lsd_slam tracking lost

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Hello, I use lsd_slam on ubuntu 14.04 and indigo. I build using rosbuild not catkin. I run lsd_slam with my own data.

I have a video and extract images from it using 50 fps. Then I convert all images bgr to gray. I calibrate my camera using /rosbuild_ws/package_dir$ rosrun camera_calibration camacalibrator.py --size 8x5 --square 0.030 image:=/usb_cam/image_raw --no-service-check. Output of this command is

('D = ', [-0.018886062736404145, 0.26942503786920685, -0.007379703201997424, -0.010431827630318656, 0.0])
('K = ', [1073.8528937019455, 0.0, 235.9957316222547, 0.0, 1074.390849488722, 187.00905237645208, 0.0, 0.0, 1.0])
 ('R = ', [1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0])
(P = ', [1072.824462890625, 0.0, 233.22498772363906, 0.0, 0.0, 1075.8095703125, 185.30739976715995, 0.0, 0.0, 0.0, 1.0, 0.0])
 None
# oST version 5.0 parameters
[image]

  width   640

 height  480

[narrow_stereo]

camera matrix
1073.852894 0.000000 235.995732 
0.000000 1074.390849 187.009052  
0.000000 0.000000 1.000000

 distortion
 -0.018886 0.269425 -0.007380 -0.010432 0.000000

But I couldn't run lsd_slam using this output. I searched on google, and found some advices. One of them said that I use this calibration file:

0.825 1.1 0.5 0.5 0
1280 720
crop
640 480

I can run lsd_slam using my own data with this calibration file. But tracking lost at runtime.Maybe my input video is bad. But I want to know how can I use best calibration datas? Why tracking lost? How can I obtain calibration value?