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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
* Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com)
* June 2003
*
* subband.c - subband transform (synthesis filterbank implemented via 32-point DCT
* followed by polyphase filter)
**************************************************************************************/
#include "coder.h"
#include "assembly.h"
/**************************************************************************************
* 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;
IMDCTInfo *mi;
SubbandInfo *sbi;
/* validate pointers */
if (!mp3DecInfo || !mp3DecInfo->HuffmanInfoPS || !mp3DecInfo->IMDCTInfoPS || !mp3DecInfo->SubbandInfoPS)
return -1;
mi = (IMDCTInfo *)(mp3DecInfo->IMDCTInfoPS);
sbi = (SubbandInfo*)(mp3DecInfo->SubbandInfoPS);
if (mp3DecInfo->nChans == 2) {
/* stereo */
for (b = 0; b < BLOCK_SIZE; b++) {
FDCT32(mi->outBuf[0][b], sbi->vbuf + 0*32, sbi->vindex, (b & 0x01), mi->gb[0]);
FDCT32(mi->outBuf[1][b], sbi->vbuf + 1*32, sbi->vindex, (b & 0x01), mi->gb[1]);
PolyphaseStereo(pcmBuf, sbi->vbuf + sbi->vindex + VBUF_LENGTH * (b & 0x01), polyCoef);
sbi->vindex = (sbi->vindex - (b & 0x01)) & 7;
pcmBuf += (2 * NBANDS);
}
} else {
/* mono */
for (b = 0; b < BLOCK_SIZE; b++) {
FDCT32(mi->outBuf[0][b], sbi->vbuf + 0*32, sbi->vindex, (b & 0x01), mi->gb[0]);
PolyphaseMono(pcmBuf, sbi->vbuf + sbi->vindex + VBUF_LENGTH * (b & 0x01), polyCoef);
sbi->vindex = (sbi->vindex - (b & 0x01)) & 7;
pcmBuf += NBANDS;
}
}
return 0;
}
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