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comparison libgsmefr/dec_12k2.c @ 53:49dd1ac8e75b

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libgsmefr: import most *.c files from ETSI source
author Mychaela Falconia <falcon@freecalypso.org>
date Fri, 25 Nov 2022 16:18:21 +0000
parents
children 1cc2968f883f
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52:988fd7ff514f 53:49dd1ac8e75b
1 /***************************************************************************
2 *
3 * FILE NAME: dec_12k2.c
4 *
5 * FUNCTIONS DEFINED IN THIS FILE:
6 * Init_Decoder_12k2 and Decoder_12k2
7 *
8 *
9 * Init_Decoder_12k2():
10 * Initialization of variables for the decoder section.
11 *
12 * Decoder_12k2():
13 * Speech decoder routine operating on a frame basis.
14 *
15 ***************************************************************************/
16
17 #include "typedef.h"
18 #include "basic_op.h"
19 #include "sig_proc.h"
20 #include "count.h"
21 #include "codec.h"
22 #include "cnst.h"
23
24 #include "dtx.h"
25
26 extern Word16 dtx_mode;
27
28 /*---------------------------------------------------------------*
29 * Decoder constant parameters (defined in "cnst.h") *
30 *---------------------------------------------------------------*
31 * L_FRAME : Frame size. *
32 * L_FRAME_BY2 : Half the frame size. *
33 * L_SUBFR : Sub-frame size. *
34 * M : LPC order. *
35 * MP1 : LPC order+1 *
36 * PIT_MIN : Minimum pitch lag. *
37 * PIT_MAX : Maximum pitch lag. *
38 * L_INTERPOL : Length of filter for interpolation *
39 * PRM_SIZE : size of vector containing analysis parameters *
40 *---------------------------------------------------------------*/
41
42 /*--------------------------------------------------------*
43 * Static memory allocation. *
44 *--------------------------------------------------------*/
45
46 /* Excitation vector */
47
48 static Word16 old_exc[L_FRAME + PIT_MAX + L_INTERPOL];
49 static Word16 *exc;
50
51 /* Lsp (Line spectral pairs) */
52
53 static Word16 lsp_old[M];
54
55 /* Filter's memory */
56
57 static Word16 mem_syn[M];
58
59 /* Memories for bad frame handling */
60
61 static Word16 prev_bf;
62 static Word16 state;
63
64 /***************************************************************************
65 *
66 * FUNCTION: Init_Decoder_12k2
67 *
68 * PURPOSE: Initialization of variables for the decoder section.
69 *
70 ***************************************************************************/
71
72 void Init_Decoder_12k2 (void)
73 {
74 /* Initialize static pointer */
75
76 exc = old_exc + PIT_MAX + L_INTERPOL;
77
78 /* Static vectors to zero */
79
80 Set_zero (old_exc, PIT_MAX + L_INTERPOL);
81 Set_zero (mem_syn, M);
82
83 /* Initialize lsp_old [] */
84
85 lsp_old[0] = 30000;
86 lsp_old[1] = 26000;
87 lsp_old[2] = 21000;
88 lsp_old[3] = 15000;
89 lsp_old[4] = 8000;
90 lsp_old[5] = 0;
91 lsp_old[6] = -8000;
92 lsp_old[7] = -15000;
93 lsp_old[8] = -21000;
94 lsp_old[9] = -26000;
95
96 /* Initialize memories of bad frame handling */
97
98 prev_bf = 0;
99 state = 0;
100
101 return;
102 }
103
104 /***************************************************************************
105 *
106 * FUNCTION: Decoder_12k2
107 *
108 * PURPOSE: Speech decoder routine.
109 *
110 ***************************************************************************/
111
112 void Decoder_12k2 (
113 Word16 parm[], /* input : vector of synthesis parameters
114 parm[0] = bad frame indicator (bfi) */
115 Word16 synth[],/* output: synthesis speech */
116 Word16 A_t[], /* output: decoded LP filter in 4 subframes */
117 Word16 TAF,
118 Word16 SID_flag
119 )
120 {
121
122 /* LPC coefficients */
123
124 Word16 *Az; /* Pointer on A_t */
125
126 /* LSPs */
127
128 Word16 lsp_new[M];
129 Word16 lsp_mid[M];
130
131 /* Algebraic codevector */
132
133 Word16 code[L_SUBFR];
134
135 /* excitation */
136
137 Word16 excp[L_SUBFR];
138
139 /* Scalars */
140
141 Word16 i, i_subfr;
142 Word16 T0, T0_frac, index;
143 Word16 gain_pit, gain_code, bfi, pit_sharp;
144 Word16 temp;
145 Word32 L_temp;
146
147 extern Word16 rxdtx_ctrl, rx_dtx_state;
148 extern Word32 L_pn_seed_rx;
149
150 /* Test bad frame indicator (bfi) */
151
152 bfi = *parm++; move16 ();
153
154 /* Set state machine */
155
156 test (); test ();
157 if (bfi != 0)
158 {
159 state = add (state, 1);
160 }
161 else if (sub (state, 6) == 0)
162 {
163 state = 5;
164 }
165 else
166 {
167 state = 0;
168 }
169
170 test ();
171 if (sub (state, 6) > 0)
172 {
173 state = 6;
174 }
175 rx_dtx (&rxdtx_ctrl, TAF, bfi, SID_flag);
176
177 /* If this frame is the first speech frame after CNI period, */
178 /* set the BFH state machine to an appropriate state depending */
179 /* on whether there was DTX muting before start of speech or not */
180 /* If there was DTX muting, the first speech frame is muted. */
181 /* If there was no DTX muting, the first speech frame is not */
182 /* muted. The BFH state machine starts from state 5, however, to */
183 /* keep the audible noise resulting from a SID frame which is */
184 /* erroneously interpreted as a good speech frame as small as */
185 /* possible (the decoder output in this case is quickly muted) */
186 test (); logic16 ();
187 if ((rxdtx_ctrl & RX_FIRST_SP_FLAG) != 0)
188 {
189 test (); logic16 ();
190 if ((rxdtx_ctrl & RX_PREV_DTX_MUTING) != 0)
191 {
192 state = 5; move16 ();
193 prev_bf = 1; move16 ();
194 }
195 else
196 {
197 state = 5; move16 ();
198 prev_bf = 0; move16 ();
199 }
200 }
201
202 #if (WMOPS)
203 fwc (); /* function worst case */
204
205 /* Note! The following test is performed only for determining
206 whether or not DTX mode is active, in order to switch off
207 worst worst case complexity printout when DTX mode is active
208 */
209 if ((rxdtx_ctrl & RX_SP_FLAG) == 0)
210 {
211 dtx_mode = 1;
212 }
213 #endif
214
215 D_plsf_5 (parm, lsp_mid, lsp_new, bfi, rxdtx_ctrl, rx_dtx_state);
216
217 #if (WMOPS)
218 fwc (); /* function worst case */
219 #endif
220 /* Advance synthesis parameters pointer */
221 parm += 5; move16 ();
222
223 test (); logic16 ();
224 if ((rxdtx_ctrl & RX_SP_FLAG) != 0)
225 {
226 /* Interpolation of LPC for the 4 subframes */
227
228 Int_lpc (lsp_old, lsp_mid, lsp_new, A_t);
229 }
230 else
231 {
232 /* Comfort noise: use the same parameters in each subframe */
233 Lsp_Az (lsp_new, A_t);
234
235 for (i = 0; i < MP1; i++)
236 {
237 A_t[i + MP1] = A_t[i]; move16 ();
238 A_t[i + 2 * MP1] = A_t[i]; move16 ();
239 A_t[i + 3 * MP1] = A_t[i]; move16 ();
240 }
241 }
242
243 /* update the LSPs for the next frame */
244 for (i = 0; i < M; i++)
245 {
246 lsp_old[i] = lsp_new[i]; move16 ();
247 }
248 #if (WMOPS)
249 fwc (); /* function worst case */
250 #endif
251
252 /*---------------------------------------------------------------------*
253 * Loop for every subframe in the analysis frame *
254 *---------------------------------------------------------------------*
255 * The subframe size is L_SUBFR and the loop is repeated *
256 * L_FRAME/L_SUBFR times *
257 * - decode the pitch delay *
258 * - decode algebraic code *
259 * - decode pitch and codebook gains *
260 * - find the excitation and compute synthesis speech *
261 *---------------------------------------------------------------------*/
262
263 /* pointer to interpolated LPC parameters */
264 Az = A_t; move16 ();
265
266 for (i_subfr = 0; i_subfr < L_FRAME; i_subfr += L_SUBFR)
267 {
268
269 index = *parm++; move16 (); /* pitch index */
270
271 test (); logic16 ();
272 if ((rxdtx_ctrl & RX_SP_FLAG) != 0)
273 {
274 T0 = Dec_lag6 (index, PIT_MIN, PIT_MAX, i_subfr, L_FRAME_BY2,
275 &T0_frac, bfi);
276 #if (WMOPS)
277 fwc (); /* function worst case */
278 #endif
279
280 /*-------------------------------------------------*
281 * - Find the adaptive codebook vector. *
282 *-------------------------------------------------*/
283
284 Pred_lt_6 (&exc[i_subfr], T0, T0_frac, L_SUBFR);
285 #if (WMOPS)
286 fwc (); /* function worst case */
287 #endif
288 }
289 else
290 {
291 T0 = L_SUBFR; move16 ();
292 }
293
294 /*-------------------------------------------------------*
295 * - Decode pitch gain. *
296 *-------------------------------------------------------*/
297
298 index = *parm++; move16 ();
299
300 gain_pit = d_gain_pitch (index, bfi, state, prev_bf, rxdtx_ctrl);
301 move16 ();
302 #if (WMOPS)
303 fwc (); /* function worst case */
304 #endif
305
306 /*-------------------------------------------------------*
307 * - Decode innovative codebook. *
308 *-------------------------------------------------------*/
309
310 test (); logic16 ();
311 if ((rxdtx_ctrl & RX_SP_FLAG) != 0)
312 {
313 dec_10i40_35bits (parm, code);
314 }
315 else
316 { /* Use pseudo noise for excitation when SP_flag == 0 */
317 build_CN_code (code, &L_pn_seed_rx);
318 }
319
320 parm += 10; move16 ();
321 #if (WMOPS)
322 fwc (); /* function worst case */
323 #endif
324
325 /*-------------------------------------------------------*
326 * - Add the pitch contribution to code[]. *
327 *-------------------------------------------------------*/
328
329 /* pit_sharp = gain_pit; */
330 /* if (pit_sharp > 1.0) pit_sharp = 1.0; */
331
332 pit_sharp = shl (gain_pit, 3);
333
334 /* This loop is not entered when SP_FLAG is 0 */
335 for (i = T0; i < L_SUBFR; i++)
336 {
337 temp = mult (code[i - T0], pit_sharp);
338 code[i] = add (code[i], temp);
339 move16 ();
340 }
341 #if (WMOPS)
342 fwc (); /* function worst case */
343 #endif
344 /* post processing of excitation elements */
345
346 test (); /* This test is not passed when SP_FLAG is 0 */
347 if (sub (pit_sharp, 16384) > 0)
348 {
349 for (i = 0; i < L_SUBFR; i++)
350 {
351 temp = mult (exc[i + i_subfr], pit_sharp);
352 L_temp = L_mult (temp, gain_pit);
353 L_temp = L_shl (L_temp, 1);
354 excp[i] = round (L_temp);
355 move16 ();
356 }
357 }
358 /*-------------------------------------------------*
359 * - Decode codebook gain. *
360 *-------------------------------------------------*/
361
362 index = *parm++; move16 (); /* index of energy VQ */
363
364 d_gain_code (index, code, L_SUBFR, &gain_code, bfi, state, prev_bf,
365 rxdtx_ctrl, i_subfr, rx_dtx_state);
366 #if (WMOPS)
367 fwc (); /* function worst case */
368 #endif
369
370 /*-------------------------------------------------------*
371 * - Find the total excitation. *
372 * - Find synthesis speech corresponding to exc[]. *
373 *-------------------------------------------------------*/
374 for (i = 0; i < L_SUBFR; i++)
375 {
376 /* exc[i] = gain_pit*exc[i] + gain_code*code[i]; */
377
378 L_temp = L_mult (exc[i + i_subfr], gain_pit);
379 L_temp = L_mac (L_temp, code[i], gain_code);
380 L_temp = L_shl (L_temp, 3);
381
382 exc[i + i_subfr] = round (L_temp);
383 move16 ();
384 }
385 #if (WMOPS)
386 fwc (); /* function worst case */
387 #endif
388
389 test ();
390 if (sub (pit_sharp, 16384) > 0)
391 {
392 for (i = 0; i < L_SUBFR; i++)
393 {
394 excp[i] = add (excp[i], exc[i + i_subfr]);
395 move16 ();
396 }
397 agc2 (&exc[i_subfr], excp, L_SUBFR);
398 Syn_filt (Az, excp, &synth[i_subfr], L_SUBFR, mem_syn, 1);
399 }
400 else
401 {
402 Syn_filt (Az, &exc[i_subfr], &synth[i_subfr], L_SUBFR, mem_syn, 1);
403 }
404
405 #if (WMOPS)
406 fwc (); /* function worst case */
407 #endif
408 /* interpolated LPC parameters for next subframe */
409 Az += MP1; move16 ();
410 }
411
412 /*--------------------------------------------------*
413 * Update signal for next frame. *
414 * -> shift to the left by L_FRAME exc[] *
415 *--------------------------------------------------*/
416
417 Copy (&old_exc[L_FRAME], &old_exc[0], PIT_MAX + L_INTERPOL);
418 #if (WMOPS)
419 fwc (); /* function worst case */
420 #endif
421 prev_bf = bfi; move16 ();
422
423 return;
424 }