From 7bc6116e213ae128fc403d8f28862513f00a2276 Mon Sep 17 00:00:00 2001
From: ouwou <26526779+ouwou@users.noreply.github.com>
Date: Tue, 18 Jul 2023 01:47:46 -0400
Subject: add ability to change vad method

---
 src/audio/manager.cpp | 63 ++++++++++++++++++++++++++++++++++++++++++---------
 src/audio/manager.hpp | 15 ++++++++++++
 2 files changed, 67 insertions(+), 11 deletions(-)

(limited to 'src/audio')

diff --git a/src/audio/manager.cpp b/src/audio/manager.cpp
index f86c484..84e1fcf 100644
--- a/src/audio/manager.cpp
+++ b/src/audio/manager.cpp
@@ -64,9 +64,6 @@ void capture_data_callback(ma_device *pDevice, void *pOutput, const void *pInput
 AudioManager::AudioManager() {
     m_ok = true;
 
-    m_rnnoise = rnnoise_create(nullptr);
-    spdlog::get("audio")->info("RNNoise expects {} frames", rnnoise_get_frame_size());
-
     int err;
     m_encoder = opus_encoder_create(48000, 2, OPUS_APPLICATION_VOIP, &err);
     if (err != OPUS_OK) {
@@ -85,6 +82,7 @@ AudioManager::AudioManager() {
     spdlog::get("audio")->info("Audio backend: {}", ma_get_backend_name(m_context.backend));
 
     Enumerate();
+    SetVADMethod(VADMethod::RNNoise);
 
     m_playback_config = ma_device_config_init(ma_device_type_playback);
     m_playback_config.playback.format = ma_format_f32;
@@ -146,7 +144,7 @@ AudioManager::~AudioManager() {
     ma_device_uninit(&m_capture_device);
     ma_context_uninit(&m_context);
     RemoveAllSSRCs();
-    rnnoise_destroy(m_rnnoise);
+    RNNoiseUninitialize();
 }
 
 void AudioManager::AddSSRC(uint32_t ssrc) {
@@ -423,14 +421,14 @@ void AudioManager::OnCapturedPCM(const int16_t *pcm, ma_uint32 frames) {
 
     UpdateCaptureVolume(new_pcm.data(), frames);
 
-    static float idc[480];
-    static float rnnoise_input[480];
-    // take left channel
-    for (int i = 0; i < 480; i++) {
-        rnnoise_input[i] = static_cast<float>(pcm[i * 2]);
+    switch (m_vad_method) {
+        case VADMethod::Gate:
+            if (!CheckVADVoiceGate()) return;
+            break;
+        case VADMethod::RNNoise:
+            if (!CheckVADRNNoise(pcm)) return;
+            break;
     }
-    float prob = rnnoise_process_frame(m_rnnoise, idc, rnnoise_input);
-    if (prob < m_capture_gate) return;
 
     m_enc_mutex.lock();
     int payload_len = opus_encode(m_encoder, new_pcm.data(), 480, static_cast<unsigned char *>(m_opus_buffer), 1275);
@@ -473,6 +471,39 @@ bool AudioManager::DecayVolumeMeters() {
     return true;
 }
 
+bool AudioManager::CheckVADVoiceGate() {
+    return m_capture_peak_meter / 32768.0 > m_capture_gate;
+}
+
+bool AudioManager::CheckVADRNNoise(const int16_t *pcm) {
+    static float denoised[480];
+    static float rnnoise_input[480];
+    // take left channel
+    for (size_t i = 0; i < 480; i++) {
+        rnnoise_input[i] = static_cast<float>(pcm[i * 2]);
+    }
+    float vad_prob = rnnoise_process_frame(m_rnnoise, denoised, rnnoise_input);
+    return vad_prob > m_prob_threshold;
+}
+
+void AudioManager::RNNoiseInitialize() {
+    spdlog::get("audio")->debug("Initializing RNNoise");
+    RNNoiseUninitialize();
+    m_rnnoise = rnnoise_create(nullptr);
+    const auto expected = rnnoise_get_frame_size();
+    if (expected != 480) {
+        spdlog::get("audio")->warn("RNNoise expects a frame count other than 480");
+    }
+}
+
+void AudioManager::RNNoiseUninitialize() {
+    spdlog::get("audio")->debug("Uninitializing RNNoise");
+    if (m_rnnoise != nullptr) {
+        rnnoise_destroy(m_rnnoise);
+        m_rnnoise = nullptr;
+    }
+}
+
 bool AudioManager::OK() const {
     return m_ok;
 }
@@ -497,6 +528,16 @@ uint32_t AudioManager::GetRTPTimestamp() const noexcept {
     return m_rtp_timestamp;
 }
 
+void AudioManager::SetVADMethod(VADMethod method) {
+    m_vad_method = method;
+
+    if (method == VADMethod::RNNoise) {
+        RNNoiseInitialize();
+    } else {
+        RNNoiseUninitialize();
+    }
+}
+
 AudioManager::type_signal_opus_packet AudioManager::signal_opus_packet() {
     return m_signal_opus_packet;
 }
diff --git a/src/audio/manager.hpp b/src/audio/manager.hpp
index 005a4a3..c3867df 100644
--- a/src/audio/manager.hpp
+++ b/src/audio/manager.hpp
@@ -67,6 +67,13 @@ public:
 
     uint32_t GetRTPTimestamp() const noexcept;
 
+    enum class VADMethod {
+        Gate,
+        RNNoise,
+    };
+
+    void SetVADMethod(VADMethod method);
+
 private:
     void OnCapturedPCM(const int16_t *pcm, ma_uint32 frames);
 
@@ -76,6 +83,12 @@ private:
 
     bool DecayVolumeMeters();
 
+    bool CheckVADVoiceGate();
+    bool CheckVADRNNoise(const int16_t *pcm);
+
+    void RNNoiseInitialize();
+    void RNNoiseUninitialize();
+
     friend void data_callback(ma_device *, void *, const void *, ma_uint32);
     friend void capture_data_callback(ma_device *, void *, const void *, ma_uint32);
 
@@ -108,6 +121,7 @@ private:
 
     std::atomic<double> m_capture_gate = 0.0;
     std::atomic<double> m_capture_gain = 1.0;
+    std::atomic<double> m_prob_threshold = 0.5;
 
     std::unordered_set<uint32_t> m_muted_ssrcs;
     std::unordered_map<uint32_t, double> m_volume_ssrc;
@@ -117,6 +131,7 @@ private:
 
     AudioDevices m_devices;
 
+    VADMethod m_vad_method;
     DenoiseState *m_rnnoise;
     std::atomic<uint32_t> m_rtp_timestamp = 0;
 
-- 
cgit v1.2.3