/* ------------------------------------------------------------------ * 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. * ------------------------------------------------------------------- */ /* Pathname: ./src/deinterleave.c ------------------------------------------------------------------------------ REVISION HISTORY Description: Modified from original shareware code Description: (1) Modified with new template, rename variables (2) Removed for-loop to calculate win_inc, win_inc = SN2 (128) (3) Replaced for-loop with memcpy (4) Converted Int16 -> Int Description: Modified per review comments Who: Date: Description: ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS Inputs: interleaved = input array that contains interleaved coefficients Data Type Int deinterleaved = output array that will be updated with de-interleaved coefficients of input array. Data Type Int pFrameInfo = pointer to structure that holds information of current frame. Data Type FrameInfo Local Stores/Buffers/Pointers Needed: None Global Stores/Buffers/Pointers Needed: None Outputs: None Pointers and Buffers Modified: deinterleaved contents updated with de-interleaved coefficients from the input array: interleaved Local Stores Modified: None Global Stores Modified: None ------------------------------------------------------------------------------ FUNCTION DESCRIPTION This function performs the deinterleaving across all short windows in each group ------------------------------------------------------------------------------ REQUIREMENTS This function should replace the contents of pDeinterleaved with the de-interleaved 1024 coefficients of one frame ------------------------------------------------------------------------------ REFERENCES (1) MPEG-2 NBC Audio Decoder "This software module was originally developed by AT&T, Dolby Laboratories, Fraunhofer Gesellschaft IIS in the course of development of the MPEG-2 NBC/MPEG-4 Audio standard ISO/IEC 13818-7, 14496-1,2 and 3. This software module is an implementation of a part of one or more MPEG-2 NBC/MPEG-4 Audio tools as specified by the MPEG-2 NBC/MPEG-4 Audio standard. ISO/IEC gives users of the MPEG-2 NBC/MPEG-4 Audio standards free license to this software module or modifications thereof for use in hardware or software products claiming conformance to the MPEG-2 NBC/MPEG-4 Audio standards. Those intending to use this software module in hardware or software products are advised that this use may infringe existing patents. The original developer of this software module and his/her company, the subsequent editors and their companies, and ISO/IEC have no liability for use of this software module or modifications thereof in an implementation. Copyright is not released for non MPEG-2 NBC/MPEG-4 Audio conforming products.The original developer retains full right to use the code for his/her own purpose, assign or donate the code to a third party and to inhibit third party from using the code for non MPEG-2 NBC/MPEG-4 Audio conforming products. This copyright notice must be included in all copies or derivative works." Copyright(c)1996. (2) ISO/IEC 14496-3: 1999(E) Subpart 4 p78 quant_to_spec ------------------------------------------------------------------------------ PSEUDO-CODE pInterleaved = interleaved; pDeinterleaved = deinterleaved; pSfbPerWin = pFrameInfo->sfb_per_win; ngroups = pFrameInfo->num_groups; pGroupLen = pFrameInfo->group_len; pGroup = pDeinterleaved; FOR (group = ngroups; group > 0; group--) pSfbWidth = pFrameInfo->sfb_width_128; sfb_inc = 0; pStart = pInterleaved; FOR (sfb = pSfbPerWin[ngroups-group]; sfb > 0; sfb--) pWin = pGroup; FOR (win = pGroupLen[ngroups-group]; win > 0; win--) pDeinterleaved = pWin + sfb_inc; pv_memcpy( pDeinterleaved, pInterleaved, *pSfbWidth*sizeof(*pInterleaved)); pInterleaved += *pSfbWidth; pWin += SN2; ENDFOR (win) sfb_inc += *pSfbWidth++; ENDFOR (sfb) pGroup += (pInterleaved - pStart); ENDFOR (group) ------------------------------------------------------------------------------ RESOURCES USED When the code is written for a specific target processor the the resources used should be documented below. STACK USAGE: [stack count for this module] + [variable to represent stack usage for each subroutine called] where: [stack usage variable] = stack usage for [subroutine name] (see [filename].ext) DATA MEMORY USED: x words PROGRAM MEMORY USED: x words CLOCK CYCLES: [cycle count equation for this module] + [variable used to represent cycle count for each subroutine called] where: [cycle count variable] = cycle count for [subroutine name] (see [filename].ext) ------------------------------------------------------------------------------ */ /*---------------------------------------------------------------------------- ; INCLUDES ----------------------------------------------------------------------------*/ #include "pv_audio_type_defs.h" #include "huffman.h" #include "aac_mem_funcs.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 deinterleave( Int16 interleaved[], Int16 deinterleaved[], FrameInfo *pFrameInfo) { Int group; /* group index */ Int sfb; /* scalefactor band index */ Int win; /* window index */ Int16 *pGroup; Int16 *pWin; Int16 *pStart; Int16 *pInterleaved; Int16 *pDeinterleaved; Int sfb_inc; Int ngroups; Int *pGroupLen; Int *pSfbPerWin; Int *pSfbWidth; pInterleaved = interleaved; pDeinterleaved = deinterleaved; pSfbPerWin = pFrameInfo->sfb_per_win; ngroups = pFrameInfo->num_groups; pGroupLen = pFrameInfo->group_len; pGroup = pDeinterleaved; for (group = ngroups; group > 0; group--) { pSfbWidth = pFrameInfo->sfb_width_128; sfb_inc = 0; pStart = pInterleaved; /* Perform the deinterleaving across all windows in a group */ for (sfb = pSfbPerWin[ngroups-group]; sfb > 0; sfb--) { pWin = pGroup; for (win = pGroupLen[ngroups-group]; win > 0; win--) { pDeinterleaved = pWin + sfb_inc; pv_memcpy( pDeinterleaved, pInterleaved, *pSfbWidth*sizeof(*pInterleaved)); pInterleaved += *pSfbWidth; pWin += SN2; } /* for (win) */ sfb_inc += *pSfbWidth++; } /* for (sfb) */ pGroup += (pInterleaved - pStart); } /* for (group) */ } /* deinterleave */