Introduction of Audio mixer

* Audio configuration was extended (available only via protobuf config)
* Only one audio sink is created now and all the streams are new being mixed

Bug: 449972591

Author: thjnk

base/cvd/cuttlefish/host/commands/assemble_cvd/guest_config.cc

@@ -112,10 +112,8 @@ Result<void> ParseGuestConfigTextProto(const std::string& guest_config_path,
         DefaultHostArtifactsPath(input_config.domkey_mapping_config());
   }
 
-  const auto& audio_config = proto_config.audio();
-  if (audio_config.has_output_audio_streams_count()) {
-    guest_config.output_audio_streams_count =
-        audio_config.output_audio_streams_count();
+  if(proto_config.has_audio()) {
+    guest_config.audio_settings = proto_config.audio();
   }
 
   const auto& network_config = proto_config.network();

base/cvd/cuttlefish/host/commands/assemble_cvd/guest_config.h

@@ -25,6 +25,8 @@
 #include "cuttlefish/host/commands/assemble_cvd/flags/kernel_path.h"
 #include "cuttlefish/host/commands/assemble_cvd/flags/system_image_dir.h"
 
+#include "cuttlefish/host/commands/assemble_cvd/proto/guest_config.pb.h"
+
 namespace cuttlefish {
 
 struct GuestConfig {
@@ -44,6 +46,7 @@ struct GuestConfig {
   std::optional<std::string> custom_keyboard_config;
   std::optional<std::string> domkey_mapping_config;
   int output_audio_streams_count = 1;
+  std::optional<::cuttlefish::config::Audio> audio_settings;
   std::optional<bool> enforce_mac80211_hwsim;
   int blank_data_image_mb = 0;
 };

base/cvd/cuttlefish/host/commands/assemble_cvd/proto/guest_config.proto

@@ -35,8 +35,41 @@ message Graphics {
 }
 
 message Audio {
-  // The number of output audio streams the guest device supports.
-  int32 output_audio_streams_count = 1;
+  enum ChannelLayout {
+    option features.enum_type = CLOSED;
+
+    // Single channel
+    MONO = 0;
+    // Channel order: FL, FR
+    STEREO = 1;
+    // Channel order: FL, FR, FC, LFE, SL, SR
+    SURROUND51 = 2;
+  }
+
+  enum SampleRate {
+    option features.enum_type = CLOSED;
+    RATE_32000 = 0;
+    RATE_44100 = 1;
+    RATE_48000 = 2;
+    RATE_64000 = 3;
+  }
+
+  message AudioMixer {
+    ChannelLayout channel_layout = 1;
+    SampleRate sample_rate = 2;
+  }
+
+  message PCMDevice {
+    message Stream {
+      uint32 id = 1;
+      ChannelLayout channel_layout = 2;
+    }
+    repeated Stream capture_streams = 1;
+    repeated Stream playback_streams = 2;
+    AudioMixer mixer = 3;
+  }
+
+  repeated PCMDevice pcm_devices = 1;
 }
 
 message Input {
@@ -76,22 +109,21 @@ message Virtualization {
 
 // Specifies the type of the emulated device
 enum DeviceType {
-    Phone = 0;
-    Wear = 1;
-    Auto = 2;
-    Foldable = 3;
-    Tv = 4;
-    Minidroid = 5;
-    Go = 6;
-    Unknown = 7;
+  Phone = 0;
+  Wear = 1;
+  Auto = 2;
+  Foldable = 3;
+  Tv = 4;
+  Minidroid = 5;
+  Go = 6;
+  Unknown = 7;
 }
 
 // GuestConfigFile represents the configuration for a Cuttlefish guest device,
 // typically parsed from an cuttlefish-guest-config.txtpb file. It defines the
 // device's hardware capabilities, software features, and virtualization
 // settings.
 message GuestConfigFile {
-
   DeviceType device_type = 1;
 
   Graphics graphics = 2;

base/cvd/cuttlefish/host/frontend/webrtc/BUILD.bazel

@@ -33,6 +33,9 @@ cf_cc_binary(
         "adb_handler.h",
         "audio_handler.cpp",
         "audio_handler.h",
+        "audio_mixer.cpp",
+        "audio_mixer.h",
+        "audio_settings.h",
         "bluetooth_handler.cpp",
         "bluetooth_handler.h",
         "client_server.cpp",
@@ -68,6 +71,7 @@ cf_cc_binary(
         "//cuttlefish/common/libs/utils:json",
         "//cuttlefish/common/libs/utils:result",
         "//cuttlefish/common/libs/utils:size_utils",
+        "//cuttlefish/host/commands/assemble_cvd:guest_config_cc_proto",
         "//cuttlefish/host/commands/kernel_log_monitor:kernel_log_monitor_utils",
         "//cuttlefish/host/frontend/webrtc/libcommon:audio_source",
         "//cuttlefish/host/frontend/webrtc/libdevice",
@@ -97,5 +101,6 @@ cf_cc_binary(
         "@libwebrtc",
         "@libwebsockets",
         "@libyuv",
+        "@protobuf",
     ],
 )