/* ***** BEGIN LICENSE BLOCK *****   * Source last modified: $Id: imdct.c,v 1.1 2005/02/26 01:47:34 jrecker Exp $  *    * Portions Copyright (c) 1995-2005 RealNetworks, Inc. All Rights Reserved.   *        * The contents of this file, and the files included with this file,  * are subject to the current version of the RealNetworks Public  * Source License (the "RPSL") available at  * http://www.helixcommunity.org/content/rpsl unless you have licensed  * the file under the current version of the RealNetworks Community  * Source License (the "RCSL") available at  * http://www.helixcommunity.org/content/rcsl, in which case the RCSL  * will apply. You may also obtain the license terms directly from  * RealNetworks.  You may not use this file except in compliance with  * the RPSL or, if you have a valid RCSL with RealNetworks applicable  * to this file, the RCSL.  Please see the applicable RPSL or RCSL for  * the rights, obligations and limitations governing use of the  * contents of the file.  *    * This file is part of the Helix DNA Technology. RealNetworks is the  * developer of the Original Code and owns the copyrights in the  * portions it created.  *    * This file, and the files included with this file, is distributed  * and made available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY  * KIND, EITHER EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS  * ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET  * ENJOYMENT OR NON-INFRINGEMENT.  *   * Technology Compatibility Kit Test Suite(s) Location:   *    http://www.helixcommunity.org/content/tck   *   * Contributor(s):   *    * ***** END LICENSE BLOCK ***** */  /************************************************************************************** * Fixed-point AAC decoder using Intel IPP libraries * Jon Recker (jrecker@real.com) * February 2005 * * imdct.c - inverse MDCT **************************************************************************************/#include "coder.h"	/************************************************************************************** * Function:    IMDCT * * Description: inverse transform and convert to 16-bit PCM * * Inputs:      valid AACDecInfo struct *              index of current channel (0 for SCE/LFE, 0 or 1 for CPE) *              output channel (range = [0, nChans-1]) * * Outputs:     complete frame of decoded PCM, after inverse transform * * Return:      0 if successful, -1 if error * * Notes:       interleaves samples for nChans > 1, unless SBR is enabled *              if SBR is enabled, do not interleave channels **************************************************************************************/int IMDCT(AACDecInfo *aacDecInfo, int ch, int chOut, short *outbuf){	int i, pcmMode, iFactor;	short *outptr;	PSInfoBase *psi;	IppStatus err;	IppAACChanInfo *chanInfo;	IppAACIcsInfo *icsInfo;	/* validate pointers */	if (!aacDecInfo || !aacDecInfo->psInfoBase)		return -1;	psi = (PSInfoBase *)(aacDecInfo->psInfoBase);	chanInfo = &(psi->chanInfo[ch]); 	icsInfo = chanInfo->pIcsInfo;	iFactor = aacDecInfo->nChans;	/* interleave by total number of channels in stream */	pcmMode = (aacDecInfo->nChans == 2 ? 2 : 1);	outbuf += chOut;	/* interleave LRLRLR... only if nChans == 2 (for multichannel must do separate pass) */	outptr = (iFactor <= 2 ? outbuf : (short *)psi->workBuf);	err = ippsMDCTInv_AAC_32s16s(psi->coef[ch], outptr, psi->overlap[chOut], 		icsInfo->winSequence, icsInfo->winShape, psi->prevWinShape[chOut], pcmMode);	psi->prevWinShape[chOut] = icsInfo->winShape;	if (iFactor > 2) {		for (i = 0; i < AAC_MAX_NSAMPS; i++) {			*outbuf = outptr[i];			outbuf += iFactor;		}		outbuf -= (iFactor*AAC_MAX_NSAMPS);	}#ifdef AAC_ENABLE_SBR	/* if SBR is enabled, convert 16-bit PCM back to 32-bit ints */	for (i = 0; i < AAC_MAX_NSAMPS; i++) {		psi->coef[ch][i] = (int)(*outbuf);		outbuf += iFactor;	}	aacDecInfo->rawSampleBuf[ch] = psi->coef[ch];	aacDecInfo->rawSampleBytes = sizeof(int);	aacDecInfo->rawSampleFBits = 0;#else	aacDecInfo->rawSampleBuf[ch] = 0;	aacDecInfo->rawSampleBytes = 0;	aacDecInfo->rawSampleFBits = 0;#endif 	if (err)		return -1;	return 0;}