Allow VideoCaptureImpl to suspend/resume frame delivery to its client.

content/renderer/media/video_capture_impl.cc

 // 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/media/video_capture_impl.h"
 
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "content/common/child_process.h"
 #include "content/common/media/video_capture_messages.h"
@@ skipping 38 matching lines @@
     const media::VideoCaptureSessionId id,
     base::MessageLoopProxy* capture_message_loop_proxy,
     VideoCaptureMessageFilter* filter)
     : VideoCapture(),
       message_filter_(filter),
       capture_message_loop_proxy_(capture_message_loop_proxy),
       io_message_loop_proxy_(ChildProcess::current()->io_message_loop_proxy()),
       device_id_(0),
       video_type_(media::VideoCaptureCapability::kI420),
       device_info_available_(false),
+      suspended_(false),
       state_(VIDEO_CAPTURE_STATE_STOPPED) {
   DCHECK(filter);
   memset(&current_params_, 0, sizeof(current_params_));
   memset(&device_info_, 0, sizeof(device_info_));
   current_params_.session_id = id;
 }
 
 VideoCaptureImpl::~VideoCaptureImpl() {
   STLDeleteValues(&cached_dibs_);
 }
@@ skipping 62 matching lines @@
       base::Bind(&VideoCaptureImpl::DoDeviceInfoReceivedOnCaptureThread,
                  base::Unretained(this), device_info));
 }
 
 void VideoCaptureImpl::OnDelegateAdded(int32 device_id) {
   capture_message_loop_proxy_->PostTask(FROM_HERE,
       base::Bind(&VideoCaptureImpl::DoDelegateAddedOnCaptureThread,
                  base::Unretained(this), device_id));
 }
 
+void VideoCaptureImpl::SuspendCapture(bool suspend) {
+  capture_message_loop_proxy_->PostTask(FROM_HERE,
+      base::Bind(&VideoCaptureImpl::DoSuspendCaptureOnCaptureThread,
+                 base::Unretained(this), suspend));
+}
+
 void VideoCaptureImpl::DoDeInitOnCaptureThread(base::Closure task) {
   if (state_ == VIDEO_CAPTURE_STATE_STARTED)
     Send(new VideoCaptureHostMsg_Stop(device_id_));
 
   io_message_loop_proxy_->PostTask(FROM_HERE,
       base::Bind(&VideoCaptureImpl::RemoveDelegateOnIOThread,
                  base::Unretained(this), task));
 }
 
 void VideoCaptureImpl::DoStartCaptureOnCaptureThread(
@@ skipping 117 matching lines @@
   buffer->stride = device_info_.width;
 
   DIBBuffer* dib_buffer = new DIBBuffer(dib, buffer);
   cached_dibs_[buffer_id] = dib_buffer;
 }
 
 void VideoCaptureImpl::DoBufferReceivedOnCaptureThread(
     int buffer_id, base::Time timestamp) {
   DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
 
-  if (state_ != VIDEO_CAPTURE_STATE_STARTED) {
+  if (state_ != VIDEO_CAPTURE_STATE_STARTED || suspended_) {
     Send(new VideoCaptureHostMsg_BufferReady(device_id_, buffer_id));
     return;
   }
 
   media::VideoCapture::VideoFrameBuffer* buffer;
   DCHECK(cached_dibs_.find(buffer_id) != cached_dibs_.end());
   buffer = cached_dibs_[buffer_id]->mapped_memory;
   buffer->timestamp = timestamp;
 
   for (ClientInfo::iterator it = clients_.begin(); it != clients_.end(); ++it) {
@@ skipping 68 matching lines @@
   device_id_ = device_id;
   for (ClientInfo::iterator it = clients_pending_on_filter_.begin();
        it != clients_pending_on_filter_.end(); ) {
     media::VideoCapture::EventHandler* handler = it->first;
     const media::VideoCaptureCapability capability = it->second;
     clients_pending_on_filter_.erase(it++);
     StartCapture(handler, capability);
   }
 }
 
+void VideoCaptureImpl::DoSuspendCaptureOnCaptureThread(bool suspend) {
+  DVLOG(1) << "DoSuspendCapture: suspend " << (suspend ? "yes" : "no");
+  DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
+
+  suspended_ = suspend;
+}
+
 void VideoCaptureImpl::StopDevice() {
   DCHECK(capture_message_loop_proxy_->BelongsToCurrentThread());
 
   device_info_available_ = false;
   if (state_ == VIDEO_CAPTURE_STATE_STARTED) {
     state_ = VIDEO_CAPTURE_STATE_STOPPING;
     Send(new VideoCaptureHostMsg_Stop(device_id_));
     current_params_.width = current_params_.height = 0;
   }
 }
@@ skipping 68 matching lines @@
   if (it != clients->end()) {
     handler->OnStopped(this);
     handler->OnRemoved(this);
     clients->erase(it);
     found = true;
   }
   return found;
 }
 
 }  // namespace content