media/video/capture/win/video_capture_device_win.h

   1 // Copyright (c) 2011 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 #pragma once
  12
  13 // Avoid including strsafe.h via dshow as it will cause build warnings.
  14 #define NO_DSHOW_STRSAFE
  15 #include <dshow.h>
  16
  17 #include <map>
  18 #include <string>
  19
  20 #include "base/threading/thread.h"
  21 #include "base/win/scoped_com_initializer.h"
  22 #include "base/win/scoped_comptr.h"
  23 #include "media/video/capture/video_capture_device.h"
  24 #include "media/video/capture/win/sink_filter_win.h"
  25 #include "media/video/capture/win/sink_input_pin_win.h"
  26
  27 namespace media {
  28
  29 class VideoCaptureDeviceWin
  30     : public VideoCaptureDevice,
  31       public SinkFilterObserver {
  32  public:
  33   explicit VideoCaptureDeviceWin(const Name& device_name);
  34   virtual ~VideoCaptureDeviceWin();
  35   // Opens the device driver for this device.
  36   // This function is used by the static VideoCaptureDevice::Create function.
  37   bool Init();
  38
  39   // VideoCaptureDevice implementation.
  40   virtual void Allocate(int width,
  41                         int height,
  42                         int frame_rate,
  43                         VideoCaptureDevice::EventHandler* observer) OVERRIDE;
  44   virtual void Start() OVERRIDE;
  45   virtual void Stop() OVERRIDE;
  46   virtual void DeAllocate() OVERRIDE;
  47   virtual const Name& device_name() OVERRIDE;
  48
  49  private:
  50   enum InternalState {
  51     kIdle,  // The device driver is opened but camera is not in use.
  52     kAllocated,  // The camera has been allocated and can be started.
  53     kCapturing,  // Video is being captured.
  54     kError  // Error accessing HW functions.
  55             // User needs to recover by destroying the object.
  56   };
  57   typedef std::map<int, Capability> CapabilityMap;
  58
  59   // Implements SinkFilterObserver.
  60   virtual void FrameReceived(const uint8* buffer, int length);
  61
  62   bool CreateCapabilityMap();
  63   int GetBestMatchedCapability(int width, int height, int frame_rate);
  64   void SetErrorState(const char* reason);
  65
  66   base::win::ScopedCOMInitializer initialize_com_;
  67
  68   Name device_name_;
  69   InternalState state_;
  70   VideoCaptureDevice::EventHandler* observer_;
  71
  72   base::win::ScopedComPtr<IBaseFilter> capture_filter_;
  73   base::win::ScopedComPtr<IGraphBuilder> graph_builder_;
  74   base::win::ScopedComPtr<IMediaControl> media_control_;
  75   base::win::ScopedComPtr<IPin> input_sink_pin_;
  76   base::win::ScopedComPtr<IPin> output_capture_pin_;
  77   // Used when using a MJPEG decoder.
  78   base::win::ScopedComPtr<IBaseFilter> mjpg_filter_;
  79   base::win::ScopedComPtr<IPin> input_mjpg_pin_;
  80   base::win::ScopedComPtr<IPin> output_mjpg_pin_;
  81
  82   scoped_refptr<SinkFilter> sink_filter_;
  83
  84   // Map of all capabilities this device support.
  85   CapabilityMap capabilities_;
  86
  87   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin);
  88 };
  89
  90 }  // namespace media
  91
  92 #endif  // MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_