[png-mng-implement] =?gb2312?B?tPC4tDogW3BuZy1tbmctaW1wbGVtZW50XSC08Li0OiBbcG5nLW1uZw==?= =?gb2312?B?LWltcGxlbWVudF0gcXVlc3Rpb24gYWJvdXQgcmVhZCBwbmcgZmlsZQ==?=

[yinhua <hy...@cd...>]

Thank you very much for your answer.
>It depends on the nature of your app--if you _need_ the A and BGR as
separate 
>buffers, then you have to walk the ABGR buffer and split it into two
others. 
>Or you could move only the alpha to a new buffer and pack the BGR data into
the 
>same ABGR buffer.)  This is just basic C pointer-manipulation.
In my application, I use 
row_pointers = png_get_rows(png_ptr, info_ptr); 
to get the row_pointers. I want to separate alpha information away from BGR
information. So I create a image[4*width*height] array to store the A,R,G,B
information by sequence. For each pixel, it should has four bytes to store
its ABGR information, while from the png_get_rowbytes, it can only hold 3
bytes for each pixel, it seems that png data pack some information, right?
How can I split these information between A and BGR, I mean how to set the
ABGR data into the image array by sequence? I think this question is too
easy for you, but I find few reference sin the web for this. Would you
please to help me solve this problem? 

Thank you very much for your help!
Frank