From d79e096a558e983e89c10858b4a5ad8027c14661 Mon Sep 17 00:00:00 2001
From: cloudwebrtc <duanweiwei1982@gmail.com>
Date: Thu, 15 Aug 2024 21:38:22 +0800
Subject: [PATCH] Add Virtual Capturer for Audio/Video.

---
 include/rtc_audio_source.h   | 10 +++++++
 include/rtc_video_source.h   | 11 ++++++++
 src/rtc_audio_source_impl.cc | 53 ++++++++++++++++++++++++++++++++++++
 src/rtc_video_frame_impl.h   |  2 ++
 src/rtc_video_source_impl.cc | 52 +++++++++++++++++++++++++++++++++++
 src/rtc_video_source_impl.h  |  1 +
 6 files changed, 129 insertions(+)

diff --git a/include/rtc_audio_source.h b/include/rtc_audio_source.h
index 43e39fd801..b27cfcbe50 100644
--- a/include/rtc_audio_source.h
+++ b/include/rtc_audio_source.h
@@ -2,6 +2,7 @@
 #define LIB_WEBRTC_RTC_AUDIO_SOURCE_HXX
 
 #include "rtc_types.h"
+#include "rtc_audio_frame.h"
 
 namespace libwebrtc {
 
@@ -20,6 +21,15 @@ class RTCAudioSource : public RefCountInterface {
   virtual ~RTCAudioSource() {}
 };
 
+class VirtualAudioCapturer : public RefCountInterface {
+ public:
+  LIB_WEBRTC_API static scoped_refptr<VirtualAudioCapturer> Create();
+
+  virtual void OnDataCaptured(scoped_refptr<RTCAudioFrame> data) = 0;
+
+  virtual scoped_refptr<RTCAudioSource> source() = 0;
+};
+
 }  // namespace libwebrtc
 
 #endif  // LIB_WEBRTC_RTC_AUDIO_TRACK_HXX
diff --git a/include/rtc_video_source.h b/include/rtc_video_source.h
index cb61abbb49..3343966265 100644
--- a/include/rtc_video_source.h
+++ b/include/rtc_video_source.h
@@ -2,6 +2,7 @@
 #define LIB_WEBRTC_RTC_VIDEO_SOURCE_HXX
 
 #include "rtc_types.h"
+#include "rtc_video_frame.h"
 
 namespace libwebrtc {
 
@@ -9,6 +10,16 @@ class RTCVideoSource : public RefCountInterface {
  public:
   ~RTCVideoSource() {}
 };
+
+class VirtualVideoCapturer : public RefCountInterface {
+ public:
+  LIB_WEBRTC_API static scoped_refptr<VirtualVideoCapturer> Create();
+
+  virtual void OnFrameCaptured(scoped_refptr<RTCVideoFrame> frame) = 0; 
+
+  virtual scoped_refptr<RTCVideoSource> source() = 0;
+};
+
 }  // namespace libwebrtc
 
 #endif  // LIB_WEBRTC_RTC_VIDEO_SOURCE_HXX
diff --git a/src/rtc_audio_source_impl.cc b/src/rtc_audio_source_impl.cc
index a9e2526c80..04bdbdeb9a 100644
--- a/src/rtc_audio_source_impl.cc
+++ b/src/rtc_audio_source_impl.cc
@@ -1,5 +1,7 @@
 #include "rtc_audio_source_impl.h"
 
+#include "pc/local_audio_source.h"
+
 namespace libwebrtc {
 
 RTCAudioSourceImpl::RTCAudioSourceImpl(
@@ -12,4 +14,55 @@ RTCAudioSourceImpl::~RTCAudioSourceImpl() {
   RTC_LOG(LS_INFO) << __FUNCTION__ << ": dtor ";
 }
 
+class AdaptedVirtualAudioCapturer : public webrtc::LocalAudioSource {
+ public:
+  AdaptedVirtualAudioCapturer() {}
+  ~AdaptedVirtualAudioCapturer() {}
+
+  void AddSink(webrtc::AudioTrackSinkInterface* sink) override {
+    webrtc::MutexLock lock(&mutex_);
+    sinks_.push_back(sink);
+  }
+
+  void RemoveSink(webrtc::AudioTrackSinkInterface* sink) override {
+    webrtc::MutexLock lock(&mutex_);
+    sinks_.erase(std::remove(sinks_.begin(), sinks_.end(), sink), sinks_.end());
+  }
+
+  void OnCaptureData(scoped_refptr<RTCAudioFrame> frame) {
+    webrtc::MutexLock lock(&mutex_);
+    for (auto sink : sinks_) {
+      sink->OnData((const void*)frame->data(), 16, frame->sample_rate_hz(),
+                   frame->num_channels(), frame->samples_per_channel());
+    }
+  }
+
+ private:
+  mutable webrtc::Mutex mutex_;
+  std::vector<webrtc::AudioTrackSinkInterface*> sinks_;
+};
+
+class VirtualAudioCapturerImpl : public VirtualAudioCapturer {
+ public:
+  VirtualAudioCapturerImpl() {}
+  virtual ~VirtualAudioCapturerImpl() {}
+
+  virtual void OnDataCaptured(scoped_refptr<RTCAudioFrame> frame) override {
+    adapted_source_->OnCaptureData(frame);
+  }
+
+  virtual scoped_refptr<RTCAudioSource> source() override {
+    return rtc_audio_source_;
+  }
+
+ private:
+  scoped_refptr<RTCAudioSourceImpl> rtc_audio_source_;
+  rtc::scoped_refptr<AdaptedVirtualAudioCapturer> adapted_source_;
+};
+
+scoped_refptr<VirtualAudioCapturer> VirtualAudioCapturer::Create() {
+  return scoped_refptr<VirtualAudioCapturer>(
+      new RefCountedObject<VirtualAudioCapturerImpl>());
+}
+
 }  // namespace libwebrtc
diff --git a/src/rtc_video_frame_impl.h b/src/rtc_video_frame_impl.h
index 3af6845abb..0fbe094ee1 100644
--- a/src/rtc_video_frame_impl.h
+++ b/src/rtc_video_frame_impl.h
@@ -51,6 +51,8 @@ class VideoFrameBufferImpl : public RTCVideoFrame {
 
   void set_rotation(webrtc::VideoRotation rotation) { rotation_ = rotation; }
 
+  webrtc::VideoRotation rtc_rotation() { return rotation_; }
+
  private:
   rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer_;
   int64_t timestamp_us_ = 0;
diff --git a/src/rtc_video_source_impl.cc b/src/rtc_video_source_impl.cc
index ef4ec9c5a6..df3c438f2b 100644
--- a/src/rtc_video_source_impl.cc
+++ b/src/rtc_video_source_impl.cc
@@ -6,6 +6,58 @@
 
 namespace libwebrtc {
 
+class AdaptedVirtualVideoCapturer : public rtc::AdaptedVideoTrackSource {
+ public:
+  AdaptedVirtualVideoCapturer() {}
+  ~AdaptedVirtualVideoCapturer() override {}
+
+  bool is_screencast() const override { return false; }
+
+  absl::optional<bool> needs_denoising() const override { return false; }
+
+  SourceState state() const override { return kLive; }
+
+  bool remote() const override { return false; }
+
+  void OnFrameCaptured(scoped_refptr<RTCVideoFrame> frame) {
+    VideoFrameBufferImpl* impl =
+        static_cast<VideoFrameBufferImpl*>(frame.get());
+    auto newFrame = webrtc::VideoFrame::Builder()
+                        .set_video_frame_buffer(impl->buffer())
+                        .set_rotation(impl->rtc_rotation())
+                        .set_timestamp_us(impl->timestamp_us())
+                        .build();
+    OnFrame(newFrame);
+  }
+};
+
+class VirtualVideoCapturerImpl : public VirtualVideoCapturer {
+ public:
+  VirtualVideoCapturerImpl() {
+    adapted_source_ = new rtc::RefCountedObject<AdaptedVirtualVideoCapturer>();
+    rtc_source_ = scoped_refptr<RTCVideoSourceImpl>(
+        new RefCountedObject<RTCVideoSourceImpl>(adapted_source_));
+  }
+  virtual ~VirtualVideoCapturerImpl() {}
+
+  virtual scoped_refptr<RTCVideoSource> source() override {
+    return rtc_source_;
+  }
+
+  virtual void OnFrameCaptured(scoped_refptr<RTCVideoFrame> frame) override {
+    adapted_source_->OnFrameCaptured(frame);
+  }
+
+ private:
+  rtc::scoped_refptr<AdaptedVirtualVideoCapturer> adapted_source_;
+  scoped_refptr<RTCVideoSourceImpl> rtc_source_;
+};
+
+scoped_refptr<VirtualVideoCapturer> VirtualVideoCapturer::Create() {
+  return scoped_refptr<VirtualVideoCapturer>(
+      new RefCountedObject<VirtualVideoCapturerImpl>());
+}
+
 RTCVideoSourceImpl::RTCVideoSourceImpl(
     rtc::scoped_refptr<webrtc::VideoTrackSourceInterface> rtc_source_track)
     : rtc_source_track_(rtc_source_track) {
diff --git a/src/rtc_video_source_impl.h b/src/rtc_video_source_impl.h
index 568355701c..9433379d3f 100644
--- a/src/rtc_video_source_impl.h
+++ b/src/rtc_video_source_impl.h
@@ -2,6 +2,7 @@
 #define LIB_WEBRTC_VIDEO_SOURCE_IMPL_HXX
 
 #include "api/media_stream_interface.h"
+#include "media/base/adapted_video_track_source.h"
 #include "media/base/video_broadcaster.h"
 #include "media/base/video_source_base.h"
 #include "rtc_peerconnection_factory_impl.h"