src/media/video/capture/win/video_capture_device_win.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // Windows specific implementation of VideoCaptureDevice.
   6 // DirectShow is used for capturing. DirectShow provide its own threads
   7 // for capturing.
   8
   9 #ifndef MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_
  10 #define MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_
  11
  12 // Avoid including strsafe.h via dshow as it will cause build warnings.
  13 #define NO_DSHOW_STRSAFE
  14 #include <dshow.h>
  15
  16 #include <map>
  17 #include <string>
  18
  19 #include "base/threading/non_thread_safe.h"
  20 #include "base/threading/thread.h"
  21 #include "base/win/scoped_comptr.h"
  22 #include "media/video/capture/video_capture_device.h"
  23 #include "media/video/capture/video_capture_types.h"
  24 #include "media/video/capture/win/capability_list_win.h"
  25 #include "media/video/capture/win/sink_filter_win.h"
  26 #include "media/video/capture/win/sink_input_pin_win.h"
  27
  28 namespace media {
  29
  30 // All the methods in the class can only be run on a COM initialized thread.
  31 class VideoCaptureDeviceWin
  32     : public base::NonThreadSafe,
  33       public VideoCaptureDevice,
  34       public SinkFilterObserver {
  35  public:
  36   explicit VideoCaptureDeviceWin(const Name& device_name);
  37   virtual ~VideoCaptureDeviceWin();
  38   // Opens the device driver for this device.
  39   // This function is used by the static VideoCaptureDevice::Create function.
  40   bool Init();
  41
  42   // VideoCaptureDevice implementation.
  43   virtual void AllocateAndStart(
  44       const VideoCaptureCapability& capture_format,
  45       scoped_ptr<VideoCaptureDevice::Client> client) OVERRIDE;
  46   virtual void StopAndDeAllocate() OVERRIDE;
  47
  48   static void GetDeviceNames(Names* device_names);
  49
  50  private:
  51   enum InternalState {
  52     kIdle,  // The device driver is opened but camera is not in use.
  53     kCapturing,  // Video is being captured.
  54     kError  // Error accessing HW functions.
  55             // User needs to recover by destroying the object.
  56   };
  57
  58   // Implements SinkFilterObserver.
  59   virtual void FrameReceived(const uint8* buffer, int length);
  60
  61   bool CreateCapabilityMap();
  62   void SetErrorState(const char* reason);
  63
  64   Name device_name_;
  65   InternalState state_;
  66   scoped_ptr<VideoCaptureDevice::Client> client_;
  67
  68   base::win::ScopedComPtr<IBaseFilter> capture_filter_;
  69   base::win::ScopedComPtr<IGraphBuilder> graph_builder_;
  70   base::win::ScopedComPtr<IMediaControl> media_control_;
  71   base::win::ScopedComPtr<IPin> input_sink_pin_;
  72   base::win::ScopedComPtr<IPin> output_capture_pin_;
  73   // Used when using a MJPEG decoder.
  74   base::win::ScopedComPtr<IBaseFilter> mjpg_filter_;
  75   base::win::ScopedComPtr<IPin> input_mjpg_pin_;
  76   base::win::ScopedComPtr<IPin> output_mjpg_pin_;
  77
  78   scoped_refptr<SinkFilter> sink_filter_;
  79
  80   // Map of all capabilities this device support.
  81   CapabilityList capabilities_;
  82
  83   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin);
  84 };
  85
  86 }  // namespace media
  87
  88 #endif  // MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_