enable video capture to support sharing across multiple renderer processes

content/renderer/media/video_capture_impl.cc

Index: content/renderer/media/video_capture_impl.cc
===================================================================
--- content/renderer/media/video_capture_impl.cc	(revision 106642)
+++ content/renderer/media/video_capture_impl.cc	(working copy)
@@ -9,14 +9,21 @@
 #include "content/common/child_process.h"
 #include "content/common/media/video_capture_messages.h"
 
-VideoCaptureImpl::DIBBuffer::DIBBuffer(
-    base::SharedMemory* d, media::VideoCapture::VideoFrameBuffer* ptr)
-    : dib(d),
-      mapped_memory(ptr) {}
+struct VideoCaptureImpl::DIBBuffer {
+ public:
+  DIBBuffer(
+      base::SharedMemory* d,
+      media::VideoCapture::VideoFrameBuffer* ptr)
+      : dib(d),
+        mapped_memory(ptr) {
+  }
+  ~DIBBuffer() {
+    delete dib;
+  }
 
-VideoCaptureImpl::DIBBuffer::~DIBBuffer() {
-  delete dib;
-}
+  base::SharedMemory* dib;
+  scoped_refptr<media::VideoCapture::VideoFrameBuffer> mapped_memory;
+};
 
 bool VideoCaptureImpl::CaptureStarted() {
   return state_ == kStarted;
@@ -47,8 +54,7 @@
       state_(kStopped) {
   DCHECK(filter);
   memset(&current_params_, 0, sizeof(current_params_));
-  memset(&new_params_, 0, sizeof(new_params_));
-  current_params_.session_id = new_params_.session_id = id;
+  current_params_.session_id = id;
 }
 
 VideoCaptureImpl::~VideoCaptureImpl() {
@@ -147,6 +153,12 @@
     const VideoCaptureCapability& capability) {
   DCHECK(ml_proxy_->BelongsToCurrentThread());
 
+  if (state_ == kError) {
+    handler->OnError(this, 1);
+    handler->OnRemoved(this);
+    return;
+  }
+
   if (pending_clients_.find(handler) != pending_clients_.end() ||
       clients_.find(handler) != clients_.end() ) {
     // This client has started.
@@ -158,69 +170,39 @@
     return;
   }
 
-  if (capability.resolution_fixed && master_clients_.size()) {
-    bool matches_current_params =
-        CapabilityMatchesParameters(capability, current_params_);
-    bool matches_new_params =
-        CapabilityMatchesParameters(capability, new_params_);
-    if ((state_ == kStarted && !matches_current_params) ||
-        (state_ == kStopping && !matches_new_params)) {
-      // Can't have 2 master clients with different resolutions.
-      handler->OnError(this, 1);
-      handler->OnRemoved(this);
-      return;
-    }
-  }
-
-  handler->OnStarted(this);
   clients_[handler] = capability;
-  if (capability.resolution_fixed) {
-    master_clients_.push_back(handler);
-    if (master_clients_.size() > 1) {
-      if (device_info_available_)
-        handler->OnDeviceInfoReceived(this, device_info_);
+  handler->OnStarted(this);
+  if (state_ == kStarted) {
+    if (!device_info_available_) {
       return;
     }
-  }
 
-  if (state_ == kStarted) {
-    // Take the resolution of master client.
-    if (capability.resolution_fixed &&
-        !CapabilityMatchesParameters(capability, current_params_)) {
-      new_params_.width = capability.width;
-      new_params_.height = capability.height;
-      new_params_.frame_per_second = capability.max_fps;
-      DLOG(INFO) << "StartCapture: Got master client with new resolution ("
-                 << new_params_.width << ", " << new_params_.height << ") "
-                 << "during started, try to restart.";
+    if (capability.width > device_info_.width ||
+        capability.height > device_info_.height) {
       StopDevice();
-    } else if (device_info_available_) {
-      handler->OnDeviceInfoReceived(this, device_info_);
+      DLOG(INFO) << "StartCapture: Got client with higher resolution ("
+                 << capability.width << ", " << capability.height << ") "
+                 << "after started, try to restart.";
+      return;
     }
+
+    handler->OnDeviceInfoReceived(this, device_info_);
     return;
   }
 
   if (state_ == kStopping) {
-    if (capability.resolution_fixed || !pending_start()) {
-      new_params_.width = capability.width;
-      new_params_.height = capability.height;
-      new_params_.frame_per_second = capability.max_fps;
-      DLOG(INFO) << "StartCapture: Got new resolution ("
-                 << new_params_.width << ", " << new_params_.height << ") "
-                 << ", already in stopping.";
-    }
+    DLOG(INFO) << "StartCapture: Got new resolution ("
+               << capability.width << ", " << capability.height << ") "
+               << ", during stopping.";
     return;
   }
 
   DCHECK_EQ(clients_.size(), 1ul);
   video_type_ = capability.raw_type;
-  new_params_.width = 0;
-  new_params_.height = 0;
-  new_params_.frame_per_second = 0;
   current_params_.width = capability.width;
   current_params_.height = capability.height;
   current_params_.frame_per_second = capability.max_fps;
-  DLOG(INFO) << "StartCapture: resolution ("
+  DLOG(INFO) << "StartCapture: starting with first resolution ("
              << current_params_.width << ", " << current_params_.height << ")";
 
   StartCaptureInternal();
@@ -244,56 +226,8 @@
   handler->OnStopped(this);
   handler->OnRemoved(this);
   clients_.erase(handler);
-  master_clients_.remove(handler);
 
-  // Still have at least one master client.
-  if (master_clients_.size() > 0)
-    return;
-
-  // TODO(wjia): Is it really needed to handle resolution change for non-master
-  // clients, except no client case?
-  if (clients_.size() > 0) {
-    DLOG(INFO) << "StopCapture: No master client.";
-    int max_width = 0;
-    int max_height = 0;
-    int frame_rate = 0;
-    for (ClientInfo::iterator it = clients_.begin();
-         it != clients_.end(); it++) {
-      if (it->second.width > max_width && it->second.height > max_height) {
-        max_width = it->second.width;
-        max_height = it->second.height;
-        frame_rate = it->second.max_fps;
-      }
-    }
-
-    if (state_ == kStarted) {
-      // Only handle resolution reduction.
-      if (max_width < current_params_.width &&
-          max_height < current_params_.height) {
-        new_params_.width = max_width;
-        new_params_.height = max_height;
-        new_params_.frame_per_second = frame_rate;
-        DLOG(INFO) << "StopCapture: New smaller resolution ("
-                   << new_params_.width << ", " << new_params_.height << ") "
-                   << "), stopping ...";
-        StopDevice();
-      }
-      return;
-    }
-
-    if (state_ == kStopping) {
-      new_params_.width = max_width;
-      new_params_.height = max_height;
-      new_params_.frame_per_second = frame_rate;
-      DLOG(INFO) << "StopCapture: New resolution ("
-                 << new_params_.width << ", " << new_params_.height << ") "
-                 << "), during stopping.";
-      return;
-    }
-  } else {
-    new_params_.width = current_params_.width = 0;
-    new_params_.height = current_params_.height = 0;
-    new_params_.frame_per_second = current_params_.frame_per_second = 0;
+  if (clients_.size() == 0) {
     DLOG(INFO) << "StopCapture: No more client, stopping ...";
     StopDevice();
   }
@@ -322,6 +256,7 @@
     base::SharedMemoryHandle handle,
     int length, int buffer_id) {
   DCHECK(ml_proxy_->BelongsToCurrentThread());
+  DCHECK(device_info_available_);
 
   media::VideoCapture::VideoFrameBuffer* buffer;
   DCHECK(cached_dibs_.find(buffer_id) == cached_dibs_.end());
@@ -331,8 +266,9 @@
   buffer = new VideoFrameBuffer();
   buffer->memory_pointer = static_cast<uint8*>(dib->memory());
   buffer->buffer_size = length;
-  buffer->width = current_params_.width;
-  buffer->height = current_params_.height;
+  buffer->width = device_info_.width;
+  buffer->height = device_info_.height;
+  buffer->stride = device_info_.width;
 
   DIBBuffer* dib_buffer = new DIBBuffer(dib, buffer);
   cached_dibs_[buffer_id] = dib_buffer;
@@ -366,7 +302,7 @@
       state_ = kStopped;
       DLOG(INFO) << "OnStateChanged: stopped!, device_id = " << device_id_;
       STLDeleteValues(&cached_dibs_);
-      if (pending_start())
+      if (clients_.size() > 0)
         RestartCapture();
       break;
     case media::VideoCapture::kPaused:
@@ -376,6 +312,7 @@
       }
       break;
     case media::VideoCapture::kError:
+      DLOG(INFO) << "OnStateChanged: error!, device_id = " << device_id_;
       for (ClientInfo::iterator it = clients_.begin();
            it != clients_.end(); it++) {
         // TODO(wjia): browser process would send error code.
@@ -383,9 +320,7 @@
         it->first->OnRemoved(this);
       }
       clients_.clear();
-      master_clients_.clear();
-      state_ = kStopped;
-      current_params_.width = current_params_.height = 0;
+      state_ = kError;
       break;
     default:
       break;
@@ -395,8 +330,16 @@
 void VideoCaptureImpl::DoDeviceInfoReceived(
     const media::VideoCaptureParams& device_info) {
   DCHECK(ml_proxy_->BelongsToCurrentThread());
-  if (state_ != kStarted)
+  DCHECK(!ClientHasDIB());
+
+  STLDeleteValues(&cached_dibs_);
+
+  GetMaxWidthHeight(current_params_.width, current_params_.height);
+  if (current_params_.width > device_info.width ||
+      current_params_.height > device_info.height) {
+    StopDevice();
     return;
+  }
 
   device_info_ = device_info;
   device_info_available_ = true;
@@ -434,14 +377,7 @@
   DCHECK(ml_proxy_->BelongsToCurrentThread());
   DCHECK_EQ(state_, kStopped);
 
-  current_params_.width = new_params_.width;
-  current_params_.height = new_params_.height;
-  current_params_.frame_per_second = new_params_.frame_per_second;
-
-  new_params_.width = 0;
-  new_params_.height = 0;
-  new_params_.frame_per_second = 0;
-
+  GetMaxWidthHeight(current_params_.width, current_params_.height);
   DLOG(INFO) << "RestartCapture, " << current_params_.width << ", "
              << current_params_.height;
   StartCaptureInternal();
@@ -473,10 +409,22 @@
                                           message_filter_.get(), message)));
 }
 
-bool VideoCaptureImpl::CapabilityMatchesParameters(
-    const VideoCaptureCapability& capability,
-    const media::VideoCaptureParams& params) {
-  return (capability.width == params.width &&
-          capability.height == params.height &&
-          capability.max_fps == params.frame_per_second);
+bool VideoCaptureImpl::ClientHasDIB() {
+  for (ClientSideDIB::iterator dit = client_side_dibs_.begin();
+       dit != client_side_dibs_.end(); dit++) {
+    if (dit->second > 0)
+      return true;
+  }
+  return false;
 }
+
+void VideoCaptureImpl::GetMaxWidthHeight(int& width, int& height) {
+  width = height = 0;
+  for (ClientInfo::iterator it = clients_.begin();
+       it != clients_.end(); it++) {
+    if (it->second.width > width)
+      width = it->second.width;
+    if (it->second.height > height)
+      height = it->second.height;
+  }
+}