97 lines
3.8 KiB
C
97 lines
3.8 KiB
C
|
/* ***** 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;
|
||
|
|
HuffmanInfo *hi;
|
||
|
|
IMDCTInfo *mi;
|
||
|
|
SubbandInfo *sbi;
|
||
|
|
|
||
|
|
/* validate pointers */
|
||
|
|
if (!mp3DecInfo || !mp3DecInfo->HuffmanInfoPS || !mp3DecInfo->IMDCTInfoPS || !mp3DecInfo->SubbandInfoPS)
|
||
|
|
return -1;
|
||
|
|
|
||
|
|
hi = (HuffmanInfo *)mp3DecInfo->HuffmanInfoPS;
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|