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: ScopedMediaType()41 ScopedMediaType() : media_type_(NULL) {} ~ScopedMediaType()42 ~ScopedMediaType() { Free(); } 43 44 AM_MEDIA_TYPE* operator->() { return media_type_; } get()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 Name& device_name, 57 IBaseFilter** filter); 58 static bool PinMatchesCategory(IPin* pin, REFGUID category); 59 static base::win::ScopedComPtr<IPin> GetPin(IBaseFilter* filter, 60 PIN_DIRECTION pin_dir, 61 REFGUID category); 62 static VideoPixelFormat TranslateMediaSubtypeToPixelFormat( 63 const GUID& sub_type); 64 65 explicit VideoCaptureDeviceWin(const Name& device_name); 66 virtual ~VideoCaptureDeviceWin(); 67 // Opens the device driver for this device. 68 bool Init(); 69 70 // VideoCaptureDevice implementation. 71 virtual void AllocateAndStart( 72 const VideoCaptureParams& params, 73 scoped_ptr<VideoCaptureDevice::Client> client) OVERRIDE; 74 virtual void StopAndDeAllocate() OVERRIDE; 75 76 private: 77 enum InternalState { 78 kIdle, // The device driver is opened but camera is not in use. 79 kCapturing, // Video is being captured. 80 kError // Error accessing HW functions. 81 // User needs to recover by destroying the object. 82 }; 83 84 // Implements SinkFilterObserver. 85 virtual void FrameReceived(const uint8* buffer, int length); 86 87 bool CreateCapabilityMap(); 88 void SetAntiFlickerInCaptureFilter(); 89 void SetErrorState(const std::string& reason); 90 91 Name device_name_; 92 InternalState state_; 93 scoped_ptr<VideoCaptureDevice::Client> client_; 94 95 base::win::ScopedComPtr<IBaseFilter> capture_filter_; 96 base::win::ScopedComPtr<IGraphBuilder> graph_builder_; 97 base::win::ScopedComPtr<IMediaControl> media_control_; 98 base::win::ScopedComPtr<IPin> input_sink_pin_; 99 base::win::ScopedComPtr<IPin> output_capture_pin_; 100 // Used when using a MJPEG decoder. 101 base::win::ScopedComPtr<IBaseFilter> mjpg_filter_; 102 base::win::ScopedComPtr<IPin> input_mjpg_pin_; 103 base::win::ScopedComPtr<IPin> output_mjpg_pin_; 104 105 scoped_refptr<SinkFilter> sink_filter_; 106 107 // Map of all capabilities this device support. 108 CapabilityList capabilities_; 109 VideoCaptureFormat capture_format_; 110 111 DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceWin); 112 }; 113 114 } // namespace media 115 116 #endif // MEDIA_VIDEO_CAPTURE_WIN_VIDEO_CAPTURE_DEVICE_WIN_H_ 117