VideoCaptureHost

content/browser/renderer_host/video_capture_host_unittest.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <list>
+#include <string>
+
+#include "base/file_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
+#include "base/process_util.h"
+#include "base/stringprintf.h"
+#include "content/browser/browser_thread.h"
+#include "content/browser/media_stream/video_capture_manager.h"
+#include "content/browser/renderer_host/video_capture_host.h"
+#include "content/common/video_capture_messages.h"
+#include "media/video/capture/video_capture_types.h"
+
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using ::testing::_;
+using ::testing::AtLeast;
+using ::testing::AnyNumber;
+using ::testing::DoAll;
+using ::testing::InSequence;
+using ::testing::Mock;
+using ::testing::Return;
+
+// IPC::Msg.routing_id.
+static const int32 kRouteId = 200;
+// Id used to identify the capture session between renderer and
+// video_capture_host.
+static const int kDeviceId = 1;
+// Id of a video capture device
+static const media::VideoCaptureSessionId kTestFakeDeviceId =
+    media_stream::VideoCaptureManager::kStartOpenSessionId;
+
+// Define to enable test where video is dumped to file.
+// #define DUMP_VIDEO
+
+// Define to use a real video capture device.
+// #define TEST_REAL_CAPTURE_DEVICE
+
+// Simple class used for dumping video to a file. This can be used for
+// verifying the output.
+class DumpVideo {
+ public:
+  DumpVideo() : expected_size_(0) {}
+  void StartDump(int widht, int height) {

[scherkus (not reviewing), 2011/05/23 05:05:09]

s/widht/width

[Per K, 2011/05/23 12:05:47]

Done.

+    // Create an FilePath that works on all platforms. There should
+    // be a better way.
+    FilePath file_name =
+        FilePath::FromWStringHack(StringPrintf(L"dump_w%d_h%d.yuv", widht,
+                                               height));
+    file_.reset(file_util::OpenFile(file_name, "wb"));
+    expected_size_ = widht * height * 3 / 2;
+  }
+  void NewVideoFrame(const void* buffer) {
+    if (file_.get() != NULL) {
+      fwrite(buffer, expected_size_, 1, file_.get());
+    }
+  }
+
+ private:
+  file_util::ScopedFILE file_;
+  int expected_size_;
+};
+
+class MockVideoCaptureHost : public VideoCaptureHost {
+ public:
+  MockVideoCaptureHost() : return_buffers_(false), dump_video_(false) {}
+  virtual ~MockVideoCaptureHost() {}
+
+  // A list of mock methods.
+  MOCK_METHOD3(OnBufferFilled,
+               void(int routing_id, int device_id, TransportDIB::Handle));
+  MOCK_METHOD3(OnStateChanged,
+               void(int routing_id, int device_id,
+                    media::VideoCapture::State state));
+  MOCK_METHOD2(OnDeviceInfo, void(int routing_id, int device_id));
+
+  // Use class DumpVideo to write I420 video to file.
+  void SetDumpVideo(bool enable) {
+    dump_video_ = enable;
+  }
+  void SetReturnReceviedDibs(bool enable) {
+    return_buffers_ = enable;
+  }
+
+  // Return Dibs we currently have received.
+  void ReturnReceivedDibs(int device_id)  {
+    TransportDIB::Handle handle = GetReceivedDib();
+    while (handle != 0) {
+      IPC::Message msg;
+      msg.set_routing_id(kRouteId);
+      this->OnReceiveEmptyBuffer(msg, device_id, handle);
+      handle = GetReceivedDib();
+    }
+  }
+  TransportDIB::Handle GetReceivedDib() {
+    if (filled_dib_.empty())
+      return 0;
+    TransportDIB::Handle h = filled_dib_.front();
+    filled_dib_.pop_front();
+
+    return h;
+  }
+
+ private:
+  // This method is used to dispatch IPC messages to the renderer. We intercept
+  // these messages here and dispatch to our mock methods to verify the
+  // conversation between this object and the renderer.
+  virtual bool Send(IPC::Message* message) {
+    CHECK(message);
+
+    // In this method we dispatch the messages to the according handlers as if
+    // we are the renderer.
+    bool handled = true;
+    IPC_BEGIN_MESSAGE_MAP(MockVideoCaptureHost, *message)
+      IPC_MESSAGE_HANDLER(VideoCaptureMsg_BufferReady, OnBufferFilled)
+      IPC_MESSAGE_HANDLER(VideoCaptureMsg_StateChanged, OnStateChanged)
+      IPC_MESSAGE_HANDLER(VideoCaptureMsg_DeviceInfo, OnDeviceInfo)
+      IPC_MESSAGE_UNHANDLED(handled = false)
+    IPC_END_MESSAGE_MAP()
+    EXPECT_TRUE(handled);
+
+    delete message;
+    return true;
+  }
+
+  // These handler methods do minimal things and delegate to the mock methods.
+  void OnBufferFilled(const IPC::Message& msg, int device_id,
+                      TransportDIB::Handle  dib_handle) {
+    if (dump_video_) {
+      TransportDIB* dib = TransportDIB::Map(dib_handle);
+      ASSERT_TRUE(dib != NULL);
+      dumper_.NewVideoFrame(dib->memory());
+    }
+
+    OnBufferFilled(msg.routing_id(), device_id, dib_handle);
+    if (return_buffers_) {
+      VideoCaptureHost::OnReceiveEmptyBuffer(msg, device_id, dib_handle);
+    } else {
+      filled_dib_.push_back(dib_handle);
+    }
+  }
+
+  void OnStateChanged(const IPC::Message& msg, int device_id,
+                      media::VideoCapture::State state) {
+    OnStateChanged(msg.routing_id(), device_id, state);
+  }
+
+  void OnDeviceInfo(const IPC::Message& msg, int device_id,
+                      media::VideoCaptureParams params) {
+    if (dump_video_) {
+        dumper_.StartDump(params.width, params.height);

[scherkus (not reviewing), 2011/05/23 05:05:09]

de-indent by 2 spaces

[Per K, 2011/05/23 12:05:47]

Done.

+    }
+    OnDeviceInfo(msg.routing_id(), device_id);
+  }
+
+  std::list<TransportDIB::Handle> filled_dib_;
+  bool return_buffers_;
+  bool dump_video_;
+  DumpVideo dumper_;
+};
+
+ACTION_P(ExitMessageLoop, message_loop) {
+  message_loop->PostTask(FROM_HERE, new MessageLoop::QuitTask());
+}
+
+class VideoCaptureHostTest : public testing::Test {
+ public:
+  VideoCaptureHostTest() {}
+
+ protected:
+  virtual void SetUp() {
+    // Setup the VideoCaptureManager to use fake video capture device.
+  #ifndef TEST_REAL_CAPTURE_DEVICE

[scherkus (not reviewing), 2011/05/23 05:05:09]

nit: don't indent preprocessor statements

[Per K, 2011/05/23 12:05:47]

Done.

+    media_stream::VideoCaptureManager* manager =
+        media_stream::VideoCaptureManager::Get();
+    manager->UseFakeDevice();
+  #endif
+    // Create a message loop so VideoCaptureHostTest can use it.
+    message_loop_.reset(new MessageLoop(MessageLoop::TYPE_IO));
+    io_thread_.reset(new BrowserThread(BrowserThread::IO, message_loop_.get()));
+    host_ = new MockVideoCaptureHost();
+
+    // Simulate IPC channel connected.
+    host_->OnChannelConnected(base::GetCurrentProcId());
+  }
+
+  virtual void TearDown() {
+    // Verifies and removes the expectations on host_ and
+    // returns true iff successful.
+    Mock::VerifyAndClearExpectations(host_);
+
+    EXPECT_CALL(*host_, OnStateChanged(kRouteId, kDeviceId,
+                                       media::VideoCapture::kStopped))
+              .Times(AnyNumber());

[scherkus (not reviewing), 2011/05/23 05:05:09]

indentation

[Per K, 2011/05/23 12:05:47]

Done.

+
+    // Simulate closing the IPC channel.
+    host_->OnChannelClosing();
+
+    // Release the reference to the mock object. The object will be destructed
+    // on message_loop_.
+    host_ = NULL;
+
+    // We need to continue running message_loop_ to complete all destructions.
+    SyncWithVideoCaptureManagerThread();
+
+    io_thread_.reset();
+  }
+
+  // Called on the VideoCaptureManager thread.
+  static void PostQuitMessageLoop(MessageLoop* message_loop) {
+    message_loop->PostTask(FROM_HERE, new MessageLoop::QuitTask());
+  }
+
+  // Called on the main thread.
+  static void PostQuitOnVideoCaptureManagerThread(MessageLoop* message_loop) {
+    media_stream::VideoCaptureManager::Get()->GetMessageLoop()->PostTask(
+        FROM_HERE, NewRunnableFunction(&PostQuitMessageLoop, message_loop));
+  }
+
+  // SyncWithVideoCaptureManagerThread() waits until all pending tasks on the
+  // video_capture_manager thread are executed while also processing pending
+  // task in message_loop_ on the current thread. It is used to synchronize
+  // with the video capture manager thread when we are stopping a video
+  // capture device.
+  void SyncWithVideoCaptureManagerThread() {
+    message_loop_->PostTask(
+        FROM_HERE, NewRunnableFunction(&PostQuitOnVideoCaptureManagerThread,

[scherkus (not reviewing), 2011/05/23 05:05:09]

I think you can replace this by calling message_loop_->RunAllPending();

[Per K, 2011/05/23 12:05:47]

Please see below.

+                                       message_loop_.get()));
+    message_loop_->Run();
+  }
+
+  void StartCapture() {
+    InSequence s;
+    // 1. First - get info about the new resolution
+    EXPECT_CALL(*host_, OnDeviceInfo(kRouteId, kDeviceId));
+
+    // 2. Change state to started
+    EXPECT_CALL(*host_, OnStateChanged(kRouteId, kDeviceId,
+                                       media::VideoCapture::kStarted));
+
+    // 3. First filled buffer will arrive.
+    EXPECT_CALL(*host_, OnBufferFilled(kRouteId, kDeviceId, _))
+            .Times(AnyNumber())

[scherkus (not reviewing), 2011/05/23 05:05:09]

indentation (should be 4 spaces)

[Per K, 2011/05/23 12:05:47]

Done.

+            .WillOnce(ExitMessageLoop(message_loop_.get()));

[scherkus (not reviewing), 2011/05/23 05:05:09]

you usually don't need to do this kind of stuff and can call
message_loop_->RunAllPending() instead (assuming everything executes on the
single message_loop_ until work has completed)

[Per K, 2011/05/23 12:05:47]

Video Capture uses 3 different threads :
1. Browser IO thread for IPC
2. VideoCaptureManager owns a thread for starting and stopping video_capture
devices. It runs in its own thread because it can take a while.
3. The thread that do the actual capturing. DirectShow on windows and the
v4l2_thread_ in VideoCaptureDeviceLinux.h on Linux.

So in this test:
host_->OnStartCapture is called on the IO thread.
The implementation call 
VideoCaptureManager::OnStart on vc_device_thread_ in  VideoCaptureManager.cc
When a capture device is started the video frames are delivered to
VideoCaptureController::OnIncomingCapturedFrame 
on the v4l2_thread (or DirectShow). 
The dib for the video frame is then posted back to the IO thread in void
VideoCaptureHost::OnBufferReady to be sent on IPC.

[scherkus (not reviewing), 2011/05/26 05:27:35]

Hrmm... if you design your classes to accept message loops to run on you can
inject a single message loop everywhere inside your unittests -- effectively
making them single threaded and avoiding such code.

For example if VideoCaptureManager is _given_ a thread, then in the unit test
you wouldn't create a new thread where as in chrome it would be sensible to
create a new thread.

+
+    IPC::Message msg;
+    msg.set_routing_id(kRouteId);
+
+    media::VideoCaptureParams params;
+    params.width = 352;
+    params.height = 288;
+    params.frame_per_second = 30;
+    params.session_id = kTestFakeDeviceId;
+    host_->OnStartCapture(msg, kDeviceId, params);
+    message_loop_->Run();
+  }
+
+  void CaptureAndDumpVideo(int width, int heigt, int frame_rate) {
+    InSequence s;
+    // 1. First - get info about the new resolution
+    EXPECT_CALL(*host_, OnDeviceInfo(kRouteId, kDeviceId));
+
+    // 2. Change state to started
+    EXPECT_CALL(*host_, OnStateChanged(kRouteId, kDeviceId,
+                                       media::VideoCapture::kStarted));
+
+    // 3. First filled buffer will arrive.
+    EXPECT_CALL(*host_, OnBufferFilled(kRouteId, kDeviceId, _))
+            .Times(AnyNumber())

[scherkus (not reviewing), 2011/05/23 05:05:09]

indentation (should be 4 spaces)

[Per K, 2011/05/23 12:05:47]

Done.

+            .WillOnce(ExitMessageLoop(message_loop_.get()));

[scherkus (not reviewing), 2011/05/23 05:05:09]

ditto w/ RunAllPending()

[Per K, 2011/05/23 12:05:47]

please see comment above.

+
+    IPC::Message msg;
+    msg.set_routing_id(kRouteId);
+
+    media::VideoCaptureParams params;
+    params.width = width;
+    params.height = heigt;
+    params.frame_per_second = frame_rate;
+    params.session_id = kTestFakeDeviceId;
+    host_->SetDumpVideo(true);
+    host_->OnStartCapture(msg, kDeviceId, params);
+    message_loop_->Run();
+  }
+
+  void StopCapture() {
+    EXPECT_CALL(*host_, OnStateChanged(kRouteId, kDeviceId,
+                                       media::VideoCapture::kStopped))
+              .Times(AtLeast(1));

[scherkus (not reviewing), 2011/05/23 05:05:09]

indentation (should be 4 spaces)

[Per K, 2011/05/23 12:05:47]

Done.

+
+    IPC::Message msg;
+    msg.set_routing_id(kRouteId);
+    host_->OnStopCapture(msg, kDeviceId);
+    host_->SetReturnReceviedDibs(true);
+    host_->ReturnReceivedDibs(kDeviceId);
+
+    SyncWithVideoCaptureManagerThread();
+    host_->SetReturnReceviedDibs(false);
+    // Expect the VideoCaptureDevice has been stopped
+    EXPECT_EQ(0u, host_->entries_.size());
+  }
+
+  void NotifyPacketReady() {
+    EXPECT_CALL(*host_, OnBufferFilled(kRouteId, kDeviceId, _))
+            .Times(AnyNumber())

[scherkus (not reviewing), 2011/05/23 05:05:09]

indentation (should be 4 spaces)

[Per K, 2011/05/23 12:05:47]

Done.

+            .WillOnce(ExitMessageLoop(message_loop_.get()))

[scherkus (not reviewing), 2011/05/23 05:05:09]

ditto w/ RunAllPending()

[Per K, 2011/05/23 12:05:47]

please see comment above.

+            .RetiresOnSaturation();
+    message_loop_->Run();
+  }
+
+  void ReturnReceivedPackets() {
+    host_->ReturnReceivedDibs(kDeviceId);
+  }
+
+  void SimulateError() {
+    // Expect a change state to error state  sent through IPC.
+    EXPECT_CALL(*host_, OnStateChanged(kRouteId, kDeviceId,
+                                       media::VideoCapture::kError))
+        .Times(1);
+    VideoCaptureController::ControllerId id(kRouteId, kDeviceId);
+    host_->OnError(id);
+    SyncWithVideoCaptureManagerThread();
+  }
+
+  scoped_refptr<MockVideoCaptureHost> host_;
+ private:
+  scoped_ptr<MessageLoop> message_loop_;
+  scoped_ptr<BrowserThread> io_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(VideoCaptureHostTest);
+};
+
+TEST_F(VideoCaptureHostTest, StartCapture) {
+  StartCapture();
+}
+
+TEST_F(VideoCaptureHostTest, StartCapturePlayStop) {
+  StartCapture();
+  NotifyPacketReady();
+  NotifyPacketReady();
+  ReturnReceivedPackets();
+  StopCapture();
+}
+
+TEST_F(VideoCaptureHostTest, StartCaptureErrorStop) {
+  StartCapture();
+  SimulateError();
+  StopCapture();
+}
+
+TEST_F(VideoCaptureHostTest, StartCaptureError) {
+  EXPECT_CALL(*host_, OnStateChanged(kRouteId, kDeviceId,
+                                     media::VideoCapture::kStopped))
+      .Times(0);
+  StartCapture();
+  NotifyPacketReady();
+  SimulateError();
+  base::PlatformThread::Sleep(200);
+}
+
+#ifdef DUMP_VIDEO
+TEST_F(VideoCaptureHostTest, CaptureAndDumpVideoVga) {
+  CaptureAndDumpVideo(640, 480, 30);
+}
+TEST_F(VideoCaptureHostTest, CaptureAndDump720P) {
+  CaptureAndDumpVideo(1280, 720, 30);
+}
+#endif