Reland: FrameGeneratorCapturer: don't generate video before Start is called

It is partial reland, which adds call to Start() to all relevant places,
but doesn't actually switches frame generator to not produce frames from
the moment it was created.

Bug: b/272350185
Change-Id: I6e3bd7af6f5cd8d9baff79c2aada7b2ddfae1c8d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/310782
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40379}

call/bitrate_estimator_tests.cc

@@ -186,6 +186,7 @@ class BitrateEstimatorTest : public test::CallTest {
               test::VideoTestConstants::kDefaultFramerate,
               *test->task_queue_factory_);
       frame_generator_capturer_->Init();
+      frame_generator_capturer_->Start();
       send_stream_->SetSource(frame_generator_capturer_.get(),
                               DegradationPreference::MAINTAIN_FRAMERATE);
       send_stream_->Start();

pc/peer_connection_field_trial_tests.cc

@@ -237,6 +237,7 @@ TEST_F(PeerConnectionFieldTrialTest, ApplyFakeNetworkConfig) {
   auto video_track_source =
       rtc::make_ref_counted<FrameGeneratorCapturerVideoTrackSource>(
           config, clock_, /*is_screencast=*/false);
+  video_track_source->Start();
   caller->AddTrack(pc_factory_->CreateVideoTrack(video_track_source, "v"));
   WrapperPtr callee = CreatePeerConnection();
 

pc/test/frame_generator_capturer_video_track_source.h

@@ -64,9 +64,15 @@ class FrameGeneratorCapturerVideoTrackSource : public VideoTrackSource {
 
   ~FrameGeneratorCapturerVideoTrackSource() = default;
 
-  void Start() { SetState(kLive); }
+  void Start() {
+    SetState(kLive);
+    video_capturer_->Start();
+  }
 
-  void Stop() { SetState(kMuted); }
+  void Stop() {
+    SetState(kMuted);
+    video_capturer_->Stop();
+  }
 
   bool is_screencast() const override { return is_screencast_; }
 

test/BUILD.gn

@@ -1260,6 +1260,7 @@ if (!build_with_chromium) {
       ":run_loop",
       ":scoped_key_value_config",
       ":test_support",
+      ":test_video_capturer",
       ":video_test_common",
       ":video_test_constants",
       "../api:array_view",

test/call_test.cc

@@ -634,7 +634,14 @@ void CallTest::Start() {
     audio_recv_stream->Start();
 }
 
+void CallTest::StartVideoSources() {
+  for (size_t i = 0; i < video_sources_.size(); ++i) {
+    video_sources_[i]->Start();
+  }
+}
+
 void CallTest::StartVideoStreams() {
+  StartVideoSources();
   for (size_t i = 0; i < video_send_streams_.size(); ++i) {
     std::vector<bool> active_rtp_streams(
         video_send_configs_[i].rtp.ssrcs.size(), true);

test/call_test.h

@@ -36,6 +36,7 @@
 #include "test/rtp_rtcp_observer.h"
 #include "test/run_loop.h"
 #include "test/scoped_key_value_config.h"
+#include "test/test_video_capturer.h"
 #include "test/video_test_constants.h"
 
 namespace webrtc {
@@ -162,6 +163,7 @@ class CallTest : public ::testing::Test, public RtpPacketSinkInterface {
   void ConnectVideoSourcesToStreams();
 
   void Start();
+  void StartVideoSources();
   void StartVideoStreams();
   void Stop();
   void StopVideoStreams();
@@ -210,8 +212,7 @@ class CallTest : public ::testing::Test, public RtpPacketSinkInterface {
   std::vector<FlexfecReceiveStream*> flexfec_receive_streams_;
 
   test::FrameGeneratorCapturer* frame_generator_capturer_;
-  std::vector<std::unique_ptr<rtc::VideoSourceInterface<VideoFrame>>>
-      video_sources_;
+  std::vector<std::unique_ptr<TestVideoCapturer>> video_sources_;
   DegradationPreference degradation_preference_ =
       DegradationPreference::MAINTAIN_FRAMERATE;
 

test/peer_scenario/peer_scenario_client.cc

@@ -338,6 +338,7 @@ PeerScenarioClient::VideoSendTrack PeerScenarioClient::CreateVideo(
   capturer->Init();
   res.source = rtc::make_ref_counted<FrameGeneratorCapturerVideoTrackSource>(
       std::move(capturer), config.screencast);
+  res.source->Start();
   auto track = pc_factory_->CreateVideoTrack(res.source, track_id);
   res.track = track.get();
   res.sender =

test/scenario/video_stream.cc

@@ -419,6 +419,7 @@ SendVideoStream::SendVideoStream(CallClient* sender,
   send_config.suspend_below_min_bitrate =
       config.encoder.suspend_below_min_bitrate;
 
+  video_capturer_->Start();
   sender_->SendTask([&] {
     if (config.stream.fec_controller_factory) {
       send_stream_ = sender_->call_->CreateVideoSendStream(

video/end_to_end_tests/multi_codec_receive_tests.cc

@@ -254,6 +254,7 @@ void MultiCodecReceiveTest::RunTestWithCodecs(
       GetVideoSendStream()->Start();
       CreateFrameGeneratorCapturer(kFps, kWidth / 2, kHeight / 2);
       ConnectVideoSourcesToStreams();
+      StartVideoSources();
     });
     EXPECT_TRUE(observer_.Wait()) << "Timed out waiting for frames.";
   }

video/end_to_end_tests/rtp_rtcp_tests.cc

@@ -339,6 +339,7 @@ void RtpRtcpEndToEndTest::TestRtpStatePreservation(
             ->SendRtcp(packet.data(), packet.size());
       }
       CreateFrameGeneratorCapturer(30, 1280, 720);
+      StartVideoSources();
     });
 
     observer.ResetExpectedSsrcs(1);