Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 215 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/audio_coding/neteq/dtmf_tone_generator.cc b/third_party/libwebrtc/modules/audio_coding/neteq/dtmf_tone_generator.cc
new file mode 100644
index 0000000000..9061e27c67
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/neteq/dtmf_tone_generator.cc
@@ -0,0 +1,215 @@
+/*
+ *  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.
+ */
+
+// This class provides a generator for DTMF tones. The tone generation is based
+// on a sinusoid recursion. Each sinusoid is generated using a recursion
+// formula; x[n] = a * x[n-1] - x[n-2], where the coefficient
+// a = 2*cos(2*pi*f/fs). The recursion is started with x[-1] = 0 and
+// x[-2] = sin(2*pi*f/fs). (Note that with this initialization, the resulting
+// sinusoid gets a "negative" rotation; x[n] = sin(-2*pi*f/fs * n + phi), but
+// kept this way due to historical reasons.)
+// TODO(hlundin): Change to positive rotation?
+//
+// Each key on the telephone keypad corresponds to an "event", 0-15. Each event
+// is mapped to a tone pair, with a low and a high frequency. There are four
+// low and four high frequencies, each corresponding to a row and column,
+// respectively, on the keypad as illustrated below.
+//
+//          1209 Hz  1336 Hz  1477 Hz  1633 Hz
+// 697 Hz      1        2        3       12
+// 770 Hz      4        5        6       13
+// 852 Hz      7        8        9       14
+// 941 Hz     10        0       11       15
+
+#include "modules/audio_coding/neteq/dtmf_tone_generator.h"
+
+#include "modules/audio_coding/neteq/audio_vector.h"
+#include "rtc_base/arraysize.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+
+// The filter coefficient a = 2*cos(2*pi*f/fs) for the low frequency tone, for
+// sample rates fs = {8000, 16000, 32000, 48000} Hz, and events 0 through 15.
+// Values are in Q14.
+const int DtmfToneGenerator::kCoeff1[4][16] = {
+    {24219, 27980, 27980, 27980, 26956, 26956, 26956, 25701, 25701, 25701,
+     24219, 24219, 27980, 26956, 25701, 24219},
+    {30556, 31548, 31548, 31548, 31281, 31281, 31281, 30951, 30951, 30951,
+     30556, 30556, 31548, 31281, 30951, 30556},
+    {32210, 32462, 32462, 32462, 32394, 32394, 32394, 32311, 32311, 32311,
+     32210, 32210, 32462, 32394, 32311, 32210},
+    {32520, 32632, 32632, 32632, 32602, 32602, 32602, 32564, 32564, 32564,
+     32520, 32520, 32632, 32602, 32564, 32520}};
+
+// The filter coefficient a = 2*cos(2*pi*f/fs) for the high frequency tone, for
+// sample rates fs = {8000, 16000, 32000, 48000} Hz, and events 0 through 15.
+// Values are in Q14.
+const int DtmfToneGenerator::kCoeff2[4][16] = {
+    {16325, 19073, 16325, 13085, 19073, 16325, 13085, 19073, 16325, 13085,
+     19073, 13085, 9315, 9315, 9315, 9315},
+    {28361, 29144, 28361, 27409, 29144, 28361, 27409, 29144, 28361, 27409,
+     29144, 27409, 26258, 26258, 26258, 26258},
+    {31647, 31849, 31647, 31400, 31849, 31647, 31400, 31849, 31647, 31400,
+     31849, 31400, 31098, 31098, 31098, 31098},
+    {32268, 32359, 32268, 32157, 32359, 32268, 32157, 32359, 32268, 32157,
+     32359, 32157, 32022, 32022, 32022, 32022}};
+
+// The initialization value x[-2] = sin(2*pi*f/fs) for the low frequency tone,
+// for sample rates fs = {8000, 16000, 32000, 48000} Hz, and events 0-15.
+// Values are in Q14.
+const int DtmfToneGenerator::kInitValue1[4][16] = {
+    {11036, 8528, 8528, 8528, 9315, 9315, 9315, 10163, 10163, 10163, 11036,
+     11036, 8528, 9315, 10163, 11036},
+    {5918, 4429, 4429, 4429, 4879, 4879, 4879, 5380, 5380, 5380, 5918, 5918,
+     4429, 4879, 5380, 5918},
+    {3010, 2235, 2235, 2235, 2468, 2468, 2468, 2728, 2728, 2728, 3010, 3010,
+     2235, 2468, 2728, 3010},
+    {2013, 1493, 1493, 1493, 1649, 1649, 1649, 1823, 1823, 1823, 2013, 2013,
+     1493, 1649, 1823, 2013}};
+
+// The initialization value x[-2] = sin(2*pi*f/fs) for the high frequency tone,
+// for sample rates fs = {8000, 16000, 32000, 48000} Hz, and events 0-15.
+// Values are in Q14.
+const int DtmfToneGenerator::kInitValue2[4][16] = {
+    {14206, 13323, 14206, 15021, 13323, 14206, 15021, 13323, 14206, 15021,
+     13323, 15021, 15708, 15708, 15708, 15708},
+    {8207, 7490, 8207, 8979, 7490, 8207, 8979, 7490, 8207, 8979, 7490, 8979,
+     9801, 9801, 9801, 9801},
+    {4249, 3853, 4249, 4685, 3853, 4249, 4685, 3853, 4249, 4685, 3853, 4685,
+     5164, 5164, 5164, 5164},
+    {2851, 2582, 2851, 3148, 2582, 2851, 3148, 2582, 2851, 3148, 2582, 3148,
+     3476, 3476, 3476, 3476}};
+
+// Amplitude multipliers for volume values 0 through 63, corresponding to
+// 0 dBm0 through -63 dBm0. Values are in Q14.
+// for a in range(0, 64):
+//   print round(16141.0 * 10**(-float(a)/20))
+const int DtmfToneGenerator::kAmplitude[64] = {
+    16141, 14386, 12821, 11427, 10184, 9077, 8090, 7210, 6426, 5727, 5104,
+    4549,  4054,  3614,  3221,  2870,  2558, 2280, 2032, 1811, 1614, 1439,
+    1282,  1143,  1018,  908,   809,   721,  643,  573,  510,  455,  405,
+    361,   322,   287,   256,   228,   203,  181,  161,  144,  128,  114,
+    102,   91,    81,    72,    64,    57,   51,   45,   41,   36,   32,
+    29,    26,    23,    20,    18,    16,   14,   13,   11};
+
+// Constructor.
+DtmfToneGenerator::DtmfToneGenerator()
+    : initialized_(false), coeff1_(0), coeff2_(0), amplitude_(0) {}
+
+// Initialize the DTMF generator with sample rate fs Hz (8000, 16000, 32000,
+// 48000), event (0-15) and attenuation (0-36 dB).
+// Returns 0 on success, otherwise an error code.
+int DtmfToneGenerator::Init(int fs, int event, int attenuation) {
+  initialized_ = false;
+  size_t fs_index;
+  if (fs == 8000) {
+    fs_index = 0;
+  } else if (fs == 16000) {
+    fs_index = 1;
+  } else if (fs == 32000) {
+    fs_index = 2;
+  } else if (fs == 48000) {
+    fs_index = 3;
+  } else {
+    RTC_DCHECK_NOTREACHED();
+    fs_index = 1;  // Default to 8000 Hz.
+  }
+
+  if (event < 0 || event > 15) {
+    return kParameterError;  // Invalid event number.
+  }
+
+  if (attenuation < 0 || attenuation > 63) {
+    return kParameterError;  // Invalid attenuation.
+  }
+
+  // Look up oscillator coefficient for low and high frequencies.
+  RTC_DCHECK_LE(0, fs_index);
+  RTC_DCHECK_GT(arraysize(kCoeff1), fs_index);
+  RTC_DCHECK_GT(arraysize(kCoeff2), fs_index);
+  RTC_DCHECK_LE(0, event);
+  RTC_DCHECK_GT(arraysize(kCoeff1[fs_index]), event);
+  RTC_DCHECK_GT(arraysize(kCoeff2[fs_index]), event);
+  coeff1_ = kCoeff1[fs_index][event];
+  coeff2_ = kCoeff2[fs_index][event];
+
+  // Look up amplitude multiplier.
+  RTC_DCHECK_LE(0, attenuation);
+  RTC_DCHECK_GT(arraysize(kAmplitude), attenuation);
+  amplitude_ = kAmplitude[attenuation];
+
+  // Initialize sample history.
+  RTC_DCHECK_LE(0, fs_index);
+  RTC_DCHECK_GT(arraysize(kInitValue1), fs_index);
+  RTC_DCHECK_GT(arraysize(kInitValue2), fs_index);
+  RTC_DCHECK_LE(0, event);
+  RTC_DCHECK_GT(arraysize(kInitValue1[fs_index]), event);
+  RTC_DCHECK_GT(arraysize(kInitValue2[fs_index]), event);
+  sample_history1_[0] = kInitValue1[fs_index][event];
+  sample_history1_[1] = 0;
+  sample_history2_[0] = kInitValue2[fs_index][event];
+  sample_history2_[1] = 0;
+
+  initialized_ = true;
+  return 0;
+}
+
+// Reset tone generator to uninitialized state.
+void DtmfToneGenerator::Reset() {
+  initialized_ = false;
+}
+
+// Generate num_samples of DTMF signal and write to `output`.
+int DtmfToneGenerator::Generate(size_t num_samples, AudioMultiVector* output) {
+  if (!initialized_) {
+    return kNotInitialized;
+  }
+
+  if (!output) {
+    return kParameterError;
+  }
+
+  output->AssertSize(num_samples);
+  for (size_t i = 0; i < num_samples; ++i) {
+    // Use recursion formula y[n] = a * y[n - 1] - y[n - 2].
+    int16_t temp_val_low =
+        ((coeff1_ * sample_history1_[1] + 8192) >> 14) - sample_history1_[0];
+    int16_t temp_val_high =
+        ((coeff2_ * sample_history2_[1] + 8192) >> 14) - sample_history2_[0];
+
+    // Update recursion memory.
+    sample_history1_[0] = sample_history1_[1];
+    sample_history1_[1] = temp_val_low;
+    sample_history2_[0] = sample_history2_[1];
+    sample_history2_[1] = temp_val_high;
+
+    // Attenuate the low frequency tone 3 dB.
+    int32_t temp_val =
+        kAmpMultiplier * temp_val_low + temp_val_high * (1 << 15);
+    // Normalize the signal to Q14 with proper rounding.
+    temp_val = (temp_val + 16384) >> 15;
+    // Scale the signal to correct volume.
+    (*output)[0][i] =
+        static_cast<int16_t>((temp_val * amplitude_ + 8192) >> 14);
+  }
+  // Copy first channel to all other channels.
+  for (size_t channel = 1; channel < output->Channels(); ++channel) {
+    output->CopyChannel(0, channel);
+  }
+
+  return static_cast<int>(num_samples);
+}
+
+bool DtmfToneGenerator::initialized() const {
+  return initialized_;
+}
+
+}  // namespace webrtc