[FFmpeg-trac] #10958(avcodec:new): Enhanced coupling support for E-AC-3 / Dolby Digital Plus - with sample file

[FFmpeg]

#10958: Enhanced coupling support for E-AC-3 / Dolby Digital Plus - with sample
file
-------------------------------------+-------------------------------------
             Reporter:  BuccoBruce   |                     Type:
                                     |  enhancement
               Status:  new          |                 Priority:  normal
            Component:  avcodec      |                  Version:  git-
             Keywords:  eac3         |  master
  avcodec                            |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug: Enhanced coupling is currently unsupported per eac3dec
 {{{
   24  * There are several features of E-AC-3 that this decoder does not
 yet support.
   25  *
   26  * Enhanced Coupling
   27  *     No known samples exist.  If any ever surface, this feature
 should not be
   28  *     too difficult to implement.
 }}}
 How to reproduce:
 {{{
 % ffplay -i ".\08 - It's Not Unusual_88.ec3"
 ffplay version 7.0-full_build-www.gyan.dev Copyright (c) 2003-2024 the
 FFmpeg developers
   built with gcc 13.2.0 (Rev5, Built by MSYS2 project)
 [eac3 @ 000001f4a04c5c80] Enhanced coupling is not implemented. Update
 your FFmpeg version to the newest one from Git. If the problem still
 occurs, it means that your file has a feature which has not been
 implemented.
 [eac3 @ 000001f4a04c5c80] If you want to help, upload a sample of this
 file to https://streams.videolan.org/upload/ and contact the ffmpeg-devel
 mailing list. (ffmpeg-devel at ffmpeg.org)
 [eac3 @ 000001f4a04c5c80] error decoding the audio block
 }}}

 It appears that the Dolby encoder previously provided by Rovi (?) for use
 with Adobe Audition versions prior to 2018 automatically enables enhanced
 coupling for bitrates lower than 48 kbps per channel. Here's a sample file
 for you.

 Windows 10 is able to decode it using whatever Media Foundation ''things''
 Groove Music defaults to and outputs PCM. Windows Media Player
 automatically starts bit-streaming it - I probably have LAV enabled. MPV
 does too, but if I disable my bit-streaming options in .config, it
 (understandably) gives the same error that ffmpeg does.

 I am not sure where else enhanced coupling exists in the wild as I have
 never seen DD+ used below 128kbps stereo (64k/ch).
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10958>
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