camera/hal/usb_v1/v4l2_camera_device.h

/*
 * Copyright 2015 The Chromium OS 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 CAMERA_HAL_USB_V1_V4L2_CAMERA_DEVICE_H_
#define CAMERA_HAL_USB_V1_V4L2_CAMERA_DEVICE_H_

#include <string>
#include <unordered_map>
#include <utility>
#include <vector>

#include <base/files/scoped_file.h>

#include "cros-camera/timezone.h"
#include "hal/usb_v1/camera_device_delegate.h"

namespace arc {

class V4L2CameraDevice : public CameraDeviceDelegate {
 public:
  V4L2CameraDevice();
  ~V4L2CameraDevice() override;

  int Connect(const std::string& device_path) override;
  void Disconnect() override;
  int StreamOn(uint32_t width,
               uint32_t height,
               uint32_t pixel_format,
               float frame_rate,
               std::vector<int>* fds,
               uint32_t* buffer_size) override;
  int StreamOff() override;
  int GetNextFrameBuffer(uint32_t* buffer_id, uint32_t* data_size) override;
  int ReuseFrameBuffer(uint32_t buffer_id) override;
  const SupportedFormats GetDeviceSupportedFormats(
      const std::string& device_path) override;
  const DeviceInfos GetCameraDeviceInfos() override;

 private:
  std::vector<float> GetFrameRateList(int fd,
                                      uint32_t fourcc,
                                      uint32_t width,
                                      uint32_t height);
  const std::unordered_map<std::string, std::string> GetCameraDevicesByPattern(
      std::string pattern);
  int RetryDeviceOpen(const std::string& device_path, int flags);

  // External camera is the only one camera device of /dev/video* which is not
  // in |internal_devices_|. Ruturns <VID:PID, device_path> if external camera
  // is found. Otherwise, returns empty strings.
  std::pair<std::string, std::string> FindExternalCamera();

  // Get power frequency supported from device.
  cros::PowerLineFrequency GetPowerLineFrequency(
      const std::string& device_path);

  // Set power frequency supported from device.
  int SetPowerLineFrequency(cros::PowerLineFrequency setting);

  // The number of video buffers we want to request in kernel.
  const int kNumVideoBuffers = 4;

  // The opened device fd.
  base::ScopedFD device_fd_;

  // Power line frequency.
  cros::PowerLineFrequency power_line_frequency_;

  // StreamOn state
  bool stream_on_;

  // True if the buffer is used by client after GetNextFrameBuffer().
  std::vector<bool> buffers_at_client_;

  // Keep internal camera devices to distinguish external camera.
  // First index is VID:PID and second index is the device path.
  std::unordered_map<std::string, std::string> internal_devices_;

  DISALLOW_COPY_AND_ASSIGN(V4L2CameraDevice);
};

}  // namespace arc

#endif  // CAMERA_HAL_USB_V1_V4L2_CAMERA_DEVICE_H_