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 Allocate(const VideoCaptureCapability& capture_format, 44 VideoCaptureDevice::EventHandler* observer) OVERRIDE; 45 virtual void Start() OVERRIDE; 46 virtual void Stop() OVERRIDE; 47 virtual void DeAllocate() OVERRIDE; 48 virtual const Name& device_name() OVERRIDE; 49 50 static void GetDeviceNames(Names* device_names); 51 52 private: 53 enum InternalState { 54 kIdle, // The device driver is opened but camera is not in use. 55 kAllocated, // The camera has been allocated and can be started. 56 kCapturing, // Video is being captured. 57 kError // Error accessing HW functions. 58 // User needs to recover by destroying the object. 59 }; 60 61 // Implements SinkFilterObserver. 62 virtual void FrameReceived(const uint8* buffer, int length); 63 64 bool CreateCapabilityMap(); 65 void SetErrorState(const char* reason); 66 67 Name device_name_; 68 InternalState state_; 69 VideoCaptureDevice::EventHandler* observer_; 70 71 base::win::ScopedComPtr<IBaseFilter> capture_filter_; 72 base::win::ScopedComPtr<IGraphBuilder> graph_builder_; 73 base::win::ScopedComPtr<IMediaControl> media_control_; 74 base::win::ScopedComPtr<IPin> input_sink_pin_; 75 base::win::ScopedComPtr<IPin> output_capture_pin_; 76 // Used when using a MJPEG decoder. 77 base::win::ScopedComPtr<IBaseFilter> mjpg_filter_; 78 base::win::ScopedComPtr<IPin> input_mjpg_pin_; 79 base::win::ScopedComPtr<IPin> output_mjpg_pin_; 80 81 scoped_refptr<SinkFilter> sink_filter_; 82 83 // Map of all capabilities this device support. 84 CapabilityList capabilities_; 85 86 DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin); 87 }; 88 89 } // namespace media 90 91 #endif // MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_ 92
