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Dark-Cracker
3rd October 2002, 14:27
Hi,

i have make some search but nothing realy interested, i suppose someone could easy answer my question:

i want to get some informations on the .ac3 file, i want to know : the frequecy , the number of channels, and the bitrate.

if somone have some informations of the header to find easyly the informations wanted on the .ac3 file, this will be great.

Bye
Thank u.

DSPguru
3rd October 2002, 17:47
http://www.atsc.org/standards/a_52a.pdf
taken from here :
http://www.atsc.org/standards.html

Dark-Cracker
3rd October 2002, 21:02
thank u very much for this interested document :) (but a bit to hard to understand with my crap english).

i was think i could find the desired informations (bitrate,chanel, frequency) only with finding at an specified offset the hex value of these informations . but i think it was more complicated than that :) (i was dreaming) , can u confirme me that i can't get these informations simply by using an offset and a typestructure ?

i hope u have understand my msg. and sorry again for my crap english.

alexnoe
4th October 2002, 17:07
You got it right. This information is not stored as a hex value...it's spread over 7 bytes :angry:

Suiryc
4th October 2002, 18:53
Not only it's spread, but you have to use tables (one with two entries) to get all the important information (channels, frequency, bitrate, size of the frame) :p

If you want you can see in OGMuxer sources (AC3Reader.h file for the tables, and AC3Reader.cpp to see how to retrieve the info).

BloodySword
9th August 2005, 14:23
Cloud anyone post a vb6-code?