media/capture/video/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. DirectShow is used for
   6 // capturing. DirectShow provide its own threads for capturing.
   7
   8 #ifndef MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_
   9 #define MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_
  10
  11 // Avoid including strsafe.h via dshow as it will cause build warnings.
  12 #define NO_DSHOW_STRSAFE
  13 #include <dshow.h>
  14
  15 #include <map>
  16 #include <string>
  17
  18 #include "base/threading/thread_checker.h"
  19 #include "base/win/scoped_comptr.h"
  20 #include "media/base/video_capture_types.h"
  21 #include "media/capture/video/video_capture_device.h"
  22 #include "media/capture/video/win/capability_list_win.h"
  23 #include "media/capture/video/win/sink_filter_win.h"
  24 #include "media/capture/video/win/sink_input_pin_win.h"
  25
  26 namespace media {
  27
  28 // All the methods in the class can only be run on a COM initialized thread.
  29 class VideoCaptureDeviceWin : public VideoCaptureDevice,
  30                               public SinkFilterObserver {
  31  public:
  32   // A utility class that wraps the AM_MEDIA_TYPE type and guarantees that
  33   // we free the structure when exiting the scope.  DCHECKing is also done to
  34   // avoid memory leaks.
  35   class ScopedMediaType {
  36    public:
  37     ScopedMediaType() : media_type_(NULL) {}
  38     ~ScopedMediaType() { Free(); }
  39
  40     AM_MEDIA_TYPE* operator->() { return media_type_; }
  41     AM_MEDIA_TYPE* get() { return media_type_; }
  42     void Free();
  43     AM_MEDIA_TYPE** Receive();
  44
  45    private:
  46     void FreeMediaType(AM_MEDIA_TYPE* mt);
  47     void DeleteMediaType(AM_MEDIA_TYPE* mt);
  48
  49     AM_MEDIA_TYPE* media_type_;
  50   };
  51
  52   static HRESULT GetDeviceFilter(const std::string& device_id,
  53                                  IBaseFilter** filter);
  54   static base::win::ScopedComPtr<IPin> GetPin(IBaseFilter* filter,
  55                                               PIN_DIRECTION pin_dir,
  56                                               REFGUID category,
  57                                               REFGUID major_type);
  58   static VideoPixelFormat TranslateMediaSubtypeToPixelFormat(
  59       const GUID& sub_type);
  60
  61   explicit VideoCaptureDeviceWin(const Name& device_name);
  62   ~VideoCaptureDeviceWin() override;
  63   // Opens the device driver for this device.
  64   bool Init();
  65
  66   // VideoCaptureDevice implementation.
  67   void AllocateAndStart(const VideoCaptureParams& params,
  68                         scoped_ptr<VideoCaptureDevice::Client> client) override;
  69   void StopAndDeAllocate() override;
  70
  71  private:
  72   enum InternalState {
  73     kIdle,       // The device driver is opened but camera is not in use.
  74     kCapturing,  // Video is being captured.
  75     kError       // Error accessing HW functions.
  76                  // User needs to recover by destroying the object.
  77   };
  78
  79   // Implements SinkFilterObserver.
  80   void FrameReceived(const uint8* buffer, int length,
  81                      base::TimeTicks timestamp) override;
  82
  83   bool CreateCapabilityMap();
  84   void SetAntiFlickerInCaptureFilter(const VideoCaptureParams& params);
  85   void SetErrorState(const std::string& reason);
  86
  87   const Name device_name_;
  88   InternalState state_;
  89   scoped_ptr<VideoCaptureDevice::Client> client_;
  90
  91   base::win::ScopedComPtr<IBaseFilter> capture_filter_;
  92
  93   base::win::ScopedComPtr<IGraphBuilder> graph_builder_;
  94   base::win::ScopedComPtr<ICaptureGraphBuilder2> capture_graph_builder_;
  95
  96   base::win::ScopedComPtr<IMediaControl> media_control_;
  97   base::win::ScopedComPtr<IPin> input_sink_pin_;
  98   base::win::ScopedComPtr<IPin> output_capture_pin_;
  99
 100   scoped_refptr<SinkFilter> sink_filter_;
 101
 102   // Map of all capabilities this device support.
 103   CapabilityList capabilities_;
 104   VideoCaptureFormat capture_format_;
 105
 106   base::ThreadChecker thread_checker_;
 107
 108   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin);
 109 };
 110
 111 }  // namespace media
 112
 113 #endif  // MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_