30 static void Autocorrelation P2((s, L_ACF),
56 for (k = 0; k <= 159; k++) {
57 temp = GSM_ABS( s[k] );
58 if (temp > smax) smax = temp;
63 lmax = k6maxmin(s,160,NULL);
64 smax = (lmax > MAX_WORD) ? MAX_WORD : lmax;
69 if (smax == 0) scalauto = 0;
72 scalauto = 4 - gsm_norm( (longword)smax << 16 );
83 case n: for (k = 0; k <= 159; k++) \
84 float_s[k] = (float) \
85 (s[k] = GSM_MULT_R(s[k], 16384 >> (n-1)));\
89 case n: for (k = 0; k <= 159; k++) \
90 s[k] = (word)GSM_MULT_R( s[k], 16384 >> (n-1) );\
103 k6vsraw(s,160,scalauto);
106 # ifdef USE_FLOAT_MUL
107 else for (k = 0; k <= 159; k++) float_s[k] = (
float) s[k];
114 # ifdef USE_FLOAT_MUL
115 register float * sp = float_s;
116 register float sl = *sp;
118 # define STEP(k) L_ACF[k] += (longword)(sl * sp[ -(k) ]);
123 # define STEP(k) L_ACF[k] += ((longword)sl * sp[ -(k) ]);
126 # define NEXTI sl = *++sp
129 for (k = 9; k--; L_ACF[k] = 0) ;
135 STEP(0); STEP(1); STEP(2);
137 STEP(0); STEP(1); STEP(2); STEP(3);
139 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4);
141 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5);
143 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); STEP(6);
145 STEP(0); STEP(1); STEP(2); STEP(3); STEP(4); STEP(5); STEP(6); STEP(7);
147 for (i = 8; i <= 159; i++) {
152 STEP(1); STEP(2); STEP(3); STEP(4);
153 STEP(5); STEP(6); STEP(7); STEP(8);
156 for (k = 9; k--; L_ACF[k] <<= 1) ;
163 for (k=0; k<9; k++) {
164 L_ACF[k] = 2*k6iprod(s,s+k,160-k);
171 assert(scalauto <= 4);
173 for (k = 160; k--; *s++ <<= scalauto) ;
175 k6vsllw(s,160,scalauto);
180 #if defined(USE_FLOAT_MUL) && defined(FAST)
182 static void Fast_Autocorrelation P2((s, L_ACF),
191 register float *sf = s_f;
193 for (i = 0; i < 160; ++i) sf[i] = s[i];
194 for (k = 0; k <= 8; k++) {
195 register float L_temp2 = 0;
196 register float *sfl = sf - k;
197 for (i = k; i < 160; ++i) L_temp2 += sf[i] * sfl[i];
198 f_L_ACF[k] = L_temp2;
200 scale = MAX_LONGWORD / f_L_ACF[0];
202 for (k = 0; k <= 8; k++) {
203 L_ACF[k] = f_L_ACF[k] * scale;
210 static void Reflection_coefficients P2( (L_ACF, r),
215 register int i, m, n;
225 for (i = 8; i--; *r++ = 0) ;
229 assert( L_ACF[0] != 0 );
230 temp = gsm_norm( L_ACF[0] );
232 assert(temp >= 0 && temp < 32);
235 for (i = 0; i <= 8; i++) ACF[i] = (word)SASR( L_ACF[i] << temp, 16 );
240 for (i = 1; i <= 7; i++) K[ i ] = ACF[ i ];
241 for (i = 0; i <= 8; i++) P[ i ] = ACF[ i ];
245 for (n = 1; n <= 8; n++, r++) {
248 temp = GSM_ABS(temp);
250 for (i = n; i <= 8; i++) *r++ = 0;
254 *r = gsm_div( temp, P[0] );
257 if (P[1] > 0) *r = -*r;
258 assert (*r != MIN_WORD);
263 temp = (word)GSM_MULT_R( P[1], *r );
264 P[0] = GSM_ADD( P[0], temp );
266 for (m = 1; m <= 8 - n; m++) {
267 temp = (word)GSM_MULT_R( K[ m ], *r );
268 P[m] = GSM_ADD( P[ m+1 ], temp );
270 temp = (word)GSM_MULT_R( P[ m+1 ], *r );
271 K[m] = GSM_ADD( K[ m ], temp );
278 static void Transformation_to_Log_Area_Ratios P1((r),
295 for (i = 1; i <= 8; i++, r++) {
298 temp = GSM_ABS(temp);
303 }
else if (temp < 31130) {
304 assert( temp >= 11059 );
307 assert( temp >= 26112 );
312 *r = *r < 0 ? -temp : temp;
313 assert( *r != MIN_WORD );
319 static void Quantization_and_coding P1((LAR),
336 # define STEP( A, B, MAC, MIC ) \
337 temp = (word)GSM_MULT( A, *LAR ); \
338 temp = GSM_ADD( temp, B ); \
339 temp = GSM_ADD( temp, 256 ); \
340 temp = (word)SASR( temp, 9 ); \
341 *LAR = temp>MAC ? MAC - MIC : (temp<MIC ? 0 : temp - MIC); \
344 STEP( 20480, 0, 31, -32 );
345 STEP( 20480, 0, 31, -32 );
346 STEP( 20480, 2048, 15, -16 );
347 STEP( 20480, -2560, 15, -16 );
349 STEP( 13964, 94, 7, -8 );
350 STEP( 15360, -1792, 7, -8 );
351 STEP( 8534, -341, 3, -4 );
352 STEP( 9036, -1144, 3, -4 );
357 void Gsm_LPC_Analysis P3((S, s,LARc),
364 #if defined(USE_FLOAT_MUL) && defined(FAST)
365 if (S->fast) Fast_Autocorrelation (s, L_ACF );
368 Autocorrelation (s, L_ACF );
369 Reflection_coefficients (L_ACF, LARc );
370 Transformation_to_Log_Area_Ratios (LARc);
371 Quantization_and_coding (LARc);