1/*
2 * Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
3 * Universitaet Berlin.  See the accompanying file "COPYRIGHT" for
4 * details.  THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE.
5 */
6
7/* $Header: /tmp_amd/presto/export/kbs/jutta/src/gsm/RCS/short_term.c,v 1.2 1994/05/10 20:18:47 jutta Exp $ */
8
9#include <stdio.h>
10#include <assert.h>
11
12#include "private.h"
13
14#include "gsm.h"
15#include "proto.h"
16
17/*
18 *  SHORT TERM ANALYSIS FILTERING SECTION
19 */
20
21/* 4.2.8 */
22
23static void Decoding_of_the_coded_Log_Area_Ratios P2((LARc,LARpp),
24	word 	* LARc,		/* coded log area ratio	[0..7] 	IN	*/
25	word	* LARpp)	/* out: decoded ..			*/
26{
27	register word	temp1 /* , temp2 */;
28	register long	ltmp;	/* for GSM_ADD */
29
30	/*  This procedure requires for efficient implementation
31	 *  two tables.
32 	 *
33	 *  INVA[1..8] = integer( (32768 * 8) / real_A[1..8])
34	 *  MIC[1..8]  = minimum value of the LARc[1..8]
35	 */
36
37	/*  Compute the LARpp[1..8]
38	 */
39
40	/* 	for (i = 1; i <= 8; i++, B++, MIC++, INVA++, LARc++, LARpp++) {
41	 *
42	 *		temp1  = GSM_ADD( *LARc, *MIC ) << 10;
43	 *		temp2  = *B << 1;
44	 *		temp1  = GSM_SUB( temp1, temp2 );
45	 *
46	 *		assert(*INVA != MIN_WORD);
47	 *
48	 *		temp1  = GSM_MULT_R( *INVA, temp1 );
49	 *		*LARpp = GSM_ADD( temp1, temp1 );
50	 *	}
51	 */
52
53#undef	STEP
54#define	STEP( B, MIC, INVA )	\
55		temp1    = GSM_ADD( *LARc++, MIC ) << 10;	\
56		temp1    = GSM_SUB( temp1, B << 1 );		\
57		temp1    = GSM_MULT_R( INVA, temp1 );		\
58		*LARpp++ = GSM_ADD( temp1, temp1 );
59
60	STEP(      0,  -32,  13107 );
61	STEP(      0,  -32,  13107 );
62	STEP(   2048,  -16,  13107 );
63	STEP(  -2560,  -16,  13107 );
64
65	STEP(     94,   -8,  19223 );
66	STEP(  -1792,   -8,  17476 );
67	STEP(   -341,   -4,  31454 );
68	STEP(  -1144,   -4,  29708 );
69
70	/* NOTE: the addition of *MIC is used to restore
71	 * 	 the sign of *LARc.
72	 */
73}
74
75/* 4.2.9 */
76/* Computation of the quantized reflection coefficients
77 */
78
79/* 4.2.9.1  Interpolation of the LARpp[1..8] to get the LARp[1..8]
80 */
81
82/*
83 *  Within each frame of 160 analyzed speech samples the short term
84 *  analysis and synthesis filters operate with four different sets of
85 *  coefficients, derived from the previous set of decoded LARs(LARpp(j-1))
86 *  and the actual set of decoded LARs (LARpp(j))
87 *
88 * (Initial value: LARpp(j-1)[1..8] = 0.)
89 */
90
91static void Coefficients_0_12 P3((LARpp_j_1, LARpp_j, LARp),
92	register word * LARpp_j_1,
93	register word * LARpp_j,
94	register word * LARp)
95{
96	register int 	i;
97	register longword ltmp;
98
99	for (i = 1; i <= 8; i++, LARp++, LARpp_j_1++, LARpp_j++) {
100		*LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
101		*LARp = GSM_ADD( *LARp,  SASR( *LARpp_j_1, 1));
102	}
103}
104
105static void Coefficients_13_26 P3((LARpp_j_1, LARpp_j, LARp),
106	register word * LARpp_j_1,
107	register word * LARpp_j,
108	register word * LARp)
109{
110	register int i;
111	register longword ltmp;
112	for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
113		*LARp = GSM_ADD( SASR( *LARpp_j_1, 1), SASR( *LARpp_j, 1 ));
114	}
115}
116
117static void Coefficients_27_39 P3((LARpp_j_1, LARpp_j, LARp),
118	register word * LARpp_j_1,
119	register word * LARpp_j,
120	register word * LARp)
121{
122	register int i;
123	register longword ltmp;
124
125	for (i = 1; i <= 8; i++, LARpp_j_1++, LARpp_j++, LARp++) {
126		*LARp = GSM_ADD( SASR( *LARpp_j_1, 2 ), SASR( *LARpp_j, 2 ));
127		*LARp = GSM_ADD( *LARp, SASR( *LARpp_j, 1 ));
128	}
129}
130
131
132static void Coefficients_40_159 P2((LARpp_j, LARp),
133	register word * LARpp_j,
134	register word * LARp)
135{
136	register int i;
137
138	for (i = 1; i <= 8; i++, LARp++, LARpp_j++)
139		*LARp = *LARpp_j;
140}
141
142/* 4.2.9.2 */
143
144static void LARp_to_rp P1((LARp),
145	register word * LARp)	/* [0..7] IN/OUT  */
146/*
147 *  The input of this procedure is the interpolated LARp[0..7] array.
148 *  The reflection coefficients, rp[i], are used in the analysis
149 *  filter and in the synthesis filter.
150 */
151{
152	register int 		i;
153	register word		temp;
154	register longword	ltmp;
155
156	for (i = 1; i <= 8; i++, LARp++) {
157
158		/* temp = GSM_ABS( *LARp );
159	         *
160		 * if (temp < 11059) temp <<= 1;
161		 * else if (temp < 20070) temp += 11059;
162		 * else temp = GSM_ADD( temp >> 2, 26112 );
163		 *
164		 * *LARp = *LARp < 0 ? -temp : temp;
165		 */
166
167		if (*LARp < 0) {
168			temp = *LARp == MIN_WORD ? MAX_WORD : -(*LARp);
169			*LARp = - ((temp < 11059) ? temp << 1
170				: ((temp < 20070) ? temp + 11059
171				:  GSM_ADD( temp >> 2, 26112 )));
172		} else {
173			temp  = *LARp;
174			*LARp =    (temp < 11059) ? temp << 1
175				: ((temp < 20070) ? temp + 11059
176				:  GSM_ADD( temp >> 2, 26112 ));
177		}
178	}
179}
180
181
182/* 4.2.10 */
183static void Short_term_analysis_filtering P4((S,rp,k_n,s),
184	struct gsm_state * S,
185	register word	* rp,	/* [0..7]	IN	*/
186	register int 	k_n, 	/*   k_end - k_start	*/
187	register word	* s	/* [0..n-1]	IN/OUT	*/
188)
189/*
190 *  This procedure computes the short term residual signal d[..] to be fed
191 *  to the RPE-LTP loop from the s[..] signal and from the local rp[..]
192 *  array (quantized reflection coefficients).  As the call of this
193 *  procedure can be done in many ways (see the interpolation of the LAR
194 *  coefficient), it is assumed that the computation begins with index
195 *  k_start (for arrays d[..] and s[..]) and stops with index k_end
196 *  (k_start and k_end are defined in 4.2.9.1).  This procedure also
197 *  needs to keep the array u[0..7] in memory for each call.
198 */
199{
200	register word		* u = S->u;
201	register int		i;
202	register word		di, zzz, ui, sav, rpi;
203	register longword 	ltmp;
204
205	for (; k_n--; s++) {
206
207		di = sav = *s;
208
209		for (i = 0; i < 8; i++) {		/* YYY */
210
211			ui    = u[i];
212			rpi   = rp[i];
213			u[i]  = sav;
214
215			zzz   = GSM_MULT_R(rpi, di);
216			sav   = GSM_ADD(   ui,  zzz);
217
218			zzz   = GSM_MULT_R(rpi, ui);
219			di    = GSM_ADD(   di,  zzz );
220		}
221
222		*s = di;
223	}
224}
225
226#if defined(USE_FLOAT_MUL) && defined(FAST)
227
228static void Fast_Short_term_analysis_filtering P4((S,rp,k_n,s),
229	struct gsm_state * S,
230	register word	* rp,	/* [0..7]	IN	*/
231	register int 	k_n, 	/*   k_end - k_start	*/
232	register word	* s	/* [0..n-1]	IN/OUT	*/
233)
234{
235	register word		* u = S->u;
236	register int		i;
237
238	float 	  uf[8],
239		 rpf[8];
240
241	register float scalef = 3.0517578125e-5;
242	register float		sav, di, temp;
243
244	for (i = 0; i < 8; ++i) {
245		uf[i]  = u[i];
246		rpf[i] = rp[i] * scalef;
247	}
248	for (; k_n--; s++) {
249		sav = di = *s;
250		for (i = 0; i < 8; ++i) {
251			register float rpfi = rpf[i];
252			register float ufi  = uf[i];
253
254			uf[i] = sav;
255			temp  = rpfi * di + ufi;
256			di   += rpfi * ufi;
257			sav   = temp;
258		}
259		*s = di;
260	}
261	for (i = 0; i < 8; ++i) u[i] = uf[i];
262}
263#endif /* ! (defined (USE_FLOAT_MUL) && defined (FAST)) */
264
265static void Short_term_synthesis_filtering P5((S,rrp,k,wt,sr),
266	struct gsm_state * S,
267	register word	* rrp,	/* [0..7]	IN	*/
268	register int	k,	/* k_end - k_start	*/
269	register word	* wt,	/* [0..k-1]	IN	*/
270	register word	* sr	/* [0..k-1]	OUT	*/
271)
272{
273	register word		* v = S->v;
274	register int		i;
275	register word		sri, tmp1, tmp2;
276	register longword	ltmp;	/* for GSM_ADD  & GSM_SUB */
277
278	while (k--) {
279		sri = *wt++;
280		for (i = 8; i--;) {
281
282			/* sri = GSM_SUB( sri, gsm_mult_r( rrp[i], v[i] ) );
283			 */
284			tmp1 = rrp[i];
285			tmp2 = v[i];
286			tmp2 =  ( tmp1 == MIN_WORD && tmp2 == MIN_WORD
287				? MAX_WORD
288				: 0x0FFFF & (( (longword)tmp1 * (longword)tmp2
289					     + 16384) >> 15)) ;
290
291			sri  = GSM_SUB( sri, tmp2 );
292
293			/* v[i+1] = GSM_ADD( v[i], gsm_mult_r( rrp[i], sri ) );
294			 */
295			tmp1  = ( tmp1 == MIN_WORD && sri == MIN_WORD
296				? MAX_WORD
297				: 0x0FFFF & (( (longword)tmp1 * (longword)sri
298					     + 16384) >> 15)) ;
299
300			v[i+1] = GSM_ADD( v[i], tmp1);
301		}
302		*sr++ = v[0] = sri;
303	}
304}
305
306
307#if defined(FAST) && defined(USE_FLOAT_MUL)
308
309static void Fast_Short_term_synthesis_filtering P5((S,rrp,k,wt,sr),
310	struct gsm_state * S,
311	register word	* rrp,	/* [0..7]	IN	*/
312	register int	k,	/* k_end - k_start	*/
313	register word	* wt,	/* [0..k-1]	IN	*/
314	register word	* sr	/* [0..k-1]	OUT	*/
315)
316{
317	register word		* v = S->v;
318	register int		i;
319
320	float va[9], rrpa[8];
321	register float scalef = 3.0517578125e-5, temp;
322
323	for (i = 0; i < 8; ++i) {
324		va[i]   = v[i];
325		rrpa[i] = (float)rrp[i] * scalef;
326	}
327	while (k--) {
328		register float sri = *wt++;
329		for (i = 8; i--;) {
330			sri -= rrpa[i] * va[i];
331			if     (sri < -32768.) sri = -32768.;
332			else if (sri > 32767.) sri =  32767.;
333
334			temp = va[i] + rrpa[i] * sri;
335			if     (temp < -32768.) temp = -32768.;
336			else if (temp > 32767.) temp =  32767.;
337			va[i+1] = temp;
338		}
339		*sr++ = va[0] = sri;
340	}
341	for (i = 0; i < 9; ++i) v[i] = va[i];
342}
343
344#endif /* defined(FAST) && defined(USE_FLOAT_MUL) */
345
346void Gsm_Short_Term_Analysis_Filter P3((S,LARc,s),
347
348	struct gsm_state * S,
349
350	word	* LARc,		/* coded log area ratio [0..7]  IN	*/
351	word	* s		/* signal [0..159]		IN/OUT	*/
352)
353{
354	word		* LARpp_j	= S->LARpp[ S->j      ];
355	word		* LARpp_j_1	= S->LARpp[ S->j ^= 1 ];
356
357	word		LARp[8];
358
359#undef	FILTER
360#if 	defined(FAST) && defined(USE_FLOAT_MUL)
361# 	define	FILTER 	(* (S->fast			\
362			   ? Fast_Short_term_analysis_filtering	\
363		    	   : Short_term_analysis_filtering	))
364
365#else
366# 	define	FILTER	Short_term_analysis_filtering
367#endif
368
369	Decoding_of_the_coded_Log_Area_Ratios( LARc, LARpp_j );
370
371	Coefficients_0_12(  LARpp_j_1, LARpp_j, LARp );
372	LARp_to_rp( LARp );
373	FILTER( S, LARp, 13, s);
374
375	Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
376	LARp_to_rp( LARp );
377	FILTER( S, LARp, 14, s + 13);
378
379	Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
380	LARp_to_rp( LARp );
381	FILTER( S, LARp, 13, s + 27);
382
383	Coefficients_40_159( LARpp_j, LARp);
384	LARp_to_rp( LARp );
385	FILTER( S, LARp, 120, s + 40);
386}
387
388void Gsm_Short_Term_Synthesis_Filter P4((S, LARcr, wt, s),
389	struct gsm_state * S,
390
391	word	* LARcr,	/* received log area ratios [0..7] IN  */
392	word	* wt,		/* received d [0..159]		   IN  */
393
394	word	* s		/* signal   s [0..159]		  OUT  */
395)
396{
397	word		* LARpp_j	= S->LARpp[ S->j     ];
398	word		* LARpp_j_1	= S->LARpp[ S->j ^=1 ];
399
400	word		LARp[8];
401
402#undef	FILTER
403#if 	defined(FAST) && defined(USE_FLOAT_MUL)
404
405# 	define	FILTER 	(* (S->fast			\
406			   ? Fast_Short_term_synthesis_filtering	\
407		    	   : Short_term_synthesis_filtering	))
408#else
409#	define	FILTER	Short_term_synthesis_filtering
410#endif
411
412	Decoding_of_the_coded_Log_Area_Ratios( LARcr, LARpp_j );
413
414	Coefficients_0_12( LARpp_j_1, LARpp_j, LARp );
415	LARp_to_rp( LARp );
416	FILTER( S, LARp, 13, wt, s );
417
418	Coefficients_13_26( LARpp_j_1, LARpp_j, LARp);
419	LARp_to_rp( LARp );
420	FILTER( S, LARp, 14, wt + 13, s + 13 );
421
422	Coefficients_27_39( LARpp_j_1, LARpp_j, LARp);
423	LARp_to_rp( LARp );
424	FILTER( S, LARp, 13, wt + 27, s + 27 );
425
426	Coefficients_40_159( LARpp_j, LARp );
427	LARp_to_rp( LARp );
428	FILTER(S, LARp, 120, wt + 40, s + 40);
429}
430