enable video capture to support sharing across multiple renderer processes

content/browser/renderer_host/media/video_capture_host.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 "content/browser/renderer_host/media/video_capture_host.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stl_util.h"
 #include "content/browser/renderer_host/media/media_stream_manager.h"
+#include "content/browser/renderer_host/media/video_capture_manager.h"
 #include "content/browser/resource_context.h"
 #include "content/common/media/video_capture_messages.h"
 
 VideoCaptureHost::VideoCaptureHost(
     const content::ResourceContext* resource_context)
     : resource_context_(resource_context) {
 }
 
 VideoCaptureHost::~VideoCaptureHost() {}
 
 void VideoCaptureHost::OnChannelClosing() {
   BrowserMessageFilter::OnChannelClosing();
 
   // Since the IPC channel is gone, close all requested VideCaptureDevices.
   for (EntryMap::iterator it = entries_.begin(); it != entries_.end(); it++) {
     VideoCaptureController* controller = it->second;
-    // Since the channel is closing we need a task to make sure VideoCaptureHost
-    // is not deleted before VideoCaptureController.
-    controller->StopCapture(
-        base::Bind(&VideoCaptureHost::OnReadyToDelete, this, it->first));
+    VideoCaptureControllerID controller_id(it->first);
+    controller->StopCapture(controller_id, this, true);
   }
 }
 
 void VideoCaptureHost::OnDestruct() const {
   BrowserThread::DeleteOnIOThread::Destruct(this);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 // Implements VideoCaptureControllerEventHandler.
@@ skipping 60 matching lines @@
 void VideoCaptureHost::DoHandleError(int device_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   Send(new VideoCaptureMsg_StateChanged(device_id,
                                         media::VideoCapture::kError));
 
   VideoCaptureControllerID id(device_id);
   EntryMap::iterator it = entries_.find(id);
   if (it != entries_.end()) {
     VideoCaptureController* controller = it->second;
-    controller->StopCapture(base::Closure());
+    controller->StopCapture(id, this, false);
   }
 }
 
 void VideoCaptureHost::DoSendFrameInfo(int device_id,
                                        int width,
                                        int height,
                                        int frame_per_second) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   media::VideoCaptureParams params;
@@ skipping 17 matching lines @@
     IPC_MESSAGE_HANDLER(VideoCaptureHostMsg_BufferReady, OnReceiveEmptyBuffer)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
 
   return handled;
 }
 
 void VideoCaptureHost::OnStartCapture(int device_id,
                                       const media::VideoCaptureParams& params) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  VideoCaptureControllerID controller_id(device_id);
+  DCHECK(entries_.find(controller_id) == entries_.end());
+  DCHECK(entry_state_.find(controller_id) == entry_state_.end());
 
+  entry_state_[controller_id] = media::VideoCapture::kStarted;
+  GetVideoCaptureManager()->AddController(
+      params, this, base::Bind(&VideoCaptureHost::OnControllerAdded, this,
+                               device_id, params));
+}
+
+void VideoCaptureHost::OnControllerAdded(
+    int device_id, const media::VideoCaptureParams& params,
+    VideoCaptureController* controller) {
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&VideoCaptureHost::DoControllerAddedOnIOThreead,

[perkj_chrome, 2011/10/17 08:39:43]

isn't this already on the io thread?

[mflodman_chromium_OOO, 2011/10/19 18:18:23]

This is called from the video manager thread.

Wei,
Q: VideoCaptureManager is always posting to IO thread internally before calling
MediaStreamManager. Do you think we should do the same for these callbacks or do
you want to keep it like this?

[wjia(left Chromium), 2011/10/21 00:56:13]

It's called from manager's device thread.

[wjia(left Chromium), 2011/10/21 00:56:13]

I am fine with either way. VCManager will have lots of functions if it takes
care of thread switching. It's 1:3.

+                 this, device_id, params, make_scoped_refptr(controller)));
+}
+
+void VideoCaptureHost::DoControllerAddedOnIOThreead(
+    int device_id, const media::VideoCaptureParams params,
+    VideoCaptureController* controller) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   VideoCaptureControllerID controller_id(device_id);
+  DCHECK(entries_.find(controller_id) == entries_.end());
+  DCHECK(entry_state_.find(controller_id) != entry_state_.end());
 
-  DCHECK(entries_.find(controller_id) == entries_.end());
+  if (controller == NULL) {
+    Send(new VideoCaptureMsg_StateChanged(device_id,
+                                          media::VideoCapture::kError));
+    return;
+  }
 
-  scoped_refptr<VideoCaptureController> controller =
-      new VideoCaptureController(
-          controller_id, peer_handle(), this,
-          resource_context_->media_stream_manager()->video_capture_manager());
   entries_.insert(std::make_pair(controller_id, controller));
-  controller->StartCapture(params);
+  if (entry_state_[controller_id] == media::VideoCapture::kStarted) {
+    controller->StartCapture(controller_id, this, peer_handle(), params);
+  } else if (entry_state_[controller_id] == media::VideoCapture::kStopped) {
+    controller->StopCapture(controller_id, this, false);
+  }
 }
 
 void VideoCaptureHost::OnStopCapture(int device_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  VideoCaptureControllerID controller_id(device_id);
 
-  VideoCaptureControllerID controller_id(device_id);
+  if (entry_state_.find(controller_id) == entry_state_.end()) {
+    // It does not exist. So it must have been stopped already.
+    Send(new VideoCaptureMsg_StateChanged(device_id,
+                                          media::VideoCapture::kStopped));
+  }
+
+  entry_state_[controller_id] = media::VideoCapture::kStopped;
+
   EntryMap::iterator it = entries_.find(controller_id);
   if (it != entries_.end()) {
     scoped_refptr<VideoCaptureController> controller = it->second;
-    controller->StopCapture(base::Closure());
-  } else {
-    // It does not exist so it must have been stopped already.
-    Send(new VideoCaptureMsg_StateChanged(device_id,
-                                          media::VideoCapture::kStopped));
+    controller->StopCapture(controller_id, this, false);
   }
 }
 
 void VideoCaptureHost::OnPauseCapture(int device_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   // Not used.
   Send(new VideoCaptureMsg_StateChanged(device_id,
                                         media::VideoCapture::kError));
 }
 
 void VideoCaptureHost::OnReceiveEmptyBuffer(int device_id, int buffer_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   VideoCaptureControllerID controller_id(device_id);
   EntryMap::iterator it = entries_.find(controller_id);
   if (it != entries_.end()) {
     scoped_refptr<VideoCaptureController> controller = it->second;
-    controller->ReturnBuffer(buffer_id);
+    controller->ReturnBuffer(controller_id, this, buffer_id);
   }
 }
 
 void VideoCaptureHost::DoDeleteVideoCaptureController(
     const VideoCaptureControllerID& id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   // Report that the device have successfully been stopped.
   Send(new VideoCaptureMsg_StateChanged(id.device_id,
                                         media::VideoCapture::kStopped));
+  EntryMap::iterator it = entries_.find(id);
+  if (it != entries_.end()) {
+    GetVideoCaptureManager()->RemoveController(it->second, this);
+  }
   entries_.erase(id);
+  entry_state_.erase(id);
 }
+
+media_stream::VideoCaptureManager* VideoCaptureHost::GetVideoCaptureManager() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  return resource_context_->media_stream_manager()->video_capture_manager();
+}