media: add video capture device for ARC++ camera HAL v3

media/capture/video/chromeos/video_capture_device_arc_chromeos.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_CAPTURE_VIDEO_CHROMEOS_VIDEO_CAPTURE_DEVICE_CHROMEOS_H_
+#define MEDIA_CAPTURE_VIDEO_CHROMEOS_VIDEO_CAPTURE_DEVICE_CHROMEOS_H_
+
+#include <stdint.h>
+
+#include <memory>
+#include <string>
+
+#include "base/macros.h"
+#include "base/threading/thread.h"
+#include "media/capture/video/chromeos/mojo/arc_camera3.mojom.h"
+#include "media/capture/video/video_capture_device.h"
+#include "media/capture/video/video_capture_device_descriptor.h"
+#include "media/capture/video_capture_types.h"
+
+namespace display {
+
+class Display;
+
+}  // namespace display
+
+namespace media {
+
+class CameraHalDelegate;
+class CameraDeviceDelegate;
+
+// Implementation of VideoCaptureDevice for ChromeOS with ARC++ camera HALv3.
+class CAPTURE_EXPORT VideoCaptureDeviceArcChromeOS final
+    : public VideoCaptureDevice {
+ public:
+  // Converts the HAL pixel format |from| to Chromium pixel format.  Returns
+  // PIXEL_FORMAT_UNKNOWN if |from| is not supported.
+  static VideoPixelFormat PixFormatHalToChromium(
+      arc::mojom::HalPixelFormat from);
+
+  // Converts the Chromium pixel format |from| to DRM pixel format.  Returns 0
+  // if |from| is not supported.
+  static uint32_t PixFormatChromiumToDrm(VideoPixelFormat from);
+
+  VideoCaptureDeviceArcChromeOS(
+      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,

[wuchengli, 2017/05/05 08:10:55]

We discussed offline. Not using const & means the implementation will increase
the ref count.

+      const VideoCaptureDeviceDescriptor& device_descriptor,
+      scoped_refptr<CameraHalDelegate> camera_hal_delegate);
+
+  ~VideoCaptureDeviceArcChromeOS() final;
+
+  // VideoCaptureDevice implementation.
+  void AllocateAndStart(const VideoCaptureParams& params,
+                        std::unique_ptr<Client> client) final;
+  void StopAndDeAllocate() final;
+  void TakePhoto(TakePhotoCallback callback) final;
+  void GetPhotoCapabilities(GetPhotoCapabilitiesCallback callback) final;
+  void SetPhotoOptions(mojom::PhotoSettingsPtr settings,
+                       SetPhotoOptionsCallback callback) final;
+
+ private:
+  // Internal methods which AllocateAndStart depends on to create a camera
+  // device. OnGotCameraInfo and OnOpenDevice are callbacks provided to the
+  // |camera_hal_delegate_| Mojo IPC calls, and are run on the
+  // |module_task_runner_| of |camera_hal_delegate_|.
+  void OnGotCameraInfo(const VideoCaptureParams& params,
+                       std::unique_ptr<Client> client,
+                       int32_t result,
+                       arc::mojom::CameraInfoPtr camera_info);
+  void OnOpenedDevice(const VideoCaptureParams& params,
+                      std::unique_ptr<Client> client,
+                      arc::mojom::CameraMetadataPtr static_metadata,
+                      int32_t result,
+                      arc::mojom::Camera3DeviceOpsPtr device_ops);
+
+  // CreateDeviceOnCaptureThread creates the CameraDeviceDelegate instance and
+  // assigns to |camera_device_delegate_|.  This method runs on
+  // |capture_task_runner_| to make sure the access to |camera_device_delegate_|
+  // and |device_thread_| is sequenced.
+  void CreateDeviceOnCaptureThread(
+      const VideoCaptureParams& params,
+      std::unique_ptr<Client> client,
+      arc::mojom::CameraMetadataPtr static_metadata,
+      int32_t result,
+      mojo::InterfacePtrInfo<arc::mojom::Camera3DeviceOps> device_ops_info);
+
+  const VideoCaptureDeviceDescriptor device_descriptor_;
+
+  // A reference to the CameraHalDelegate instance in the VCD factory.  This is
+  // used by AllocateAndStart to query camera info and create the camera device.
+  const scoped_refptr<CameraHalDelegate> camera_hal_delegate_;
+
+  // A reference to the thread that all the VideoCaptureDevice interface methods
+  // are called.
+  const scoped_refptr<base::SingleThreadTaskRunner> capture_task_runner_;
+
+  // The thread that all the Mojo operations of |camera_device_delegate_| take
+  // place.  Started in CreateDeviceOnCaptureThread and stopped in
+  // StopAndDeAllocate, where the access to the base::Thread methods are
+  // sequenced on |capture_task_runner_|.
+  base::Thread device_thread_;
+
+  // Variable indicating whether VideoCaptureDevice instance is being stopped.
+  // We need |stopping_| to ensure correct behavior because AllocateAndStart is
+  // asynchronous and StopAndDeAllocate may be called between when
+  // AllocateAndStart is called and when |camera_device_delegate_| is actually
+  // created.  |stopping_| must only be accessed on |capture_task_runner_|.
+  bool stopping_;
+
+  // Internal delegate doing the actual capture setting, buffer allocation and
+  // circulation with the camera HAL. Created and deleted in the thread where
+  // VideoCaptureDeviceArcChromeOS lives, but otherwise operates on
+  // |device_thread_|.
+  scoped_refptr<CameraDeviceDelegate> camera_device_delegate_;
+
+  class ScreenObserverDelegate;
+
+  void SetRotation(int rotation);
+  void SetDisplayRotation(const display::Display& display);
+
+  scoped_refptr<ScreenObserverDelegate> screen_observer_delegate_;
+  const VideoFacingMode lens_facing_;
+  const int camera_orientation_;
+  // Whether the incoming frames should rotate when the device rotates.
+  const bool rotates_with_device_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceArcChromeOS);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_CAPTURE_VIDEO_CHROMEOS_VIDEO_CAPTURE_DEVICE_CHROMEOS_H_