#coding=utf-8
import cv2
import numpy as np
import mvsdk
import platform

class Camera(object):
	def __init__(self, DevInfo):
		super(Camera, self).__init__()
		self.DevInfo = DevInfo
		self.hCamera = 0
		self.cap = None
		self.pFrameBuffer = 0

	def open(self):
		if self.hCamera > 0:
			return True

		# 打开相机
		hCamera = 0
		try:
			hCamera = mvsdk.CameraInit(self.DevInfo, -1, -1)
		except mvsdk.CameraException as e:
			print("CameraInit Failed({}): {}".format(e.error_code, e.message) )
			return False

		# 获取相机特性描述
		cap = mvsdk.CameraGetCapability(hCamera)

		# 判断是黑白相机还是彩色相机
		monoCamera = (cap.sIspCapacity.bMonoSensor != 0)

		# 黑白相机让ISP直接输出MONO数据，而不是扩展成R=G=B的24位灰度
		if monoCamera:
			mvsdk.CameraSetIspOutFormat(hCamera, mvsdk.CAMERA_MEDIA_TYPE_MONO8)
		else:
			mvsdk.CameraSetIspOutFormat(hCamera, mvsdk.CAMERA_MEDIA_TYPE_BGR8)

		# 计算RGB buffer所需的大小，这里直接按照相机的最大分辨率来分配
		FrameBufferSize = cap.sResolutionRange.iWidthMax * cap.sResolutionRange.iHeightMax * (1 if monoCamera else 3)

		# 分配RGB buffer，用来存放ISP输出的图像
		# 备注：从相机传输到PC端的是RAW数据，在PC端通过软件ISP转为RGB数据（如果是黑白相机就不需要转换格式，但是ISP还有其它处理，所以也需要分配这个buffer）
		pFrameBuffer = mvsdk.CameraAlignMalloc(FrameBufferSize, 16)

		# 相机模式切换成连续采集
		mvsdk.CameraSetTriggerMode(hCamera, 0)

		# 手动曝光，曝光时间30ms
		mvsdk.CameraSetAeState(hCamera, 0)
		mvsdk.CameraSetExposureTime(hCamera, 30 * 1000)

		# 让SDK内部取图线程开始工作
		mvsdk.CameraPlay(hCamera)

		self.hCamera = hCamera
		self.pFrameBuffer = pFrameBuffer
		self.cap = cap
		return True

	def close(self):
		if self.hCamera > 0:
			mvsdk.CameraUnInit(self.hCamera)
			self.hCamera = 0

		mvsdk.CameraAlignFree(self.pFrameBuffer)
		self.pFrameBuffer = 0

	def grab(self):
		# 从相机取一帧图片
		hCamera = self.hCamera
		pFrameBuffer = self.pFrameBuffer
		try:
			pRawData, FrameHead = mvsdk.CameraGetImageBuffer(hCamera, 200)
			mvsdk.CameraImageProcess(hCamera, pRawData, pFrameBuffer, FrameHead)
			mvsdk.CameraReleaseImageBuffer(hCamera, pRawData)

			# windows下取到的图像数据是上下颠倒的，以BMP格式存放。转换成opencv则需要上下翻转成正的
			# linux下直接输出正的，不需要上下翻转
			if platform.system() == "Windows":
				mvsdk.CameraFlipFrameBuffer(pFrameBuffer, FrameHead, 1)
			
			# 此时图片已经存储在pFrameBuffer中，对于彩色相机pFrameBuffer=RGB数据，黑白相机pFrameBuffer=8位灰度数据
			# 把pFrameBuffer转换成opencv的图像格式以进行后续算法处理
			frame_data = (mvsdk.c_ubyte * FrameHead.uBytes).from_address(pFrameBuffer)
			frame = np.frombuffer(frame_data, dtype=np.uint8)
			frame = frame.reshape((FrameHead.iHeight, FrameHead.iWidth, 1 if FrameHead.uiMediaType == mvsdk.CAMERA_MEDIA_TYPE_MONO8 else 3) )
			return frame
		except mvsdk.CameraException as e:
			if e.error_code != mvsdk.CAMERA_STATUS_TIME_OUT:
				print("CameraGetImageBuffer failed({}): {}".format(e.error_code, e.message) )
			return None

def main_loop():
	# 枚举相机
	DevList = mvsdk.CameraEnumerateDevice()
	nDev = len(DevList)
	if nDev < 1:
		print("No camera was found!")
		return

	for i, DevInfo in enumerate(DevList):
		print("{}: {} {}".format(i, DevInfo.GetFriendlyName(), DevInfo.GetPortType()))

	cams = []
	for i in map(lambda x: int(x), raw_input("Select cameras: ").split()):
		cam = Camera(DevList[i])
		if cam.open():
			cams.append(cam)

	while (cv2.waitKey(1) & 0xFF) != ord('q'):
		for cam in cams:
			frame = cam.grab()
			if frame is not None:
				frame = cv2.resize(frame, (640,480), interpolation = cv2.INTER_LINEAR)
				cv2.imshow("{} Press q to end".format(cam.DevInfo.GetFriendlyName()), frame)

	for cam in cams:
		cam.close()

def main():
	try:
		main_loop()
	finally:
		cv2.destroyAllWindows()

main()