VideoCaptureHost

content/browser/renderer_host/video_capture_memory.h

+// 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.
+
+// VideoCaptureMemory is responsible for keeping track of TransportDIBs and
+// filling them with I420 video frames for IPC communication between
+// VideoCaptureHost and VideoCaptureMessageFilter.
+// It implements media::VideoCaptureDevice::EventHandler to get video frames
+// from a VideoCaptureDevice object and do color conversion straight into the
+// TransportDIBs to avoid a memory copy.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_VIDEO_CAPTURE_MEMORY_H_
+#define CONTENT_BROWSER_RENDERER_HOST_VIDEO_CAPTURE_MEMORY_H_
+
+#include <list>
+#include <map>
+
+#include "base/synchronization/lock.h"
+#include "media/video/capture/video_capture_device.h"
+#include "media/video/capture/video_capture_types.h"
+#include "ui/gfx/surface/transport_dib.h"
+
+class VideoCaptureMemory: public media::VideoCaptureDevice::EventHandler {
+ public:
+  struct VCEntryId {
+    VCEntryId(int32 render_id,
+              int device_id,
+              media::VideoCaptureSessionId session_id)
+        : render_id(render_id),
+          device_id(device_id),
+          session_id(session_id) {
+    }
+    // Render view id that requested the VideoCaptureDevice.
+    int32 render_id;
+    // Id created by VideoCaptureImpl to identify a session
+    // between a VideoCaptureImpl and a VideoCaptureHost.
+    int device_id;
+    // The media stream session id of a specific VideoCaptureDevice.
+    media::VideoCaptureSessionId session_id;
+  };
+
+  class EventHandler {
+   public:
+    virtual void OnError(VideoCaptureMemory::VCEntryId entry) = 0;
+    virtual void OnBufferReady(VideoCaptureMemory::VCEntryId entry,
+                               TransportDIB::Handle handle,
+                               base::Time timestamp) = 0;
+    virtual void OnFrameInfo(VideoCaptureMemory::VCEntryId entry,
+                             int width,
+                             int height,
+                             int frame_rate) = 0;
+   protected:
+    virtual ~EventHandler() {}
+  };
+
+  VideoCaptureMemory(VideoCaptureMemory::EventHandler* event_handler,
+                     VCEntryId entry_id);
+  ~VideoCaptureMemory();
+
+  VCEntryId entry_id();
+  bool AddTransportDIB(TransportDIB::Handle handle);
+  bool ReadyToDelete();
+
+  // Implement media::VideoCaptureDevice::EventHandler
+  virtual void OnIncomingCapturedFrame(const uint8* data,
+                                       int length,
+                                       base::Time timestamp);
+  virtual void OnError();
+  virtual void OnFrameInfo(const media::VideoCaptureDevice::Capability& info);
+
+ private:
+  typedef std::list<TransportDIB::Handle> DIBHANDLEList;
+  typedef std::map<TransportDIB::Handle, TransportDIB*> DIBMap;
+
+  // Lock to protect free_dibs_.
+  base::Lock lock_;
+
+  // Free DIBS that can be filled with video frames.
+  DIBHANDLEList free_dibs_;
+  // All DIBS created by this object.
+  DIBMap owned_dibs_;
+  EventHandler& event_handler_;
+  VCEntryId entry_id_;
+  media::VideoCaptureDevice::Capability frame_info_;
+};
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_VIDEO_CAPTURE_MEMORY_H_