1 /*
2  *  Copyright (c) 2011 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 /*
12  * bandwidth_estimator.c
13  *
14  * This file contains the code for the Bandwidth Estimator designed
15  * for iSAC.
16  *
17  * NOTE! Castings needed for C55, do not remove!
18  *
19  */
20 
21 #include "bandwidth_estimator.h"
22 #include "settings.h"
23 
24 
25 /* array of quantization levels for bottle neck info; Matlab code: */
26 /* sprintf('%4.1ff, ', logspace(log10(5000), log10(40000), 12)) */
27 static const WebRtc_Word16 kQRateTable[12] = {
28   10000, 11115, 12355, 13733, 15265, 16967,
29   18860, 20963, 23301, 25900, 28789, 32000
30 };
31 
32 /* 0.1 times the values in the table kQRateTable */
33 /* values are in Q16                                         */
34 static const WebRtc_Word32 KQRate01[12] = {
35   65536000,  72843264,  80969728,  90000589,  100040704, 111194931,
36   123600896, 137383117, 152705434, 169738240, 188671590, 209715200
37 };
38 
39 /* Bits per Bytes Seconds
40  * 8 bits/byte * 1000 msec/sec * 1/framelength (in msec)->bits/byte*sec
41  * frame length will either be 30 or 60 msec. 8738 is 1/60 in Q19 and 1/30 in Q18
42  * The following number is either in Q15 or Q14 depending on the current frame length */
43 static const WebRtc_Word32 kBitsByteSec = 4369000;
44 
45 /* Received header rate. First value is for 30 ms packets and second for 60 ms */
46 static const WebRtc_Word16 kRecHeaderRate[2] = {
47   9333, 4666
48 };
49 
50 /* Inverted minimum and maximum bandwidth in Q30.
51    minBwInv 30 ms, maxBwInv 30 ms,
52    minBwInv 60 ms, maxBwInv 69 ms
53 */
54 static const WebRtc_Word32 kInvBandwidth[4] = {
55   55539, 25978,
56   73213, 29284
57 };
58 
59 /* Number of samples in 25 msec */
60 static const WebRtc_Word32 kSamplesIn25msec = 400;
61 
62 
63 /****************************************************************************
64  * WebRtcIsacfix_InitBandwidthEstimator(...)
65  *
66  * This function initializes the struct for the bandwidth estimator
67  *
68  * Input/Output:
69  *      - bweStr        : Struct containing bandwidth information.
70  *
71  * Return value            : 0
72  */
WebRtcIsacfix_InitBandwidthEstimator(BwEstimatorstr * bweStr)73 WebRtc_Word32 WebRtcIsacfix_InitBandwidthEstimator(BwEstimatorstr *bweStr)
74 {
75   bweStr->prevFrameSizeMs       = INIT_FRAME_LEN;
76   bweStr->prevRtpNumber         = 0;
77   bweStr->prevSendTime          = 0;
78   bweStr->prevArrivalTime       = 0;
79   bweStr->prevRtpRate           = 1;
80   bweStr->lastUpdate            = 0;
81   bweStr->lastReduction         = 0;
82   bweStr->countUpdates          = -9;
83 
84   /* INIT_BN_EST = 20000
85    * INIT_BN_EST_Q7 = 2560000
86    * INIT_HDR_RATE = 4666
87    * INIT_REC_BN_EST_Q5 = 789312
88    *
89    * recBwInv = 1/(INIT_BN_EST + INIT_HDR_RATE) in Q30
90    * recBwAvg = INIT_BN_EST + INIT_HDR_RATE in Q5
91    */
92   bweStr->recBwInv              = 43531;
93   bweStr->recBw                 = INIT_BN_EST;
94   bweStr->recBwAvgQ             = INIT_BN_EST_Q7;
95   bweStr->recBwAvg              = INIT_REC_BN_EST_Q5;
96   bweStr->recJitter             = (WebRtc_Word32) 327680;   /* 10 in Q15 */
97   bweStr->recJitterShortTerm    = 0;
98   bweStr->recJitterShortTermAbs = (WebRtc_Word32) 40960;    /* 5 in Q13 */
99   bweStr->recMaxDelay           = (WebRtc_Word32) 10;
100   bweStr->recMaxDelayAvgQ       = (WebRtc_Word32) 5120;     /* 10 in Q9 */
101   bweStr->recHeaderRate         = INIT_HDR_RATE;
102   bweStr->countRecPkts          = 0;
103   bweStr->sendBwAvg             = INIT_BN_EST_Q7;
104   bweStr->sendMaxDelayAvg       = (WebRtc_Word32) 5120;     /* 10 in Q9 */
105 
106   bweStr->countHighSpeedRec     = 0;
107   bweStr->highSpeedRec          = 0;
108   bweStr->countHighSpeedSent    = 0;
109   bweStr->highSpeedSend         = 0;
110   bweStr->inWaitPeriod          = 0;
111 
112   /* Find the inverse of the max bw and min bw in Q30
113    *  (1 / (MAX_ISAC_BW + INIT_HDR_RATE) in Q30
114    *  (1 / (MIN_ISAC_BW + INIT_HDR_RATE) in Q30
115    */
116   bweStr->maxBwInv              = kInvBandwidth[3];
117   bweStr->minBwInv              = kInvBandwidth[2];
118 
119   return 0;
120 }
121 
122 /****************************************************************************
123  * WebRtcIsacfix_UpdateUplinkBwImpl(...)
124  *
125  * This function updates bottle neck rate received from other side in payload
126  * and calculates a new bottle neck to send to the other side.
127  *
128  * Input/Output:
129  *      - bweStr           : struct containing bandwidth information.
130  *      - rtpNumber        : value from RTP packet, from NetEq
131  *      - frameSize        : length of signal frame in ms, from iSAC decoder
132  *      - sendTime         : value in RTP header giving send time in samples
133  *      - arrivalTime      : value given by timeGetTime() time of arrival in
134  *                           samples of packet from NetEq
135  *      - pksize           : size of packet in bytes, from NetEq
136  *      - Index            : integer (range 0...23) indicating bottle neck &
137  *                           jitter as estimated by other side
138  *
139  * Return value            : 0 if everything went fine,
140  *                           -1 otherwise
141  */
WebRtcIsacfix_UpdateUplinkBwImpl(BwEstimatorstr * bweStr,const WebRtc_UWord16 rtpNumber,const WebRtc_Word16 frameSize,const WebRtc_UWord32 sendTime,const WebRtc_UWord32 arrivalTime,const WebRtc_Word16 pksize,const WebRtc_UWord16 Index)142 WebRtc_Word32 WebRtcIsacfix_UpdateUplinkBwImpl(BwEstimatorstr *bweStr,
143                                                const WebRtc_UWord16 rtpNumber,
144                                                const WebRtc_Word16  frameSize,
145                                                const WebRtc_UWord32 sendTime,
146                                                const WebRtc_UWord32 arrivalTime,
147                                                const WebRtc_Word16  pksize,
148                                                const WebRtc_UWord16 Index)
149 {
150   WebRtc_UWord16  weight = 0;
151   WebRtc_UWord32  currBwInv = 0;
152   WebRtc_UWord16  recRtpRate;
153   WebRtc_UWord32  arrTimeProj;
154   WebRtc_Word32   arrTimeDiff;
155   WebRtc_Word32   arrTimeNoise;
156   WebRtc_Word32   arrTimeNoiseAbs;
157   WebRtc_Word32   sendTimeDiff;
158 
159   WebRtc_Word32 delayCorrFactor = DELAY_CORRECTION_MED;
160   WebRtc_Word32 lateDiff = 0;
161   WebRtc_Word16 immediateSet = 0;
162   WebRtc_Word32 frameSizeSampl;
163 
164   WebRtc_Word32  temp;
165   WebRtc_Word32  msec;
166   WebRtc_UWord32 exponent;
167   WebRtc_UWord32 reductionFactor;
168   WebRtc_UWord32 numBytesInv;
169   WebRtc_Word32  sign;
170 
171   WebRtc_UWord32 byteSecondsPerBit;
172   WebRtc_UWord32 tempLower;
173   WebRtc_UWord32 tempUpper;
174   WebRtc_Word32 recBwAvgInv;
175   WebRtc_Word32 numPktsExpected;
176 
177   WebRtc_Word16 errCode;
178 
179   /* UPDATE ESTIMATES FROM OTHER SIDE */
180 
181   /* The function also checks if Index has a valid value */
182   errCode = WebRtcIsacfix_UpdateUplinkBwRec(bweStr, Index);
183   if (errCode <0) {
184     return(errCode);
185   }
186 
187 
188   /* UPDATE ESTIMATES ON THIS SIDE */
189 
190   /* Bits per second per byte * 1/30 or 1/60 */
191   if (frameSize == 60) {
192     /* If frameSize changed since last call, from 30 to 60, recalculate some values */
193     if ( (frameSize != bweStr->prevFrameSizeMs) && (bweStr->countUpdates > 0)) {
194       bweStr->countUpdates = 10;
195       bweStr->recHeaderRate = kRecHeaderRate[1];
196 
197       bweStr->maxBwInv = kInvBandwidth[3];
198       bweStr->minBwInv = kInvBandwidth[2];
199       bweStr->recBwInv = WEBRTC_SPL_UDIV(1073741824, (bweStr->recBw + bweStr->recHeaderRate));
200     }
201 
202     /* kBitsByteSec is in Q15 */
203     recRtpRate = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(kBitsByteSec,
204                                                                      (WebRtc_Word32)pksize), 15) + bweStr->recHeaderRate;
205 
206   } else {
207     /* If frameSize changed since last call, from 60 to 30, recalculate some values */
208     if ( (frameSize != bweStr->prevFrameSizeMs) && (bweStr->countUpdates > 0)) {
209       bweStr->countUpdates = 10;
210       bweStr->recHeaderRate = kRecHeaderRate[0];
211 
212       bweStr->maxBwInv = kInvBandwidth[1];
213       bweStr->minBwInv = kInvBandwidth[0];
214       bweStr->recBwInv = WEBRTC_SPL_UDIV(1073741824, (bweStr->recBw + bweStr->recHeaderRate));
215     }
216 
217     /* kBitsByteSec is in Q14 */
218     recRtpRate = (WebRtc_UWord16)WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(kBitsByteSec,
219                                                                       (WebRtc_Word32)pksize), 14) + bweStr->recHeaderRate;
220   }
221 
222 
223   /* Check for timer wrap-around */
224   if (arrivalTime < bweStr->prevArrivalTime) {
225     bweStr->prevArrivalTime = arrivalTime;
226     bweStr->lastUpdate      = arrivalTime;
227     bweStr->lastReduction   = arrivalTime + FS3;
228 
229     bweStr->countRecPkts      = 0;
230 
231     /* store frame size */
232     bweStr->prevFrameSizeMs = frameSize;
233 
234     /* store far-side transmission rate */
235     bweStr->prevRtpRate = recRtpRate;
236 
237     /* store far-side RTP time stamp */
238     bweStr->prevRtpNumber = rtpNumber;
239 
240     return 0;
241   }
242 
243   bweStr->countRecPkts++;
244 
245   /* Calculate framesize in msec */
246   frameSizeSampl = WEBRTC_SPL_MUL_16_16((WebRtc_Word16)SAMPLES_PER_MSEC, frameSize);
247 
248   /* Check that it's not one of the first 9 packets */
249   if ( bweStr->countUpdates > 0 ) {
250 
251     /* Stay in Wait Period for 1.5 seconds (no updates in wait period) */
252     if(bweStr->inWaitPeriod) {
253       if ((arrivalTime - bweStr->startWaitPeriod)> FS_1_HALF) {
254         bweStr->inWaitPeriod = 0;
255       }
256     }
257 
258     /* If not been updated for a long time, reduce the BN estimate */
259 
260     /* Check send time difference between this packet and previous received      */
261     sendTimeDiff = sendTime - bweStr->prevSendTime;
262     if (sendTimeDiff <= WEBRTC_SPL_LSHIFT_W32(frameSizeSampl, 1)) {
263 
264       /* Only update if 3 seconds has past since last update */
265       if ((arrivalTime - bweStr->lastUpdate) > FS3) {
266 
267         /* Calculate expected number of received packets since last update */
268         numPktsExpected =  WEBRTC_SPL_UDIV(arrivalTime - bweStr->lastUpdate, frameSizeSampl);
269 
270         /* If received number of packets is more than 90% of expected (922 = 0.9 in Q10): */
271         /* do the update, else not                                                        */
272         if(WEBRTC_SPL_LSHIFT_W32(bweStr->countRecPkts, 10)  > WEBRTC_SPL_MUL_16_16(922, numPktsExpected)) {
273           /* Q4 chosen to approx dividing by 16 */
274           msec = (arrivalTime - bweStr->lastReduction);
275 
276           /* the number below represents 13 seconds, highly unlikely
277              but to insure no overflow when reduction factor is multiplied by recBw inverse */
278           if (msec > 208000) {
279             msec = 208000;
280           }
281 
282           /* Q20 2^(negative number: - 76/1048576) = .99995
283              product is Q24 */
284           exponent = WEBRTC_SPL_UMUL(0x0000004C, msec);
285 
286           /* do the approx with positive exponent so that value is actually rf^-1
287              and multiply by bw inverse */
288           reductionFactor = WEBRTC_SPL_RSHIFT_U32(0x01000000 | (exponent & 0x00FFFFFF),
289                                                   WEBRTC_SPL_RSHIFT_U32(exponent, 24));
290 
291           /* reductionFactor in Q13 */
292           reductionFactor = WEBRTC_SPL_RSHIFT_U32(reductionFactor, 11);
293 
294           if ( reductionFactor != 0 ) {
295             bweStr->recBwInv = WEBRTC_SPL_MUL((WebRtc_Word32)bweStr->recBwInv, (WebRtc_Word32)reductionFactor);
296             bweStr->recBwInv = WEBRTC_SPL_RSHIFT_W32((WebRtc_Word32)bweStr->recBwInv, 13);
297 
298           } else {
299             /* recBwInv = 1 / (INIT_BN_EST + INIT_HDR_RATE) in Q26 (Q30??)*/
300             bweStr->recBwInv = WEBRTC_SPL_DIV((1073741824 +
301                                                WEBRTC_SPL_LSHIFT_W32(((WebRtc_Word32)INIT_BN_EST + INIT_HDR_RATE), 1)), INIT_BN_EST + INIT_HDR_RATE);
302           }
303 
304           /* reset time-since-update counter */
305           bweStr->lastReduction = arrivalTime;
306         } else {
307           /* Delay last reduction with 3 seconds */
308           bweStr->lastReduction = arrivalTime + FS3;
309           bweStr->lastUpdate    = arrivalTime;
310           bweStr->countRecPkts  = 0;
311         }
312       }
313     } else {
314       bweStr->lastReduction = arrivalTime + FS3;
315       bweStr->lastUpdate    = arrivalTime;
316       bweStr->countRecPkts  = 0;
317     }
318 
319 
320     /*   update only if previous packet was not lost */
321     if ( rtpNumber == bweStr->prevRtpNumber + 1 ) {
322       arrTimeDiff = arrivalTime - bweStr->prevArrivalTime;
323 
324       if (!(bweStr->highSpeedSend && bweStr->highSpeedRec)) {
325         if (arrTimeDiff > frameSizeSampl) {
326           if (sendTimeDiff > 0) {
327             lateDiff = arrTimeDiff - sendTimeDiff -
328                 WEBRTC_SPL_LSHIFT_W32(frameSizeSampl, 1);
329           } else {
330             lateDiff = arrTimeDiff - frameSizeSampl;
331           }
332 
333           /* 8000 is 1/2 second (in samples at FS) */
334           if (lateDiff > 8000) {
335             delayCorrFactor = (WebRtc_Word32) DELAY_CORRECTION_MAX;
336             bweStr->inWaitPeriod = 1;
337             bweStr->startWaitPeriod = arrivalTime;
338             immediateSet = 1;
339           } else if (lateDiff > 5120) {
340             delayCorrFactor = (WebRtc_Word32) DELAY_CORRECTION_MED;
341             immediateSet = 1;
342             bweStr->inWaitPeriod = 1;
343             bweStr->startWaitPeriod = arrivalTime;
344           }
345         }
346       }
347 
348       if ((bweStr->prevRtpRate > WEBRTC_SPL_RSHIFT_W32((WebRtc_Word32) bweStr->recBwAvg, 5)) &&
349           (recRtpRate > WEBRTC_SPL_RSHIFT_W32((WebRtc_Word32)bweStr->recBwAvg, 5)) &&
350           !bweStr->inWaitPeriod) {
351 
352         /* test if still in initiation period and increment counter */
353         if (bweStr->countUpdates++ > 99) {
354           /* constant weight after initiation part, 0.01 in Q13 */
355           weight = (WebRtc_UWord16) 82;
356         } else {
357           /* weight decreases with number of updates, 1/countUpdates in Q13  */
358           weight = (WebRtc_UWord16) WebRtcSpl_DivW32W16(
359               (WebRtc_Word32)(8192 + WEBRTC_SPL_RSHIFT_W32((WebRtc_Word32) bweStr->countUpdates, 1)),
360               (WebRtc_Word16)bweStr->countUpdates);
361         }
362 
363         /* Bottle Neck Estimation */
364 
365         /* limit outliers, if more than 25 ms too much */
366         if (arrTimeDiff > frameSizeSampl + kSamplesIn25msec) {
367           arrTimeDiff = frameSizeSampl + kSamplesIn25msec;
368         }
369 
370         /* don't allow it to be less than frame rate - 10 ms */
371         if (arrTimeDiff < frameSizeSampl - FRAMESAMPLES_10ms) {
372           arrTimeDiff = frameSizeSampl - FRAMESAMPLES_10ms;
373         }
374 
375         /* compute inverse receiving rate for last packet, in Q19 */
376         numBytesInv = (WebRtc_UWord16) WebRtcSpl_DivW32W16(
377             (WebRtc_Word32)(524288 + WEBRTC_SPL_RSHIFT_W32(((WebRtc_Word32)pksize + HEADER_SIZE), 1)),
378             (WebRtc_Word16)(pksize + HEADER_SIZE));
379 
380         /* 8389 is  ~ 1/128000 in Q30 */
381         byteSecondsPerBit = WEBRTC_SPL_MUL_16_16(arrTimeDiff, 8389);
382 
383         /* get upper N bits */
384         tempUpper = WEBRTC_SPL_RSHIFT_U32(byteSecondsPerBit, 15);
385 
386         /* get lower 15 bits */
387         tempLower = byteSecondsPerBit & 0x00007FFF;
388 
389         tempUpper = WEBRTC_SPL_MUL(tempUpper, numBytesInv);
390         tempLower = WEBRTC_SPL_MUL(tempLower, numBytesInv);
391         tempLower = WEBRTC_SPL_RSHIFT_U32(tempLower, 15);
392 
393         currBwInv = tempUpper + tempLower;
394         currBwInv = WEBRTC_SPL_RSHIFT_U32(currBwInv, 4);
395 
396         /* Limit inv rate. Note that minBwInv > maxBwInv! */
397         if(currBwInv < bweStr->maxBwInv) {
398           currBwInv = bweStr->maxBwInv;
399         } else if(currBwInv > bweStr->minBwInv) {
400           currBwInv = bweStr->minBwInv;
401         }
402 
403         /* update bottle neck rate estimate */
404         bweStr->recBwInv = WEBRTC_SPL_UMUL(weight, currBwInv) +
405             WEBRTC_SPL_UMUL((WebRtc_UWord32) 8192 - weight, bweStr->recBwInv);
406 
407         /* Shift back to Q30 from Q40 (actual used bits shouldn't be more than 27 based on minBwInv)
408            up to 30 bits used with Q13 weight */
409         bweStr->recBwInv = WEBRTC_SPL_RSHIFT_U32(bweStr->recBwInv, 13);
410 
411         /* reset time-since-update counter */
412         bweStr->lastUpdate    = arrivalTime;
413         bweStr->lastReduction = arrivalTime + FS3;
414         bweStr->countRecPkts  = 0;
415 
416         /* to save resolution compute the inverse of recBwAvg in Q26 by left shifting numerator to 2^31
417            and NOT right shifting recBwAvg 5 bits to an integer
418            At max 13 bits are used
419            shift to Q5 */
420         recBwAvgInv = WEBRTC_SPL_UDIV((WebRtc_UWord32)(0x80000000 + WEBRTC_SPL_RSHIFT_U32(bweStr->recBwAvg, 1)),
421                                       bweStr->recBwAvg);
422 
423         /* Calculate Projected arrival time difference */
424 
425         /* The numerator of the quotient can be 22 bits so right shift inv by 4 to avoid overflow
426            result in Q22 */
427         arrTimeProj = WEBRTC_SPL_MUL((WebRtc_Word32)8000, recBwAvgInv);
428         /* shift to Q22 */
429         arrTimeProj = WEBRTC_SPL_RSHIFT_U32(arrTimeProj, 4);
430         /* complete calulation */
431         arrTimeProj = WEBRTC_SPL_MUL(((WebRtc_Word32)pksize + HEADER_SIZE), arrTimeProj);
432         /* shift to Q10 */
433         arrTimeProj = WEBRTC_SPL_RSHIFT_U32(arrTimeProj, 12);
434 
435         /* difference between projected and actual arrival time differences */
436         /* Q9 (only shift arrTimeDiff by 5 to simulate divide by 16 (need to revisit if change sampling rate) DH */
437         if (WEBRTC_SPL_LSHIFT_W32(arrTimeDiff, 6) > (WebRtc_Word32)arrTimeProj) {
438           arrTimeNoise = WEBRTC_SPL_LSHIFT_W32(arrTimeDiff, 6) -  arrTimeProj;
439           sign = 1;
440         } else {
441           arrTimeNoise = arrTimeProj - WEBRTC_SPL_LSHIFT_W32(arrTimeDiff, 6);
442           sign = -1;
443         }
444 
445         /* Q9 */
446         arrTimeNoiseAbs = arrTimeNoise;
447 
448         /* long term averaged absolute jitter, Q15 */
449         weight = WEBRTC_SPL_RSHIFT_W32(weight, 3);
450         bweStr->recJitter = WEBRTC_SPL_MUL(weight, WEBRTC_SPL_LSHIFT_W32(arrTimeNoiseAbs, 5))
451             +  WEBRTC_SPL_MUL(1024 - weight, bweStr->recJitter);
452 
453         /* remove the fractional portion */
454         bweStr->recJitter = WEBRTC_SPL_RSHIFT_W32(bweStr->recJitter, 10);
455 
456         /* Maximum jitter is 10 msec in Q15 */
457         if (bweStr->recJitter > (WebRtc_Word32)327680) {
458           bweStr->recJitter = (WebRtc_Word32)327680;
459         }
460 
461         /* short term averaged absolute jitter */
462         /* Calculation in Q13 products in Q23 */
463         bweStr->recJitterShortTermAbs = WEBRTC_SPL_MUL(51, WEBRTC_SPL_LSHIFT_W32(arrTimeNoiseAbs, 3)) +
464             WEBRTC_SPL_MUL(973, bweStr->recJitterShortTermAbs);
465         bweStr->recJitterShortTermAbs = WEBRTC_SPL_RSHIFT_W32(bweStr->recJitterShortTermAbs , 10);
466 
467         /* short term averaged jitter */
468         /* Calculation in Q13 products in Q23 */
469         bweStr->recJitterShortTerm = WEBRTC_SPL_MUL(205, WEBRTC_SPL_LSHIFT_W32(arrTimeNoise, 3)) * sign +
470             WEBRTC_SPL_MUL(3891, bweStr->recJitterShortTerm);
471 
472         if (bweStr->recJitterShortTerm < 0) {
473           temp = -bweStr->recJitterShortTerm;
474           temp = WEBRTC_SPL_RSHIFT_W32(temp, 12);
475           bweStr->recJitterShortTerm = -temp;
476         } else {
477           bweStr->recJitterShortTerm = WEBRTC_SPL_RSHIFT_W32(bweStr->recJitterShortTerm, 12);
478         }
479       }
480     }
481   } else {
482     /* reset time-since-update counter when receiving the first 9 packets */
483     bweStr->lastUpdate    = arrivalTime;
484     bweStr->lastReduction = arrivalTime + FS3;
485     bweStr->countRecPkts  = 0;
486     bweStr->countUpdates++;
487   }
488 
489   /* Limit to minimum or maximum bottle neck rate (in Q30) */
490   if (bweStr->recBwInv > bweStr->minBwInv) {
491     bweStr->recBwInv = bweStr->minBwInv;
492   } else if (bweStr->recBwInv < bweStr->maxBwInv) {
493     bweStr->recBwInv = bweStr->maxBwInv;
494   }
495 
496 
497   /* store frame length */
498   bweStr->prevFrameSizeMs = frameSize;
499 
500   /* store far-side transmission rate */
501   bweStr->prevRtpRate = recRtpRate;
502 
503   /* store far-side RTP time stamp */
504   bweStr->prevRtpNumber = rtpNumber;
505 
506   /* Replace bweStr->recMaxDelay by the new value (atomic operation) */
507   if (bweStr->prevArrivalTime != 0xffffffff) {
508     bweStr->recMaxDelay = WEBRTC_SPL_MUL(3, bweStr->recJitter);
509   }
510 
511   /* store arrival time stamp */
512   bweStr->prevArrivalTime = arrivalTime;
513   bweStr->prevSendTime = sendTime;
514 
515   /* Replace bweStr->recBw by the new value */
516   bweStr->recBw = WEBRTC_SPL_UDIV(1073741824, bweStr->recBwInv) - bweStr->recHeaderRate;
517 
518   if (immediateSet) {
519     /* delay correction factor is in Q10 */
520     bweStr->recBw = WEBRTC_SPL_UMUL(delayCorrFactor, bweStr->recBw);
521     bweStr->recBw = WEBRTC_SPL_RSHIFT_U32(bweStr->recBw, 10);
522 
523     if (bweStr->recBw < (WebRtc_Word32) MIN_ISAC_BW) {
524       bweStr->recBw = (WebRtc_Word32) MIN_ISAC_BW;
525     }
526 
527     bweStr->recBwAvg = WEBRTC_SPL_LSHIFT_U32(bweStr->recBw + bweStr->recHeaderRate, 5);
528 
529     bweStr->recBwAvgQ = WEBRTC_SPL_LSHIFT_U32(bweStr->recBw, 7);
530 
531     bweStr->recJitterShortTerm = 0;
532 
533     bweStr->recBwInv = WEBRTC_SPL_UDIV(1073741824, bweStr->recBw + bweStr->recHeaderRate);
534 
535     immediateSet = 0;
536   }
537 
538 
539   return 0;
540 }
541 
542 /* This function updates the send bottle neck rate                                                   */
543 /* Index         - integer (range 0...23) indicating bottle neck & jitter as estimated by other side */
544 /* returns 0 if everything went fine, -1 otherwise                                                   */
WebRtcIsacfix_UpdateUplinkBwRec(BwEstimatorstr * bweStr,const WebRtc_Word16 Index)545 WebRtc_Word16 WebRtcIsacfix_UpdateUplinkBwRec(BwEstimatorstr *bweStr,
546                                               const WebRtc_Word16 Index)
547 {
548   WebRtc_UWord16 RateInd;
549 
550   if ( (Index < 0) || (Index > 23) ) {
551     return -ISAC_RANGE_ERROR_BW_ESTIMATOR;
552   }
553 
554   /* UPDATE ESTIMATES FROM OTHER SIDE */
555 
556   if ( Index > 11 ) {
557     RateInd = Index - 12;
558     /* compute the jitter estimate as decoded on the other side in Q9 */
559     /* sendMaxDelayAvg = 0.9 * sendMaxDelayAvg + 0.1 * MAX_ISAC_MD */
560     bweStr->sendMaxDelayAvg = WEBRTC_SPL_MUL(461, bweStr->sendMaxDelayAvg) +
561         WEBRTC_SPL_MUL(51, WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)MAX_ISAC_MD, 9));
562     bweStr->sendMaxDelayAvg = WEBRTC_SPL_RSHIFT_W32(bweStr->sendMaxDelayAvg, 9);
563 
564   } else {
565     RateInd = Index;
566     /* compute the jitter estimate as decoded on the other side in Q9 */
567     /* sendMaxDelayAvg = 0.9 * sendMaxDelayAvg + 0.1 * MIN_ISAC_MD */
568     bweStr->sendMaxDelayAvg = WEBRTC_SPL_MUL(461, bweStr->sendMaxDelayAvg) +
569         WEBRTC_SPL_MUL(51, WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)MIN_ISAC_MD,9));
570     bweStr->sendMaxDelayAvg = WEBRTC_SPL_RSHIFT_W32(bweStr->sendMaxDelayAvg, 9);
571 
572   }
573 
574 
575   /* compute the BN estimate as decoded on the other side */
576   /* sendBwAvg = 0.9 * sendBwAvg + 0.1 * kQRateTable[RateInd]; */
577   bweStr->sendBwAvg = WEBRTC_SPL_UMUL(461, bweStr->sendBwAvg) +
578       WEBRTC_SPL_UMUL(51, WEBRTC_SPL_LSHIFT_U32(kQRateTable[RateInd], 7));
579   bweStr->sendBwAvg = WEBRTC_SPL_RSHIFT_U32(bweStr->sendBwAvg, 9);
580 
581 
582   if (WEBRTC_SPL_RSHIFT_U32(bweStr->sendBwAvg, 7) > 28000 && !bweStr->highSpeedSend) {
583     bweStr->countHighSpeedSent++;
584 
585     /* approx 2 seconds with 30ms frames */
586     if (bweStr->countHighSpeedSent >= 66) {
587       bweStr->highSpeedSend = 1;
588     }
589   } else if (!bweStr->highSpeedSend) {
590     bweStr->countHighSpeedSent = 0;
591   }
592 
593   return 0;
594 }
595 
596 /****************************************************************************
597  * WebRtcIsacfix_GetDownlinkBwIndexImpl(...)
598  *
599  * This function calculates and returns the bandwidth/jitter estimation code
600  * (integer 0...23) to put in the sending iSAC payload.
601  *
602  * Input:
603  *      - bweStr       : BWE struct
604  *
605  * Return:
606  *      bandwith and jitter index (0..23)
607  */
WebRtcIsacfix_GetDownlinkBwIndexImpl(BwEstimatorstr * bweStr)608 WebRtc_UWord16 WebRtcIsacfix_GetDownlinkBwIndexImpl(BwEstimatorstr *bweStr)
609 {
610   WebRtc_Word32  rate;
611   WebRtc_Word32  maxDelay;
612   WebRtc_UWord16 rateInd;
613   WebRtc_UWord16 maxDelayBit;
614   WebRtc_Word32  tempTerm1;
615   WebRtc_Word32  tempTerm2;
616   WebRtc_Word32  tempTermX;
617   WebRtc_Word32  tempTermY;
618   WebRtc_Word32  tempMin;
619   WebRtc_Word32  tempMax;
620 
621   /* Get Rate Index */
622 
623   /* Get unquantized rate. Always returns 10000 <= rate <= 32000 */
624   rate = WebRtcIsacfix_GetDownlinkBandwidth(bweStr);
625 
626   /* Compute the averaged BN estimate on this side */
627 
628   /* recBwAvg = 0.9 * recBwAvg + 0.1 * (rate + bweStr->recHeaderRate), 0.9 and 0.1 in Q9 */
629   bweStr->recBwAvg = WEBRTC_SPL_UMUL(922, bweStr->recBwAvg) +
630       WEBRTC_SPL_UMUL(102, WEBRTC_SPL_LSHIFT_U32((WebRtc_UWord32)rate + bweStr->recHeaderRate, 5));
631   bweStr->recBwAvg = WEBRTC_SPL_RSHIFT_U32(bweStr->recBwAvg, 10);
632 
633   /* find quantization index that gives the closest rate after averaging */
634   for (rateInd = 1; rateInd < 12; rateInd++) {
635     if (rate <= kQRateTable[rateInd]){
636       break;
637     }
638   }
639 
640   /* find closest quantization index, and update quantized average by taking: */
641   /* 0.9*recBwAvgQ + 0.1*kQRateTable[rateInd] */
642 
643   /* 0.9 times recBwAvgQ in Q16 */
644   /* 461/512 - 25/65536 =0.900009 */
645   tempTerm1 = WEBRTC_SPL_MUL(bweStr->recBwAvgQ, 25);
646   tempTerm1 = WEBRTC_SPL_RSHIFT_W32(tempTerm1, 7);
647   tempTermX = WEBRTC_SPL_UMUL(461, bweStr->recBwAvgQ) - tempTerm1;
648 
649   /* rate in Q16 */
650   tempTermY = WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)rate, 16);
651 
652   /* 0.1 * kQRateTable[rateInd] = KQRate01[rateInd] */
653   tempTerm1 = tempTermX + KQRate01[rateInd] - tempTermY;
654   tempTerm2 = tempTermY - tempTermX - KQRate01[rateInd-1];
655 
656   /* Compare (0.9 * recBwAvgQ + 0.1 * kQRateTable[rateInd] - rate) >
657      (rate - 0.9 * recBwAvgQ - 0.1 * kQRateTable[rateInd-1]) */
658   if (tempTerm1  > tempTerm2) {
659     rateInd--;
660   }
661 
662   /* Update quantized average by taking:                  */
663   /* 0.9*recBwAvgQ + 0.1*kQRateTable[rateInd] */
664 
665   /* Add 0.1 times kQRateTable[rateInd], in Q16 */
666   tempTermX += KQRate01[rateInd];
667 
668   /* Shift back to Q7 */
669   bweStr->recBwAvgQ = WEBRTC_SPL_RSHIFT_W32(tempTermX, 9);
670 
671   /* Count consecutive received bandwidth above 28000 kbps (28000 in Q7 = 3584000) */
672   /* If 66 high estimates in a row, set highSpeedRec to one */
673   /* 66 corresponds to ~2 seconds in 30 msec mode */
674   if ((bweStr->recBwAvgQ > 3584000) && !bweStr->highSpeedRec) {
675     bweStr->countHighSpeedRec++;
676     if (bweStr->countHighSpeedRec >= 66) {
677       bweStr->highSpeedRec = 1;
678     }
679   } else if (!bweStr->highSpeedRec)    {
680     bweStr->countHighSpeedRec = 0;
681   }
682 
683   /* Get Max Delay Bit */
684 
685   /* get unquantized max delay */
686   maxDelay = WebRtcIsacfix_GetDownlinkMaxDelay(bweStr);
687 
688   /* Update quantized max delay average */
689   tempMax = 652800; /* MAX_ISAC_MD * 0.1 in Q18 */
690   tempMin = 130560; /* MIN_ISAC_MD * 0.1 in Q18 */
691   tempTermX = WEBRTC_SPL_MUL((WebRtc_Word32)bweStr->recMaxDelayAvgQ, (WebRtc_Word32)461);
692   tempTermY = WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)maxDelay, 18);
693 
694   tempTerm1 = tempTermX + tempMax - tempTermY;
695   tempTerm2 = tempTermY - tempTermX - tempMin;
696 
697   if ( tempTerm1 > tempTerm2) {
698     maxDelayBit = 0;
699     tempTerm1 = tempTermX + tempMin;
700 
701     /* update quantized average, shift back to Q9 */
702     bweStr->recMaxDelayAvgQ = WEBRTC_SPL_RSHIFT_W32(tempTerm1, 9);
703   } else {
704     maxDelayBit = 12;
705     tempTerm1 =  tempTermX + tempMax;
706 
707     /* update quantized average, shift back to Q9 */
708     bweStr->recMaxDelayAvgQ = WEBRTC_SPL_RSHIFT_W32(tempTerm1, 9);
709   }
710 
711   /* Return bandwitdh and jitter index (0..23) */
712   return (WebRtc_UWord16)(rateInd + maxDelayBit);
713 }
714 
715 /* get the bottle neck rate from far side to here, as estimated on this side */
WebRtcIsacfix_GetDownlinkBandwidth(const BwEstimatorstr * bweStr)716 WebRtc_UWord16 WebRtcIsacfix_GetDownlinkBandwidth(const BwEstimatorstr *bweStr)
717 {
718   WebRtc_UWord32  recBw;
719   WebRtc_Word32   jitter_sign; /* Q8 */
720   WebRtc_Word32   bw_adjust;   /* Q16 */
721   WebRtc_Word32   rec_jitter_short_term_abs_inv; /* Q18 */
722   WebRtc_Word32   temp;
723 
724   /* Q18  rec jitter short term abs is in Q13, multiply it by 2^13 to save precision
725      2^18 then needs to be shifted 13 bits to 2^31 */
726   rec_jitter_short_term_abs_inv = WEBRTC_SPL_UDIV(0x80000000, bweStr->recJitterShortTermAbs);
727 
728   /* Q27 = 9 + 18 */
729   jitter_sign = WEBRTC_SPL_MUL(WEBRTC_SPL_RSHIFT_W32(bweStr->recJitterShortTerm, 4), (WebRtc_Word32)rec_jitter_short_term_abs_inv);
730 
731   if (jitter_sign < 0) {
732     temp = -jitter_sign;
733     temp = WEBRTC_SPL_RSHIFT_W32(temp, 19);
734     jitter_sign = -temp;
735   } else {
736     jitter_sign = WEBRTC_SPL_RSHIFT_W32(jitter_sign, 19);
737   }
738 
739   /* adjust bw proportionally to negative average jitter sign */
740   //bw_adjust = 1.0f - jitter_sign * (0.15f + 0.15f * jitter_sign * jitter_sign);
741   //Q8 -> Q16 .15 +.15 * jitter^2 first term is .15 in Q16 latter term is Q8*Q8*Q8
742   //38 in Q8 ~.15 9830 in Q16 ~.15
743   temp = 9830  + WEBRTC_SPL_RSHIFT_W32((WEBRTC_SPL_MUL(38, WEBRTC_SPL_MUL(jitter_sign, jitter_sign))), 8);
744 
745   if (jitter_sign < 0) {
746     temp = WEBRTC_SPL_MUL(jitter_sign, temp);
747     temp = -temp;
748     temp = WEBRTC_SPL_RSHIFT_W32(temp, 8);
749     bw_adjust = (WebRtc_UWord32)65536 + temp; /* (1 << 16) + temp; */
750   } else {
751     bw_adjust = (WebRtc_UWord32)65536 - WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(jitter_sign, temp), 8);/* (1 << 16) - ((jitter_sign * temp) >> 8); */
752   }
753 
754   //make sure following multiplication won't overflow
755   //bw adjust now Q14
756   bw_adjust = WEBRTC_SPL_RSHIFT_W32(bw_adjust, 2);//see if good resolution is maintained
757 
758   /* adjust Rate if jitter sign is mostly constant */
759   recBw = WEBRTC_SPL_UMUL(bweStr->recBw, bw_adjust);
760 
761   recBw = WEBRTC_SPL_RSHIFT_W32(recBw, 14);
762 
763   /* limit range of bottle neck rate */
764   if (recBw < MIN_ISAC_BW) {
765     recBw = MIN_ISAC_BW;
766   } else if (recBw > MAX_ISAC_BW) {
767     recBw = MAX_ISAC_BW;
768   }
769 
770   return  (WebRtc_UWord16) recBw;
771 }
772 
773 /* Returns the mmax delay (in ms) */
WebRtcIsacfix_GetDownlinkMaxDelay(const BwEstimatorstr * bweStr)774 WebRtc_Word16 WebRtcIsacfix_GetDownlinkMaxDelay(const BwEstimatorstr *bweStr)
775 {
776   WebRtc_Word16 recMaxDelay;
777 
778   recMaxDelay = (WebRtc_Word16)  WEBRTC_SPL_RSHIFT_W32(bweStr->recMaxDelay, 15);
779 
780   /* limit range of jitter estimate */
781   if (recMaxDelay < MIN_ISAC_MD) {
782     recMaxDelay = MIN_ISAC_MD;
783   } else if (recMaxDelay > MAX_ISAC_MD) {
784     recMaxDelay = MAX_ISAC_MD;
785   }
786 
787   return recMaxDelay;
788 }
789 
790 /* get the bottle neck rate from here to far side, as estimated by far side */
WebRtcIsacfix_GetUplinkBandwidth(const BwEstimatorstr * bweStr)791 WebRtc_Word16 WebRtcIsacfix_GetUplinkBandwidth(const BwEstimatorstr *bweStr)
792 {
793   WebRtc_Word16 send_bw;
794 
795   send_bw = (WebRtc_Word16) WEBRTC_SPL_RSHIFT_U32(bweStr->sendBwAvg, 7);
796 
797   /* limit range of bottle neck rate */
798   if (send_bw < MIN_ISAC_BW) {
799     send_bw = MIN_ISAC_BW;
800   } else if (send_bw > MAX_ISAC_BW) {
801     send_bw = MAX_ISAC_BW;
802   }
803 
804   return send_bw;
805 }
806 
807 
808 
809 /* Returns the max delay value from the other side in ms */
WebRtcIsacfix_GetUplinkMaxDelay(const BwEstimatorstr * bweStr)810 WebRtc_Word16 WebRtcIsacfix_GetUplinkMaxDelay(const BwEstimatorstr *bweStr)
811 {
812   WebRtc_Word16 send_max_delay;
813 
814   send_max_delay = (WebRtc_Word16) WEBRTC_SPL_RSHIFT_W32(bweStr->sendMaxDelayAvg, 9);
815 
816   /* limit range of jitter estimate */
817   if (send_max_delay < MIN_ISAC_MD) {
818     send_max_delay = MIN_ISAC_MD;
819   } else if (send_max_delay > MAX_ISAC_MD) {
820     send_max_delay = MAX_ISAC_MD;
821   }
822 
823   return send_max_delay;
824 }
825 
826 
827 
828 
829 /*
830  * update long-term average bitrate and amount of data in buffer
831  * returns minimum payload size (bytes)
832  */
WebRtcIsacfix_GetMinBytes(RateModel * State,WebRtc_Word16 StreamSize,const WebRtc_Word16 FrameSamples,const WebRtc_Word16 BottleNeck,const WebRtc_Word16 DelayBuildUp)833 WebRtc_UWord16 WebRtcIsacfix_GetMinBytes(RateModel *State,
834                                          WebRtc_Word16 StreamSize,                    /* bytes in bitstream */
835                                          const WebRtc_Word16 FrameSamples,            /* samples per frame */
836                                          const WebRtc_Word16 BottleNeck,        /* bottle neck rate; excl headers (bps) */
837                                          const WebRtc_Word16 DelayBuildUp)      /* max delay from bottle neck buffering (ms) */
838 {
839   WebRtc_Word32 MinRate = 0;
840   WebRtc_UWord16    MinBytes;
841   WebRtc_Word16 TransmissionTime;
842   WebRtc_Word32 inv_Q12;
843   WebRtc_Word32 den;
844 
845 
846   /* first 10 packets @ low rate, then INIT_BURST_LEN packets @ fixed rate of INIT_RATE bps */
847   if (State->InitCounter > 0) {
848     if (State->InitCounter-- <= INIT_BURST_LEN) {
849       MinRate = INIT_RATE;
850     } else {
851       MinRate = 0;
852     }
853   } else {
854     /* handle burst */
855     if (State->BurstCounter) {
856       if (State->StillBuffered < WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL((512 - WEBRTC_SPL_DIV(512, BURST_LEN)), DelayBuildUp), 9)) {
857         /* max bps derived from BottleNeck and DelayBuildUp values */
858         inv_Q12 = WEBRTC_SPL_DIV(4096, WEBRTC_SPL_MUL(BURST_LEN, FrameSamples));
859         MinRate = WEBRTC_SPL_MUL(512 + WEBRTC_SPL_MUL(SAMPLES_PER_MSEC, WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(DelayBuildUp, inv_Q12), 3)), BottleNeck);
860       } else {
861         /* max bps derived from StillBuffered and DelayBuildUp values */
862         inv_Q12 = WEBRTC_SPL_DIV(4096, FrameSamples);
863         if (DelayBuildUp > State->StillBuffered) {
864           MinRate = WEBRTC_SPL_MUL(512 + WEBRTC_SPL_MUL(SAMPLES_PER_MSEC, WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(DelayBuildUp - State->StillBuffered, inv_Q12), 3)), BottleNeck);
865         } else if ((den = WEBRTC_SPL_MUL(SAMPLES_PER_MSEC, (State->StillBuffered - DelayBuildUp))) >= FrameSamples) {
866           /* MinRate will be negative here */
867           MinRate = 0;
868         } else {
869           MinRate = WEBRTC_SPL_MUL((512 - WEBRTC_SPL_RSHIFT_W32(WEBRTC_SPL_MUL(den, inv_Q12), 3)), BottleNeck);
870         }
871         //if (MinRate < 1.04 * BottleNeck)
872         //    MinRate = 1.04 * BottleNeck;
873         //Q9
874         if (MinRate < WEBRTC_SPL_MUL(532, BottleNeck)) {
875           MinRate += WEBRTC_SPL_MUL(22, BottleNeck);
876         }
877       }
878 
879       State->BurstCounter--;
880     }
881   }
882 
883 
884   /* convert rate from bits/second to bytes/packet */
885   //round and shift before conversion
886   MinRate += 256;
887   MinRate = WEBRTC_SPL_RSHIFT_W32(MinRate, 9);
888   MinBytes = (WebRtc_UWord16)WEBRTC_SPL_UDIV(WEBRTC_SPL_MUL(MinRate, FrameSamples), FS8);
889 
890   /* StreamSize will be adjusted if less than MinBytes */
891   if (StreamSize < MinBytes) {
892     StreamSize = MinBytes;
893   }
894 
895   /* keep track of when bottle neck was last exceeded by at least 1% */
896   //517/512 ~ 1.01
897   if (WEBRTC_SPL_DIV(WEBRTC_SPL_MUL(StreamSize, FS8), FrameSamples) > (WEBRTC_SPL_MUL(517, BottleNeck) >> 9)) {
898     if (State->PrevExceed) {
899       /* bottle_neck exceded twice in a row, decrease ExceedAgo */
900       State->ExceedAgo -= WEBRTC_SPL_DIV(BURST_INTERVAL, BURST_LEN - 1);
901       if (State->ExceedAgo < 0) {
902         State->ExceedAgo = 0;
903       }
904     } else {
905       State->ExceedAgo += (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W16(FrameSamples, 4);       /* ms */
906       State->PrevExceed = 1;
907     }
908   } else {
909     State->PrevExceed = 0;
910     State->ExceedAgo += (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W16(FrameSamples, 4);           /* ms */
911   }
912 
913   /* set burst flag if bottle neck not exceeded for long time */
914   if ((State->ExceedAgo > BURST_INTERVAL) && (State->BurstCounter == 0)) {
915     if (State->PrevExceed) {
916       State->BurstCounter = BURST_LEN - 1;
917     } else {
918       State->BurstCounter = BURST_LEN;
919     }
920   }
921 
922 
923   /* Update buffer delay */
924   TransmissionTime = (WebRtc_Word16)WEBRTC_SPL_DIV(WEBRTC_SPL_MUL(StreamSize, 8000), BottleNeck);    /* ms */
925   State->StillBuffered += TransmissionTime;
926   State->StillBuffered -= (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W16(FrameSamples, 4);  //>>4 =  SAMPLES_PER_MSEC        /* ms */
927   if (State->StillBuffered < 0) {
928     State->StillBuffered = 0;
929   }
930 
931   if (State->StillBuffered > 2000) {
932     State->StillBuffered = 2000;
933   }
934 
935   return MinBytes;
936 }
937 
938 
939 /*
940  * update long-term average bitrate and amount of data in buffer
941  */
WebRtcIsacfix_UpdateRateModel(RateModel * State,WebRtc_Word16 StreamSize,const WebRtc_Word16 FrameSamples,const WebRtc_Word16 BottleNeck)942 void WebRtcIsacfix_UpdateRateModel(RateModel *State,
943                                    WebRtc_Word16 StreamSize,                    /* bytes in bitstream */
944                                    const WebRtc_Word16 FrameSamples,            /* samples per frame */
945                                    const WebRtc_Word16 BottleNeck)        /* bottle neck rate; excl headers (bps) */
946 {
947   WebRtc_Word16 TransmissionTime;
948 
949   /* avoid the initial "high-rate" burst */
950   State->InitCounter = 0;
951 
952   /* Update buffer delay */
953   TransmissionTime = (WebRtc_Word16)WEBRTC_SPL_DIV(WEBRTC_SPL_MUL(WEBRTC_SPL_MUL(StreamSize, 8), 1000), BottleNeck);    /* ms */
954   State->StillBuffered += TransmissionTime;
955   State->StillBuffered -= (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W16(FrameSamples, 4);            /* ms */
956   if (State->StillBuffered < 0) {
957     State->StillBuffered = 0;
958   }
959 
960 }
961 
962 
WebRtcIsacfix_InitRateModel(RateModel * State)963 void WebRtcIsacfix_InitRateModel(RateModel *State)
964 {
965   State->PrevExceed      = 0;                        /* boolean */
966   State->ExceedAgo       = 0;                        /* ms */
967   State->BurstCounter    = 0;                        /* packets */
968   State->InitCounter     = INIT_BURST_LEN + 10;    /* packets */
969   State->StillBuffered   = 1;                    /* ms */
970 }
971 
972 
973 
974 
975 
WebRtcIsacfix_GetNewFrameLength(WebRtc_Word16 bottle_neck,WebRtc_Word16 current_framesamples)976 WebRtc_Word16 WebRtcIsacfix_GetNewFrameLength(WebRtc_Word16 bottle_neck, WebRtc_Word16 current_framesamples)
977 {
978   WebRtc_Word16 new_framesamples;
979 
980   new_framesamples = current_framesamples;
981 
982   /* find new framelength */
983   switch(current_framesamples) {
984     case 480:
985       if (bottle_neck < Thld_30_60) {
986         new_framesamples = 960;
987       }
988       break;
989     case 960:
990       if (bottle_neck >= Thld_60_30) {
991         new_framesamples = 480;
992       }
993       break;
994     default:
995       new_framesamples = -1; /* Error */
996   }
997 
998   return new_framesamples;
999 }
1000 
WebRtcIsacfix_GetSnr(WebRtc_Word16 bottle_neck,WebRtc_Word16 framesamples)1001 WebRtc_Word16 WebRtcIsacfix_GetSnr(WebRtc_Word16 bottle_neck, WebRtc_Word16 framesamples)
1002 {
1003   WebRtc_Word16 s2nr = 0;
1004 
1005   /* find new SNR value */
1006   //consider BottleNeck to be in Q10 ( * 1 in Q10)
1007   switch(framesamples) {
1008     case 480:
1009       /*s2nr = -1*(a_30 << 10) + ((b_30 * bottle_neck) >> 10);*/
1010       s2nr = -22500 + (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(500, bottle_neck, 10); //* 0.001; //+ c_30 * bottle_neck * bottle_neck * 0.000001;
1011       break;
1012     case 960:
1013       /*s2nr = -1*(a_60 << 10) + ((b_60 * bottle_neck) >> 10);*/
1014       s2nr = -22500 + (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(500, bottle_neck, 10); //* 0.001; //+ c_30 * bottle_neck * bottle_neck * 0.000001;
1015       break;
1016     default:
1017       s2nr = -1; /* Error */
1018   }
1019 
1020   return s2nr; //return in Q10
1021 
1022 }
1023