Hi,

I have a question about mmap(), hope someone can clarify for me.

As I know, mmap() maps the whole file into memory, so OS can access the source file directly from memory.

However there should be a restriction to memory size on the embedded system.

In my test, I compile madplay with mmap supported, and then play a mp3 file of 43MB, and it plays well.

But my question is I only get 32MB SDRAM on my development board.

It seems that the memory size is not large enough to store all the data.

How does mmap() work?

Besides, I want to implement the fast forward/rewind function.

But it is a little slow to rewind, because it needs to search the location from the first frame, if mmap() isn't enabled.

(Maybe there are other better methods, but I don't know...)

If mmap() works, then it should be faster than without mmap(), shouldn't it?

Sorry for any unclear expression.

Thanks for help.

Regards,

Hank