Refactor video capture to new design

content/renderer/pepper/pepper_video_capture_host.cc

Index: content/renderer/pepper/pepper_video_capture_host.cc
diff --git a/content/renderer/pepper/pepper_video_capture_host.cc b/content/renderer/pepper/pepper_video_capture_host.cc
new file mode 100644
index 0000000000000000000000000000000000000000..dcefa04fe421c1ee84c321078b2369906cefa7b5
--- /dev/null
+++ b/content/renderer/pepper/pepper_video_capture_host.cc
@@ -0,0 +1,458 @@
+// Copyright (c) 2012 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 "content/renderer/pepper/pepper_video_capture_host.h"
+
+#include "content/public/renderer/renderer_ppapi_host.h"

[yzshen1, 2012/11/06 21:56:23]

you have included it in .h.

[victorhsieh, 2012/11/08 09:20:18]

IWYU says we should include them.
http://code.google.com/p/include-what-you-use/

[yzshen1, 2012/11/10 01:14:40]

I think that is not true:
--------------------
"Include what you use" means this: for every symbol (type, function variable, or
macro) that you use in foo.cc, ****either foo.cc or foo.h**** should #include a
.h file that exports the declaration of that symbol.
--------------------

Whatever you have included in foo.h file shouldn't be included again in foo.cc.


On 2012/11/08 09:20:18, Victor Hsieh wrote:

[victorhsieh, 2012/11/13 03:10:53]

I see.  Done.

+#include "ppapi/host/dispatch_host_message.h"
+#include "ppapi/host/host_message_context.h"

[yzshen1, 2012/11/06 21:56:23]

ditto.

[victorhsieh, 2012/11/13 03:10:53]

Done.

+#include "ppapi/host/ppapi_host.h"
+#include "ppapi/proxy/host_dispatcher.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/shared_impl/host_resource.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/ppb_device_ref_shared.h"

[yzshen1, 2012/11/06 21:56:23]

ditto.

[victorhsieh, 2012/11/13 03:10:53]

Done.

+#include "ppapi/thunk/enter.h"
+#include "ppapi/thunk/ppb_buffer_api.h"
+#include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
+#include "webkit/plugins/ppapi/ppb_buffer_impl.h"

[yzshen1, 2012/11/06 21:56:23]

ditto.

[victorhsieh, 2012/11/13 03:10:53]

Done.

+#include "webkit/plugins/ppapi/resource_helper.h"
+
+using ppapi::DeviceRefData;
+using ppapi::HostResource;
+using ppapi::PpapiGlobals;
+using ppapi::TrackedCallback;
+using ppapi::thunk::EnterResourceNoLock;
+using ppapi::thunk::PPB_Buffer_API;
+using ppapi::thunk::PPB_BufferTrusted_API;
+using webkit::ppapi::ResourceHelper;
+using webkit::ppapi::PPB_Buffer_Impl;
+using webkit::ppapi::PluginInstance;
+
+namespace {
+
+// Maximum number of buffers to actually allocate.
+const uint32_t kMaxBuffers = 20;
+
+}  // namespace
+
+namespace content {
+
+PepperVideoCaptureHost::PepperVideoCaptureHost(RendererPpapiHost* host,
+                         PP_Instance instance,

[yzshen1, 2012/11/06 21:56:23]

wrong indent.

[victorhsieh, 2012/11/08 09:20:18]

Done.

+                         PP_Resource resource)
+  : ResourceHost(host->GetPpapiHost(), instance, resource),

[yzshen1, 2012/11/06 21:56:23]

wrong indent: four spaces.

[victorhsieh, 2012/11/08 09:20:18]

Done.

+    status_(PP_VIDEO_CAPTURE_STATUS_STOPPED) {

[yzshen1, 2012/11/06 21:56:23]

please init buffer_count_hint_.

[victorhsieh, 2012/11/08 09:20:18]

Done.

+}
+
+PepperVideoCaptureHost::~PepperVideoCaptureHost() {
+  Close();
+}
+
+bool PepperVideoCaptureHost::Init() {
+  PluginInstance* instance = GetPluginInstance();
+  return !!instance;
+}
+
+int32_t PepperVideoCaptureHost::OnResourceMessageReceived(
+      const IPC::Message& msg,

[yzshen1, 2012/11/06 21:56:23]

wrong indent.

[victorhsieh, 2012/11/08 09:20:18]

Done.

+      ppapi::host::HostMessageContext* context) {
+  IPC_BEGIN_MESSAGE_MAP(PepperVideoCaptureHost, msg)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
+        PpapiHostMsg_VideoCapture_EnumerateDevices,
+        OnEnumerateDevices)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(
+        PpapiHostMsg_VideoCapture_Open,
+        OnOpen)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
+        PpapiHostMsg_VideoCapture_StartCapture,
+        OnStartCapture)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL(
+        PpapiHostMsg_VideoCapture_ReuseBuffer,
+        OnReuseBuffer)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
+        PpapiHostMsg_VideoCapture_StopCapture,
+        OnStopCapture)
+    PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(
+        PpapiHostMsg_VideoCapture_Close,
+        OnClose)
+  IPC_END_MESSAGE_MAP()
+  return PP_ERROR_FAILED;
+}
+
+void PepperVideoCaptureHost::OnInitialized(media::VideoCapture* capture,
+                                           bool succeeded) {
+  DCHECK(capture == platform_video_capture_.get());
+
+  if (succeeded) {
+    open_reply_context_.params.set_result(PP_OK);
+  } else {
+    DetachPlatformVideoCapture();
+    open_reply_context_.params.set_result(PP_ERROR_FAILED);
+  }
+
+  host()->SendReply(open_reply_context_,
+                    PpapiPluginMsg_VideoCapture_OpenReply());
+}
+
+void PepperVideoCaptureHost::OnStarted(media::VideoCapture* capture) {
+  if (SetStatus(PP_VIDEO_CAPTURE_STATUS_STARTED, false))
+    SendStatus();
+}
+
+void PepperVideoCaptureHost::OnStopped(media::VideoCapture* capture) {
+  if (SetStatus(PP_VIDEO_CAPTURE_STATUS_STOPPED, false))
+    SendStatus();
+}
+
+void PepperVideoCaptureHost::OnPaused(media::VideoCapture* capture) {
+  if (SetStatus(PP_VIDEO_CAPTURE_STATUS_PAUSED, false))
+    SendStatus();
+}
+
+void PepperVideoCaptureHost::OnError(media::VideoCapture* capture,
+                                     int error_code) {
+  // Today, the media layer only sends "1" as an error.
+  DCHECK(error_code == 1);
+  // It either comes because some error was detected while starting (e.g. 2
+  // conflicting "master" resolution), or because the browser failed to start
+  // the capture.
+  SetStatus(PP_VIDEO_CAPTURE_STATUS_STOPPED, true);
+  host()->SendUnsolicitedReply(pp_resource(),
+      PpapiPluginMsg_VideoCapture_OnError(PP_ERROR_FAILED));
+}
+
+void PepperVideoCaptureHost::OnRemoved(media::VideoCapture* capture) {
+}
+
+void PepperVideoCaptureHost::OnBufferReady(
+    media::VideoCapture* capture,
+    scoped_refptr<media::VideoCapture::VideoFrameBuffer> buffer) {
+  DCHECK(buffer.get());
+  for (uint32_t i = 0; i < buffers_.size(); ++i) {
+    if (!buffers_[i].in_use) {
+      // TODO(ihf): Switch to a size calculation based on stride.
+      // Stride is filled out now but not more meaningful than size
+      // until wjia unifies VideoFrameBuffer and media::VideoFrame.
+      size_t size = std::min(static_cast<size_t>(buffers_[i].buffer->size()),
+          buffer->buffer_size);
+      memcpy(buffers_[i].data, buffer->memory_pointer, size);
+      buffers_[i].in_use = true;
+      platform_video_capture_->FeedBuffer(buffer);
+      host()->SendUnsolicitedReply(pp_resource(),
+          PpapiPluginMsg_VideoCapture_OnBufferReady(i));
+      return;
+    }
+  }
+
+  // No free slot, just discard the frame and tell the media layer it can
+  // re-use the buffer.
+  platform_video_capture_->FeedBuffer(buffer);
+}
+
+void PepperVideoCaptureHost::OnDeviceInfoReceived(
+    media::VideoCapture* capture,
+    const media::VideoCaptureParams& device_info) {
+  PP_VideoCaptureDeviceInfo_Dev info = {
+    static_cast<uint32_t>(device_info.width),
+    static_cast<uint32_t>(device_info.height),
+    static_cast<uint32_t>(device_info.frame_per_second)
+  };
+  ReleaseBuffers();
+
+  // YUV 4:2:0
+  int uv_width = info.width / 2;
+  int uv_height = info.height / 2;
+  size_t size = info.width * info.height + 2 * uv_width * uv_height;
+
+  ppapi::proxy::ResourceMessageReplyParams params(pp_resource(), 0);
+
+  // Allocate buffers. We keep a reference to them, that is released in
+  // ReleaseBuffers. In the mean time, we prepare the resource and handle here
+  // for sending below.
+  std::vector<HostResource> buffer_host_resources;
+  buffers_.reserve(buffer_count_hint_);
+  ppapi::proxy::HostDispatcher* dispatcher =
+      ppapi::proxy::HostDispatcher::GetForInstance(pp_instance());
+  for (size_t i = 0; i < buffer_count_hint_; ++i) {
+    PP_Resource res = PPB_Buffer_Impl::Create(pp_instance(), size);
+    if (!res)
+      break;
+
+    EnterResourceNoLock<PPB_Buffer_API> enter(res, true);
+    DCHECK(enter.succeeded());
+
+    BufferInfo buf;
+    buf.buffer = static_cast<PPB_Buffer_Impl*>(enter.object());
+    buf.data = buf.buffer->Map();
+    if (!buf.data) {
+      PpapiGlobals::Get()->GetResourceTracker()->ReleaseResource(res);
+      break;
+    }
+    buffers_.push_back(buf);
+
+    // Add to HostResource array to be sent.
+    {
+      HostResource host_resource;

[yzshen1, 2012/11/06 21:56:23]

You have to add one more ref for the plugin side. The plugin side will take
ownership of that reference. It will be removed when the plugin side destroy the
plugin-side object and call PluginResourceTracker::RemoveResource().

Please be careful with references. It is hard to find out later. You might want
to read the implementation of resource_tracker/plugin_resource_tracker.

[victorhsieh, 2012/11/08 09:20:18]

Done.  But how does that work when running out of process?

[yzshen1, 2012/11/10 01:14:40]

What I said above is for out-of-process. And please read those files. :)

In short, we will send back a message when the plugin side no longer holds this
ref. See PpapiHostMsg_PPBCore_ReleaseResource.

On 2012/11/08 09:20:18, Victor Hsieh wrote:

[victorhsieh, 2012/11/13 03:10:53]

Done.  I was thinking in different way and got confused.  Also, I now changed
PpapiGlobals to HostGlobals.  Both works in this case, but HostGlobals makes
more sense here.  Correct me if I'm wrong.

[yzshen1, 2012/11/14 06:54:16]

HostGlobals SGTM.

+      host_resource.SetHostResource(pp_instance(), res);
+      buffer_host_resources.push_back(host_resource);
+    }
+
+    // Add the serialized shared memory handle to params. FileDescriptor is
+    // treated in special case.
+    {
+      EnterResourceNoLock<PPB_BufferTrusted_API> enter(res, true);
+      DCHECK(enter.succeeded());
+      int handle;
+      int32_t result = enter.object()->GetSharedMemory(&handle);
+      DCHECK(result == PP_OK);
+      // TODO(piman/brettw): Change trusted interface to return a PP_FileHandle,
+      // those casts are ugly.
+      base::PlatformFile platform_file =
+#if defined(OS_WIN)
+          reinterpret_cast<HANDLE>(static_cast<intptr_t>(handle));
+#elif defined(OS_POSIX)
+          handle;
+#else
+#error Not implemented.
+#endif
+      params.AppendHandle(
+          ppapi::proxy::SerializedHandle(
+              dispatcher->ShareHandleWithRemote(platform_file, false),
+              size));
+    }
+  }
+
+  if (buffers_.empty()) {
+    // We couldn't allocate/map buffers at all. Send an error and stop the
+    // capture.
+    SetStatus(PP_VIDEO_CAPTURE_STATUS_STOPPING, true);
+    platform_video_capture_->StopCapture(this);
+    OnError(capture, PP_ERROR_NOMEMORY);
+    return;
+  }
+
+  host()->Send(new PpapiPluginMsg_ResourceReply(
+      params, PpapiPluginMsg_VideoCapture_OnDeviceInfo(
+          info, buffer_host_resources, size)));
+}
+
+PluginInstance* PepperVideoCaptureHost::GetPluginInstance() const {
+  return ResourceHelper::PPInstanceToPluginInstance(pp_instance());

[yzshen1, 2012/11/06 21:56:23]

I thought this wouldn't link. Maybe you are using a non-component build?
(I did it in a different way in PepperAudioInputHost::GetDelegate() in
http://codereview.chromium.org/11366038/diff/6002/content/renderer/pepper/pep...)

[victorhsieh, 2012/11/08 09:20:18]

Actually I just learned about component build this week.  Yes, we need to add
resource_helper.cc to gyp to make this work, but I'll switch to your new code
until it is checked in.

In addition to this, we also need to add
webkit/plugin/ppapi/ppb_buffer_impl.{cc,h}  to gyp.  Do you have a better
suggestion than that?  Will that cause "multiple definition" error on compile?

[yzshen1, 2012/11/10 01:14:40]

It has been checked in.
export them?

[victorhsieh, 2012/11/13 03:10:53]

Done.

+}
+
+int32_t PepperVideoCaptureHost::OnEnumerateDevices(
+    ppapi::host::HostMessageContext* context) {
+  PluginInstance* instance = GetPluginInstance();
+  if (!instance)
+    return PP_ERROR_FAILED;
+
+  enum_reply_context_ = context->MakeReplyMessageContext();

[yzshen1, 2012/11/06 21:56:23]

If we receive a second enumerate devices request before the first completes, we
will overwrite the context.

One possible way is to use scoped_ptr<> to store a context, and reject requests
if the pointer is not NULL. Or have a bool flag.

(I agree that if the plugin side works properly, it is not likely to receive
multiple requests in this way, though.)

[victorhsieh, 2012/11/08 09:20:18]

I don't see any risk here if we don't check?  enum_reply_context_ isn't a
pointer so no leaking will happen.  In the callback, it would send a message
with wrong sequence number.  That will only cause some error message.

[yzshen1, 2012/11/10 01:14:40]

Okay.
On 2012/11/08 09:20:18, Victor Hsieh wrote:

+  instance->delegate()->EnumerateDevices(
+      PP_DEVICETYPE_DEV_VIDEOCAPTURE,
+      base::Bind(&PepperVideoCaptureHost::EnumerateDevicesCallbackFunc,
+                 AsWeakPtr()));
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t PepperVideoCaptureHost::OnOpen(
+    ppapi::host::HostMessageContext* context,
+    const std::string& device_id,
+    const PP_VideoCaptureDeviceInfo_Dev& requested_info,
+    uint32_t buffer_count) {
+  if (platform_video_capture_.get())
+    return PP_ERROR_FAILED;
+
+  PluginInstance* instance = GetPluginInstance();
+  if (!instance)
+    return PP_ERROR_FAILED;
+
+  SetRequestedInfo(requested_info, buffer_count);
+
+  platform_video_capture_ =
+      instance->delegate()->CreateVideoCapture(device_id, this);
+
+  open_reply_context_ = context->MakeReplyMessageContext();
+
+  // It is able to complete synchronously if the default device is used.
+  bool sync_completion = device_id.empty();
+  if (sync_completion) {
+    // Send OpenACK directly, but still need to return PP_OK_COMPLETIONPENDING
+    // to make PluginResource happy.
+    OnInitialized(platform_video_capture_.get(), true);
+    return PP_OK_COMPLETIONPENDING;

[yzshen1, 2012/11/06 21:56:23]

You don't need this line.

[victorhsieh, 2012/11/08 09:20:18]

Done.

+  }
+
+  return PP_OK_COMPLETIONPENDING;
+}
+
+int32_t PepperVideoCaptureHost::OnStartCapture(
+    ppapi::host::HostMessageContext* context) {
+  if (!SetStatus(PP_VIDEO_CAPTURE_STATUS_STARTING, false))
+    return PP_ERROR_FAILED;
+
+  DCHECK(platform_video_capture_.get());

[yzshen1, 2012/11/06 21:56:23]

If we want this code to handle unexpected requests in a robust way, we need to
return if platform_video_capture_ is NULL here. (The check on line 292 won't
help if we receive a start capture request before an open.)

[victorhsieh, 2012/11/08 09:20:18]

Done.

+  DCHECK(buffers_.empty());
+
+  // It's safe to call this regardless it's capturing or not, because
+  // PepperPlatformVideoCaptureImpl maintains the state.
+  platform_video_capture_->StartCapture(this, capability_);
+  return PP_OK;
+}
+
+int32_t PepperVideoCaptureHost::OnReuseBuffer(
+    ppapi::host::HostMessageContext* context,
+    uint32_t buffer) {
+  if (buffer >= buffers_.size() || !buffers_[buffer].in_use)
+    return PP_ERROR_BADARGUMENT;
+  buffers_[buffer].in_use = false;
+  return PP_OK;
+}
+
+int32_t PepperVideoCaptureHost::OnStopCapture(
+    ppapi::host::HostMessageContext* context) {
+  return StopCapture();
+}
+
+int32_t PepperVideoCaptureHost::OnClose(
+    ppapi::host::HostMessageContext* context) {
+  return Close();
+}
+
+int32_t PepperVideoCaptureHost::StopCapture() {
+  if (!SetStatus(PP_VIDEO_CAPTURE_STATUS_STOPPING, false))
+    return PP_ERROR_FAILED;
+
+  DCHECK(platform_video_capture_.get());
+
+  ReleaseBuffers();
+  // It's safe to call this regardless it's capturing or not, because
+  // PepperPlatformVideoCaptureImpl maintains the state.
+  platform_video_capture_->StopCapture(this);
+  return PP_OK;
+}
+
+int32_t PepperVideoCaptureHost::Close() {
+  if (!platform_video_capture_.get())
+    return PP_OK;
+
+  StopCapture();
+  DCHECK(buffers_.empty());
+  DetachPlatformVideoCapture();
+  return PP_OK;
+}
+
+void PepperVideoCaptureHost::ReleaseBuffers() {
+  ::ppapi::ResourceTracker* tracker = PpapiGlobals::Get()->GetResourceTracker();
+  for (size_t i = 0; i < buffers_.size(); ++i) {
+    buffers_[i].buffer->Unmap();
+    tracker->ReleaseResource(buffers_[i].buffer->pp_resource());
+  }
+  buffers_.clear();
+}
+
+void PepperVideoCaptureHost::SendStatus() {
+  host()->SendUnsolicitedReply(pp_resource(),
+      PpapiPluginMsg_VideoCapture_OnStatus(status_));
+}
+
+void PepperVideoCaptureHost::SetRequestedInfo(
+    const PP_VideoCaptureDeviceInfo_Dev& device_info,
+    uint32_t buffer_count) {
+  // Clamp the buffer count to between 1 and |kMaxBuffers|.
+  buffer_count_hint_ = std::min(std::max(buffer_count, 1U), kMaxBuffers);
+
+  capability_.width = device_info.width;
+  capability_.height = device_info.height;
+  capability_.frame_rate = device_info.frames_per_second;
+  capability_.expected_capture_delay = 0;  // Ignored.
+  capability_.color = media::VideoCaptureCapability::kI420;
+  capability_.interlaced = false;  // Ignored.
+}
+
+void PepperVideoCaptureHost::DetachPlatformVideoCapture() {
+  if (platform_video_capture_.get()) {
+    platform_video_capture_->DetachEventHandler();
+    platform_video_capture_ = NULL;
+  }
+}
+
+void PepperVideoCaptureHost::EnumerateDevicesCallbackFunc(
+    int request_id,
+    bool succeeded,
+    const std::vector<ppapi::DeviceRefData>& devices) {
+  PluginInstance* instance = GetPluginInstance();
+  if (instance)
+    instance->delegate()->StopEnumerateDevices(request_id);
+
+  if (succeeded) {
+    enum_reply_context_.params.set_result(PP_OK);
+    host()->SendReply(enum_reply_context_,
+                      PpapiPluginMsg_VideoCapture_EnumerateDevicesReply(
+                          devices));
+  } else {
+    enum_reply_context_.params.set_result(PP_ERROR_FAILED);
+    host()->SendReply(enum_reply_context_,
+                      PpapiPluginMsg_VideoCapture_EnumerateDevicesReply(
+                          std::vector<DeviceRefData>()));
+  }
+}
+
+bool PepperVideoCaptureHost::SetStatus(PP_VideoCaptureStatus_Dev status,
+                                       bool forced) {
+  if (!forced) {
+    switch (status) {
+      case PP_VIDEO_CAPTURE_STATUS_STOPPED:
+        if (status_ != PP_VIDEO_CAPTURE_STATUS_STOPPING)
+          return false;
+        break;
+      case PP_VIDEO_CAPTURE_STATUS_STARTING:
+        if (status_ != PP_VIDEO_CAPTURE_STATUS_STOPPED)
+          return false;
+        break;
+      case PP_VIDEO_CAPTURE_STATUS_STARTED:
+        switch (status_) {
+          case PP_VIDEO_CAPTURE_STATUS_STARTING:
+          case PP_VIDEO_CAPTURE_STATUS_PAUSED:
+            break;
+          default:
+            return false;
+        }
+        break;
+      case PP_VIDEO_CAPTURE_STATUS_PAUSED:
+        switch (status_) {
+          case PP_VIDEO_CAPTURE_STATUS_STARTING:
+          case PP_VIDEO_CAPTURE_STATUS_STARTED:
+            break;
+          default:
+            return false;
+        }
+        break;
+      case PP_VIDEO_CAPTURE_STATUS_STOPPING:
+        switch (status_) {
+          case PP_VIDEO_CAPTURE_STATUS_STARTING:
+          case PP_VIDEO_CAPTURE_STATUS_STARTED:
+          case PP_VIDEO_CAPTURE_STATUS_PAUSED:
+            break;
+          default:
+            return false;
+        }
+        break;
+    }
+  }
+
+  status_ = status;
+  return true;
+}
+
+PepperVideoCaptureHost::BufferInfo::BufferInfo()
+    : in_use(false),
+      data(NULL),
+      buffer() {
+}
+
+PepperVideoCaptureHost::BufferInfo::~BufferInfo() {
+}
+
+}  // namespace content