[FFmpeg-trac] #2706(avcodec:new): Native AAC encoder produces warbling with pure aevalsrc sine wave

[FFmpeg]

#2706: Native AAC encoder produces warbling with pure aevalsrc sine wave
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             Reporter:  MarkZV      |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  aac         |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by Kamedo2):

 After reading this thread, http://ffmpeg.org/pipermail/ffmpeg-
 devel/2013-May/143208.html
 I could successfully apply a patch #2686 from klaussfreire's repository.
 So I'm going to post the result with the WIP patch enabled.

 I listened to these AACs, Sampling rate: 48000Hz
 ||=
 Freq=||16||32||48||64||80||96||112||128||144||160||176||192||208||224||240||256kbps||
 ||=  750Hz=||0||0||0 ||0 ||0 ||0 ||0  ||0  ||0  ||0  ||0  ||0  ||0  ||0
 ||0  ||0  ||
 ||= 1500Hz=||0||0||0 ||0 ||0 ||0 ||0  ||0  ||0  ||0  ||0  ||0  ||0  ||0
 ||0  ||0  ||
 ||= 3000Hz=||0||0||0 ||0 ||0 ||0 ||0  ||0  ||0  ||0  ||0  ||0  ||0  ||0
 ||0  ||0  ||
 ||= 6000Hz=||-||0||0 ||0 ||0 ||0 ||0  ||0  ||0  ||0  ||0  ||0  ||0  ||0
 ||0  ||0  ||
 ||= 9000Hz=||-||-||0 ||0 ||0 ||0 ||0  ||0  ||0  ||0  ||0  ||0  ||0  ||0
 ||0  ||0  ||
 ||=12000Hz=||-||-||- ||- ||0 ||0 ||0  ||0  ||0  ||0  ||0  ||0  ||0  ||0
 ||0  ||0  ||
 0: no warbling
 1: warbling
 2: terrible warbling
 -: within cutoff range

 Yes, at least perceptually, there were no warbling at all. However, the
 patch came with another cost. It will be off topic in here, so I'll keep
 posting in #2686 thread.

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Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2706#comment:8>
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