[FFmpeg-trac] #9667(avcodec:new): HE-AAC decode samples off by one sample-time

[FFmpeg]

#9667: HE-AAC decode samples off by one sample-time
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             Reporter:  Nick         |                    Owner:  (none)
                 Type:  defect       |                   Status:  new
             Priority:  minor        |                Component:  avcodec
              Version:  unspecified  |               Resolution:
             Keywords:  he-aac       |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Comment (by Nick):

 >Is native aac encoder affected too?
 The problem is only seen with HE-AACv1/v2 which I don't think the native
 aac encoder will generate. Testing AAC-LC with the native aac encoder
 reports an initial timestamp of -1024. After converting back to WAV there
 are 1024 samples of lead-in as expected.

 >You were supposed to use mp4 container and thus there should be 0 samples
 of lead-in due to an editlist.
 That is broken for HE-AAC. Encoding WAV to HE-AACv1 mp4 file reports an
 initial timestamp of -5058 as expected. Converting the mp4 to wav results
 in losing the first 5060 samples of real audio.

 Repeating the same test with AAC-LC works correctly - perfectly aligned
 with no lead-in and no missing samples.

 The symptom suggests the mp4 edit information is based on 48kHz and is
 being incorrectly applied to 24kHz underlying AAC-LC data when handling
 HE-AAC.
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Ticket URL: <https://trac.ffmpeg.org/ticket/9667#comment:2>
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