subband.c
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上传日期:2007-06-06
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- /* ***** BEGIN LICENSE BLOCK *****
- * Version: RCSL 1.0/RPSL 1.0
- *
- * Portions Copyright (c) 1995-2002 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
- * Version 1.0 (the "RPSL") available at
- * http://www.helixcommunity.org/content/rpsl unless you have licensed
- * the file under the RealNetworks Community Source License Version 1.0
- * (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 MP3 decoder using Intel IPP libraries
- * June 2003
- *
- * subband.c - wrapper for IPP primitive which runs synthesis filter
- **************************************************************************************/
- #include "coder.h"
- #define BLOCK_SIZE 18
- #define NBANDS 32
- /**************************************************************************************
- * Function: Subband
- *
- * Description: do subband transform on all the blocks in one granule, all channels
- *
- * Inputs: filled MP3DecInfo structure, after calling IMDCT for all channels
- * vbuf[ch] and vindex[ch] must be preserved between calls
- *
- * Outputs: decoded PCM data, interleaved LRLRLR... if stereo
- *
- * Return: 0 on success, -1 if null input pointers
- **************************************************************************************/
- int Subband(MP3DecInfo *mp3DecInfo, short *pcmBuf)
- {
- int b, ch, iMode;
- short *pcmPtr;
- IMDCTInfo *mi;
- SubbandInfo *sbi;
- /* validate pointers */
- if (!mp3DecInfo || !mp3DecInfo->IMDCTInfoPS || !mp3DecInfo->SubbandInfoPS)
- return -1;
- mi = (IMDCTInfo *)(mp3DecInfo->IMDCTInfoPS);
- sbi = (SubbandInfo*)(mp3DecInfo->SubbandInfoPS);
- iMode = (mp3DecInfo->nChans == 1 ? 1 : 2);
- for (ch = 0; ch < mp3DecInfo->nChans; ch++) {
- /* IPP primitive #7 - subband transform
- * mode 2 means output samples are skipped by 2 (fills pcmBuf[0, 2, 4...])
- * - for stereo, we start at &pcmBuf[0] first time (L) and &pcmBuf[1] second time (R)
- * - for mono, we still use mode 1 (no interleaving)
- */
- pcmPtr = pcmBuf + ch; /* offset for stereo interleaving */
- for(b = 0; b < BLOCK_SIZE; b++) {
- ippsSynthPQMF_MP3_32s16s(mi->outBuf[ch] + b*NBANDS, pcmPtr, sbi->vbuf[ch], &(sbi->vindex[ch]), iMode);
- pcmPtr += NBANDS * mp3DecInfo->nChans;
- }
- }
- return 0;
- }