[Mp4-tech] BSAC and ineterleaving

[akhalife uci.edu]

Dear Folks
1) I am working on MPEG4 BSAC codec, I wonder whether the
> final bitstream we get from encoding 1 frame is interleaved
> or not, I mean, is the first bits represents the base layer,
> then the enhacement layers will follow, or the output
> bitstreams is interleaved(I mean the base and the nehacement layers are
interleaved and mixed ),?
> 2)Another question,  what is the Access Unit (AU), and AU
> start flag and AU end flag? I mean if I have 1 frame, what is
> the Access unit? and how many access units do I have in one
> frame? since I noticed that if an error in the bits happens
> in these bits, I got an error in the decoding process such as
> error in get access unit., teh strange thing that these flags are not
located
near the header? but after about 50 bytes from the header.
>
> Thanks
> Ala