Implement device enumeration for PPB_VideoCapture_Dev.

webkit/plugins/ppapi/ppb_video_capture_impl.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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 "webkit/plugins/ppapi/ppb_video_capture_impl.h"
 
 #include <algorithm>
 #include <string>
 
+#include "base/bind.h"
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
 #include "ppapi/c/dev/pp_video_capture_dev.h"
 #include "ppapi/c/dev/ppb_video_capture_dev.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/ppb_device_ref_shared.h"
 #include "ppapi/shared_impl/resource_tracker.h"
 #include "ppapi/thunk/enter.h"
 #include "webkit/plugins/ppapi/common.h"
 #include "webkit/plugins/ppapi/plugin_module.h"
 #include "webkit/plugins/ppapi/ppapi_plugin_instance.h"
 #include "webkit/plugins/ppapi/ppb_buffer_impl.h"
 #include "webkit/plugins/ppapi/resource_helper.h"
 
+using ppapi::DeviceRefData;
 using ppapi::PpapiGlobals;
 using ppapi::thunk::EnterResourceNoLock;
 using ppapi::thunk::PPB_Buffer_API;
 using ppapi::thunk::PPB_VideoCapture_API;
+using ppapi::TrackedCallback;
 
 namespace {
 
 // Maximum number of buffers to actually allocate.
 const uint32_t kMaxBuffers = 20;
 
 }  // namespace
 
 namespace webkit {
 namespace ppapi {
 
 PPB_VideoCapture_Impl::PPB_VideoCapture_Impl(PP_Instance instance)
     : Resource(instance),
       buffer_count_hint_(0),
       ppp_videocapture_(NULL),
       status_(PP_VIDEO_CAPTURE_STATUS_STOPPED),
-      is_dead_(false) {
+      ALLOW_THIS_IN_INITIALIZER_LIST(weak_ptr_factory_(this)),
+      devices_(0),
+      capability_() {
 }
 
 PPB_VideoCapture_Impl::~PPB_VideoCapture_Impl() {
+  StopCapture();
+  DCHECK(buffers_.empty());
+  ClearCachedDeviceResourceArray();
+  DetachPlatformVideoCapture();
 }
 
 bool PPB_VideoCapture_Impl::Init() {
-  DCHECK(!is_dead_);
   PluginInstance* instance = ResourceHelper::GetPluginInstance(this);
   if (!instance)
     return false;
   ppp_videocapture_ = static_cast<const PPP_VideoCapture_Dev*>(
       instance->module()->GetPluginInterface(PPP_VIDEO_CAPTURE_DEV_INTERFACE));
   if (!ppp_videocapture_)
     return false;
 
-  platform_video_capture_.reset(
-      instance->delegate()->CreateVideoCapture(this));
-  return !!platform_video_capture_.get();
+  return true;
 }
 
 PPB_VideoCapture_API* PPB_VideoCapture_Impl::AsPPB_VideoCapture_API() {
   return this;
 }
 
-void PPB_VideoCapture_Impl::LastPluginRefWasDeleted() {
-  if (platform_video_capture_.get())
-    StopCapture();
-  DCHECK(buffers_.empty());
-  ppp_videocapture_ = NULL;
-  is_dead_ = true;
+int32_t PPB_VideoCapture_Impl::EnumerateDevices(
+    PP_CompletionCallback callback) {
+  if (!callback.func)
+    return PP_ERROR_BLOCKS_MAIN_THREAD;
+  if (TrackedCallback::IsPending(enumerate_devices_callback_))
+    return PP_ERROR_INPROGRESS;
 
-  ::ppapi::Resource::LastPluginRefWasDeleted();
+  PluginInstance* instance = ResourceHelper::GetPluginInstance(this);
+  if (!instance)
+    return PP_ERROR_FAILED;
+
+  enumerate_devices_callback_ = new TrackedCallback(this, callback);
+  instance->delegate()->EnumerateDevices(
+      PP_DEVICETYPE_DEV_VIDEOCAPTURE,
+      base::Bind(&PPB_VideoCapture_Impl::OnEnumerateDevicesComplete,
+                 weak_ptr_factory_.GetWeakPtr()));
+  return PP_OK_COMPLETIONPENDING;
+}
+
+PP_Resource PPB_VideoCapture_Impl::GetDevices() {
+  if (devices_)
+    PpapiGlobals::Get()->GetResourceTracker()->AddRefResource(devices_);
+  return devices_;
 }
 
 int32_t PPB_VideoCapture_Impl::StartCapture(
+    const std::string& device_id,
     const PP_VideoCaptureDeviceInfo_Dev& requested_info,
     uint32_t buffer_count) {
-  DCHECK(!is_dead_);
   switch (status_) {
     case PP_VIDEO_CAPTURE_STATUS_STARTING:
     case PP_VIDEO_CAPTURE_STATUS_STARTED:
     case PP_VIDEO_CAPTURE_STATUS_PAUSED:
+    case PP_VIDEO_CAPTURE_STATUS_STOPPING:
     default:
       return PP_ERROR_FAILED;
     case PP_VIDEO_CAPTURE_STATUS_STOPPED:
-    case PP_VIDEO_CAPTURE_STATUS_STOPPING:
       break;
   }
+
+  PluginInstance* instance = ResourceHelper::GetPluginInstance(this);
+  if (!instance)
+    return PP_ERROR_FAILED;
+
   DCHECK(buffers_.empty());
 
   // Clamp the buffer count to between 1 and |kMaxBuffers|.
   buffer_count_hint_ = std::min(std::max(buffer_count, 1U), kMaxBuffers);
-  media::VideoCapture::VideoCaptureCapability capability = {
-    requested_info.width,
-    requested_info.height,
-    requested_info.frames_per_second,
-    0,  // ignored.
-    media::VideoFrame::I420,
-    false,  // ignored
-  };
+
+  capability_.width = requested_info.width;
+  capability_.height = requested_info.height;
+  capability_.max_fps = requested_info.frames_per_second;
+  capability_.expected_capture_delay = 0;  // Ignored.
+  capability_.raw_type = media::VideoFrame::I420;
+  capability_.interlaced = false;  // Ignored.

[wjia(left Chromium), 2012/01/27 06:13:09]

is it possible Pepper client would call StartCapture more than once (e.g., more
than one devices are used in the same plugin)? If so, |capability_| will be
possibly overwritten when it's used in OnInitialized(). One way is to let
platform_video_capture_ own capability_.

This question also affects the API of StartCapture and StopCapture. Is it needed
to have OpenDevice/CloseDevice pair as well?

[yzshen1, 2012/01/27 18:00:24]

If the status_ is not PP_VIDEO_CAPTURE_STATUS_STOPPED, this method will return
without doing anything.
So I think it is okay to reuse the capability_ member.

One PPB_VideoCapture_Impl only deals with one device at any time. If more than
one device is needed by the same plugin, the plugin can create two
PPB_VideoCapture_Dev resources, there will be two corresponding
PPB_VideoCapture_Impl objects.

On 2012/01/27 06:13:09, wjia wrote:

+
   status_ = PP_VIDEO_CAPTURE_STATUS_STARTING;
-  AddRef();  // Balanced in |OnRemoved()|.
-  platform_video_capture_->StartCapture(this, capability);
+
+  DetachPlatformVideoCapture();

[wjia(left Chromium), 2012/01/27 06:13:09]

same question as above. 

[yzshen1, 2012/01/27 18:00:24]

Please see above.

On 2012/01/27 06:13:09, wjia wrote:

+  platform_video_capture_ =
+      instance->delegate()->CreateVideoCapture(device_id, this);
+  // If |device_id| is not empty, StartCapture() will be performed in the
+  // OnInitialized() handler.
+  if (device_id.empty())
+    platform_video_capture_->StartCapture(this, capability_);
+
   return PP_OK;
 }
 
 int32_t PPB_VideoCapture_Impl::ReuseBuffer(uint32_t buffer) {
-  DCHECK(!is_dead_);
   if (buffer >= buffers_.size() || !buffers_[buffer].in_use)
     return PP_ERROR_BADARGUMENT;
   buffers_[buffer].in_use = false;
   return PP_OK;
 }
 
 int32_t PPB_VideoCapture_Impl::StopCapture() {
-  DCHECK(!is_dead_);
   switch (status_) {
     case PP_VIDEO_CAPTURE_STATUS_STOPPED:
     case PP_VIDEO_CAPTURE_STATUS_STOPPING:
     default:
       return PP_ERROR_FAILED;
     case PP_VIDEO_CAPTURE_STATUS_STARTING:
     case PP_VIDEO_CAPTURE_STATUS_STARTED:
     case PP_VIDEO_CAPTURE_STATUS_PAUSED:
       break;
   }
+  DCHECK(platform_video_capture_.get());
+
   ReleaseBuffers();
   status_ = PP_VIDEO_CAPTURE_STATUS_STOPPING;
   platform_video_capture_->StopCapture(this);
   return PP_OK;
 }
 
+const std::vector<DeviceRefData>&
+    PPB_VideoCapture_Impl::GetDeviceRefData() const {
+  return devices_data_;
+}
+
 void PPB_VideoCapture_Impl::OnStarted(media::VideoCapture* capture) {
-  if (is_dead_)
-    return;
-
   switch (status_) {
     case PP_VIDEO_CAPTURE_STATUS_STARTING:
     case PP_VIDEO_CAPTURE_STATUS_PAUSED:
       break;
     case PP_VIDEO_CAPTURE_STATUS_STOPPED:
     case PP_VIDEO_CAPTURE_STATUS_STOPPING:
     case PP_VIDEO_CAPTURE_STATUS_STARTED:
     default:
       return;
   }
   status_ = PP_VIDEO_CAPTURE_STATUS_STARTED;
   SendStatus();
 }
 
 void PPB_VideoCapture_Impl::OnStopped(media::VideoCapture* capture) {
-  if (is_dead_)
-    return;
-
   switch (status_) {
     case PP_VIDEO_CAPTURE_STATUS_STOPPING:
       break;
     case PP_VIDEO_CAPTURE_STATUS_STARTING:
     case PP_VIDEO_CAPTURE_STATUS_PAUSED:
     case PP_VIDEO_CAPTURE_STATUS_STOPPED:
     case PP_VIDEO_CAPTURE_STATUS_STARTED:
     default:
       return;
   }
+
   status_ = PP_VIDEO_CAPTURE_STATUS_STOPPED;
   SendStatus();
 }
 
 void PPB_VideoCapture_Impl::OnPaused(media::VideoCapture* capture) {
-  if (is_dead_)
-    return;
-
   switch (status_) {
     case PP_VIDEO_CAPTURE_STATUS_STARTING:
     case PP_VIDEO_CAPTURE_STATUS_STARTED:
       break;
     case PP_VIDEO_CAPTURE_STATUS_STOPPED:
     case PP_VIDEO_CAPTURE_STATUS_STOPPING:
     case PP_VIDEO_CAPTURE_STATUS_PAUSED:
     default:
       return;
   }
   status_ = PP_VIDEO_CAPTURE_STATUS_PAUSED;
   SendStatus();
 }
 
 void PPB_VideoCapture_Impl::OnError(media::VideoCapture* capture,
                                     int error_code) {
-  if (is_dead_)
-    return;
-
   // 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.
   status_ = PP_VIDEO_CAPTURE_STATUS_STOPPED;
   ppp_videocapture_->OnError(pp_instance(), pp_resource(), PP_ERROR_FAILED);
 }
 
 void PPB_VideoCapture_Impl::OnRemoved(media::VideoCapture* capture) {
-  Release();
 }
 
 void PPB_VideoCapture_Impl::OnBufferReady(
     media::VideoCapture* capture,
     scoped_refptr<media::VideoCapture::VideoFrameBuffer> buffer) {
-  if (!is_dead_) {
-    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);
-        ppp_videocapture_->OnBufferReady(pp_instance(), pp_resource(), i);
-        return;
-      }
+  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);
+      ppp_videocapture_->OnBufferReady(pp_instance(), pp_resource(), i);
+      return;
     }
   }
-  // Even after we have stopped and are dead we have to return buffers that
-  // are in flight to us. Otherwise VideoCaptureController will not tear down.
-  platform_video_capture_->FeedBuffer(buffer);
 }
 
 void PPB_VideoCapture_Impl::OnDeviceInfoReceived(
     media::VideoCapture* capture,
     const media::VideoCaptureParams& device_info) {
-  // No need to call |ReleaseBuffers()|: if we're dead, |StopCapture()| should
-  // already have been called.
-  if (is_dead_)
-    return;
-
   PP_VideoCaptureDeviceInfo_Dev info = {
     device_info.width,
     device_info.height,
     device_info.frame_per_second
   };
   ReleaseBuffers();
 
   // Allocate buffers. We keep a reference to them, that is released in
   // ReleaseBuffers.
   // YUV 4:2:0
@@ skipping 27 matching lines @@
     ppp_videocapture_->OnError(pp_instance(), pp_resource(), PP_ERROR_NOMEMORY);
     status_ = PP_VIDEO_CAPTURE_STATUS_STOPPING;
     platform_video_capture_->StopCapture(this);
     return;
   }
 
   ppp_videocapture_->OnDeviceInfo(pp_instance(), pp_resource(), &info,
                                   buffers_.size(), resources.get());
 }
 
+void PPB_VideoCapture_Impl::OnInitialized(media::VideoCapture* capture,
+                                          bool succeeded) {
+  DCHECK(capture == platform_video_capture_.get());
+
+  if (status_ != PP_VIDEO_CAPTURE_STATUS_STARTING)
+    return;
+
+  if (succeeded) {
+    platform_video_capture_->StartCapture(this, capability_);
+  } else {
+    status_ = PP_VIDEO_CAPTURE_STATUS_STOPPED;
+    SendStatus();
+  }
+}
+
 void PPB_VideoCapture_Impl::ReleaseBuffers() {
-  DCHECK(!is_dead_);
   ::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 PPB_VideoCapture_Impl::SendStatus() {
-  DCHECK(!is_dead_);
   ppp_videocapture_->OnStatus(pp_instance(), pp_resource(), status_);
 }
 
+void PPB_VideoCapture_Impl::ClearCachedDeviceResourceArray() {
+  if (devices_)
+    PpapiGlobals::Get()->GetResourceTracker()->ReleaseResource(devices_);
+  devices_ = 0;
+
+  devices_data_.clear();
+}
+
+void PPB_VideoCapture_Impl::DetachPlatformVideoCapture() {
+  if (platform_video_capture_.get()) {
+    platform_video_capture_->DetachEventHandler();
+    platform_video_capture_ = NULL;
+  }
+}
+
+void PPB_VideoCapture_Impl::OnEnumerateDevicesComplete(
+    int request_id,
+    bool succeeded,
+    const std::vector<::ppapi::DeviceRefData>& devices) {
+  ClearCachedDeviceResourceArray();
+  if (succeeded) {
+    devices_data_ = devices;
+    devices_ = ::ppapi::PPB_DeviceRef_Shared::CreateResourceArray(
+        true, pp_instance(), devices_data_);
+  }
+
+  if (!TrackedCallback::IsPending(enumerate_devices_callback_)) {
+    NOTREACHED();
+    return;
+  }
+  TrackedCallback::ClearAndRun(&enumerate_devices_callback_,
+                               succeeded ? PP_OK : PP_ERROR_FAILED);
+}
+
 PPB_VideoCapture_Impl::BufferInfo::BufferInfo()
     : in_use(false),
       data(NULL),
       buffer() {
 }
 
 PPB_VideoCapture_Impl::BufferInfo::~BufferInfo() {
 }
 
 }  // namespace ppapi
 }  // namespace webkit