| /* ------------------------------------------------------------------ |
| * 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: idct16.c |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| |
| Who: Date: MM/DD/YYYY |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Int32 x 32-bit integer input length 16 |
| |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Implement inverse discrete cosine transform of lenght 16 |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| |
| #ifdef AAC_PLUS |
| |
| |
| #include "idct16.h" |
| #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 28 |
| #define Qfmt(x) (Int32)(x*((Int32)1<<R_SHIFT) + (x>=0?0.5F:-0.5F)) |
| #define Qfmt31(x) (Int32)(x*(0x7FFFFFFF) + (x>=0?0.5F:-0.5F)) |
| |
| const Int32 CosTable_8i[8] = |
| { |
| Qfmt31(0.50241928618816F), Qfmt31(0.52249861493969F), |
| Qfmt31(0.56694403481636F), Qfmt31(0.64682178335999F), |
| Qfmt(0.78815462345125F), Qfmt(1.06067768599035F), |
| Qfmt(1.72244709823833F), Qfmt(5.10114861868916F) |
| }; |
| |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; 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_16(Int32 vec[], Int32 scratch_mem[]) /* scratch_mem size 8 */ |
| { |
| Int32 *temp_even = scratch_mem; |
| |
| Int32 i; |
| const Int32 *pt_cos = CosTable_8i; |
| Int32 tmp1, tmp2; |
| Int32 *pt_even = temp_even; |
| Int32 *pt_odd = vec; |
| Int32 *pt_vec = vec; |
| |
| Int32 tmp3; |
| Int32 *pt_vecN_1; |
| |
| |
| *(pt_even++) = *(pt_vec++); |
| tmp1 = *(pt_vec++); |
| *(pt_odd++) = tmp1; |
| |
| for (i = 2; i != 0; i--) |
| { |
| *(pt_even++) = *(pt_vec++); |
| tmp2 = *(pt_vec++); |
| *(pt_even++) = *(pt_vec++); |
| tmp3 = *(pt_vec++); |
| *(pt_odd++) = tmp2 + tmp1; |
| *(pt_odd++) = tmp3 + tmp2; |
| tmp1 = tmp3; |
| } |
| |
| *(pt_even++) = *(pt_vec++); |
| tmp2 = *(pt_vec++); |
| *(pt_even++) = *(pt_vec++); |
| tmp3 = *(pt_vec++); |
| *(pt_odd++) = tmp2 + tmp1; |
| *(pt_odd++) = tmp3 + tmp2; |
| |
| |
| *(pt_even) = *(pt_vec++); |
| *(pt_odd++) = *(pt_vec) + tmp3; |
| |
| |
| idct_8(temp_even); |
| idct_8(vec); |
| |
| |
| pt_cos = &CosTable_8i[7]; |
| |
| pt_vec = &vec[7]; |
| |
| pt_even = &temp_even[7]; |
| pt_vecN_1 = &vec[8]; |
| |
| tmp1 = *(pt_even--); |
| |
| for (i = 2; i != 0; i--) |
| { |
| tmp3 = fxp_mul32_Q28(*(pt_vec), *(pt_cos--)); |
| tmp2 = *(pt_even--); |
| *(pt_vecN_1++) = tmp1 - tmp3; |
| *(pt_vec--) = tmp1 + tmp3; |
| tmp3 = fxp_mul32_Q28(*(pt_vec), *(pt_cos--)); |
| tmp1 = *(pt_even--); |
| *(pt_vecN_1++) = tmp2 - tmp3; |
| *(pt_vec--) = tmp2 + tmp3; |
| } |
| |
| tmp3 = fxp_mul32_Q31(*(pt_vec), *(pt_cos--)) << 1; |
| tmp2 = *(pt_even--); |
| *(pt_vecN_1++) = tmp1 - tmp3; |
| *(pt_vec--) = tmp1 + tmp3; |
| tmp3 = fxp_mul32_Q31(*(pt_vec), *(pt_cos--)) << 1; |
| tmp1 = *(pt_even--); |
| *(pt_vecN_1++) = tmp2 - tmp3; |
| *(pt_vec--) = tmp2 + tmp3; |
| tmp3 = fxp_mul32_Q31(*(pt_vec), *(pt_cos--)) << 1; |
| tmp2 = *(pt_even--); |
| *(pt_vecN_1++) = tmp1 - tmp3; |
| *(pt_vec--) = tmp1 + tmp3; |
| tmp3 = fxp_mul32_Q31(*(pt_vec), *(pt_cos)) << 1; |
| *(pt_vecN_1) = tmp2 - tmp3; |
| *(pt_vec) = tmp2 + tmp3; |
| |
| } |
| |
| |
| #endif |