[Mpg123-devel] main_data_begin, amount of data in a frame

[Torsten M. <tmohr@s.netic.de>]

Hi,

i refer to the ISO spec 11172-3, on page 43 there is a description
of the meaning of "main data begin".

It is possible that the MDB (main data begin) of the side info of frame N
point to the "main info" of frame N-1 and the MDB of N+1 also point to a
part in "main info" of frame N-1.

I hope it is clear what i wanted to describe, looks complicated.  Basically
"main data begin" can point to data in a frame that shares data, also the
next "main data begin" points to the same data in that frame.

How can i tell the size of the data that a "main data begin" points to?

According to the description in the spec it does not extend to the sync
header of the next frame.

When decoding an MP3 file, do i need to know the amount of data that "main
data begin" points to?  Or is it safe to just rely on the following huffman
decoding to not eat too much data?


Thanks for any hints,
Torsten.