[M4IF Technotes] AAC test streams using coupling channels

[Jens Rennert]

Experts,
I compiled versions 1 and 2 of the mpeg4 reference software and both seemed 
unable to deal with the L6_XXX.aac bitstreams from AT&T. I tried various 
other decoders (among them the MP4Play from the IBM MPEG 4 tool kit) and so 
far I have found nothing which can decode these streams. 
I added the coupling channel functionality from the reference code into my own 
implementation and get some strange parsing results:
1:single_channel_element, window_sequence 0, window_shape 0,max_sfb 47
2:channel_pair_element, window_sequence 1, window_shape 0,max_sfb 34
3:channel_pair_element, window_sequence 0, window_shape 1, max_sfb 0
4:coupling_channel_element, element instance tag 4, ind_sw_cc 1
   num_coupled_elements 0
According to the stream description this streams should only contain 
dependently switched channels. 
Why would the number of coupled elements be zero?
Could somebody please shed some light on this.
Is there something like an AAC stream analyzer software available?
Thanks
Jens Rennert