feat: support no audio flag

Author: TzuHuanTai

src/args.h

@@ -11,6 +11,7 @@ struct Args {
     int height = 480;
     int rotation_angle = 0;
     int sample_rate = 44100;
+    bool no_audio = false;
     bool hw_accel = false;
     bool use_libcamera = false;
     uint32_t format = V4L2_PIX_FMT_MJPEG;

src/conductor.cpp

@@ -20,10 +20,10 @@
 #include <pc/video_track_source_proxy.h>
 #include <rtc_base/ssl_adapter.h>
 
+#include "capturer/libcamera_capturer.h"
+#include "capturer/v4l2_capturer.h"
 #include "common/logging.h"
 #include "common/utils.h"
-#include "capturer/v4l2_capturer.h"
-#include "capturer/libcamera_capturer.h"
 #include "customized_video_encoder_factory.h"
 #include "track/v4l2dma_track_source.h"
 
@@ -46,7 +46,7 @@ std::shared_ptr<PaCapturer> Conductor::AudioSource() const { return audio_captur
 std::shared_ptr<VideoCapturer> Conductor::VideoSource() const { return video_capture_source_; }
 
 void Conductor::InitializeTracks() {
-    if (audio_track_ == nullptr) {
+    if (audio_track_ == nullptr && !args.no_audio) {
         audio_capture_source_ = PaCapturer::Create(args);
         auto options = peer_connection_factory_->CreateAudioSource(cricket::AudioOptions());
         audio_track_ = peer_connection_factory_->CreateAudioTrack("audio_track", options.get());
@@ -280,8 +280,12 @@ void Conductor::InitializePeerConnectionFactory() {
     cricket::MediaEngineDependencies media_dependencies;
     media_dependencies.task_queue_factory = dependencies.task_queue_factory.get();
 
-    media_dependencies.adm = webrtc::AudioDeviceModule::Create(
-        webrtc::AudioDeviceModule::kLinuxPulseAudio, dependencies.task_queue_factory.get());
+    webrtc::AudioDeviceModule::AudioLayer audio_layer = webrtc::AudioDeviceModule::kLinuxPulseAudio;
+    if (args.no_audio) {
+        audio_layer = webrtc::AudioDeviceModule::kDummyAudio;
+    }
+    media_dependencies.adm =
+        webrtc::AudioDeviceModule::Create(audio_layer, dependencies.task_queue_factory.get());
     media_dependencies.audio_encoder_factory = webrtc::CreateBuiltinAudioEncoderFactory();
     media_dependencies.audio_decoder_factory = webrtc::CreateBuiltinAudioDecoderFactory();
     media_dependencies.audio_processing = webrtc::AudioProcessingBuilder().Create();

src/parser.cpp

@@ -18,6 +18,8 @@ void Parser::ParseArgs(int argc, char *argv[], Args &args) {
         "Read the specific camera file via V4L2, default is /dev/video0")(
         "use_libcamera", bpo::bool_switch()->default_value(args.use_libcamera),
         "Read YUV420 from the camera via libcamera, the `device` and `v4l2_format` flags will be suspended")(
+        "no_audio", bpo::bool_switch()->default_value(args.no_audio),
+        "Run without audio source")(
         "uid", bpo::value<std::string>()->default_value(args.uid),
         "Set the unique id to identify the device")(
         "stun_url", bpo::value<std::string>()->default_value(args.stun_url),
@@ -83,6 +85,10 @@ void Parser::ParseArgs(int argc, char *argv[], Args &args) {
         }
     }
 
+    if (vm.count("no_audio")) {
+        args.no_audio = vm["no_audio"].as<bool>();
+    }
+
     if (vm.count("uid")) {
         args.uid = vm["uid"].as<std::string>();
     }