |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; LOCAL STORE/BUFFER/POINTER DEFINITIONS |
| ; Variable declaration - defined here and used outside this module |
| ----------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------- |
| ; 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 |
| ----------------------------------------------------------------------------*/ |
| |
| void idct_8(Int32 vec[]) |
| { |
| |
| Int32 tmp0; |
| Int32 tmp1; |
| Int32 tmp2; |
| Int32 tmp3; |
| Int32 tmp4; |
| Int32 tmp5; |
| Int32 tmp6; |
| Int32 tmp7; |
| Int32 tmp8; |
| |
| |
| tmp5 = fxp_mul32_by_16(vec[4] << 1, Qfmt15(0.70710678118655F)); |
| |
| tmp1 = vec[0] + tmp5; |
| tmp5 = vec[0] - tmp5; |
| |
| tmp3 = fxp_mul32_by_16(vec[2] << 1, Qfmt15(0.54119610014620F)); /* (1/(2*cos(2*phi)));*/ |
| tmp7 = fxp_mul32_Q29(vec[6], Qfmt(1.30656296487638F)); /* (1/(2*cos(6*phi)));*/ |
| |
| tmp0 = fxp_mul32_by_16((tmp3 - tmp7) << 1, Qfmt15(0.70710678118655F)); /* (1/(2*cos(2*phi))); */ |
| tmp7 = (tmp3 + tmp7) + tmp0; |
| |
| vec[0] = tmp1 + tmp7; |
| tmp2 = fxp_mul32_by_16(vec[1] << 1, Qfmt15(0.50979557910416F)); /* (1/(2*cos( phi)));*/ |
| vec[1] = tmp5 + tmp0; |
| vec[2] = tmp5 - tmp0; |
| tmp4 = fxp_mul32_by_16(vec[3] << 1, Qfmt15(0.60134488693505F)); /* (1/(2*cos(3*phi)));*/ |
| vec[3] = tmp1 - tmp7; |
| |
| tmp6 = fxp_mul32_by_16(vec[5] << 1, Qfmt15(0.89997622313642F)); /* (1/(2*cos(5*phi)));*/ |
| tmp8 = fxp_mul32_Q29(vec[7], Qfmt(2.56291544774151F)); /* (1/(2*cos(7*phi)));*/ |
| |
| tmp7 = tmp2 + tmp8; |
| tmp5 = fxp_mul32_by_16((tmp2 - tmp8) << 1, Qfmt15(0.54119610014620F)); |
| tmp8 = tmp4 + tmp6; |
| tmp6 = fxp_mul32_Q29((tmp4 - tmp6), Qfmt(1.30656296487638F)); |
| |
| tmp0 = tmp7 + tmp8; |
| tmp2 = fxp_mul32_by_16((tmp7 - tmp8) << 1, Qfmt15(0.70710678118655F)); |
| |
| tmp3 = fxp_mul32_by_16((tmp5 - tmp6) << 1, Qfmt15(0.70710678118655F)); |
| tmp1 = (tmp5 + tmp6) + tmp3; |
| |
| tmp5 = tmp0 + tmp1; |
| tmp6 = tmp1 + tmp2; |
| tmp7 = tmp2 + tmp3; |
| |
| vec[7] = vec[0] - tmp5; |
| vec[0] += tmp5; |
| vec[6] = vec[1] - tmp6; |
| vec[1] += tmp6; |
| vec[5] = vec[2] - tmp7; |
| vec[2] += tmp7; |
| vec[4] = vec[3] - tmp3; |
| vec[3] += tmp3; |
| |
| } |
| |
| |
| #endif |
| |