[Ffmpeg-devel] E-AC3 support?

Justin Ruggles justinruggles
Sun Feb 11 17:40:21 CET 2007

M?ns Rullg?rd wrote:
> Kostya <kostya.shishkov at gmail.com> writes:
>>Just of pure curiosity - what is needed to add E-AC3 decoding
>>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.


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