media/video/capture/mac/video_capture_device_mac.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 // MacOSX implementation of generic VideoCaptureDevice, using either QTKit or
   6 // AVFoundation as native capture API. QTKit is available in all OSX versions,
   7 // although namely deprecated in 10.9, and AVFoundation is available in versions
   8 // 10.7 (Lion) and later.
   9
  10 #ifndef MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_MAC_H_
  11 #define MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_MAC_H_
  12
  13 #include <string>
  14
  15 #include "base/compiler_specific.h"
  16 #include "base/memory/ref_counted.h"
  17 #include "base/memory/weak_ptr.h"
  18 #include "media/video/capture/video_capture_device.h"
  19 #include "media/video/capture/video_capture_types.h"
  20
  21 @protocol PlatformVideoCapturingMac;
  22
  23 namespace base {
  24 class SingleThreadTaskRunner;
  25 }
  26
  27 namespace media {
  28
  29 // Called by VideoCaptureManager to open, close and start, stop Mac video
  30 // capture devices.
  31 class VideoCaptureDeviceMac : public VideoCaptureDevice {
  32  public:
  33   explicit VideoCaptureDeviceMac(const Name& device_name);
  34   virtual ~VideoCaptureDeviceMac();
  35
  36   // VideoCaptureDevice implementation.
  37   virtual void AllocateAndStart(
  38       const VideoCaptureParams& params,
  39       scoped_ptr<VideoCaptureDevice::Client> client) OVERRIDE;
  40   virtual void StopAndDeAllocate() OVERRIDE;
  41
  42   bool Init(VideoCaptureDevice::Name::CaptureApiType capture_api_type);
  43
  44   // Called to deliver captured video frames.
  45   void ReceiveFrame(const uint8* video_frame,
  46                     int video_frame_length,
  47                     const VideoCaptureFormat& frame_format,
  48                     int aspect_numerator,
  49                     int aspect_denominator);
  50
  51   void ReceiveError(const std::string& reason);
  52
  53  private:
  54   void SetErrorState(const std::string& reason);
  55   void LogMessage(const std::string& message);
  56   bool UpdateCaptureResolution();
  57
  58   // Flag indicating the internal state.
  59   enum InternalState {
  60     kNotInitialized,
  61     kIdle,
  62     kCapturing,
  63     kError
  64   };
  65
  66   Name device_name_;
  67   scoped_ptr<VideoCaptureDevice::Client> client_;
  68
  69   VideoCaptureFormat capture_format_;
  70   // These variables control the two-step configure-start process for QTKit HD:
  71   // the device is first started with no configuration and the captured frames
  72   // are inspected to check if the camera really supports HD. AVFoundation does
  73   // not need this process so |final_resolution_selected_| is false then.
  74   bool final_resolution_selected_;
  75   bool tried_to_square_pixels_;
  76
  77   // Only read and write state_ from inside this loop.
  78   const scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
  79   InternalState state_;
  80
  81   id<PlatformVideoCapturingMac> capture_device_;
  82
  83   // Used with Bind and PostTask to ensure that methods aren't called after the
  84   // VideoCaptureDeviceMac is destroyed.
  85   // NOTE: Weak pointers must be invalidated before all other member variables.
  86   base::WeakPtrFactory<VideoCaptureDeviceMac> weak_factory_;
  87
  88   DISALLOW_COPY_AND_ASSIGN(VideoCaptureDeviceMac);
  89 };
  90
  91 }  // namespace media
  92
  93 #endif  // MEDIA_VIDEO_CAPTURE_MAC_VIDEO_CAPTURE_DEVICE_MAC_H_