[Ffmpeg-devel] E-AC3 support?

[Justin Ruggles]

M?ns Rullg?rd wrote:
> Kostya <kostya.shishkov at gmail.com> writes:
> 
> 
>>Just of pure curiosity - what is needed to add E-AC3 decoding
>>support?
>>
>>IIRC, this is really called ATSC A52/B and standard is available.
> 
> 
> A52/B is the name of the ATSC standard.  E-AC3 is the name given to
> the codec by Dolby, who developed it.  The advantage of using the A52
> name would be that then Dolby can't sue for trademark infringement.
> 
> 
>>Can somebody clarify the differences between plain AC3 and E-AC3?
> 
> 
> IIRC, E-AC3 adds support for more channels and higher sample rates.
> 

also: variable (and more fine-grained) frame sizes, additional optional
DCT, gain adaptive quantization (GAQ) of mantissas, spectral extension,
enhanced coupling, new bitstream format which has more per-frame values
instead of so many redundant per-block values.  ...and other stuff I'm
probably forgetting.

-Justin