[FFmpeg-trac] #10511(undetermined:new): Want CAF with pakt in front, similar to mp4 faststart

[FFmpeg]

#10511: Want CAF with pakt in front, similar to mp4 faststart
-------------------------------------+-------------------------------------
             Reporter:  Mingye Wang  |                     Type:
                                     |  enhancement
               Status:  new          |                 Priority:  wish
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:  caf          |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 The CAF format uses a `pakt` table to enable VBR seeking, but ffmpeg
 always puts it at the end. It would be nice to have an option to put the
 table in front.

 How to reproduce:
 {{{
 % ffmpeg -i airport-af.caf -c:a copy airport-ff.caf
 ffmpeg version 4.4-full_build-www.gyan.dev Copyright (c) 2000-2021 the
 FFmpeg developers
   built with gcc 10.2.0 (Rev6, Built by MSYS2 project)
 }}}


 Pull out the two files (already attached) in a HEX editor, and the
 difference in chunk order is obvious. (I'd welcome any recommendation of a
 CAF structure dumper!) `afconvert` puts a `pakt` in front by default,
 while ffmpeg sticks it at the end.

 PS: fixing this WILL NOT allow us to create VBR-Opus CAF playable on
 macOS. This is a shortcoming of the system, not of ffmpeg.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10511>
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