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   // A utility class that wraps the AM_MEDIA_TYPE type and guarantees that
  37   // we free the structure when exiting the scope.  DCHECKing is also done to
  38   // avoid memory leaks.
  39   class ScopedMediaType {
  40    public:
  41     ScopedMediaType() : media_type_(NULL) {}
  42     ~ScopedMediaType() { Free(); }
  43
  44     AM_MEDIA_TYPE* operator->() { return media_type_; }
  45     AM_MEDIA_TYPE* get() { return media_type_; }
  46     void Free();
  47     AM_MEDIA_TYPE** Receive();
  48
  49    private:
  50     void FreeMediaType(AM_MEDIA_TYPE* mt);
  51     void DeleteMediaType(AM_MEDIA_TYPE* mt);
  52
  53     AM_MEDIA_TYPE* media_type_;
  54   };
  55
  56   static HRESULT GetDeviceFilter(const std::string& device_id,
  57                                  const CLSID device_class_id,
  58                                  IBaseFilter** filter);
  59   static base::win::ScopedComPtr<IPin> GetPin(IBaseFilter* filter,
  60                                               PIN_DIRECTION pin_dir,
  61                                               REFGUID category,
  62                                               REFGUID major_type);
  63   static VideoPixelFormat TranslateMediaSubtypeToPixelFormat(
  64       const GUID& sub_type);
  65
  66   explicit VideoCaptureDeviceWin(const Name& device_name);
  67   virtual ~VideoCaptureDeviceWin();
  68   // Opens the device driver for this device.
  69   bool Init();
  70
  71   // VideoCaptureDevice implementation.
  72   virtual void AllocateAndStart(
  73       const VideoCaptureParams& params,
  74       scoped_ptr<VideoCaptureDevice::Client> client) OVERRIDE;
  75   virtual void StopAndDeAllocate() OVERRIDE;
  76
  77  private:
  78   enum InternalState {
  79     kIdle,  // The device driver is opened but camera is not in use.
  80     kCapturing,  // Video is being captured.
  81     kError  // Error accessing HW functions.
  82             // User needs to recover by destroying the object.
  83   };
  84
  85   // Implements SinkFilterObserver.
  86   virtual void FrameReceived(const uint8* buffer, int length);
  87
  88   bool CreateCapabilityMap();
  89   void SetAntiFlickerInCaptureFilter();
  90   HRESULT InstantiateWDMFiltersAndPins();
  91   HRESULT AddWDMCrossbarFilterToGraphAndConnect();
  92   void SetErrorState(const std::string& reason);
  93
  94   Name device_name_;
  95   InternalState state_;
  96   scoped_ptr<VideoCaptureDevice::Client> client_;
  97
  98   base::win::ScopedComPtr<IBaseFilter> capture_filter_;
  99   base::win::ScopedComPtr<IGraphBuilder> graph_builder_;
 100   base::win::ScopedComPtr<IMediaControl> media_control_;
 101   base::win::ScopedComPtr<IPin> input_sink_pin_;
 102   base::win::ScopedComPtr<IPin> output_capture_pin_;
 103   // Used when using a MJPEG decoder.
 104   base::win::ScopedComPtr<IBaseFilter> mjpg_filter_;
 105   base::win::ScopedComPtr<IPin> input_mjpg_pin_;
 106   base::win::ScopedComPtr<IPin> output_mjpg_pin_;
 107   // Used for WDM devices as specified by |device_name_|. These devices need a
 108   // WDM Crossbar Filter upstream from the Capture filter.
 109   base::win::ScopedComPtr<IBaseFilter> crossbar_filter_;
 110   base::win::ScopedComPtr<IPin> crossbar_video_output_pin_;
 111   base::win::ScopedComPtr<IPin> analog_video_input_pin_;
 112
 113   scoped_refptr<SinkFilter> sink_filter_;
 114
 115   // Map of all capabilities this device support.
 116   CapabilityList capabilities_;
 117   VideoCaptureFormat capture_format_;
 118
 119   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin);
 120 };
 121
 122 }  // namespace media
 123
 124 #endif  // MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_