How to use pivot points which were generated by texturepacker?

Question

I am using TexturePacker to generate spritesheet with JSON Array format.It generates some JSON like this:

{
    "filename": "test.png",
    "frame": {"x":0,"y":0,"w":40,"h":41},
    "rotated": false,
    "trimmed": false,
    "spriteSourceSize": {"x":0,"y":0,"w":40,"h":41},
    "sourceSize": {"w":40,"h":41},
    "pivot": {"x":0.5,"y":1}
}

I am confused about the "pivot", and I find the frame animation was misplaced because the sprites have diffrent dimentions.

I find someone makes his spritesheet like this: every sprite are diffrent dimentions

How to make each sprite at correct location and how to use pivot in my code?

Any help?Thanks a lot.