1/*
2 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include "webrtc_cng.h"
12
13#include <string.h>
14#include <stdlib.h>
15
16#include "cng_helpfuns.h"
17#include "signal_processing_library.h"
18
19typedef struct WebRtcCngDecoder_ {
20  uint32_t dec_seed;
21  int32_t dec_target_energy;
22  int32_t dec_used_energy;
23  int16_t dec_target_reflCoefs[WEBRTC_CNG_MAX_LPC_ORDER + 1];
24  int16_t dec_used_reflCoefs[WEBRTC_CNG_MAX_LPC_ORDER + 1];
25  int16_t dec_filtstate[WEBRTC_CNG_MAX_LPC_ORDER + 1];
26  int16_t dec_filtstateLow[WEBRTC_CNG_MAX_LPC_ORDER + 1];
27  int16_t dec_Efiltstate[WEBRTC_CNG_MAX_LPC_ORDER + 1];
28  int16_t dec_EfiltstateLow[WEBRTC_CNG_MAX_LPC_ORDER + 1];
29  int16_t dec_order;
30  int16_t dec_target_scale_factor;  /* Q29 */
31  int16_t dec_used_scale_factor;  /* Q29 */
32  int16_t target_scale_factor;  /* Q13 */
33  int16_t errorcode;
34  int16_t initflag;
35} WebRtcCngDecoder;
36
37typedef struct WebRtcCngEncoder_ {
38  size_t enc_nrOfCoefs;
39  int enc_sampfreq;
40  int16_t enc_interval;
41  int16_t enc_msSinceSID;
42  int32_t enc_Energy;
43  int16_t enc_reflCoefs[WEBRTC_CNG_MAX_LPC_ORDER + 1];
44  int32_t enc_corrVector[WEBRTC_CNG_MAX_LPC_ORDER + 1];
45  uint32_t enc_seed;
46  int16_t errorcode;
47  int16_t initflag;
48} WebRtcCngEncoder;
49
50const int32_t WebRtcCng_kDbov[94] = {
51  1081109975,  858756178,  682134279,  541838517,  430397633,  341876992,
52  271562548,  215709799,  171344384,  136103682,  108110997,   85875618,
53  68213428,   54183852,   43039763,   34187699,   27156255,   21570980,
54  17134438,   13610368,   10811100,    8587562,    6821343,    5418385,
55  4303976,    3418770,    2715625,    2157098,    1713444,    1361037,
56  1081110,     858756,     682134,     541839,     430398,     341877,
57  271563,     215710,     171344,     136104,     108111,      85876,
58  68213,      54184,      43040,      34188,      27156,      21571,
59  17134,      13610,      10811,       8588,       6821,       5418,
60  4304,       3419,       2716,       2157,       1713,       1361,
61  1081,        859,        682,        542,        430,        342,
62  272,        216,        171,        136,        108,         86,
63  68,         54,         43,         34,         27,         22,
64  17,         14,         11,          9,          7,          5,
65  4,          3,          3,          2,          2,           1,
66  1,          1,          1,          1
67};
68
69const int16_t WebRtcCng_kCorrWindow[WEBRTC_CNG_MAX_LPC_ORDER] = {
70  32702, 32636, 32570, 32505, 32439, 32374,
71  32309, 32244, 32179, 32114, 32049, 31985
72};
73
74/****************************************************************************
75 * WebRtcCng_CreateEnc/Dec(...)
76 *
77 * These functions create an instance to the specified structure
78 *
79 * Input:
80 *      - XXX_inst      : Pointer to created instance that should be created
81 *
82 * Return value         :  0 - Ok
83 *                        -1 - Error
84 */
85int16_t WebRtcCng_CreateEnc(CNG_enc_inst** cng_inst) {
86  if (cng_inst != NULL) {
87    *cng_inst = (CNG_enc_inst*) malloc(sizeof(WebRtcCngEncoder));
88    if (*cng_inst != NULL) {
89      (*(WebRtcCngEncoder**) cng_inst)->errorcode = 0;
90      (*(WebRtcCngEncoder**) cng_inst)->initflag = 0;
91
92      /* Needed to get the right function pointers in SPLIB. */
93      WebRtcSpl_Init();
94
95      return 0;
96    } else {
97      /* The memory could not be allocated. */
98      return -1;
99    }
100  } else {
101    /* The input pointer is invalid (NULL). */
102    return -1;
103  }
104}
105
106int16_t WebRtcCng_CreateDec(CNG_dec_inst** cng_inst) {
107  if (cng_inst != NULL ) {
108    *cng_inst = (CNG_dec_inst*) malloc(sizeof(WebRtcCngDecoder));
109    if (*cng_inst != NULL ) {
110      (*(WebRtcCngDecoder**) cng_inst)->errorcode = 0;
111      (*(WebRtcCngDecoder**) cng_inst)->initflag = 0;
112
113      /* Needed to get the right function pointers in SPLIB. */
114      WebRtcSpl_Init();
115
116      return 0;
117    } else {
118      /* The memory could not be allocated */
119      return -1;
120    }
121  } else {
122    /* The input pointer is invalid (NULL). */
123    return -1;
124  }
125}
126
127/****************************************************************************
128 * WebRtcCng_InitEnc/Dec(...)
129 *
130 * This function initializes a instance
131 *
132 * Input:
133 *    - cng_inst      : Instance that should be initialized
134 *
135 *    - fs            : 8000 for narrowband and 16000 for wideband
136 *    - interval      : generate SID data every interval ms
137 *    - quality       : TBD
138 *
139 * Output:
140 *    - cng_inst      : Initialized instance
141 *
142 * Return value       :  0 - Ok
143 *                      -1 - Error
144 */
145int WebRtcCng_InitEnc(CNG_enc_inst* cng_inst, int fs, int16_t interval,
146                      int16_t quality) {
147  int i;
148  WebRtcCngEncoder* inst = (WebRtcCngEncoder*) cng_inst;
149  memset(inst, 0, sizeof(WebRtcCngEncoder));
150
151  /* Check LPC order */
152  if (quality > WEBRTC_CNG_MAX_LPC_ORDER || quality <= 0) {
153    inst->errorcode = CNG_DISALLOWED_LPC_ORDER;
154    return -1;
155  }
156
157  inst->enc_sampfreq = fs;
158  inst->enc_interval = interval;
159  inst->enc_nrOfCoefs = quality;
160  inst->enc_msSinceSID = 0;
161  inst->enc_seed = 7777;  /* For debugging only. */
162  inst->enc_Energy = 0;
163  for (i = 0; i < (WEBRTC_CNG_MAX_LPC_ORDER + 1); i++) {
164    inst->enc_reflCoefs[i] = 0;
165    inst->enc_corrVector[i] = 0;
166  }
167  inst->initflag = 1;
168
169  return 0;
170}
171
172void WebRtcCng_InitDec(CNG_dec_inst* cng_inst) {
173  int i;
174
175  WebRtcCngDecoder* inst = (WebRtcCngDecoder*) cng_inst;
176
177  memset(inst, 0, sizeof(WebRtcCngDecoder));
178  inst->dec_seed = 7777;  /* For debugging only. */
179  inst->dec_order = 5;
180  inst->dec_target_scale_factor = 0;
181  inst->dec_used_scale_factor = 0;
182  for (i = 0; i < (WEBRTC_CNG_MAX_LPC_ORDER + 1); i++) {
183    inst->dec_filtstate[i] = 0;
184    inst->dec_target_reflCoefs[i] = 0;
185    inst->dec_used_reflCoefs[i] = 0;
186  }
187  inst->dec_target_reflCoefs[0] = 0;
188  inst->dec_used_reflCoefs[0] = 0;
189  inst->dec_used_energy = 0;
190  inst->initflag = 1;
191}
192
193/****************************************************************************
194 * WebRtcCng_FreeEnc/Dec(...)
195 *
196 * These functions frees the dynamic memory of a specified instance
197 *
198 * Input:
199 *    - cng_inst      : Pointer to created instance that should be freed
200 *
201 * Return value       :  0 - Ok
202 *                      -1 - Error
203 */
204int16_t WebRtcCng_FreeEnc(CNG_enc_inst* cng_inst) {
205  free(cng_inst);
206  return 0;
207}
208
209int16_t WebRtcCng_FreeDec(CNG_dec_inst* cng_inst) {
210  free(cng_inst);
211  return 0;
212}
213
214/****************************************************************************
215 * WebRtcCng_Encode(...)
216 *
217 * These functions analyzes background noise
218 *
219 * Input:
220 *    - cng_inst      : Pointer to created instance
221 *    - speech        : Signal (noise) to be analyzed
222 *    - nrOfSamples   : Size of speech vector
223 *    - bytesOut      : Nr of bytes to transmit, might be 0
224 *
225 * Return value       :  0 - Ok
226 *                      -1 - Error
227 */
228int WebRtcCng_Encode(CNG_enc_inst* cng_inst, int16_t* speech,
229                     size_t nrOfSamples, uint8_t* SIDdata,
230                     size_t* bytesOut, int16_t forceSID) {
231  WebRtcCngEncoder* inst = (WebRtcCngEncoder*) cng_inst;
232
233  int16_t arCoefs[WEBRTC_CNG_MAX_LPC_ORDER + 1];
234  int32_t corrVector[WEBRTC_CNG_MAX_LPC_ORDER + 1];
235  int16_t refCs[WEBRTC_CNG_MAX_LPC_ORDER + 1];
236  int16_t hanningW[WEBRTC_CNG_MAX_OUTSIZE_ORDER];
237  int16_t ReflBeta = 19661;  /* 0.6 in q15. */
238  int16_t ReflBetaComp = 13107;  /* 0.4 in q15. */
239  int32_t outEnergy;
240  int outShifts;
241  size_t i;
242  int stab;
243  int acorrScale;
244  size_t index;
245  size_t ind, factor;
246  int32_t* bptr;
247  int32_t blo, bhi;
248  int16_t negate;
249  const int16_t* aptr;
250  int16_t speechBuf[WEBRTC_CNG_MAX_OUTSIZE_ORDER];
251
252  /* Check if encoder initiated. */
253  if (inst->initflag != 1) {
254    inst->errorcode = CNG_ENCODER_NOT_INITIATED;
255    return -1;
256  }
257
258  /* Check framesize. */
259  if (nrOfSamples > WEBRTC_CNG_MAX_OUTSIZE_ORDER) {
260    inst->errorcode = CNG_DISALLOWED_FRAME_SIZE;
261    return -1;
262  }
263
264  for (i = 0; i < nrOfSamples; i++) {
265    speechBuf[i] = speech[i];
266  }
267
268  factor = nrOfSamples;
269
270  /* Calculate energy and a coefficients. */
271  outEnergy = WebRtcSpl_Energy(speechBuf, nrOfSamples, &outShifts);
272  while (outShifts > 0) {
273    /* We can only do 5 shifts without destroying accuracy in
274     * division factor. */
275    if (outShifts > 5) {
276      outEnergy <<= (outShifts - 5);
277      outShifts = 5;
278    } else {
279      factor /= 2;
280      outShifts--;
281    }
282  }
283  outEnergy = WebRtcSpl_DivW32W16(outEnergy, (int16_t)factor);
284
285  if (outEnergy > 1) {
286    /* Create Hanning Window. */
287    WebRtcSpl_GetHanningWindow(hanningW, nrOfSamples / 2);
288    for (i = 0; i < (nrOfSamples / 2); i++)
289      hanningW[nrOfSamples - i - 1] = hanningW[i];
290
291    WebRtcSpl_ElementwiseVectorMult(speechBuf, hanningW, speechBuf, nrOfSamples,
292                                    14);
293
294    WebRtcSpl_AutoCorrelation(speechBuf, nrOfSamples, inst->enc_nrOfCoefs,
295                              corrVector, &acorrScale);
296
297    if (*corrVector == 0)
298      *corrVector = WEBRTC_SPL_WORD16_MAX;
299
300    /* Adds the bandwidth expansion. */
301    aptr = WebRtcCng_kCorrWindow;
302    bptr = corrVector;
303
304    /* (zzz) lpc16_1 = 17+1+820+2+2 = 842 (ordo2=700). */
305    for (ind = 0; ind < inst->enc_nrOfCoefs; ind++) {
306      /* The below code multiplies the 16 b corrWindow values (Q15) with
307       * the 32 b corrvector (Q0) and shifts the result down 15 steps. */
308      negate = *bptr < 0;
309      if (negate)
310        *bptr = -*bptr;
311
312      blo = (int32_t) * aptr * (*bptr & 0xffff);
313      bhi = ((blo >> 16) & 0xffff)
314          + ((int32_t)(*aptr++) * ((*bptr >> 16) & 0xffff));
315      blo = (blo & 0xffff) | ((bhi & 0xffff) << 16);
316
317      *bptr = (((bhi >> 16) & 0x7fff) << 17) | ((uint32_t) blo >> 15);
318      if (negate)
319        *bptr = -*bptr;
320      bptr++;
321    }
322    /* End of bandwidth expansion. */
323
324    stab = WebRtcSpl_LevinsonDurbin(corrVector, arCoefs, refCs,
325                                    inst->enc_nrOfCoefs);
326
327    if (!stab) {
328      /* Disregard from this frame */
329      *bytesOut = 0;
330      return 0;
331    }
332
333  } else {
334    for (i = 0; i < inst->enc_nrOfCoefs; i++)
335      refCs[i] = 0;
336  }
337
338  if (forceSID) {
339    /* Read instantaneous values instead of averaged. */
340    for (i = 0; i < inst->enc_nrOfCoefs; i++)
341      inst->enc_reflCoefs[i] = refCs[i];
342    inst->enc_Energy = outEnergy;
343  } else {
344    /* Average history with new values. */
345    for (i = 0; i < (inst->enc_nrOfCoefs); i++) {
346      inst->enc_reflCoefs[i] = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(
347          inst->enc_reflCoefs[i], ReflBeta, 15);
348      inst->enc_reflCoefs[i] += (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(
349          refCs[i], ReflBetaComp, 15);
350    }
351    inst->enc_Energy = (outEnergy >> 2) + (inst->enc_Energy >> 1)
352        + (inst->enc_Energy >> 2);
353  }
354
355  if (inst->enc_Energy < 1) {
356    inst->enc_Energy = 1;
357  }
358
359  if ((inst->enc_msSinceSID > (inst->enc_interval - 1)) || forceSID) {
360
361    /* Search for best dbov value. */
362    index = 0;
363    for (i = 1; i < 93; i++) {
364      /* Always round downwards. */
365      if ((inst->enc_Energy - WebRtcCng_kDbov[i]) > 0) {
366        index = i;
367        break;
368      }
369    }
370    if ((i == 93) && (index == 0))
371      index = 94;
372    SIDdata[0] = (uint8_t)index;
373
374    /* Quantize coefficients with tweak for WebRtc implementation of RFC3389. */
375    if (inst->enc_nrOfCoefs == WEBRTC_CNG_MAX_LPC_ORDER) {
376      for (i = 0; i < inst->enc_nrOfCoefs; i++) {
377        /* Q15 to Q7 with rounding. */
378        SIDdata[i + 1] = ((inst->enc_reflCoefs[i] + 128) >> 8);
379      }
380    } else {
381      for (i = 0; i < inst->enc_nrOfCoefs; i++) {
382        /* Q15 to Q7 with rounding. */
383        SIDdata[i + 1] = (127 + ((inst->enc_reflCoefs[i] + 128) >> 8));
384      }
385    }
386
387    inst->enc_msSinceSID = 0;
388    *bytesOut = inst->enc_nrOfCoefs + 1;
389
390    inst->enc_msSinceSID +=
391        (int16_t)((1000 * nrOfSamples) / inst->enc_sampfreq);
392    return (int)(inst->enc_nrOfCoefs + 1);
393  } else {
394    inst->enc_msSinceSID +=
395        (int16_t)((1000 * nrOfSamples) / inst->enc_sampfreq);
396    *bytesOut = 0;
397    return 0;
398  }
399}
400
401/****************************************************************************
402 * WebRtcCng_UpdateSid(...)
403 *
404 * These functions updates the CN state, when a new SID packet arrives
405 *
406 * Input:
407 *    - cng_inst      : Pointer to created instance that should be freed
408 *    - SID           : SID packet, all headers removed
409 *    - length        : Length in bytes of SID packet
410 *
411 * Return value       :  0 - Ok
412 *                      -1 - Error
413 */
414int16_t WebRtcCng_UpdateSid(CNG_dec_inst* cng_inst, uint8_t* SID,
415                            size_t length) {
416
417  WebRtcCngDecoder* inst = (WebRtcCngDecoder*) cng_inst;
418  int16_t refCs[WEBRTC_CNG_MAX_LPC_ORDER];
419  int32_t targetEnergy;
420  int i;
421
422  if (inst->initflag != 1) {
423    inst->errorcode = CNG_DECODER_NOT_INITIATED;
424    return -1;
425  }
426
427  /* Throw away reflection coefficients of higher order than we can handle. */
428  if (length > (WEBRTC_CNG_MAX_LPC_ORDER + 1))
429    length = WEBRTC_CNG_MAX_LPC_ORDER + 1;
430
431  inst->dec_order = (int16_t)length - 1;
432
433  if (SID[0] > 93)
434    SID[0] = 93;
435  targetEnergy = WebRtcCng_kDbov[SID[0]];
436  /* Take down target energy to 75%. */
437  targetEnergy = targetEnergy >> 1;
438  targetEnergy += targetEnergy >> 2;
439
440  inst->dec_target_energy = targetEnergy;
441
442  /* Reconstruct coeffs with tweak for WebRtc implementation of RFC3389. */
443  if (inst->dec_order == WEBRTC_CNG_MAX_LPC_ORDER) {
444    for (i = 0; i < (inst->dec_order); i++) {
445      refCs[i] = SID[i + 1] << 8; /* Q7 to Q15*/
446      inst->dec_target_reflCoefs[i] = refCs[i];
447    }
448  } else {
449    for (i = 0; i < (inst->dec_order); i++) {
450      refCs[i] = (SID[i + 1] - 127) << 8; /* Q7 to Q15. */
451      inst->dec_target_reflCoefs[i] = refCs[i];
452    }
453  }
454
455  for (i = (inst->dec_order); i < WEBRTC_CNG_MAX_LPC_ORDER; i++) {
456    refCs[i] = 0;
457    inst->dec_target_reflCoefs[i] = refCs[i];
458  }
459
460  return 0;
461}
462
463/****************************************************************************
464 * WebRtcCng_Generate(...)
465 *
466 * These functions generates CN data when needed
467 *
468 * Input:
469 *    - cng_inst      : Pointer to created instance that should be freed
470 *    - outData       : pointer to area to write CN data
471 *    - nrOfSamples   : How much data to generate
472 *
473 * Return value        :  0 - Ok
474 *                       -1 - Error
475 */
476int16_t WebRtcCng_Generate(CNG_dec_inst* cng_inst, int16_t* outData,
477                           size_t nrOfSamples, int16_t new_period) {
478  WebRtcCngDecoder* inst = (WebRtcCngDecoder*) cng_inst;
479
480  size_t i;
481  int16_t excitation[WEBRTC_CNG_MAX_OUTSIZE_ORDER];
482  int16_t low[WEBRTC_CNG_MAX_OUTSIZE_ORDER];
483  int16_t lpPoly[WEBRTC_CNG_MAX_LPC_ORDER + 1];
484  int16_t ReflBetaStd = 26214;  /* 0.8 in q15. */
485  int16_t ReflBetaCompStd = 6553;  /* 0.2 in q15. */
486  int16_t ReflBetaNewP = 19661;  /* 0.6 in q15. */
487  int16_t ReflBetaCompNewP = 13107;  /* 0.4 in q15. */
488  int16_t Beta, BetaC, tmp1, tmp2, tmp3;
489  int32_t targetEnergy;
490  int16_t En;
491  int16_t temp16;
492
493  if (nrOfSamples > WEBRTC_CNG_MAX_OUTSIZE_ORDER) {
494    inst->errorcode = CNG_DISALLOWED_FRAME_SIZE;
495    return -1;
496  }
497
498  if (new_period) {
499    inst->dec_used_scale_factor = inst->dec_target_scale_factor;
500    Beta = ReflBetaNewP;
501    BetaC = ReflBetaCompNewP;
502  } else {
503    Beta = ReflBetaStd;
504    BetaC = ReflBetaCompStd;
505  }
506
507  /* Here we use a 0.5 weighting, should possibly be modified to 0.6. */
508  tmp1 = inst->dec_used_scale_factor << 2; /* Q13->Q15 */
509  tmp2 = inst->dec_target_scale_factor << 2; /* Q13->Q15 */
510  tmp3 = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(tmp1, Beta, 15);
511  tmp3 += (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(tmp2, BetaC, 15);
512  inst->dec_used_scale_factor = tmp3 >> 2; /* Q15->Q13 */
513
514  inst->dec_used_energy = inst->dec_used_energy >> 1;
515  inst->dec_used_energy += inst->dec_target_energy >> 1;
516
517  /* Do the same for the reflection coeffs. */
518  for (i = 0; i < WEBRTC_CNG_MAX_LPC_ORDER; i++) {
519    inst->dec_used_reflCoefs[i] = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(
520        inst->dec_used_reflCoefs[i], Beta, 15);
521    inst->dec_used_reflCoefs[i] += (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(
522        inst->dec_target_reflCoefs[i], BetaC, 15);
523  }
524
525  /* Compute the polynomial coefficients. */
526  WebRtcCng_K2a16(inst->dec_used_reflCoefs, WEBRTC_CNG_MAX_LPC_ORDER, lpPoly);
527
528
529  targetEnergy = inst->dec_used_energy;
530
531  /* Calculate scaling factor based on filter energy. */
532  En = 8192;  /* 1.0 in Q13. */
533  for (i = 0; i < (WEBRTC_CNG_MAX_LPC_ORDER); i++) {
534
535    /* Floating point value for reference.
536       E *= 1.0 - (inst->dec_used_reflCoefs[i] / 32768.0) *
537       (inst->dec_used_reflCoefs[i] / 32768.0);
538     */
539
540    /* Same in fixed point. */
541    /* K(i).^2 in Q15. */
542    temp16 = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(
543        inst->dec_used_reflCoefs[i], inst->dec_used_reflCoefs[i], 15);
544    /* 1 - K(i).^2 in Q15. */
545    temp16 = 0x7fff - temp16;
546    En = (int16_t) WEBRTC_SPL_MUL_16_16_RSFT(En, temp16, 15);
547  }
548
549  /* float scaling= sqrt(E * inst->dec_target_energy / (1 << 24)); */
550
551  /* Calculate sqrt(En * target_energy / excitation energy) */
552  targetEnergy = WebRtcSpl_Sqrt(inst->dec_used_energy);
553
554  En = (int16_t) WebRtcSpl_Sqrt(En) << 6;
555  En = (En * 3) >> 1;  /* 1.5 estimates sqrt(2). */
556  inst->dec_used_scale_factor = (int16_t)((En * targetEnergy) >> 12);
557
558  /* Generate excitation. */
559  /* Excitation energy per sample is 2.^24 - Q13 N(0,1). */
560  for (i = 0; i < nrOfSamples; i++) {
561    excitation[i] = WebRtcSpl_RandN(&inst->dec_seed) >> 1;
562  }
563
564  /* Scale to correct energy. */
565  WebRtcSpl_ScaleVector(excitation, excitation, inst->dec_used_scale_factor,
566                        nrOfSamples, 13);
567
568  /* |lpPoly| - Coefficients in Q12.
569   * |excitation| - Speech samples.
570   * |nst->dec_filtstate| - State preservation.
571   * |outData| - Filtered speech samples. */
572  WebRtcSpl_FilterAR(lpPoly, WEBRTC_CNG_MAX_LPC_ORDER + 1, excitation,
573                     nrOfSamples, inst->dec_filtstate, WEBRTC_CNG_MAX_LPC_ORDER,
574                     inst->dec_filtstateLow, WEBRTC_CNG_MAX_LPC_ORDER, outData,
575                     low, nrOfSamples);
576
577  return 0;
578}
579
580/****************************************************************************
581 * WebRtcCng_GetErrorCodeEnc/Dec(...)
582 *
583 * This functions can be used to check the error code of a CNG instance. When
584 * a function returns -1 a error code will be set for that instance. The
585 * function below extract the code of the last error that occured in the
586 * specified instance.
587 *
588 * Input:
589 *    - CNG_inst    : CNG enc/dec instance
590 *
591 * Return value     : Error code
592 */
593int16_t WebRtcCng_GetErrorCodeEnc(CNG_enc_inst* cng_inst) {
594  /* Typecast pointer to real structure. */
595  WebRtcCngEncoder* inst = (WebRtcCngEncoder*) cng_inst;
596  return inst->errorcode;
597}
598
599int16_t WebRtcCng_GetErrorCodeDec(CNG_dec_inst* cng_inst) {
600  /* Typecast pointer to real structure. */
601  WebRtcCngDecoder* inst = (WebRtcCngDecoder*) cng_inst;
602  return inst->errorcode;
603}
604