[FFmpeg-trac] #5910(undetermined:new): AAC to PCM conversion inserts extra silence in the beginning

[FFmpeg]

#5910: AAC to PCM conversion inserts extra silence in the beginning
-------------------------------------+-------------------------------------
             Reporter:               |                    Owner:  (none)
  jwilhelmsson                       |
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:  aac mov      |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Comment (by Balling):

 The other file is HE-AAC. Apple uses 5186 samples for priming delay in
 that case, not 2112. Out of 5186 you have 2112*2 normal delay and then 481
 * 2 of SBR decoder delay. Together they add up to 5186. There was a bug in
 decoding that ffmpeg has: 5114ce1e2a4c71ddf4971ad3cf9bd43ae16571c3

 Obviously even then it assumes 960 SBR delay, not 481. Because of that
 FFmpeg still removes too much: 6144 and not 5186. Indeed, 6144 - 2 * 2112
 will be 960*2.

 **So this is a bug about SBR delay.
 **
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/5910#comment:19>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker