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-rw-r--r--third_party/libwebrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc436
1 files changed, 436 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc b/third_party/libwebrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc
new file mode 100644
index 0000000000..48f1b8c296
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/codecs/cng/webrtc_cng.cc
@@ -0,0 +1,436 @@
+/*
+ * 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.
+ */
+
+#include "modules/audio_coding/codecs/cng/webrtc_cng.h"
+
+#include <algorithm>
+
+#include "common_audio/signal_processing/include/signal_processing_library.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_conversions.h"
+
+namespace webrtc {
+
+namespace {
+
+const size_t kCngMaxOutsizeOrder = 640;
+
+// TODO(ossu): Rename the left-over WebRtcCng according to style guide.
+void WebRtcCng_K2a16(int16_t* k, int useOrder, int16_t* a);
+
+const int32_t WebRtcCng_kDbov[94] = {
+ 1081109975, 858756178, 682134279, 541838517, 430397633, 341876992,
+ 271562548, 215709799, 171344384, 136103682, 108110997, 85875618,
+ 68213428, 54183852, 43039763, 34187699, 27156255, 21570980,
+ 17134438, 13610368, 10811100, 8587562, 6821343, 5418385,
+ 4303976, 3418770, 2715625, 2157098, 1713444, 1361037,
+ 1081110, 858756, 682134, 541839, 430398, 341877,
+ 271563, 215710, 171344, 136104, 108111, 85876,
+ 68213, 54184, 43040, 34188, 27156, 21571,
+ 17134, 13610, 10811, 8588, 6821, 5418,
+ 4304, 3419, 2716, 2157, 1713, 1361,
+ 1081, 859, 682, 542, 430, 342,
+ 272, 216, 171, 136, 108, 86,
+ 68, 54, 43, 34, 27, 22,
+ 17, 14, 11, 9, 7, 5,
+ 4, 3, 3, 2, 2, 1,
+ 1, 1, 1, 1};
+
+const int16_t WebRtcCng_kCorrWindow[WEBRTC_CNG_MAX_LPC_ORDER] = {
+ 32702, 32636, 32570, 32505, 32439, 32374,
+ 32309, 32244, 32179, 32114, 32049, 31985};
+
+} // namespace
+
+ComfortNoiseDecoder::ComfortNoiseDecoder() {
+ /* Needed to get the right function pointers in SPLIB. */
+ Reset();
+}
+
+void ComfortNoiseDecoder::Reset() {
+ dec_seed_ = 7777; /* For debugging only. */
+ dec_target_energy_ = 0;
+ dec_used_energy_ = 0;
+ for (auto& c : dec_target_reflCoefs_)
+ c = 0;
+ for (auto& c : dec_used_reflCoefs_)
+ c = 0;
+ for (auto& c : dec_filtstate_)
+ c = 0;
+ for (auto& c : dec_filtstateLow_)
+ c = 0;
+ dec_order_ = 5;
+ dec_target_scale_factor_ = 0;
+ dec_used_scale_factor_ = 0;
+}
+
+void ComfortNoiseDecoder::UpdateSid(rtc::ArrayView<const uint8_t> sid) {
+ int16_t refCs[WEBRTC_CNG_MAX_LPC_ORDER];
+ int32_t targetEnergy;
+ size_t length = sid.size();
+ /* Throw away reflection coefficients of higher order than we can handle. */
+ if (length > (WEBRTC_CNG_MAX_LPC_ORDER + 1))
+ length = WEBRTC_CNG_MAX_LPC_ORDER + 1;
+
+ dec_order_ = static_cast<uint16_t>(length - 1);
+
+ uint8_t sid0 = std::min<uint8_t>(sid[0], 93);
+ targetEnergy = WebRtcCng_kDbov[sid0];
+ /* Take down target energy to 75%. */
+ targetEnergy = targetEnergy >> 1;
+ targetEnergy += targetEnergy >> 2;
+
+ dec_target_energy_ = targetEnergy;
+
+ /* Reconstruct coeffs with tweak for WebRtc implementation of RFC3389. */
+ if (dec_order_ == WEBRTC_CNG_MAX_LPC_ORDER) {
+ for (size_t i = 0; i < (dec_order_); i++) {
+ refCs[i] = sid[i + 1] << 8; /* Q7 to Q15*/
+ dec_target_reflCoefs_[i] = refCs[i];
+ }
+ } else {
+ for (size_t i = 0; i < (dec_order_); i++) {
+ refCs[i] = (sid[i + 1] - 127) * (1 << 8); /* Q7 to Q15. */
+ dec_target_reflCoefs_[i] = refCs[i];
+ }
+ }
+
+ for (size_t i = (dec_order_); i < WEBRTC_CNG_MAX_LPC_ORDER; i++) {
+ refCs[i] = 0;
+ dec_target_reflCoefs_[i] = refCs[i];
+ }
+}
+
+bool ComfortNoiseDecoder::Generate(rtc::ArrayView<int16_t> out_data,
+ bool new_period) {
+ int16_t excitation[kCngMaxOutsizeOrder];
+ int16_t low[kCngMaxOutsizeOrder];
+ int16_t lpPoly[WEBRTC_CNG_MAX_LPC_ORDER + 1];
+ int16_t ReflBetaStd = 26214; /* 0.8 in q15. */
+ int16_t ReflBetaCompStd = 6553; /* 0.2 in q15. */
+ int16_t ReflBetaNewP = 19661; /* 0.6 in q15. */
+ int16_t ReflBetaCompNewP = 13107; /* 0.4 in q15. */
+ int16_t Beta, BetaC; /* These are in Q15. */
+ int32_t targetEnergy;
+ int16_t En;
+ int16_t temp16;
+ const size_t num_samples = out_data.size();
+
+ if (num_samples > kCngMaxOutsizeOrder) {
+ return false;
+ }
+
+ if (new_period) {
+ dec_used_scale_factor_ = dec_target_scale_factor_;
+ Beta = ReflBetaNewP;
+ BetaC = ReflBetaCompNewP;
+ } else {
+ Beta = ReflBetaStd;
+ BetaC = ReflBetaCompStd;
+ }
+
+ /* Calculate new scale factor in Q13 */
+ dec_used_scale_factor_ = rtc::checked_cast<int16_t>(
+ WEBRTC_SPL_MUL_16_16_RSFT(dec_used_scale_factor_, Beta >> 2, 13) +
+ WEBRTC_SPL_MUL_16_16_RSFT(dec_target_scale_factor_, BetaC >> 2, 13));
+
+ dec_used_energy_ = dec_used_energy_ >> 1;
+ dec_used_energy_ += dec_target_energy_ >> 1;
+
+ /* Do the same for the reflection coeffs, albeit in Q15. */
+ for (size_t i = 0; i < WEBRTC_CNG_MAX_LPC_ORDER; i++) {
+ dec_used_reflCoefs_[i] =
+ (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(dec_used_reflCoefs_[i], Beta, 15);
+ dec_used_reflCoefs_[i] +=
+ (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(dec_target_reflCoefs_[i], BetaC, 15);
+ }
+
+ /* Compute the polynomial coefficients. */
+ WebRtcCng_K2a16(dec_used_reflCoefs_, WEBRTC_CNG_MAX_LPC_ORDER, lpPoly);
+
+ targetEnergy = dec_used_energy_;
+
+ /* Calculate scaling factor based on filter energy. */
+ En = 8192; /* 1.0 in Q13. */
+ for (size_t i = 0; i < (WEBRTC_CNG_MAX_LPC_ORDER); i++) {
+ /* Floating point value for reference.
+ E *= 1.0 - (dec_used_reflCoefs_[i] / 32768.0) *
+ (dec_used_reflCoefs_[i] / 32768.0);
+ */
+
+ /* Same in fixed point. */
+ /* K(i).^2 in Q15. */
+ temp16 = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(dec_used_reflCoefs_[i],
+ dec_used_reflCoefs_[i], 15);
+ /* 1 - K(i).^2 in Q15. */
+ temp16 = 0x7fff - temp16;
+ En = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(En, temp16, 15);
+ }
+
+ /* float scaling= sqrt(E * dec_target_energy_ / (1 << 24)); */
+
+ /* Calculate sqrt(En * target_energy / excitation energy) */
+ targetEnergy = WebRtcSpl_Sqrt(dec_used_energy_);
+
+ En = (int16_t)WebRtcSpl_Sqrt(En) << 6;
+ En = (En * 3) >> 1; /* 1.5 estimates sqrt(2). */
+ dec_used_scale_factor_ = (int16_t)((En * targetEnergy) >> 12);
+
+ /* Generate excitation. */
+ /* Excitation energy per sample is 2.^24 - Q13 N(0,1). */
+ for (size_t i = 0; i < num_samples; i++) {
+ excitation[i] = WebRtcSpl_RandN(&dec_seed_) >> 1;
+ }
+
+ /* Scale to correct energy. */
+ WebRtcSpl_ScaleVector(excitation, excitation, dec_used_scale_factor_,
+ num_samples, 13);
+
+ /* `lpPoly` - Coefficients in Q12.
+ * `excitation` - Speech samples.
+ * `nst->dec_filtstate` - State preservation.
+ * `out_data` - Filtered speech samples. */
+ WebRtcSpl_FilterAR(lpPoly, WEBRTC_CNG_MAX_LPC_ORDER + 1, excitation,
+ num_samples, dec_filtstate_, WEBRTC_CNG_MAX_LPC_ORDER,
+ dec_filtstateLow_, WEBRTC_CNG_MAX_LPC_ORDER,
+ out_data.data(), low, num_samples);
+
+ return true;
+}
+
+ComfortNoiseEncoder::ComfortNoiseEncoder(int fs, int interval, int quality)
+ : enc_nrOfCoefs_(quality),
+ enc_sampfreq_(fs),
+ enc_interval_(interval),
+ enc_msSinceSid_(0),
+ enc_Energy_(0),
+ enc_reflCoefs_{0},
+ enc_corrVector_{0},
+ enc_seed_(7777) /* For debugging only. */ {
+ RTC_CHECK_GT(quality, 0);
+ RTC_CHECK_LE(quality, WEBRTC_CNG_MAX_LPC_ORDER);
+}
+
+void ComfortNoiseEncoder::Reset(int fs, int interval, int quality) {
+ RTC_CHECK_GT(quality, 0);
+ RTC_CHECK_LE(quality, WEBRTC_CNG_MAX_LPC_ORDER);
+ enc_nrOfCoefs_ = quality;
+ enc_sampfreq_ = fs;
+ enc_interval_ = interval;
+ enc_msSinceSid_ = 0;
+ enc_Energy_ = 0;
+ for (auto& c : enc_reflCoefs_)
+ c = 0;
+ for (auto& c : enc_corrVector_)
+ c = 0;
+ enc_seed_ = 7777; /* For debugging only. */
+}
+
+size_t ComfortNoiseEncoder::Encode(rtc::ArrayView<const int16_t> speech,
+ bool force_sid,
+ rtc::Buffer* output) {
+ int16_t arCoefs[WEBRTC_CNG_MAX_LPC_ORDER + 1];
+ int32_t corrVector[WEBRTC_CNG_MAX_LPC_ORDER + 1];
+ int16_t refCs[WEBRTC_CNG_MAX_LPC_ORDER + 1];
+ int16_t hanningW[kCngMaxOutsizeOrder];
+ int16_t ReflBeta = 19661; /* 0.6 in q15. */
+ int16_t ReflBetaComp = 13107; /* 0.4 in q15. */
+ int32_t outEnergy;
+ int outShifts;
+ size_t i;
+ int stab;
+ int acorrScale;
+ size_t index;
+ size_t ind, factor;
+ int32_t* bptr;
+ int32_t blo, bhi;
+ int16_t negate;
+ const int16_t* aptr;
+ int16_t speechBuf[kCngMaxOutsizeOrder];
+
+ const size_t num_samples = speech.size();
+ RTC_CHECK_LE(num_samples, kCngMaxOutsizeOrder);
+
+ for (i = 0; i < num_samples; i++) {
+ speechBuf[i] = speech[i];
+ }
+
+ factor = num_samples;
+
+ /* Calculate energy and a coefficients. */
+ outEnergy = WebRtcSpl_Energy(speechBuf, num_samples, &outShifts);
+ while (outShifts > 0) {
+ /* We can only do 5 shifts without destroying accuracy in
+ * division factor. */
+ if (outShifts > 5) {
+ outEnergy <<= (outShifts - 5);
+ outShifts = 5;
+ } else {
+ factor /= 2;
+ outShifts--;
+ }
+ }
+ outEnergy = WebRtcSpl_DivW32W16(outEnergy, (int16_t)factor);
+
+ if (outEnergy > 1) {
+ /* Create Hanning Window. */
+ WebRtcSpl_GetHanningWindow(hanningW, num_samples / 2);
+ for (i = 0; i < (num_samples / 2); i++)
+ hanningW[num_samples - i - 1] = hanningW[i];
+
+ WebRtcSpl_ElementwiseVectorMult(speechBuf, hanningW, speechBuf, num_samples,
+ 14);
+
+ WebRtcSpl_AutoCorrelation(speechBuf, num_samples, enc_nrOfCoefs_,
+ corrVector, &acorrScale);
+
+ if (*corrVector == 0)
+ *corrVector = WEBRTC_SPL_WORD16_MAX;
+
+ /* Adds the bandwidth expansion. */
+ aptr = WebRtcCng_kCorrWindow;
+ bptr = corrVector;
+
+ /* (zzz) lpc16_1 = 17+1+820+2+2 = 842 (ordo2=700). */
+ for (ind = 0; ind < enc_nrOfCoefs_; ind++) {
+ /* The below code multiplies the 16 b corrWindow values (Q15) with
+ * the 32 b corrvector (Q0) and shifts the result down 15 steps. */
+ negate = *bptr < 0;
+ if (negate)
+ *bptr = -*bptr;
+
+ blo = (int32_t)*aptr * (*bptr & 0xffff);
+ bhi = ((blo >> 16) & 0xffff) +
+ ((int32_t)(*aptr++) * ((*bptr >> 16) & 0xffff));
+ blo = (blo & 0xffff) | ((bhi & 0xffff) << 16);
+
+ *bptr = (((bhi >> 16) & 0x7fff) << 17) | ((uint32_t)blo >> 15);
+ if (negate)
+ *bptr = -*bptr;
+ bptr++;
+ }
+ /* End of bandwidth expansion. */
+
+ stab = WebRtcSpl_LevinsonDurbin(corrVector, arCoefs, refCs, enc_nrOfCoefs_);
+
+ if (!stab) {
+ /* Disregard from this frame */
+ return 0;
+ }
+
+ } else {
+ for (i = 0; i < enc_nrOfCoefs_; i++)
+ refCs[i] = 0;
+ }
+
+ if (force_sid) {
+ /* Read instantaneous values instead of averaged. */
+ for (i = 0; i < enc_nrOfCoefs_; i++)
+ enc_reflCoefs_[i] = refCs[i];
+ enc_Energy_ = outEnergy;
+ } else {
+ /* Average history with new values. */
+ for (i = 0; i < enc_nrOfCoefs_; i++) {
+ enc_reflCoefs_[i] =
+ (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(enc_reflCoefs_[i], ReflBeta, 15);
+ enc_reflCoefs_[i] +=
+ (int16_t)WEBRTC_SPL_MUL_16_16_RSFT(refCs[i], ReflBetaComp, 15);
+ }
+ enc_Energy_ = (outEnergy >> 2) + (enc_Energy_ >> 1) + (enc_Energy_ >> 2);
+ }
+
+ if (enc_Energy_ < 1) {
+ enc_Energy_ = 1;
+ }
+
+ if ((enc_msSinceSid_ > (enc_interval_ - 1)) || force_sid) {
+ /* Search for best dbov value. */
+ index = 0;
+ for (i = 1; i < 93; i++) {
+ /* Always round downwards. */
+ if ((enc_Energy_ - WebRtcCng_kDbov[i]) > 0) {
+ index = i;
+ break;
+ }
+ }
+ if ((i == 93) && (index == 0))
+ index = 94;
+
+ const size_t output_coefs = enc_nrOfCoefs_ + 1;
+ output->AppendData(output_coefs, [&](rtc::ArrayView<uint8_t> output) {
+ output[0] = (uint8_t)index;
+
+ /* Quantize coefficients with tweak for WebRtc implementation of
+ * RFC3389. */
+ if (enc_nrOfCoefs_ == WEBRTC_CNG_MAX_LPC_ORDER) {
+ for (i = 0; i < enc_nrOfCoefs_; i++) {
+ /* Q15 to Q7 with rounding. */
+ output[i + 1] = ((enc_reflCoefs_[i] + 128) >> 8);
+ }
+ } else {
+ for (i = 0; i < enc_nrOfCoefs_; i++) {
+ /* Q15 to Q7 with rounding. */
+ output[i + 1] = (127 + ((enc_reflCoefs_[i] + 128) >> 8));
+ }
+ }
+
+ return output_coefs;
+ });
+
+ enc_msSinceSid_ =
+ static_cast<int16_t>((1000 * num_samples) / enc_sampfreq_);
+ return output_coefs;
+ } else {
+ enc_msSinceSid_ +=
+ static_cast<int16_t>((1000 * num_samples) / enc_sampfreq_);
+ return 0;
+ }
+}
+
+namespace {
+/* Values in `k` are Q15, and `a` Q12. */
+void WebRtcCng_K2a16(int16_t* k, int useOrder, int16_t* a) {
+ int16_t any[WEBRTC_SPL_MAX_LPC_ORDER + 1];
+ int16_t* aptr;
+ int16_t* aptr2;
+ int16_t* anyptr;
+ const int16_t* kptr;
+ int m, i;
+
+ kptr = k;
+ *a = 4096; /* i.e., (Word16_MAX >> 3) + 1 */
+ *any = *a;
+ a[1] = (*k + 4) >> 3;
+ for (m = 1; m < useOrder; m++) {
+ kptr++;
+ aptr = a;
+ aptr++;
+ aptr2 = &a[m];
+ anyptr = any;
+ anyptr++;
+
+ any[m + 1] = (*kptr + 4) >> 3;
+ for (i = 0; i < m; i++) {
+ *anyptr++ =
+ (*aptr++) +
+ (int16_t)((((int32_t)(*aptr2--) * (int32_t)*kptr) + 16384) >> 15);
+ }
+
+ aptr = a;
+ anyptr = any;
+ for (i = 0; i < (m + 2); i++) {
+ *aptr++ = *anyptr++;
+ }
+ }
+}
+
+} // namespace
+
+} // namespace webrtc
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