在自定义视图中移动位图

I have a bitmap with the size of 400 x 70 pixels. I would like to scroll this bitmap up by one row and fill up row 70 with new pixels. I have tried to scroll the bitmap by copying it to an IntBuffer , copy it to another IntBuffer (starting at the second row) and the then write it back to the bitmap. This works but it takes a lot of CPU power and it is kind of slow. Is there any faster way to do this ? I have a bitmap with the size of 400 x 70 pixel