| /* ------------------------------------------------------------------ |
| * 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. |
| * ------------------------------------------------------------------- |
| */ |
| /* |
| ------------------------------------------------------------------------------ |
| |
| PacketVideo Corp. |
| MP3 Decoder Library |
| |
| Filename: pvmp3_dct6.cpp |
| |
| Date: 09/21/2007 |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| Input |
| Int32 vec[] vector of 6 32-bit integers |
| Returns |
| Int32 vec[] dct computation in-place |
| |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Returns the dct of length 6 of the input vector |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| |
| #include "pvmp3_audio_type_defs.h" |
| #include "pv_mp3dec_fxd_op.h" |
| #include "pvmp3_mdct_6.h" |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; MACROS |
| ; Define module specific macros here |
| ----------------------------------------------------------------------------*/ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; DEFINES |
| ; Include all pre-processor statements here. Include conditional |
| ; compile variables also. |
| ----------------------------------------------------------------------------*/ |
| #define Qfmt30(a) (Int32)((a)*((Int32)1<<30) + ((a)>=0?0.5F:-0.5F)) |
| |
| #define cos_pi_6 Qfmt30( 0.86602540378444f) |
| #define cos_2_pi_6 Qfmt30( 0.5f) |
| #define cos_7_pi_12 Qfmt30( -0.25881904510252f) |
| #define cos_3_pi_12 Qfmt30( 0.70710678118655f) |
| #define cos_11_pi_12 Qfmt30( -0.96592582628907f) |
| |
| /*---------------------------------------------------------------------------- |
| ; 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 pvmp3_dct_6(int32 vec[]) |
| { |
| |
| Int32 tmp0; |
| Int32 tmp1; |
| Int32 tmp2; |
| Int32 tmp3; |
| Int32 tmp4; |
| Int32 tmp5; |
| |
| |
| /* split input vector */ |
| |
| tmp0 = vec[5] + vec[0]; |
| tmp5 = vec[5] - vec[0]; |
| tmp1 = vec[4] + vec[1]; |
| tmp4 = vec[4] - vec[1]; |
| tmp2 = vec[3] + vec[2]; |
| tmp3 = vec[3] - vec[2]; |
| |
| vec[0] = tmp0 + tmp2 ; |
| vec[2] = fxp_mul32_Q30(tmp0 - tmp2, cos_pi_6); |
| vec[4] = (vec[0] >> 1) - tmp1; |
| vec[0] += tmp1; |
| |
| tmp0 = fxp_mul32_Q30(tmp3, cos_7_pi_12); |
| tmp0 = fxp_mac32_Q30(tmp4, -cos_3_pi_12, tmp0); |
| vec[1] = fxp_mac32_Q30(tmp5, cos_11_pi_12, tmp0); |
| |
| vec[3] = fxp_mul32_Q30((tmp3 + tmp4 - tmp5), cos_3_pi_12); |
| tmp0 = fxp_mul32_Q30(tmp3, cos_11_pi_12); |
| tmp0 = fxp_mac32_Q30(tmp4, cos_3_pi_12, tmp0); |
| vec[5] = fxp_mac32_Q30(tmp5, cos_7_pi_12, tmp0); |
| |
| } |
| |
| |
| |
| |