px4_autopilot/boards/parrot/bebop/flow/video_device.h

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#pragma once

#include <stdint.h>
#include <unistd.h>

#define VIDEO_DEVICE_IMAGE_WIDTH 320
#define VIDEO_DEVICE_IMAGE_HEIGHT 240

struct frame_data {
	uint32_t timestamp;
	uint32_t seq;
	uint32_t bytes;
	uint32_t index;
	void *data;
};

struct buffer {
	void *start;
	size_t length;
};

class VideoDevice
{
public:
	VideoDevice(char const *dev_name, uint32_t n_buffers) :
		_fd(-1), _dev_name(dev_name), _n_buffers(n_buffers), _buffers(nullptr) {}

	~VideoDevice() = default;

	/// Start the device
	int start();

	/// Stop the device
	int stop();

	/// Print various infos
	int print_info();

	/// Non-blocking call to fetch an image. Returns 0 if the images was read, -1 on error
	/// and 1 no new image is ready.
	int get_frame(struct frame_data &frame);

	/// Return a frame when the data is not needed any more.
	int put_frame(struct frame_data &frame);

private:
	int _fd;
	const char *_dev_name;
	uint32_t _n_buffers;
	struct buffer *_buffers;

	int open_device();
	int close_device();
	int init_device();
	int init_buffers();
	int init_crop();
	int init_format();
	int start_capturing();
	int stop_capturing();
};