1 /* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18 /*
19 ------------------------------------------------------------------------------
20
21 PacketVideo Corp.
22 MP3 Decoder Library
23
24 Filename: pvmp3_stereo_proc.cpp
25
26 Functions:
27
28 pvmp3_st_mid_side
29 pvmp3_st_intensity
30 pvmp3_stereo_proc
31
32 ------------------------------------------------------------------------------
33
34 pvmp3_st_mid_side
35
36 INPUT AND OUTPUT DEFINITIONS
37
38 Input
39
40 int32 xr[], input channel
41 int32 xl[],
42 int32 Start, Location of first element where stereo intensity is applied
43 int32 Number number of elements affected
44
45 Returns
46
47 int32 xl[], generated stereo channel
48
49
50 ------------------------------------------------------------------------------
51
52 pvmp3_st_intensity
53
54 INPUT AND OUTPUT DEFINITIONS
55
56 Input
57
58 int32 xr[], input channel
59 int32 xl[],
60 int32 is_pos, index to table is_ratio_factor[]
61 int32 Start, Location of first element where stereo intensity is applied
62 int32 Number number of elements affected
63
64 Returns
65
66 int32 xl[], generated stereo channel
67
68
69 ------------------------------------------------------------------------------
70
71 pvmp3_stereo_proc
72
73 INPUT AND OUTPUT DEFINITIONS
74
75 Input
76
77 int32 xr[], input channel
78 int32 xl[],
79 mp3ScaleFactors *scalefac, scale factors structure
80 struct gr_info_s *gr_info, granule structure
81 mp3Header *info mp3 header info
82 Returns
83
84 int32 xl[], generated stereo channel
85
86
87 ------------------------------------------------------------------------------
88 FUNCTION DESCRIPTION
89
90 stereo processing for mpeg1 layer III
91 After requantization, the reconstructed values are processed for ms_stereo
92 or intensity_stereo modes or both, before passing them to the synthesis
93 filterbank
94
95 In ms_stereo mode the values of the normalized middle/side channels
96 M[l] and S[l] are transmitted instead of the left/right channel values
97 L[l] and R[l]. From here, L[l] and R[l] are reconstructed
98
99 Intensity_stereo is done by specifying the magnitude (via the
100 scalefactors of the left channel) and a stereo position is_pos[sfb],
101 which is transmitted instead of scalefactors of the right channel.
102 The stereo position is used to derive the left and right channel signals
103
104 ------------------------------------------------------------------------------
105 REQUIREMENTS
106
107
108 ------------------------------------------------------------------------------
109 REFERENCES
110
111 [1] ISO MPEG Audio Subgroup Software Simulation Group (1996)
112 ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension
113
114 ------------------------------------------------------------------------------
115 PSEUDO-CODE
116
117 ------------------------------------------------------------------------------
118 */
119
120
121 /*----------------------------------------------------------------------------
122 ; INCLUDES
123 ----------------------------------------------------------------------------*/
124
125 #include "pvmp3_stereo_proc.h"
126 #include "pv_mp3dec_fxd_op.h"
127 #include "pvmp3_tables.h"
128
129
130 /*----------------------------------------------------------------------------
131 ; MACROS
132 ; Define module specific macros here
133 ----------------------------------------------------------------------------*/
134
135
136 /*----------------------------------------------------------------------------
137 ; DEFINES
138 ; Include all pre-processor statements here. Include conditional
139 ; compile variables also.
140 ----------------------------------------------------------------------------*/
141 #define N31 31
142
143 #define Q31_fmt(a) (int32(double(0x7FFFFFFF)*(a)))
144
145 /*----------------------------------------------------------------------------
146 ; LOCAL FUNCTION DEFINITIONS
147 ; Function Prototype declaration
148 ----------------------------------------------------------------------------*/
149
150 /*----------------------------------------------------------------------------
151 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
152 ; Variable declaration - defined here and used outside this module
153 ----------------------------------------------------------------------------*/
154 /*
155 * TmpFac= tan(is_pos * (PI /12));
156 *
157 * TmpFac /= (1 + TmpFac);
158 *
159 */
160
161 const int32 is_ratio_factor[8] = {0,
162 Q31_fmt(0.21132486540519), Q31_fmt(0.36602540378444), Q31_fmt(0.50000000000000),
163 Q31_fmt(0.63397459621556), Q31_fmt(0.78867513459481), Q31_fmt(1.00000000000000),
164 0
165 };
166
167 /*----------------------------------------------------------------------------
168 ; EXTERNAL FUNCTION REFERENCES
169 ; Declare functions defined elsewhere and referenced in this module
170 ----------------------------------------------------------------------------*/
171
172 /*----------------------------------------------------------------------------
173 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
174 ; Declare variables used in this module but defined elsewhere
175 ----------------------------------------------------------------------------*/
176
177 /*----------------------------------------------------------------------------
178 ; FUNCTION CODE
179 ----------------------------------------------------------------------------*/
180
181 #if __has_attribute(no_sanitize)
182 // deliberately playing near overflow points of int32
183 __attribute__((no_sanitize("integer")))
184 #endif
pvmp3_st_mid_side(int32 xr[SUBBANDS_NUMBER * FILTERBANK_BANDS],int32 xl[SUBBANDS_NUMBER * FILTERBANK_BANDS],int32 Start,int32 Number)185 void pvmp3_st_mid_side(int32 xr[SUBBANDS_NUMBER*FILTERBANK_BANDS],
186 int32 xl[SUBBANDS_NUMBER*FILTERBANK_BANDS],
187 int32 Start,
188 int32 Number)
189 {
190
191 int32 *pt_xr = &xr[Start];
192 int32 *pt_xl = &xl[Start];
193
194 for (int32 i = Number >> 1; i != 0; i--)
195 {
196 int32 xxr = *(pt_xr) << 1;
197 int32 xxl = *(pt_xl) << 1;
198 *(pt_xr++) = fxp_mul32_Q32((xxr + xxl), Q31_fmt(0.70710678118655)); /* Sum */
199 *(pt_xl++) = fxp_mul32_Q32((xxr - xxl), Q31_fmt(0.70710678118655)); /* Diff */
200 xxr = *(pt_xr) << 1;
201 xxl = *(pt_xl) << 1;
202 *(pt_xr++) = fxp_mul32_Q32((xxr + xxl), Q31_fmt(0.70710678118655)); /* Sum */
203 *(pt_xl++) = fxp_mul32_Q32((xxr - xxl), Q31_fmt(0.70710678118655)); /* Diff */
204 }
205
206
207 if (Number&1)
208 {
209 int32 xxr = *(pt_xr) << 1;
210 int32 xxl = *(pt_xl) << 1;
211 *(pt_xr) = fxp_mul32_Q32((xxr + xxl), Q31_fmt(0.70710678118655)); /* Sum */
212 *(pt_xl) = fxp_mul32_Q32((xxr - xxl), Q31_fmt(0.70710678118655)); /* Diff */
213 }
214
215 }
216
217
218 /*----------------------------------------------------------------------------
219 ; FUNCTION CODE
220 ----------------------------------------------------------------------------*/
221
pvmp3_st_intensity(int32 xr[SUBBANDS_NUMBER * FILTERBANK_BANDS],int32 xl[SUBBANDS_NUMBER * FILTERBANK_BANDS],int32 is_pos,int32 Start,int32 Number)222 void pvmp3_st_intensity(int32 xr[SUBBANDS_NUMBER*FILTERBANK_BANDS],
223 int32 xl[SUBBANDS_NUMBER*FILTERBANK_BANDS],
224 int32 is_pos,
225 int32 Start,
226 int32 Number)
227 {
228
229 int32 TmpFac = is_ratio_factor[ is_pos & 7];
230
231 int32 *pt_xr = &xr[Start];
232 int32 *pt_xl = &xl[Start];
233
234 for (int32 i = Number >> 1; i != 0; i--)
235 {
236 int32 tmp = fxp_mul32_Q32((*pt_xr) << 1, TmpFac);
237 *(pt_xl++) = (*pt_xr) - tmp;
238 *(pt_xr++) = tmp;
239 tmp = fxp_mul32_Q32((*pt_xr) << 1, TmpFac);
240 *(pt_xl++) = (*pt_xr) - tmp;
241 *(pt_xr++) = tmp;
242 }
243
244 if (Number&1)
245 {
246 int32 tmp = fxp_mul32_Q32((*pt_xr) << 1, TmpFac);
247 *(pt_xl) = (*pt_xr) - tmp;
248 *(pt_xr) = tmp;
249 }
250
251 }
252
253 /*----------------------------------------------------------------------------
254 ; FUNCTION CODE
255 ----------------------------------------------------------------------------*/
pvmp3_stereo_proc(int32 xr[SUBBANDS_NUMBER * FILTERBANK_BANDS],int32 xl[SUBBANDS_NUMBER * FILTERBANK_BANDS],mp3ScaleFactors * scalefac,granuleInfo * gr_info,int32 used_freq_lines,mp3Header * info)256 void pvmp3_stereo_proc(int32 xr[SUBBANDS_NUMBER*FILTERBANK_BANDS],
257 int32 xl[SUBBANDS_NUMBER*FILTERBANK_BANDS],
258 mp3ScaleFactors *scalefac,
259 granuleInfo *gr_info,
260 int32 used_freq_lines,
261 mp3Header *info)
262 {
263
264
265 int32 sb;
266 int32 ss;
267 int32 sfbNo;
268 int32 sfbStart;
269
270 int32 sfb;
271 int32 sfbTemp;
272 int32 i;
273 int32 j;
274
275
276 int32 i_stereo = (info->mode == MPG_MD_JOINT_STEREO) &&
277 (info->mode_ext & 0x1);
278
279 int32 ms_stereo = (info->mode == MPG_MD_JOINT_STEREO) &&
280 (info->mode_ext & 0x2);
281
282 int32 sfreq = info->version_x + (info->version_x << 1);
283 sfreq += info->sampling_frequency;
284
285
286
287
288 if (i_stereo)
289 {
290 if (gr_info->window_switching_flag && (gr_info->block_type == 2))
291 {
292 if (gr_info->mixed_block_flag)
293 {
294 /*
295 * mixed blocks processing
296 */
297 i = 31;
298 ss = 17;
299 sb = 0;
300 while (i >= 0)
301 {
302 if (xl[(i*FILTERBANK_BANDS) + ss])
303 {
304 sb = (i << 4) + (i << 1) + ss;
305 i = -1;
306 }
307 else
308 {
309 ss--;
310 if (ss < 0)
311 {
312 i--;
313 ss = 17;
314 }
315 }
316 }
317
318 if (sb < 36)
319 {
320 /*
321 * mixed blocks processing: intensity bound inside long blocks
322 */
323 /* 1. long blocks up to intensity border: not intensity */
324
325 if (mp3_sfBandIndex[sfreq].l[4] <= sb)
326 {
327 sfb = 4;
328 }
329 else
330 {
331 sfb = 0;
332 }
333
334 while (mp3_sfBandIndex[sfreq].l[sfb] < sb)
335 {
336 sfb++;
337 }
338
339 /* from that sfb on intensity stereo */
340 sfbTemp = sfb; /* save for later use */
341
342 sfbStart = mp3_sfBandIndex[sfreq].l[sfb];
343
344 /* from 0 up to sfbStart do ms_stereo or normal stereo */
345
346 if (ms_stereo)
347 {
348 pvmp3_st_mid_side(xr, xl, 0, sfbStart);
349 }
350
351 /* 2. long blocks from intensity border up to sfb band 8: intensity */
352 /* calc. is_ratio */
353
354
355 /* Start of intensity stereo of remaining sfc bands: */
356 for (; sfbTemp < 8; sfbTemp++)
357 {
358 sfbStart = mp3_sfBandIndex[sfreq].l[sfbTemp]; /* = Start in 0 ... 575 */
359 sfbNo = mp3_sfBandIndex[sfreq].l[sfbTemp+1] - mp3_sfBandIndex[sfreq].l[sfbTemp]; /* No of lines to process */
360
361 if (scalefac->l[sfbTemp] != 7)
362 {
363 pvmp3_st_intensity(xr, xl, scalefac->l[sfbTemp], sfbStart, sfbNo);
364 }
365 else if (ms_stereo)
366 {
367 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
368 }
369
370 } /* for (; sfbTemp < 8; sfbTemp++) */
371
372 for (j = 0; j < 3; j++)
373 {
374 /* 3. short blocks from sfbcnt to last sfb do intensity stereo */
375 for (sfbTemp = 3; sfbTemp < 13; sfbTemp++)
376 {
377 sfbNo = mp3_sfBandIndex[sfreq].s[sfbTemp+1] - mp3_sfBandIndex[sfreq].s[sfbTemp]; /* No of lines to process */
378 sfbStart = 3 * mp3_sfBandIndex[sfreq].s[sfbTemp] + j * sfbNo;
379
380 if (scalefac->s[j][sfbTemp] != 7)
381 {
382 pvmp3_st_intensity(xr, xl, scalefac->s[j][sfbTemp], sfbStart, sfbNo);
383 }
384 else if (ms_stereo)
385 {
386 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
387 }
388
389 } /* for (; sfbTemp < 22; sfbTemp++) */
390 } /* for (j = 0; j < 3; j++) */
391 }
392 else /* else for (sb >= 36) */
393 {
394 /*
395 * mixed blocks processing: intensity bound outside long blocks
396 */
397
398
399 /*
400 * 2. short blocks from sfb band 3 up to intensity border: normal stereo, ms stereo and intensity
401 */
402 for (j = 0; j < 3; j++)
403 {
404 int32 sfbcnt;
405 sfbcnt = -1;
406
407 for (sfb = 12; sfb >= 3; sfb--)
408 {
409 int32 lines;
410 lines = mp3_sfBandIndex[sfreq].s[sfb+1] - mp3_sfBandIndex[sfreq].s[sfb];
411 i = 3 * mp3_sfBandIndex[sfreq].s[sfb] + (j + 1) * lines - 1;
412
413 while (lines > 0)
414 {
415 if (xl[i])
416 {
417 sfbcnt = sfb;
418 sfb = -10;
419 lines = -10;
420 }
421 lines--;
422 i--;
423 }
424 }
425
426 sfbcnt += 1;
427 if (sfbcnt < 3)
428 {
429 sfbcnt = 3;
430 }
431
432 sfbTemp = sfbcnt; /* for later use */
433
434
435 /*
436 * do normal stereo or MS stereo from sfb 3 to < sfbcnt:
437 */
438 for (sb = 3; sb < sfbcnt; sb++)
439 {
440 sfbNo = mp3_sfBandIndex[sfreq].s[sb+1] - mp3_sfBandIndex[sfreq].s[sb];
441 sfbStart = 3 * mp3_sfBandIndex[sfreq].s[sb] + j * sfbNo;
442
443 if (ms_stereo)
444 {
445 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
446 }
447
448 }
449
450 /* from sfbcnt to last sfb do intensity stereo */
451 for (; sfbTemp < 13; sfbTemp++)
452 {
453 sfbNo = mp3_sfBandIndex[sfreq].s[sfbTemp+1] - mp3_sfBandIndex[sfreq].s[sfbTemp]; /* No of lines to process */
454 sfbStart = 3 * mp3_sfBandIndex[sfreq].s[sfbTemp] + j * sfbNo;
455
456 if (scalefac->s[j][sfbTemp] != 7)
457 {
458 pvmp3_st_intensity(xr, xl, scalefac->s[j][sfbTemp], sfbStart, sfbNo);
459 }
460 else if (ms_stereo)
461 {
462 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
463 }
464
465 } /* for (; sfbTemp < 22; sfbTemp++) */
466
467 } /* for (j = 0; j < 3; j++) */
468
469 /* 1. long blocks up to sfb band 8: not intensity */
470 /* from 0 to sfb 8 ms_stereo or normal stereo */
471
472 sfbStart = mp3_sfBandIndex[sfreq].l[8];
473
474 if (ms_stereo)
475 {
476 pvmp3_st_mid_side(xr, xl, 0, sfbStart);
477 }
478
479 }
480 } /* if (gr_info->mixed_block_flag) */
481 else
482 {
483 /*
484 * short block processing
485 */
486 for (j = 0; j < 3; j++)
487 {
488 int32 sfbcnt = -1;
489
490 for (sfb = 12; sfb >= 0; sfb--)
491 {
492 int32 lines = mp3_sfBandIndex[sfreq].s[sfb+1] - mp3_sfBandIndex[sfreq].s[sfb];
493 i = 3 * mp3_sfBandIndex[sfreq].s[sfb] + (j + 1) * lines - 1;
494
495 while (lines > 0)
496 {
497 if (xl[i])
498 {
499 sfbcnt = sfb;
500 sfb = -10;
501 lines = -10;
502 }
503 lines--;
504 i--;
505 }
506 }
507
508 sfbcnt += 1;
509 sfbTemp = sfbcnt; /* for later use */
510
511 /* do normal stereo or MS stereo from 0 to sfbcnt */
512 for (sb = 0; sb < sfbcnt; sb++)
513 {
514 sfbNo = mp3_sfBandIndex[sfreq].s[sb+1] - mp3_sfBandIndex[sfreq].s[sb];
515 sfbStart = 3 * mp3_sfBandIndex[sfreq].s[sb] + j * sfbNo;
516
517 if (ms_stereo)
518 {
519 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
520 }
521 }
522
523
524 /* from sfbcnt to last sfb do intensity stereo */
525 for (; sfbTemp < 13; sfbTemp++)
526 {
527 sfbNo = mp3_sfBandIndex[sfreq].s[sfbTemp+1] - mp3_sfBandIndex[sfreq].s[sfbTemp]; /* No of lines to process */
528 sfbStart = 3 * mp3_sfBandIndex[sfreq].s[sfbTemp] + j * sfbNo;
529
530 if (scalefac->s[j][sfbTemp] != 7)
531 {
532 pvmp3_st_intensity(xr, xl, scalefac->s[j][sfbTemp], sfbStart, sfbNo);
533 }
534 else if (ms_stereo)
535 {
536 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
537 }
538
539 } /* for (; sfbTemp < 22; sfbTemp++) */
540
541 } /* for (j = 0; j < 3; j++) */
542
543 } /* if( gr_info->mixed_block_flag) */
544
545
546
547 } /* if (gr_info->window_switching_flag && (gr_info->block_type == 2)) */
548 else
549 {
550 /*
551 * long block processing
552 */
553 i = 31;
554 ss = 17;
555 sb = 0;
556
557 while (i >= 0)
558 {
559 if (xl[(i*FILTERBANK_BANDS) + ss] != 0)
560 {
561 sb = (i << 4) + (i << 1) + ss;
562 i = -2;
563 }
564 else
565 {
566 ss--;
567 if (ss < 0)
568 {
569 i--;
570 ss = 17;
571 }
572 }
573 }
574
575 if (sb)
576 {
577 if (mp3_sfBandIndex[sfreq].l[14] <= sb)
578 {
579 sfb = 14;
580 }
581 else if (mp3_sfBandIndex[sfreq].l[7] <= sb)
582 {
583 sfb = 7;
584 }
585 else
586 {
587 sfb = 0;
588 }
589
590
591 while (mp3_sfBandIndex[sfreq].l[sfb] <= sb)
592 {
593 sfb++;
594 }
595 }
596 else
597 {
598 if (i == -1)
599 {
600 /* all xr[1][][] are 0: set IS bound sfb to 0 */
601 sfb = 0;
602 }
603 else
604 {
605 /* xr[1][0][0] is unequal 0 and all others are 0: set IS bound sfb to 1 */
606 sfb = 1;
607 }
608 }
609
610 sfbTemp = sfb; /* save for later use */
611
612
613 sfbStart = mp3_sfBandIndex[sfreq].l[sfb];
614
615 /* from 0 to sfbStart ms_stereo or normal stereo */
616 if (ms_stereo)
617 {
618 pvmp3_st_mid_side(xr, xl, 0, sfbStart);
619 }
620
621 /* now intensity stereo of the remaining sfb's: */
622 for (; sfb < 21; sfb++)
623 {
624 sfbStart = mp3_sfBandIndex[sfreq].l[sfb];
625 sfbNo = mp3_sfBandIndex[sfreq].l[sfb+1] - mp3_sfBandIndex[sfreq].l[sfb]; /* No of lines to process */
626
627 if (scalefac->l[sfb] != 7)
628 {
629 pvmp3_st_intensity(xr, xl, scalefac->l[sfb], sfbStart, sfbNo);
630 }
631 else if (ms_stereo)
632 {
633 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
634 }
635
636 } /* for (; sfbTemp < 22; sfbTemp++) */
637
638
639
640 sfbStart = mp3_sfBandIndex[sfreq].l[21];
641 sfbNo = mp3_sfBandIndex[sfreq].l[22] - mp3_sfBandIndex[sfreq].l[21]; /* No of lines to process */
642
643 if (scalefac->l[21] != 7)
644 {
645 if (sfbTemp < 21)
646 {
647 sfbTemp = scalefac->l[20];
648 }
649 else
650 {
651 sfbTemp = 0; /* if scalefac[20] is not an intensity position, is_pos = 0 */
652 }
653
654 pvmp3_st_intensity(xr, xl, sfbTemp, sfbStart, sfbNo);
655 }
656 else if (ms_stereo)
657 {
658 pvmp3_st_mid_side(xr, xl, sfbStart, sfbNo);
659 }
660
661 } /* if (gr_info->window_switching_flag && (gr_info->block_type == 2)) */
662
663
664 } /* if (i_stereo) */
665 else
666 {
667 /*
668 * normal or ms stereo processing
669 */
670 if (ms_stereo)
671 {
672
673 pvmp3_st_mid_side(xr, xl, 0, used_freq_lines);
674
675 }
676
677 } /* if (i_stereo) */
678
679 }
680
681