/ src / stproc.cpp
stproc.cpp
  1  /* ***** BEGIN LICENSE BLOCK ***** 
  2   * Version: RCSL 1.0/RPSL 1.0 
  3   *  
  4   * Portions Copyright (c) 1995-2002 RealNetworks, Inc. All Rights Reserved. 
  5   *      
  6   * The contents of this file, and the files included with this file, are 
  7   * subject to the current version of the RealNetworks Public Source License 
  8   * Version 1.0 (the "RPSL") available at 
  9   * http://www.helixcommunity.org/content/rpsl unless you have licensed 
 10   * the file under the RealNetworks Community Source License Version 1.0 
 11   * (the "RCSL") available at http://www.helixcommunity.org/content/rcsl, 
 12   * in which case the RCSL will apply. You may also obtain the license terms 
 13   * directly from RealNetworks.  You may not use this file except in 
 14   * compliance with the RPSL or, if you have a valid RCSL with RealNetworks 
 15   * applicable to this file, the RCSL.  Please see the applicable RPSL or 
 16   * RCSL for the rights, obligations and limitations governing use of the 
 17   * contents of the file.  
 18   *  
 19   * This file is part of the Helix DNA Technology. RealNetworks is the 
 20   * developer of the Original Code and owns the copyrights in the portions 
 21   * it created. 
 22   *  
 23   * This file, and the files included with this file, is distributed and made 
 24   * available on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 
 25   * EXPRESS OR IMPLIED, AND REALNETWORKS HEREBY DISCLAIMS ALL SUCH WARRANTIES, 
 26   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS 
 27   * FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 
 28   * 
 29   * Technology Compatibility Kit Test Suite(s) Location: 
 30   *    http://www.helixcommunity.org/content/tck 
 31   * 
 32   * Contributor(s): 
 33   *  
 34   * ***** END LICENSE BLOCK ***** */ 
 35  
 36  /**************************************************************************************
 37   * Fixed-point MP3 decoder
 38   * Jon Recker (jrecker@real.com), Ken Cooke (kenc@real.com)
 39   * June 2003
 40   *
 41   * stproc.c - mid-side and intensity (MPEG1 and MPEG2) stereo processing
 42   **************************************************************************************/
 43  
 44  #include "coder.h"
 45  #include "assembly.h"
 46  
 47  /**************************************************************************************
 48   * Function:    MidSideProc
 49   *
 50   * Description: sum-difference stereo reconstruction
 51   *
 52   * Inputs:      vector x with dequantized samples from left and right channels
 53   *              number of non-zero samples (MAX of left and right)
 54   *              assume 1 guard bit in input
 55   *              guard bit mask (left and right channels)
 56   *
 57   * Outputs:     updated sample vector x
 58   *              updated guard bit mask
 59   *
 60   * Return:      none
 61   *
 62   * Notes:       assume at least 1 GB in input
 63   **************************************************************************************/
 64  void MidSideProc(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, int mOut[2])  
 65  {
 66  	int i, xr, xl, mOutL, mOutR;
 67  	
 68  	/* L = (M+S)/sqrt(2), R = (M-S)/sqrt(2) 
 69  	 * NOTE: 1/sqrt(2) done in DequantChannel() - see comments there
 70  	 */
 71  	mOutL = mOutR = 0;
 72  	for(i = 0; i < nSamps; i++) {
 73  		xl = x[0][i];
 74  		xr = x[1][i];
 75  		x[0][i] = xl + xr;
 76  		x[1][i] = xl - xr;
 77  		mOutL |= FASTABS(x[0][i]);
 78  		mOutR |= FASTABS(x[1][i]);
 79  	}
 80  	mOut[0] |= mOutL;
 81  	mOut[1] |= mOutR;
 82  }
 83  
 84  /**************************************************************************************
 85   * Function:    IntensityProcMPEG1
 86   *
 87   * Description: intensity stereo processing for MPEG1
 88   *
 89   * Inputs:      vector x with dequantized samples from left and right channels
 90   *              number of non-zero samples in left channel
 91   *              valid FrameHeader struct
 92   *              two each of ScaleFactorInfoSub, CriticalBandInfo structs (both channels)
 93   *              flags indicating midSide on/off, mixedBlock on/off
 94   *              guard bit mask (left and right channels)
 95   *
 96   * Outputs:     updated sample vector x
 97   *              updated guard bit mask
 98   *
 99   * Return:      none
100   *
101   * Notes:       assume at least 1 GB in input
102   *
103   * TODO:        combine MPEG1/2 into one function (maybe)
104   *              make sure all the mixed-block and IIP logic is right
105   **************************************************************************************/
106  void IntensityProcMPEG1(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, FrameHeader *fh, ScaleFactorInfoSub *sfis, 
107  						CriticalBandInfo *cbi, int midSideFlag, int mixFlag, int mOut[2])
108  {
109  	int i=0, j=0, n=0, cb=0, w=0;
110  	int sampsLeft, isf, mOutL, mOutR, xl, xr;
111  	int fl, fr, fls[3], frs[3];
112  	int cbStartL=0, cbStartS=0, cbEndL=0, cbEndS=0;
113  	int *isfTab;
114  	
115  	/* NOTE - this works fine for mixed blocks, as long as the switch point starts in the
116  	 *  short block section (i.e. on or after sample 36 = sfBand->l[8] = 3*sfBand->s[3]
117  	 * is this a safe assumption?
118  	 * TODO - intensity + mixed not quite right (diff = 11 on he_mode)
119  	 *  figure out correct implementation (spec ambiguous about when to do short block reorder)
120  	 */
121  	if (cbi[1].cbType == 0) {
122  		/* long block */
123  		cbStartL = cbi[1].cbEndL + 1;
124  		cbEndL =   cbi[0].cbEndL + 1;
125  		cbStartS = cbEndS = 0;
126  		i = fh->sfBand->l[cbStartL];
127  	} else if (cbi[1].cbType == 1 || cbi[1].cbType == 2) {
128  		/* short or mixed block */
129  		cbStartS = cbi[1].cbEndSMax + 1;
130  		cbEndS =   cbi[0].cbEndSMax + 1;
131  		cbStartL = cbEndL = 0;
132  		i = 3 * fh->sfBand->s[cbStartS];
133  	}
134  
135  	sampsLeft = nSamps - i;		/* process to length of left */
136  	isfTab = (int *)ISFMpeg1[midSideFlag];
137  	mOutL = mOutR = 0;
138  
139  	/* long blocks */
140  	for (cb = cbStartL; cb < cbEndL && sampsLeft > 0; cb++) {
141  		isf = sfis->l[cb];
142  		if (isf == 7) {
143  			fl = ISFIIP[midSideFlag][0];
144  			fr = ISFIIP[midSideFlag][1];
145  		} else {
146  			fl = isfTab[isf];	
147  			fr = isfTab[6] - isfTab[isf];
148  		}
149  
150  		n = fh->sfBand->l[cb + 1] - fh->sfBand->l[cb];
151  		for (j = 0; j < n && sampsLeft > 0; j++, i++) {
152  			xr = MULSHIFT32(fr, x[0][i]) << 2;	x[1][i] = xr; mOutR |= FASTABS(xr);
153  			xl = MULSHIFT32(fl, x[0][i]) << 2;	x[0][i] = xl; mOutL |= FASTABS(xl);
154  			sampsLeft--;
155  		}
156  	}
157  
158  	/* short blocks */
159  	for (cb = cbStartS; cb < cbEndS && sampsLeft >= 3; cb++) {
160  		for (w = 0; w < 3; w++) {
161  			isf = sfis->s[cb][w];
162  			if (isf == 7) {
163  				fls[w] = ISFIIP[midSideFlag][0];
164  				frs[w] = ISFIIP[midSideFlag][1];
165  			} else {
166  				fls[w] = isfTab[isf];
167  				frs[w] = isfTab[6] - isfTab[isf];
168  			}
169  		}
170  
171  		n = fh->sfBand->s[cb + 1] - fh->sfBand->s[cb];
172  		for (j = 0; j < n && sampsLeft >= 3; j++, i+=3) {
173  			xr = MULSHIFT32(frs[0], x[0][i+0]) << 2;	x[1][i+0] = xr;	mOutR |= FASTABS(xr);
174  			xl = MULSHIFT32(fls[0], x[0][i+0]) << 2;	x[0][i+0] = xl;	mOutL |= FASTABS(xl);
175  			xr = MULSHIFT32(frs[1], x[0][i+1]) << 2;	x[1][i+1] = xr;	mOutR |= FASTABS(xr);
176  			xl = MULSHIFT32(fls[1], x[0][i+1]) << 2;	x[0][i+1] = xl;	mOutL |= FASTABS(xl);
177  			xr = MULSHIFT32(frs[2], x[0][i+2]) << 2;	x[1][i+2] = xr;	mOutR |= FASTABS(xr);
178  			xl = MULSHIFT32(fls[2], x[0][i+2]) << 2;	x[0][i+2] = xl;	mOutL |= FASTABS(xl);
179  			sampsLeft -= 3;
180  		}
181  	}
182  	mOut[0] = mOutL;
183  	mOut[1] = mOutR;
184  	
185  	return;
186  }
187  
188  /**************************************************************************************
189   * Function:    IntensityProcMPEG2
190   *
191   * Description: intensity stereo processing for MPEG2
192   *
193   * Inputs:      vector x with dequantized samples from left and right channels
194   *              number of non-zero samples in left channel
195   *              valid FrameHeader struct
196   *              two each of ScaleFactorInfoSub, CriticalBandInfo structs (both channels)
197   *              ScaleFactorJS struct with joint stereo info from UnpackSFMPEG2()
198   *              flags indicating midSide on/off, mixedBlock on/off
199   *              guard bit mask (left and right channels)
200   *
201   * Outputs:     updated sample vector x
202   *              updated guard bit mask
203   *
204   * Return:      none
205   *
206   * Notes:       assume at least 1 GB in input
207   *
208   * TODO:        combine MPEG1/2 into one function (maybe)
209   *              make sure all the mixed-block and IIP logic is right
210   *                probably redo IIP logic to be simpler
211   **************************************************************************************/
212  void IntensityProcMPEG2(int x[MAX_NCHAN][MAX_NSAMP], int nSamps, FrameHeader *fh, ScaleFactorInfoSub *sfis, 
213  						CriticalBandInfo *cbi, ScaleFactorJS *sfjs, int midSideFlag, int mixFlag, int mOut[2])
214  {
215  	int i, j, k, n, r, cb, w;
216  	int fl, fr, mOutL, mOutR, xl, xr;
217  	int sampsLeft;
218  	int isf, sfIdx, tmp, il[23];
219  	int *isfTab;
220  	int cbStartL, cbStartS, cbEndL, cbEndS;
221  	
222  	isfTab = (int *)ISFMpeg2[sfjs->intensityScale][midSideFlag];
223  	mOutL = mOutR = 0;
224  
225  	/* fill buffer with illegal intensity positions (depending on slen) */
226  	for (k = r = 0; r < 4; r++) {
227  		tmp = (1 << sfjs->slen[r]) - 1;
228  		for (j = 0; j < sfjs->nr[r]; j++, k++) 
229  			il[k] = tmp;
230  	}
231  
232  	if (cbi[1].cbType == 0) {
233  		/* long blocks */
234  		il[21] = il[22] = 1;
235  		cbStartL = cbi[1].cbEndL + 1;	/* start at end of right */
236  		cbEndL =   cbi[0].cbEndL + 1;	/* process to end of left */
237  		i = fh->sfBand->l[cbStartL];
238  		sampsLeft = nSamps - i;
239  
240  		for(cb = cbStartL; cb < cbEndL; cb++) {
241  			sfIdx = sfis->l[cb];
242  			if (sfIdx == il[cb]) {
243  				fl = ISFIIP[midSideFlag][0];
244  				fr = ISFIIP[midSideFlag][1];
245  			} else {
246  				isf = (sfis->l[cb] + 1) >> 1;
247  				fl = isfTab[(sfIdx & 0x01 ? isf : 0)];
248  				fr = isfTab[(sfIdx & 0x01 ? 0 : isf)];
249  			}
250  			n = MIN(fh->sfBand->l[cb + 1] - fh->sfBand->l[cb], sampsLeft);
251  
252  			for(j = 0; j < n; j++, i++) {
253  				xr = MULSHIFT32(fr, x[0][i]) << 2;	x[1][i] = xr;	mOutR |= FASTABS(xr);
254  				xl = MULSHIFT32(fl, x[0][i]) << 2;	x[0][i] = xl;	mOutL |= FASTABS(xl);
255  			}
256  
257  			/* early exit once we've used all the non-zero samples */
258  			sampsLeft -= n;
259  			if (sampsLeft == 0)		
260  				break;
261  		}
262  	} else {
263  		/* short or mixed blocks */
264  		il[12] = 1;
265  
266  		for(w = 0; w < 3; w++) {
267  			cbStartS = cbi[1].cbEndS[w] + 1;		/* start at end of right */
268  			cbEndS =   cbi[0].cbEndS[w] + 1;		/* process to end of left */
269  			i = 3 * fh->sfBand->s[cbStartS] + w;
270  
271  			/* skip through sample array by 3, so early-exit logic would be more tricky */
272  			for(cb = cbStartS; cb < cbEndS; cb++) {
273  				sfIdx = sfis->s[cb][w];
274  				if (sfIdx == il[cb]) {
275  					fl = ISFIIP[midSideFlag][0];
276  					fr = ISFIIP[midSideFlag][1];
277  				} else {
278  					isf = (sfis->s[cb][w] + 1) >> 1;
279  					fl = isfTab[(sfIdx & 0x01 ? isf : 0)];
280  					fr = isfTab[(sfIdx & 0x01 ? 0 : isf)];
281  				}
282  				n = fh->sfBand->s[cb + 1] - fh->sfBand->s[cb];
283  
284  				for(j = 0; j < n; j++, i+=3) {
285  					xr = MULSHIFT32(fr, x[0][i]) << 2;	x[1][i] = xr;	mOutR |= FASTABS(xr);
286  					xl = MULSHIFT32(fl, x[0][i]) << 2;	x[0][i] = xl;	mOutL |= FASTABS(xl);
287  				}
288  			}
289  		}
290  	}
291  	mOut[0] = mOutL;
292  	mOut[1] = mOutR;
293  
294  	return;
295  }
296