Video Capture Pepper API

webkit/plugins/ppapi/ppb_video_capture_impl.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 "webkit/plugins/ppapi/ppb_video_capture_impl.h"
+
+#include <algorithm>
+#include <string>
+
+#include "base/logging.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/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_tracker.h"
+
+using ppapi::thunk::EnterResourceNoLock;
+using ppapi::thunk::PPB_Buffer_API;
+using ppapi::thunk::PPB_VideoCapture_API;
+
+namespace webkit {
+namespace ppapi {
+
+PPB_VideoCapture_Impl::PPB_VideoCapture_Impl(PluginInstance* instance)
+    : Resource(instance),
+      buffer_count_hint_(0),
+      ppp_videocapture_(NULL),
+      status_(PP_VIDEO_CAPTURE_STATUS_STOPPED) {
+}
+
+PPB_VideoCapture_Impl::~PPB_VideoCapture_Impl() {
+  if (platform_video_capture_.get())
+    StopCapture();
+}
+
+bool PPB_VideoCapture_Impl::Init() {
+  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();
+}
+
+PPB_VideoCapture_API* PPB_VideoCapture_Impl::AsPPB_VideoCapture_API() {
+  return this;
+}
+
+int32_t PPB_VideoCapture_Impl::StartCapture(
+    const PP_VideoCaptureDeviceInfo_Dev& requested_info,
+    uint32_t buffer_count) {
+  switch (status_) {
+    case PP_VIDEO_CAPTURE_STATUS_STARTING:
+    case PP_VIDEO_CAPTURE_STATUS_STARTED:
+    case PP_VIDEO_CAPTURE_STATUS_PAUSED:
+    default:
+      return PP_ERROR_FAILED;
+    case PP_VIDEO_CAPTURE_STATUS_STOPPED:
+    case PP_VIDEO_CAPTURE_STATUS_STOPPING:
+      break;
+  }
+  DCHECK(buffers_.empty());
+
+  buffer_count_hint_ = std::min(buffer_count, 1U);
+  media::VideoCapture::VideoCaptureCapability capability = {
+    requested_info.width,
+    requested_info.height,
+    requested_info.frames_per_second,
+    0,  // ignored.
+    media::VideoFrame::I420,
+    false,  // ignored
+    false  // resolution_fixed
+  };
+  status_ = PP_VIDEO_CAPTURE_STATUS_STARTING;
+  platform_video_capture_->StartCapture(this, capability);
+  return PP_OK;
+}
+
+int32_t PPB_VideoCapture_Impl::ReuseBuffer(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 PPB_VideoCapture_Impl::StopCapture() {
+  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;
+  }
+  ReleaseBuffers();
+  status_ = PP_VIDEO_CAPTURE_STATUS_STOPPING;
+  platform_video_capture_->StopCapture(this);
+  return PP_OK;
+}
+
+void PPB_VideoCapture_Impl::OnStarted(media::VideoCapture* capture) {
+  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) {
+  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) {
+  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) {
+  // 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(instance()->pp_instance(),
+                             ScopedResourceId(this).id,
+                             PP_ERROR_FAILED);
+}
+
+void PPB_VideoCapture_Impl::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(piman): it looks like stride isn't actually used/filled.
+      DCHECK(buffer->stride == 0);
+      size_t size = std::min(static_cast<size_t>(buffers_[i].buffer->size()),
+          buffer->buffer_size);
+      memcpy(buffers_[i].data, buffer->memory_pointer, size);
+      platform_video_capture_->FeedBuffer(buffer);
+      ppp_videocapture_->OnBufferReady(instance()->pp_instance(),
+          ScopedResourceId(this).id,
+          i);
+      return;
+    }
+  }
+  // TODO(piman): signal dropped buffers ?
+  platform_video_capture_->FeedBuffer(buffer);
+}
+
+void PPB_VideoCapture_Impl::OnDeviceInfoReceived(
+    media::VideoCapture* capture,
+    const media::VideoCaptureParams& device_info) {
+  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
+  int uv_width = info.width / 2;
+  int uv_height = info.height / 2;
+  size_t size = info.width * info.height + 2 * uv_width * uv_height;
+  scoped_array<PP_Resource> resources(new PP_Resource[buffer_count_hint_]);
+
+  buffers_.reserve(buffer_count_hint_);
+  for (size_t i = 0; i < buffer_count_hint_; ++i) {
+    resources[i] = PPB_Buffer_Impl::Create(instance(), size);
+    if (!resources[i])
+      break;
+
+    EnterResourceNoLock<PPB_Buffer_API> enter(resources[i], true);
+    DCHECK(enter.succeeded());
+
+    BufferInfo info;
+    info.buffer = static_cast<PPB_Buffer_Impl*>(enter.object());
+    info.data = info.buffer->Map();
+    if (!info.data) {
+      ResourceTracker::Get()->UnrefResource(resources[i]);
+      break;
+    }
+    buffers_.push_back(info);
+  }
+
+  if (buffers_.empty()) {
+    // We couldn't allocate/map buffers at all. Send an error and stop the
+    // capture.
+    ppp_videocapture_->OnError(instance()->pp_instance(),
+                               ScopedResourceId(this).id,
+                               PP_ERROR_NOMEMORY);
+    status_ = PP_VIDEO_CAPTURE_STATUS_STOPPING;
+    platform_video_capture_->StopCapture(this);
+    return;
+  }
+
+  ppp_videocapture_->OnDeviceInfo(instance()->pp_instance(),
+                                  ScopedResourceId(this).id,
+                                  &info,
+                                  buffers_.size(),
+                                  resources.get());
+}
+
+void PPB_VideoCapture_Impl::ReleaseBuffers() {
+  ResourceTracker *tracker = ResourceTracker::Get();
+  for (size_t i = 0; i < buffers_.size(); ++i) {
+    buffers_[i].buffer->Unmap();
+    tracker->UnrefResource(buffers_[i].buffer->GetReferenceNoAddRef());
+  }
+  buffers_.clear();
+}
+
+void PPB_VideoCapture_Impl::SendStatus() {
+  ppp_videocapture_->OnStatus(instance()->pp_instance(),
+                              ScopedResourceId(this).id,
+                              status_);
+}
+
+PPB_VideoCapture_Impl::BufferInfo::BufferInfo()
+    : in_use(false),
+      data(NULL),
+      buffer() {
+}
+
+PPB_VideoCapture_Impl::BufferInfo::~BufferInfo() {
+}
+
+}  // namespace ppapi
+}  // namespace webkit