| /* ------------------------------------------------------------------ |
| * 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: ps_hybrid_analysis.c |
| |
| |
| ------------------------------------------------------------------------------ |
| REVISION HISTORY |
| |
| |
| Who: Date: MM/DD/YYYY |
| Description: |
| |
| ------------------------------------------------------------------------------ |
| INPUT AND OUTPUT DEFINITIONS |
| |
| |
| |
| ------------------------------------------------------------------------------ |
| FUNCTION DESCRIPTION |
| |
| Does Hybrid analysis: |
| |
| Get higher frequency resolution in the lower QMF subbands |
| creating sub-subbands. This is done by low frequency filtering. |
| Lower QMF subbands are further split in order to obtain a higher |
| frequency resolution, enabling a proper stereo analysis and synthesis |
| for the lower frequencies. |
| Two hybrid are defined. Both filters have length 13 and a delay of 6. |
| In this implementation, the symmetry of the filters helps to simplify |
| the design. |
| |
| |
| Increase Freq. Resolution |
| _______ ________ |
| | | _______ | | |
| ->|Hybrid | LF ---- | |->| Hybrid |--> |
| | Anal. | | | | | Synth | QMF -> L |
| ------- o----------------------->| | -------- Synth |
| QMF | s_k(n) |Stereo |--------------> |
| Anal. -------------------------->| | |
| _______ | | | | ________ |
| | | HF --o | ----------- |Process| | | |
| ->| Delay | | ->| |-------->| |->| Hybrid |--> |
| ------- | |decorrelate| d_k(n) | | | Synth | QMF -> R |
| ---->| |-------->| | -------- Synth |
| ----------- |_______|--------------> |
| |
| |
| |
| subband k QMF channel |
| 0 ................. 0 ----------- |
| 1 ................. 0 |
| 2 ................. 0 |
| 3 ................. 0 |
| 4 ................. 0 |
| 5 ................. 0 Sub-QMF ( Increase Freq. Resolution) |
| 6 ................. 1 |
| 7 ................. 1 |
| 8 ................. 2 |
| 9 ................. 2 |
| 10 ................. 3 ----------- |
| 11 ................. 4 |
| 12 ................. 5 |
| 13 ................. 6 |
| 14 ................. 7 |
| 15 ................. 8 QMF |
| 16-17 ................. 9-10 |
| 18-20 ................. 11-13 |
| 21-24 ................. 14-17 |
| 25-29 ................. 18-22 |
| 30-41 ................. 23-34 |
| 42-70 ................. 35-63 ----------- |
| |
| ------------------------------------------------------------------------------ |
| REQUIREMENTS |
| |
| |
| ------------------------------------------------------------------------------ |
| REFERENCES |
| |
| SC 29 Software Copyright Licencing Disclaimer: |
| |
| This software module was originally developed by |
| Coding Technologies |
| |
| and edited by |
| - |
| |
| in the course of development of the ISO/IEC 13818-7 and ISO/IEC 14496-3 |
| standards for reference purposes and its performance may not have been |
| optimized. This software module is an implementation of one or more tools as |
| specified by the ISO/IEC 13818-7 and ISO/IEC 14496-3 standards. |
| ISO/IEC gives users free license to this software module or modifications |
| thereof for use in products claiming conformance to audiovisual and |
| image-coding related ITU Recommendations and/or ISO/IEC International |
| Standards. ISO/IEC gives users the same free license to this software module or |
| modifications thereof for research purposes and further ISO/IEC standardisation. |
| Those intending to use this software module in products are advised that its |
| use may infringe existing patents. ISO/IEC have no liability for use of this |
| software module or modifications thereof. Copyright is not released for |
| products that do not conform to audiovisual and image-coding related ITU |
| Recommendations and/or ISO/IEC International Standards. |
| The original developer retains full right to modify and use the code for its |
| own purpose, assign or donate the code to a third party and to inhibit third |
| parties from using the code for products that do not conform to audiovisual and |
| image-coding related ITU Recommendations and/or ISO/IEC International Standards. |
| This copyright notice must be included in all copies or derivative works. |
| Copyright (c) ISO/IEC 2003. |
| |
| ------------------------------------------------------------------------------ |
| PSEUDO-CODE |
| |
| ------------------------------------------------------------------------------ |
| */ |
| |
| |
| /*---------------------------------------------------------------------------- |
| ; INCLUDES |
| ----------------------------------------------------------------------------*/ |
| |
| #ifdef AAC_PLUS |
| |
| #ifdef PARAMETRICSTEREO |
| |
| #include "s_hybrid.h" |
| #include "aac_mem_funcs.h" |
| #include "ps_channel_filtering.h" |
| #include "ps_hybrid_analysis.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 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 ps_hybrid_analysis(const Int32 mQmfReal[][64], |
| const Int32 mQmfImag[][64], |
| Int32 *mHybridReal, |
| Int32 *mHybridImag, |
| HYBRID *pHybrid, |
| Int32 scratch_mem[], |
| Int32 i) |
| |
| { |
| |
| Int32 band; |
| HYBRID_RES hybridRes; |
| Int32 chOffset = 0; |
| |
| Int32 *ptr_mHybrid_Re; |
| Int32 *ptr_mHybrid_Im; |
| |
| Int32 *pt_mQmfBufferReal; |
| Int32 *pt_mQmfBufferImag; |
| |
| pt_mQmfBufferReal = &scratch_mem[32 + i]; |
| |
| for (band = 0; band < pHybrid->nQmfBands; band++) |
| { |
| pt_mQmfBufferImag = pt_mQmfBufferReal + 44; |
| |
| |
| pt_mQmfBufferReal[HYBRID_FILTER_LENGTH_m_1] = mQmfReal[HYBRID_FILTER_DELAY][band]; |
| pt_mQmfBufferImag[HYBRID_FILTER_LENGTH_m_1] = mQmfImag[HYBRID_FILTER_DELAY][band]; |
| |
| |
| ptr_mHybrid_Re = &mHybridReal[ chOffset]; |
| ptr_mHybrid_Im = &mHybridImag[ chOffset]; |
| |
| hybridRes = (HYBRID_RES)pHybrid->pResolution[band]; |
| switch (hybridRes) |
| { |
| /* |
| * For QMF band = 1 and 2 |
| */ |
| |
| case HYBRID_2_REAL: |
| |
| two_ch_filtering(pt_mQmfBufferReal, |
| pt_mQmfBufferImag, |
| ptr_mHybrid_Re, |
| ptr_mHybrid_Im); |
| chOffset += 2; |
| |
| break; |
| |
| /* |
| * For QMF band = 0 |
| */ |
| |
| case HYBRID_8_CPLX: |
| |
| eight_ch_filtering(pt_mQmfBufferReal, |
| pt_mQmfBufferImag, |
| pHybrid->mTempReal, |
| pHybrid->mTempImag, |
| scratch_mem); |
| |
| pv_memmove(ptr_mHybrid_Re, pHybrid->mTempReal, 4*sizeof(*pHybrid->mTempReal)); |
| |
| ptr_mHybrid_Re += 2; |
| |
| *(ptr_mHybrid_Re++) += pHybrid->mTempReal[5]; |
| *(ptr_mHybrid_Re++) += pHybrid->mTempReal[4]; |
| *(ptr_mHybrid_Re++) = pHybrid->mTempReal[6]; |
| *(ptr_mHybrid_Re) = pHybrid->mTempReal[7]; |
| |
| pv_memmove(ptr_mHybrid_Im, pHybrid->mTempImag, 4*sizeof(*pHybrid->mTempImag)); |
| ptr_mHybrid_Im += 2; |
| |
| *(ptr_mHybrid_Im++) += pHybrid->mTempImag[5]; |
| *(ptr_mHybrid_Im++) += pHybrid->mTempImag[4]; |
| *(ptr_mHybrid_Im++) = pHybrid->mTempImag[6]; |
| *(ptr_mHybrid_Im) = pHybrid->mTempImag[7]; |
| |
| chOffset += 6; |
| |
| break; |
| |
| default: |
| ; |
| } |
| |
| pt_mQmfBufferReal = pt_mQmfBufferImag + 44; |
| |
| } |
| |
| |
| } |
| #endif |
| |
| |
| #endif |
| |
