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 28namespace media { 29 30// All the methods in the class can only be run on a COM initialized thread. 31class 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_ 125