add mix mono option to voice window (closes #238)

src/audio/manager.cpp

@@ -419,13 +419,23 @@ void AudioManager::OnCapturedPCM(const int16_t *pcm, ma_uint32 frames) {
     if (m_opus_buffer == nullptr || !m_should_capture) return;
 
     const double gain = m_capture_gain;
-    // i have a suspicion i can cast the const away... but i wont
+
     std::vector<int16_t> new_pcm(pcm, pcm + frames * 2);
     for (auto &val : new_pcm) {
         const int32_t unclamped = static_cast<int32_t>(val * gain);
         val = std::clamp(unclamped, INT16_MIN, INT16_MAX);
     }
 
+    if (m_mix_mono) {
+        for (size_t i = 0; i < frames * 2; i += 2) {
+            const int sample_L = new_pcm[i];
+            const int sample_R = new_pcm[i + 1];
+            const int16_t mixed = static_cast<int16_t>((sample_L + sample_R) / 2);
+            new_pcm[i] = mixed;
+            new_pcm[i + 1] = mixed;
+        }
+    }
+
     UpdateCaptureVolume(new_pcm.data(), frames);
 
     static std::array<float, 480> denoised_L;
@@ -629,6 +639,14 @@ bool AudioManager::GetSuppressNoise() const {
 }
 #endif
 
+void AudioManager::SetMixMono(bool value) {
+    m_mix_mono = value;
+}
+
+bool AudioManager::GetMixMono() const {
+    return m_mix_mono;
+}
+
 AudioManager::type_signal_opus_packet AudioManager::signal_opus_packet() {
     return m_signal_opus_packet;
 }

src/audio/manager.hpp

@@ -87,6 +87,9 @@ public:
     bool GetSuppressNoise() const;
 #endif
 
+    void SetMixMono(bool value);
+    bool GetMixMono() const;
+
 private:
     void OnCapturedPCM(const int16_t *pcm, ma_uint32 frames);
 
@@ -144,6 +147,7 @@ private:
     std::atomic<double> m_prob_threshold = 0.5;
     std::atomic<float> m_vad_prob = 0.0;
     std::atomic<bool> m_enable_noise_suppression = false;
+    std::atomic<bool> m_mix_mono = false;
 
     std::unordered_set<uint32_t> m_muted_ssrcs;
     std::unordered_map<uint32_t, double> m_volume_ssrc;

src/windows/voicewindow.cpp

@@ -89,6 +89,7 @@ VoiceWindow::VoiceWindow(Snowflake channel_id)
     , m_mute("Mute")
     , m_deafen("Deafen")
     , m_noise_suppression("Suppress Noise")
+    , m_mix_mono("Mix Mono")
     , m_channel_id(channel_id)
     , m_menu_view("View")
     , m_menu_view_settings("More _Settings", true) {
@@ -178,6 +179,11 @@ VoiceWindow::VoiceWindow(Snowflake channel_id)
         Abaddon::Get().GetAudio().SetSuppressNoise(m_noise_suppression.get_active());
     });
 
+    m_mix_mono.set_active(audio.GetMixMono());
+    m_mix_mono.signal_toggled().connect([this]() {
+       Abaddon::Get().GetAudio().SetMixMono(m_mix_mono.get_active());
+    });
+
     auto *playback_renderer = Gtk::make_managed<Gtk::CellRendererText>();
     m_playback_combo.set_valign(Gtk::ALIGN_END);
     m_playback_combo.set_hexpand(true);
@@ -223,6 +229,7 @@ VoiceWindow::VoiceWindow(Snowflake channel_id)
     m_controls.add(m_mute);
     m_controls.add(m_deafen);
     m_controls.add(m_noise_suppression);
+    m_controls.add(m_mix_mono);
     m_main.add(m_menu_bar);
     m_main.add(m_controls);
     m_main.add(m_vad_value);

src/windows/voicewindow.hpp

@@ -54,6 +54,7 @@ private:
     Gtk::Scale m_capture_gain;
 
     Gtk::CheckButton m_noise_suppression;
+    Gtk::CheckButton m_mix_mono;
 
     Gtk::ComboBoxText m_vad_combo;
     Gtk::ComboBox m_playback_combo;