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Diffstat (limited to 'webrtc/modules/audio_coding/codecs/isac/main/source/bandwidth_estimator.c')
| -rw-r--r-- | webrtc/modules/audio_coding/codecs/isac/main/source/bandwidth_estimator.c | 1031 |
1 files changed, 1031 insertions, 0 deletions
diff --git a/webrtc/modules/audio_coding/codecs/isac/main/source/bandwidth_estimator.c b/webrtc/modules/audio_coding/codecs/isac/main/source/bandwidth_estimator.c new file mode 100644 index 0000000..82fd053 --- /dev/null +++ b/webrtc/modules/audio_coding/codecs/isac/main/source/bandwidth_estimator.c @@ -0,0 +1,1031 @@ +/* + * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ + +/* + * BwEstimator.c + * + * This file contains the code for the Bandwidth Estimator designed + * for iSAC. + * + */ + +#include "bandwidth_estimator.h" +#include "settings.h" +#include "webrtc/modules/audio_coding/codecs/isac/main/include/isac.h" + +#include <assert.h> +#include <math.h> +#include <string.h> + +/* array of quantization levels for bottle neck info; Matlab code: */ +/* sprintf('%4.1ff, ', logspace(log10(5000), log10(40000), 12)) */ +static const float kQRateTableWb[12] = +{ + 10000.0f, 11115.3f, 12355.1f, 13733.1f, 15264.8f, 16967.3f, + 18859.8f, 20963.3f, 23301.4f, 25900.3f, 28789.0f, 32000.0f}; + + +static const float kQRateTableSwb[24] = +{ + 10000.0f, 11115.3f, 12355.1f, 13733.1f, 15264.8f, 16967.3f, + 18859.8f, 20963.3f, 23153.1f, 25342.9f, 27532.7f, 29722.5f, + 31912.3f, 34102.1f, 36291.9f, 38481.7f, 40671.4f, 42861.2f, + 45051.0f, 47240.8f, 49430.6f, 51620.4f, 53810.2f, 56000.0f, +}; + + + + +int32_t WebRtcIsac_InitBandwidthEstimator( + BwEstimatorstr* bwest_str, + enum IsacSamplingRate encoderSampRate, + enum IsacSamplingRate decoderSampRate) +{ + switch(encoderSampRate) + { + case kIsacWideband: + { + bwest_str->send_bw_avg = INIT_BN_EST_WB; + break; + } + case kIsacSuperWideband: + { + bwest_str->send_bw_avg = INIT_BN_EST_SWB; + break; + } + } + + switch(decoderSampRate) + { + case kIsacWideband: + { + bwest_str->prev_frame_length = INIT_FRAME_LEN_WB; + bwest_str->rec_bw_inv = 1.0f / + (INIT_BN_EST_WB + INIT_HDR_RATE_WB); + bwest_str->rec_bw = (int32_t)INIT_BN_EST_WB; + bwest_str->rec_bw_avg_Q = INIT_BN_EST_WB; + bwest_str->rec_bw_avg = INIT_BN_EST_WB + INIT_HDR_RATE_WB; + bwest_str->rec_header_rate = INIT_HDR_RATE_WB; + break; + } + case kIsacSuperWideband: + { + bwest_str->prev_frame_length = INIT_FRAME_LEN_SWB; + bwest_str->rec_bw_inv = 1.0f / + (INIT_BN_EST_SWB + INIT_HDR_RATE_SWB); + bwest_str->rec_bw = (int32_t)INIT_BN_EST_SWB; + bwest_str->rec_bw_avg_Q = INIT_BN_EST_SWB; + bwest_str->rec_bw_avg = INIT_BN_EST_SWB + INIT_HDR_RATE_SWB; + bwest_str->rec_header_rate = INIT_HDR_RATE_SWB; + break; + } + } + + bwest_str->prev_rec_rtp_number = 0; + bwest_str->prev_rec_arr_ts = 0; + bwest_str->prev_rec_send_ts = 0; + bwest_str->prev_rec_rtp_rate = 1.0f; + bwest_str->last_update_ts = 0; + bwest_str->last_reduction_ts = 0; + bwest_str->count_tot_updates_rec = -9; + bwest_str->rec_jitter = 10.0f; + bwest_str->rec_jitter_short_term = 0.0f; + bwest_str->rec_jitter_short_term_abs = 5.0f; + bwest_str->rec_max_delay = 10.0f; + bwest_str->rec_max_delay_avg_Q = 10.0f; + bwest_str->num_pkts_rec = 0; + + bwest_str->send_max_delay_avg = 10.0f; + + bwest_str->hsn_detect_rec = 0; + + bwest_str->num_consec_rec_pkts_over_30k = 0; + + bwest_str->hsn_detect_snd = 0; + + bwest_str->num_consec_snt_pkts_over_30k = 0; + + bwest_str->in_wait_period = 0; + + bwest_str->change_to_WB = 0; + + bwest_str->numConsecLatePkts = 0; + bwest_str->consecLatency = 0; + bwest_str->inWaitLatePkts = 0; + bwest_str->senderTimestamp = 0; + bwest_str->receiverTimestamp = 0; + + bwest_str->external_bw_info.in_use = 0; + + return 0; +} + +/* This function updates both bottle neck rates */ +/* Parameters: */ +/* rtp_number - value from RTP packet, from NetEq */ +/* frame length - length of signal frame in ms, from iSAC decoder */ +/* send_ts - value in RTP header giving send time in samples */ +/* arr_ts - value given by timeGetTime() time of arrival in samples of packet from NetEq */ +/* pksize - size of packet in bytes, from NetEq */ +/* Index - integer (range 0...23) indicating bottle neck & jitter as estimated by other side */ +/* returns 0 if everything went fine, -1 otherwise */ +int16_t WebRtcIsac_UpdateBandwidthEstimator( + BwEstimatorstr* bwest_str, + const uint16_t rtp_number, + const int32_t frame_length, + const uint32_t send_ts, + const uint32_t arr_ts, + const size_t pksize + /*, const uint16_t Index*/) +{ + float weight = 0.0f; + float curr_bw_inv = 0.0f; + float rec_rtp_rate; + float t_diff_proj; + float arr_ts_diff; + float send_ts_diff; + float arr_time_noise; + float arr_time_noise_abs; + + float delay_correction_factor = 1; + float late_diff = 0.0f; + int immediate_set = 0; + int num_pkts_expected; + + assert(!bwest_str->external_bw_info.in_use); + + // We have to adjust the header-rate if the first packet has a + // frame-size different than the initialized value. + if ( frame_length != bwest_str->prev_frame_length ) + { + bwest_str->rec_header_rate = (float)HEADER_SIZE * 8.0f * + 1000.0f / (float)frame_length; /* bits/s */ + } + + /* UPDATE ESTIMATES ON THIS SIDE */ + /* compute far-side transmission rate */ + rec_rtp_rate = ((float)pksize * 8.0f * 1000.0f / (float)frame_length) + + bwest_str->rec_header_rate; + // rec_rtp_rate packet bits/s + header bits/s + + /* check for timer wrap-around */ + if (arr_ts < bwest_str->prev_rec_arr_ts) + { + bwest_str->prev_rec_arr_ts = arr_ts; + bwest_str->last_update_ts = arr_ts; + bwest_str->last_reduction_ts = arr_ts + 3*FS; + bwest_str->num_pkts_rec = 0; + + /* store frame length */ + bwest_str->prev_frame_length = frame_length; + + /* store far-side transmission rate */ + bwest_str->prev_rec_rtp_rate = rec_rtp_rate; + + /* store far-side RTP time stamp */ + bwest_str->prev_rec_rtp_number = rtp_number; + + return 0; + } + + bwest_str->num_pkts_rec++; + + /* check that it's not one of the first 9 packets */ + if ( bwest_str->count_tot_updates_rec > 0 ) + { + if(bwest_str->in_wait_period > 0 ) + { + bwest_str->in_wait_period--; + } + + bwest_str->inWaitLatePkts -= ((bwest_str->inWaitLatePkts > 0)? 1:0); + send_ts_diff = (float)(send_ts - bwest_str->prev_rec_send_ts); + + if (send_ts_diff <= (16 * frame_length)*2) + //doesn't allow for a dropped packet, not sure necessary to be + // that strict -DH + { + /* if not been updated for a long time, reduce the BN estimate */ + if((uint32_t)(arr_ts - bwest_str->last_update_ts) * + 1000.0f / FS > 3000) + { + //how many frames should have been received since the last + // update if too many have been dropped or there have been + // big delays won't allow this reduction may no longer need + // the send_ts_diff here + num_pkts_expected = (int)(((float)(arr_ts - + bwest_str->last_update_ts) * 1000.0f /(float) FS) / + (float)frame_length); + + if(((float)bwest_str->num_pkts_rec/(float)num_pkts_expected) > + 0.9) + { + float inv_bitrate = (float) pow( 0.99995, + (double)((uint32_t)(arr_ts - + bwest_str->last_reduction_ts)*1000.0f/FS) ); + + if ( inv_bitrate ) + { + bwest_str->rec_bw_inv /= inv_bitrate; + + //precautionary, likely never necessary + if (bwest_str->hsn_detect_snd && + bwest_str->hsn_detect_rec) + { + if (bwest_str->rec_bw_inv > 0.000066f) + { + bwest_str->rec_bw_inv = 0.000066f; + } + } + } + else + { + bwest_str->rec_bw_inv = 1.0f / + (INIT_BN_EST_WB + INIT_HDR_RATE_WB); + } + /* reset time-since-update counter */ + bwest_str->last_reduction_ts = arr_ts; + } + else + //reset here? + { + bwest_str->last_reduction_ts = arr_ts + 3*FS; + bwest_str->last_update_ts = arr_ts; + bwest_str->num_pkts_rec = 0; + } + } + } + else + { + bwest_str->last_reduction_ts = arr_ts + 3*FS; + bwest_str->last_update_ts = arr_ts; + bwest_str->num_pkts_rec = 0; + } + + + /* temporarily speed up adaptation if frame length has changed */ + if ( frame_length != bwest_str->prev_frame_length ) + { + bwest_str->count_tot_updates_rec = 10; + bwest_str->rec_header_rate = (float)HEADER_SIZE * 8.0f * + 1000.0f / (float)frame_length; /* bits/s */ + + bwest_str->rec_bw_inv = 1.0f /((float)bwest_str->rec_bw + + bwest_str->rec_header_rate); + } + + //////////////////////// + arr_ts_diff = (float)(arr_ts - bwest_str->prev_rec_arr_ts); + + if (send_ts_diff > 0 ) + { + late_diff = arr_ts_diff - send_ts_diff; + } + else + { + late_diff = arr_ts_diff - (float)(16 * frame_length); + } + + if((late_diff > 0) && !bwest_str->inWaitLatePkts) + { + bwest_str->numConsecLatePkts++; + bwest_str->consecLatency += late_diff; + } + else + { + bwest_str->numConsecLatePkts = 0; + bwest_str->consecLatency = 0; + } + if(bwest_str->numConsecLatePkts > 50) + { + float latencyMs = bwest_str->consecLatency/(FS/1000); + float averageLatencyMs = latencyMs / bwest_str->numConsecLatePkts; + delay_correction_factor = frame_length / (frame_length + averageLatencyMs); + immediate_set = 1; + bwest_str->inWaitLatePkts = (int16_t)((bwest_str->consecLatency/(FS/1000)) / 30);// + 150; + bwest_str->start_wait_period = arr_ts; + } + /////////////////////////////////////////////// + + + + /* update only if previous packet was not lost */ + if ( rtp_number == bwest_str->prev_rec_rtp_number + 1 ) + { + + + if (!(bwest_str->hsn_detect_snd && bwest_str->hsn_detect_rec)) + { + if ((arr_ts_diff > (float)(16 * frame_length))) + { + //1/2 second + if ((late_diff > 8000.0f) && !bwest_str->in_wait_period) + { + delay_correction_factor = 0.7f; + bwest_str->in_wait_period = 55; + bwest_str->start_wait_period = arr_ts; + immediate_set = 1; + } + //320 ms + else if (late_diff > 5120.0f && !bwest_str->in_wait_period) + { + delay_correction_factor = 0.8f; + immediate_set = 1; + bwest_str->in_wait_period = 44; + bwest_str->start_wait_period = arr_ts; + } + } + } + + + if ((bwest_str->prev_rec_rtp_rate > bwest_str->rec_bw_avg) && + (rec_rtp_rate > bwest_str->rec_bw_avg) && + !bwest_str->in_wait_period) + { + /* test if still in initiation period and increment counter */ + if (bwest_str->count_tot_updates_rec++ > 99) + { + /* constant weight after initiation part */ + weight = 0.01f; + } + else + { + /* weight decreases with number of updates */ + weight = 1.0f / (float) bwest_str->count_tot_updates_rec; + } + /* Bottle Neck Estimation */ + + /* limit outliers */ + /* if more than 25 ms too much */ + if (arr_ts_diff > frame_length * FS/1000 + 400.0f) + { + // in samples, why 25ms?? + arr_ts_diff = frame_length * FS/1000 + 400.0f; + } + if(arr_ts_diff < (frame_length * FS/1000) - 160.0f) + { + /* don't allow it to be less than frame rate - 10 ms */ + arr_ts_diff = (float)frame_length * FS/1000 - 160.0f; + } + + /* compute inverse receiving rate for last packet */ + curr_bw_inv = arr_ts_diff / ((float)(pksize + HEADER_SIZE) * + 8.0f * FS); // (180+35)*8*16000 = 27.5 Mbit.... + + + if(curr_bw_inv < + (1.0f / (MAX_ISAC_BW + bwest_str->rec_header_rate))) + { + // don't allow inv rate to be larger than MAX + curr_bw_inv = (1.0f / + (MAX_ISAC_BW + bwest_str->rec_header_rate)); + } + + /* update bottle neck rate estimate */ + bwest_str->rec_bw_inv = weight * curr_bw_inv + + (1.0f - weight) * bwest_str->rec_bw_inv; + + /* reset time-since-update counter */ + bwest_str->last_update_ts = arr_ts; + bwest_str->last_reduction_ts = arr_ts + 3 * FS; + bwest_str->num_pkts_rec = 0; + + /* Jitter Estimation */ + /* projected difference between arrival times */ + t_diff_proj = ((float)(pksize + HEADER_SIZE) * 8.0f * + 1000.0f) / bwest_str->rec_bw_avg; + + + // difference between projected and actual + // arrival time differences + arr_time_noise = (float)(arr_ts_diff*1000.0f/FS) - + t_diff_proj; + arr_time_noise_abs = (float) fabs( arr_time_noise ); + + /* long term averaged absolute jitter */ + bwest_str->rec_jitter = weight * arr_time_noise_abs + + (1.0f - weight) * bwest_str->rec_jitter; + if (bwest_str->rec_jitter > 10.0f) + { + bwest_str->rec_jitter = 10.0f; + } + /* short term averaged absolute jitter */ + bwest_str->rec_jitter_short_term_abs = 0.05f * + arr_time_noise_abs + 0.95f * + bwest_str->rec_jitter_short_term_abs; + + /* short term averaged jitter */ + bwest_str->rec_jitter_short_term = 0.05f * arr_time_noise + + 0.95f * bwest_str->rec_jitter_short_term; + } + } + } + else + { + // reset time-since-update counter when + // receiving the first 9 packets + bwest_str->last_update_ts = arr_ts; + bwest_str->last_reduction_ts = arr_ts + 3*FS; + bwest_str->num_pkts_rec = 0; + + bwest_str->count_tot_updates_rec++; + } + + /* limit minimum bottle neck rate */ + if (bwest_str->rec_bw_inv > 1.0f / ((float)MIN_ISAC_BW + + bwest_str->rec_header_rate)) + { + bwest_str->rec_bw_inv = 1.0f / ((float)MIN_ISAC_BW + + bwest_str->rec_header_rate); + } + + // limit maximum bitrate + if (bwest_str->rec_bw_inv < 1.0f / ((float)MAX_ISAC_BW + + bwest_str->rec_header_rate)) + { + bwest_str->rec_bw_inv = 1.0f / ((float)MAX_ISAC_BW + + bwest_str->rec_header_rate); + } + + /* store frame length */ + bwest_str->prev_frame_length = frame_length; + + /* store far-side transmission rate */ + bwest_str->prev_rec_rtp_rate = rec_rtp_rate; + + /* store far-side RTP time stamp */ + bwest_str->prev_rec_rtp_number = rtp_number; + + // Replace bwest_str->rec_max_delay by the new + // value (atomic operation) + bwest_str->rec_max_delay = 3.0f * bwest_str->rec_jitter; + + /* store send and arrival time stamp */ + bwest_str->prev_rec_arr_ts = arr_ts ; + bwest_str->prev_rec_send_ts = send_ts; + + /* Replace bwest_str->rec_bw by the new value (atomic operation) */ + bwest_str->rec_bw = (int32_t)(1.0f / bwest_str->rec_bw_inv - + bwest_str->rec_header_rate); + + if (immediate_set) + { + bwest_str->rec_bw = (int32_t) (delay_correction_factor * + (float) bwest_str->rec_bw); + + if (bwest_str->rec_bw < (int32_t) MIN_ISAC_BW) + { + bwest_str->rec_bw = (int32_t) MIN_ISAC_BW; + } + + bwest_str->rec_bw_avg = bwest_str->rec_bw + + bwest_str->rec_header_rate; + + bwest_str->rec_bw_avg_Q = (float) bwest_str->rec_bw; + + bwest_str->rec_jitter_short_term = 0.0f; + + bwest_str->rec_bw_inv = 1.0f / (bwest_str->rec_bw + + bwest_str->rec_header_rate); + + bwest_str->count_tot_updates_rec = 1; + + immediate_set = 0; + bwest_str->consecLatency = 0; + bwest_str->numConsecLatePkts = 0; + } + + return 0; +} + + +/* This function updates the send bottle neck rate */ +/* Index - integer (range 0...23) indicating bottle neck & jitter as estimated by other side */ +/* returns 0 if everything went fine, -1 otherwise */ +int16_t WebRtcIsac_UpdateUplinkBwImpl( + BwEstimatorstr* bwest_str, + int16_t index, + enum IsacSamplingRate encoderSamplingFreq) +{ + assert(!bwest_str->external_bw_info.in_use); + + if((index < 0) || (index > 23)) + { + return -ISAC_RANGE_ERROR_BW_ESTIMATOR; + } + + /* UPDATE ESTIMATES FROM OTHER SIDE */ + if(encoderSamplingFreq == kIsacWideband) + { + if(index > 11) + { + index -= 12; + /* compute the jitter estimate as decoded on the other side */ + bwest_str->send_max_delay_avg = 0.9f * bwest_str->send_max_delay_avg + + 0.1f * (float)MAX_ISAC_MD; + } + else + { + /* compute the jitter estimate as decoded on the other side */ + bwest_str->send_max_delay_avg = 0.9f * bwest_str->send_max_delay_avg + + 0.1f * (float)MIN_ISAC_MD; + } + + /* compute the BN estimate as decoded on the other side */ + bwest_str->send_bw_avg = 0.9f * bwest_str->send_bw_avg + + 0.1f * kQRateTableWb[index]; + } + else + { + /* compute the BN estimate as decoded on the other side */ + bwest_str->send_bw_avg = 0.9f * bwest_str->send_bw_avg + + 0.1f * kQRateTableSwb[index]; + } + + if (bwest_str->send_bw_avg > (float) 28000 && !bwest_str->hsn_detect_snd) + { + bwest_str->num_consec_snt_pkts_over_30k++; + + if (bwest_str->num_consec_snt_pkts_over_30k >= 66) + { + //approx 2 seconds with 30ms frames + bwest_str->hsn_detect_snd = 1; + } + } + else if (!bwest_str->hsn_detect_snd) + { + bwest_str->num_consec_snt_pkts_over_30k = 0; + } + return 0; +} + +// called when there is upper-band bit-stream to update jitter +// statistics. +int16_t WebRtcIsac_UpdateUplinkJitter( + BwEstimatorstr* bwest_str, + int32_t index) +{ + assert(!bwest_str->external_bw_info.in_use); + + if((index < 0) || (index > 23)) + { + return -ISAC_RANGE_ERROR_BW_ESTIMATOR; + } + + if(index > 0) + { + /* compute the jitter estimate as decoded on the other side */ + bwest_str->send_max_delay_avg = 0.9f * bwest_str->send_max_delay_avg + + 0.1f * (float)MAX_ISAC_MD; + } + else + { + /* compute the jitter estimate as decoded on the other side */ + bwest_str->send_max_delay_avg = 0.9f * bwest_str->send_max_delay_avg + + 0.1f * (float)MIN_ISAC_MD; + } + + return 0; +} + + + +// Returns the bandwidth/jitter estimation code (integer 0...23) +// to put in the sending iSAC payload +void +WebRtcIsac_GetDownlinkBwJitIndexImpl( + BwEstimatorstr* bwest_str, + int16_t* bottleneckIndex, + int16_t* jitterInfo, + enum IsacSamplingRate decoderSamplingFreq) +{ + float MaxDelay; + //uint16_t MaxDelayBit; + + float rate; + float r; + float e1, e2; + const float weight = 0.1f; + const float* ptrQuantizationTable; + int16_t addJitterInfo; + int16_t minInd; + int16_t maxInd; + int16_t midInd; + + if (bwest_str->external_bw_info.in_use) { + *bottleneckIndex = bwest_str->external_bw_info.bottleneck_idx; + *jitterInfo = bwest_str->external_bw_info.jitter_info; + return; + } + + /* Get Max Delay Bit */ + /* get unquantized max delay */ + MaxDelay = (float)WebRtcIsac_GetDownlinkMaxDelay(bwest_str); + + if ( ((1.f - weight) * bwest_str->rec_max_delay_avg_Q + weight * + MAX_ISAC_MD - MaxDelay) > (MaxDelay - (1.f-weight) * + bwest_str->rec_max_delay_avg_Q - weight * MIN_ISAC_MD) ) + { + jitterInfo[0] = 0; + /* update quantized average */ + bwest_str->rec_max_delay_avg_Q = + (1.f - weight) * bwest_str->rec_max_delay_avg_Q + weight * + (float)MIN_ISAC_MD; + } + else + { + jitterInfo[0] = 1; + /* update quantized average */ + bwest_str->rec_max_delay_avg_Q = + (1.f-weight) * bwest_str->rec_max_delay_avg_Q + weight * + (float)MAX_ISAC_MD; + } + + // Get unquantized rate. + rate = (float)WebRtcIsac_GetDownlinkBandwidth(bwest_str); + + /* Get Rate Index */ + if(decoderSamplingFreq == kIsacWideband) + { + ptrQuantizationTable = kQRateTableWb; + addJitterInfo = 1; + maxInd = 11; + } + else + { + ptrQuantizationTable = kQRateTableSwb; + addJitterInfo = 0; + maxInd = 23; + } + + minInd = 0; + while(maxInd > minInd + 1) + { + midInd = (maxInd + minInd) >> 1; + if(rate > ptrQuantizationTable[midInd]) + { + minInd = midInd; + } + else + { + maxInd = midInd; + } + } + // Chose the index which gives results an average which is closest + // to rate + r = (1 - weight) * bwest_str->rec_bw_avg_Q - rate; + e1 = weight * ptrQuantizationTable[minInd] + r; + e2 = weight * ptrQuantizationTable[maxInd] + r; + e1 = (e1 > 0)? e1:-e1; + e2 = (e2 > 0)? e2:-e2; + if(e1 < e2) + { + bottleneckIndex[0] = minInd; + } + else + { + bottleneckIndex[0] = maxInd; + } + + bwest_str->rec_bw_avg_Q = (1 - weight) * bwest_str->rec_bw_avg_Q + + weight * ptrQuantizationTable[bottleneckIndex[0]]; + bottleneckIndex[0] += jitterInfo[0] * 12 * addJitterInfo; + + bwest_str->rec_bw_avg = (1 - weight) * bwest_str->rec_bw_avg + weight * + (rate + bwest_str->rec_header_rate); +} + + + +/* get the bottle neck rate from far side to here, as estimated on this side */ +int32_t WebRtcIsac_GetDownlinkBandwidth( const BwEstimatorstr *bwest_str) +{ + int32_t rec_bw; + float jitter_sign; + float bw_adjust; + + assert(!bwest_str->external_bw_info.in_use); + + /* create a value between -1.0 and 1.0 indicating "average sign" of jitter */ + jitter_sign = bwest_str->rec_jitter_short_term / + bwest_str->rec_jitter_short_term_abs; + + /* adjust bw proportionally to negative average jitter sign */ + bw_adjust = 1.0f - jitter_sign * (0.15f + 0.15f * jitter_sign * jitter_sign); + + /* adjust Rate if jitter sign is mostly constant */ + rec_bw = (int32_t)(bwest_str->rec_bw * bw_adjust); + + /* limit range of bottle neck rate */ + if (rec_bw < MIN_ISAC_BW) + { + rec_bw = MIN_ISAC_BW; + } + else if (rec_bw > MAX_ISAC_BW) + { + rec_bw = MAX_ISAC_BW; + } + return rec_bw; +} + +/* Returns the max delay (in ms) */ +int32_t +WebRtcIsac_GetDownlinkMaxDelay(const BwEstimatorstr *bwest_str) +{ + int32_t rec_max_delay; + + assert(!bwest_str->external_bw_info.in_use); + + rec_max_delay = (int32_t)(bwest_str->rec_max_delay); + + /* limit range of jitter estimate */ + if (rec_max_delay < MIN_ISAC_MD) + { + rec_max_delay = MIN_ISAC_MD; + } + else if (rec_max_delay > MAX_ISAC_MD) + { + rec_max_delay = MAX_ISAC_MD; + } + return rec_max_delay; +} + +/* Clamp val to the closed interval [min,max]. */ +static int32_t clamp(int32_t val, int32_t min, int32_t max) { + assert(min <= max); + return val < min ? min : (val > max ? max : val); +} + +int32_t WebRtcIsac_GetUplinkBandwidth(const BwEstimatorstr* bwest_str) { + return bwest_str->external_bw_info.in_use + ? bwest_str->external_bw_info.send_bw_avg + : clamp(bwest_str->send_bw_avg, MIN_ISAC_BW, MAX_ISAC_BW); +} + +int32_t WebRtcIsac_GetUplinkMaxDelay(const BwEstimatorstr* bwest_str) { + return bwest_str->external_bw_info.in_use + ? bwest_str->external_bw_info.send_max_delay_avg + : clamp(bwest_str->send_max_delay_avg, MIN_ISAC_MD, MAX_ISAC_MD); +} + +void WebRtcIsacBw_GetBandwidthInfo(BwEstimatorstr* bwest_str, + enum IsacSamplingRate decoder_sample_rate_hz, + IsacBandwidthInfo* bwinfo) { + assert(!bwest_str->external_bw_info.in_use); + bwinfo->in_use = 1; + bwinfo->send_bw_avg = WebRtcIsac_GetUplinkBandwidth(bwest_str); + bwinfo->send_max_delay_avg = WebRtcIsac_GetUplinkMaxDelay(bwest_str); + WebRtcIsac_GetDownlinkBwJitIndexImpl(bwest_str, &bwinfo->bottleneck_idx, + &bwinfo->jitter_info, + decoder_sample_rate_hz); +} + +void WebRtcIsacBw_SetBandwidthInfo(BwEstimatorstr* bwest_str, + const IsacBandwidthInfo* bwinfo) { + memcpy(&bwest_str->external_bw_info, bwinfo, + sizeof bwest_str->external_bw_info); +} + +/* + * update long-term average bitrate and amount of data in buffer + * returns minimum payload size (bytes) + */ +int WebRtcIsac_GetMinBytes( + RateModel* State, + int StreamSize, /* bytes in bitstream */ + const int FrameSamples, /* samples per frame */ + const double BottleNeck, /* bottle neck rate; excl headers (bps) */ + const double DelayBuildUp, /* max delay from bottleneck buffering (ms) */ + enum ISACBandwidth bandwidth + /*,int16_t frequentLargePackets*/) +{ + double MinRate = 0.0; + int MinBytes; + double TransmissionTime; + int burstInterval = BURST_INTERVAL; + + // first 10 packets @ low rate, then INIT_BURST_LEN packets @ + // fixed rate of INIT_RATE bps + if (State->InitCounter > 0) + { + if (State->InitCounter-- <= INIT_BURST_LEN) + { + if(bandwidth == isac8kHz) + { + MinRate = INIT_RATE_WB; + } + else + { + MinRate = INIT_RATE_SWB; + } + } + else + { + MinRate = 0; + } + } + else + { + /* handle burst */ + if (State->BurstCounter) + { + if (State->StillBuffered < (1.0 - 1.0/BURST_LEN) * DelayBuildUp) + { + /* max bps derived from BottleNeck and DelayBuildUp values */ + MinRate = (1.0 + (FS/1000) * DelayBuildUp / + (double)(BURST_LEN * FrameSamples)) * BottleNeck; + } + else + { + // max bps derived from StillBuffered and DelayBuildUp + // values + MinRate = (1.0 + (FS/1000) * (DelayBuildUp - + State->StillBuffered) / (double)FrameSamples) * BottleNeck; + if (MinRate < 1.04 * BottleNeck) + { + MinRate = 1.04 * BottleNeck; + } + } + State->BurstCounter--; + } + } + + + /* convert rate from bits/second to bytes/packet */ + MinBytes = (int) (MinRate * FrameSamples / (8.0 * FS)); + + /* StreamSize will be adjusted if less than MinBytes */ + if (StreamSize < MinBytes) + { + StreamSize = MinBytes; + } + + /* keep track of when bottle neck was last exceeded by at least 1% */ + if (StreamSize * 8.0 * FS / FrameSamples > 1.01 * BottleNeck) { + if (State->PrevExceed) { + /* bottle_neck exceded twice in a row, decrease ExceedAgo */ + State->ExceedAgo -= /*BURST_INTERVAL*/ burstInterval / (BURST_LEN - 1); + if (State->ExceedAgo < 0) + State->ExceedAgo = 0; + } + else + { + State->ExceedAgo += (FrameSamples * 1000) / FS; /* ms */ + State->PrevExceed = 1; + } + } + else + { + State->PrevExceed = 0; + State->ExceedAgo += (FrameSamples * 1000) / FS; /* ms */ + } + + /* set burst flag if bottle neck not exceeded for long time */ + if ((State->ExceedAgo > burstInterval) && + (State->BurstCounter == 0)) + { + if (State->PrevExceed) + { + State->BurstCounter = BURST_LEN - 1; + } + else + { + State->BurstCounter = BURST_LEN; + } + } + + + /* Update buffer delay */ + TransmissionTime = StreamSize * 8.0 * 1000.0 / BottleNeck; /* ms */ + State->StillBuffered += TransmissionTime; + State->StillBuffered -= (FrameSamples * 1000) / FS; /* ms */ + if (State->StillBuffered < 0.0) + { + State->StillBuffered = 0.0; + } + + return MinBytes; +} + + +/* + * update long-term average bitrate and amount of data in buffer + */ +void WebRtcIsac_UpdateRateModel( + RateModel *State, + int StreamSize, /* bytes in bitstream */ + const int FrameSamples, /* samples per frame */ + const double BottleNeck) /* bottle neck rate; excl headers (bps) */ +{ + double TransmissionTime; + + /* avoid the initial "high-rate" burst */ + State->InitCounter = 0; + + /* Update buffer delay */ + TransmissionTime = StreamSize * 8.0 * 1000.0 / BottleNeck; /* ms */ + State->StillBuffered += TransmissionTime; + State->StillBuffered -= (FrameSamples * 1000) / FS; /* ms */ + if (State->StillBuffered < 0.0) + State->StillBuffered = 0.0; + +} + + +void WebRtcIsac_InitRateModel( + RateModel *State) +{ + State->PrevExceed = 0; /* boolean */ + State->ExceedAgo = 0; /* ms */ + State->BurstCounter = 0; /* packets */ + State->InitCounter = INIT_BURST_LEN + 10; /* packets */ + State->StillBuffered = 1.0; /* ms */ +} + +int WebRtcIsac_GetNewFrameLength( + double bottle_neck, + int current_framesamples) +{ + int new_framesamples; + + const int Thld_20_30 = 20000; + + //const int Thld_30_20 = 30000; + const int Thld_30_20 = 1000000; // disable 20 ms frames + + const int Thld_30_60 = 18000; + //const int Thld_30_60 = 0; // disable 60 ms frames + + const int Thld_60_30 = 27000; + + + new_framesamples = current_framesamples; + + /* find new framelength */ + switch(current_framesamples) { + case 320: + if (bottle_neck < Thld_20_30) + new_framesamples = 480; + break; + case 480: + if (bottle_neck < Thld_30_60) + new_framesamples = 960; + else if (bottle_neck > Thld_30_20) + new_framesamples = 320; + break; + case 960: + if (bottle_neck >= Thld_60_30) + new_framesamples = 480; + break; + } + + return new_framesamples; +} + +double WebRtcIsac_GetSnr( + double bottle_neck, + int framesamples) +{ + double s2nr; + + const double a_20 = -30.0; + const double b_20 = 0.8; + const double c_20 = 0.0; + + const double a_30 = -23.0; + const double b_30 = 0.48; + const double c_30 = 0.0; + + const double a_60 = -23.0; + const double b_60 = 0.53; + const double c_60 = 0.0; + + + /* find new SNR value */ + switch(framesamples) { + case 320: + s2nr = a_20 + b_20 * bottle_neck * 0.001 + c_20 * bottle_neck * + bottle_neck * 0.000001; + break; + case 480: + s2nr = a_30 + b_30 * bottle_neck * 0.001 + c_30 * bottle_neck * + bottle_neck * 0.000001; + break; + case 960: + s2nr = a_60 + b_60 * bottle_neck * 0.001 + c_60 * bottle_neck * + bottle_neck * 0.000001; + break; + default: + s2nr = 0; + } + + return s2nr; + +} |