97 lines
3.8 KiB
C
97 lines
3.8 KiB
C
/* ***** BEGIN LICENSE BLOCK *****
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* Version: RCSL 1.0/RPSL 1.0
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*
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* Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved.
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*
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* The contents of this file, and the files included with this file, are
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* subject to the current version of the RealNetworks Public Source License
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* Version 1.0 (the "RPSL") available at
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* http://www.helixcommunity.org/content/rpsl unless you have licensed
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* the file under the RealNetworks Community Source License Version 1.0
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* (the "RCSL") available at http://www.helixcommunity.org/content/rcsl,
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* in which case the RCSL will apply. You may also obtain the license terms
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* directly from RealNetworks. You may not use this file except in
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* compliance with the RPSL or, if you have a valid RCSL with RealNetworks
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* applicable to this file, the RCSL. Please see the applicable RPSL or
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* RCSL for the rights, obligations and limitations governing use of the
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* contents of the file.
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*
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* This file is part of the Helix DNA Technology. RealNetworks is the
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* developer of the Original Code and owns the copyrights in the portions
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* it created.
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*
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* This file, and the files included with this file, is distributed and made
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* available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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* EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS
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* FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
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*
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* Technology Compatibility Kit Test Suite(s) Location:
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* http://www.helixcommunity.org/content/tck
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*
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* Contributor(s):
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*
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* ***** END LICENSE BLOCK ***** */
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/**************************************************************************************
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* Fixed-point MP3 decoder
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* Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com)
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* June 2003
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*
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* subband.c - subband transform (synthesis filterbank implemented via 32-point DCT
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* followed by polyphase filter)
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**************************************************************************************/
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#include "coder.h"
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#include "assembly.h"
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/**************************************************************************************
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* Function: Subband
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*
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* Description: do subband transform on all the blocks in one granule, all channels
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*
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* Inputs: filled MP3DecInfo structure, after calling IMDCT for all channels
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* vbuf[ch] and vindex[ch] must be preserved between calls
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*
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* Outputs: decoded PCM data, interleaved LRLRLR... if stereo
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*
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* Return: 0 on success, -1 if null input pointers
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**************************************************************************************/
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int Subband(MP3DecInfo *mp3DecInfo, short *pcmBuf)
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{
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int b;
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HuffmanInfo *hi;
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IMDCTInfo *mi;
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SubbandInfo *sbi;
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/* validate pointers */
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if (!mp3DecInfo || !mp3DecInfo->HuffmanInfoPS || !mp3DecInfo->IMDCTInfoPS || !mp3DecInfo->SubbandInfoPS)
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return -1;
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hi = (HuffmanInfo *)mp3DecInfo->HuffmanInfoPS;
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mi = (IMDCTInfo *)(mp3DecInfo->IMDCTInfoPS);
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sbi = (SubbandInfo*)(mp3DecInfo->SubbandInfoPS);
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if (mp3DecInfo->nChans == 2) {
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/* stereo */
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for (b = 0; b < BLOCK_SIZE; b++) {
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FDCT32(mi->outBuf[0][b], sbi->vbuf + 0*32, sbi->vindex, (b & 0x01), mi->gb[0]);
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FDCT32(mi->outBuf[1][b], sbi->vbuf + 1*32, sbi->vindex, (b & 0x01), mi->gb[1]);
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PolyphaseStereo(pcmBuf, sbi->vbuf + sbi->vindex + VBUF_LENGTH * (b & 0x01), polyCoef);
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sbi->vindex = (sbi->vindex - (b & 0x01)) & 7;
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pcmBuf += (2 * NBANDS);
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}
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} else {
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/* mono */
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for (b = 0; b < BLOCK_SIZE; b++) {
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FDCT32(mi->outBuf[0][b], sbi->vbuf + 0*32, sbi->vindex, (b & 0x01), mi->gb[0]);
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PolyphaseMono(pcmBuf, sbi->vbuf + sbi->vindex + VBUF_LENGTH * (b & 0x01), polyCoef);
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sbi->vindex = (sbi->vindex - (b & 0x01)) & 7;
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pcmBuf += NBANDS;
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}
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}
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return 0;
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}
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